Sencore LC53 Service manual

LC53

“Z M ET ER "

C A P A CIT O R — IN DUCT OR

ANALYZER

Operation, Application, and Maintenance Ma nu a l

" '• 4 .

S E N C O R E

.. . th e e lectr onic inst ru m en t “analyzer peop l e ”

3200 S E N CO R E DRIVE . SIOUX FAL LS . SO UT H DA K O T A 57107 -(6 0 5 ) 339-010 0

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T A B L E OF CONTENTS

SAFETY PRECA UT ION S SIMPLIFIED OPERATIONS DESCRIPTION

Int r oduc t i on........................................................... 6

Feat ur es... .

Speci f i cati ons ..................................................... 6

C on t rol s ................................................................. 8

Sup p lie d Acc essor i es........................................10

Op tio n a l Ac c e s s o r i e s

OPERATION

In tr o d u c t ion ..........................................................12

Pow er Co nn ec t ion Fuse Repl ace me nt

Test Le ad s .............................................................12

Tes t Lead Mo un tin g Cl i p....................................12

Capacitor Testing

Spe cia l No t es on C a pa c ito r Tes ti ng

Cap a c it y M e as ur em e n t A c c ur a cy .....................13

To E lim i na t e Lead Capac i t y

Ch ec k in g C a pa c it o rs Beio w 2 pF.....................14

Inte r p re t in g “Z ME TER ” Value R e a ding s

Te s ti ng Large Scre w Term inal Lyt ics

Ch e c ki n g C a p a ci to rs fo r Leakag e

Ceramic, Paper, Mica, and Film Ty pe s .. . 16

Alu min u m Ly t i c s ..........................................16

Tanta lu m Lyt ics..........................................16

Leakage Char t s................................................... 17

Ide n ti fy in g C a p a ci to r Type s

Tan ta lu m Lytics Cer am ic Discs

Film Types Tes tin g fo r D ie l e ct ric Ab so r pt ion.. Ref or m in g Ly ti c s on the “Z METER” Ref o rm in g Ly ti cs w it h a Power S upply

Capacitor Testing Application Tips

No Value Readi ng on Small Value

C ap aci t ors

Leakage in C era mic , Paper, Film, and

Mic a Capaci t or s

Ch ec k in g fo r Leakage Between S ect ion s

of a Mu l ti -S e c t io n Ly ti c

Large Flu ctu ati o n s in Lytic Leakage

Re a d i n g s

Leakage M eas ure me nts of Non-Polarized

L yt i cs........................................................... 21

Lyt ic s S it ti n g in S t o ck ................................ 21

Low Value L y tic s Used in High

Freq ue ncy Ci rcuit s..................................21

Inte r m i tt e n t Ca paci t or s

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Inside Front Cover

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13 14 14

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20 20 20

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Time Required to O b ta in a Value

Reading on a Cap a c i to r ...........................

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Chec kin g C e ra m ic C a pa c ito rs for

Temper ature Sensi t i vi t y ...........................22

Chec kin g Film T yp e Ca p ac it or s f or

Temper ature Sensi t ivi t y...........................22

Testing Ca pa cit y of Si li co n Diodes

and Tr a ns i s t o r s

Tes tin g High V o lt a g e Di odes

Test ing Sil ico n C on tr o ll e d R e ctif ier s

(SCRs) and TRIACS

Testing SCRs and TR IACS fo r

DC L a tch i n g

Testing SCRs and TRIACS for AC Latch

and Unlatch Co nd i ti ons ...........................24

Determin ing the Len gth of RF Coaxial

C abl e............................................................24

How to Find a Short in a Coaxial Cable .. 25 How to Find the In d uc t an c e Per Foot of

Coaxial Cabl e............................................ 25

Inductor Testing

Checki ng In d uc to rs fo r Ind uct ance

V alue..........................................................

Balanci ng Out Lead I n du c t a n c e

Chec kin g Co ils B e lo w 2 M i c r o he n r ys . . .. 26

Open Wind in g in a Coi l

Chec kin g In d u ct a n ce I n- Ci r cu i t

Testing In du c to rs on Printed C irc u it

Bo ards ..........................................................27

Mutual i n duc t anc e

Value Reading on H ig h R es istan ce

C oi l s

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Indu ct or Cod i ng..........................................28

Checki ng In d uc to rs for Good or Bad

With the Rin g ing Test

Inductor Testing Applicat ion Tips

Qualit y T estin g on Gener al C oil s

and Transfo rm er s

Peaking C oi ls

Coils in Me tal Sh ield s.........................31

Ferrite Core Tran s fo r m er s and

Coiis....................................................31

Testing Flyb ack T r a ns fo r m er s and Yokes

With the R i ng i ng Te st .........................31

In-Circuit Qu i c k T e st...........................31

Testin g Yokes wi th t he R ing ing Test .... 31

Testing H or iz o n ta l Yoke Win d in gs

for Good or B ad

Testing V er ti c al Yoke W in d in g s for

Good or B ad

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MAINTE NAN CE

in t r oduc t i on

...............................................................34

A c c e ss / Disa s se mbl y ..............................................34

Equ ip m en t Required for Ca li bra tio n......................34

Meter Cali b r a t io n......................................................34

Input P rote ct ion Relay Trip Point Ad ju s t .............. 35

Indu c ta n ce C a lib r at io n............................................35

Ringin g Test Cali br at ion

Ca pa c it or C ali br a t i on

APPEN DIX

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Cap ac it or Theory and the “Z METER” .................. 38

Ca pa c ito r Color Code and Marking C ha r t s

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Glos s ar y of Terms ....................................................46

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SE RVI CE A N D WARRANTY

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Insid e Ba ck C o v e r

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SI MP L IFI ED OPERATIONS

CAPA C IT OR TESTS

7. Select de sir e d volt ag e for Le a k a ge test

5. Read VALUE of ca p aci t o r in pF o r

uF on D isp l a y

9. Read LEAKAGE in mi c r o a mps on

8. Pu sh But to n

4. Push b u t to n

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. S e le c t LEAKAGE RANGE

INDUC TOR TESTS

5. Read VALUE of co il in uH or mH on Dis play

r,

2. Adj ust fo r 000 rea dou t wh i l e pu sh ing Capa

c i t or Val u e b u t t on.

4. Push Bu tt on

1. Ope n t e st leads

3. Connec t cap ac i t or t o test l eads

8. Read RIN G IN G TEST on d is pla y 10 o r mor e i n d i c a tes g o o d co il.

6

. Push

Button

7. Rotate t o Red pos i  tions f or Yoke & Flyback ALL p osi  tions f or

coils

2. Ad ju s t f or 000 re adout w hil e p u s h in g I n d u c t o r Val u e but ton

1. Short test lea ds

3. Conne ct coil, yok e , o r f l y ba ck

Not es

5

DE SC RI PT IO N

INTRODUCTION

The use of capac itors in electronics ha s d ramat ic all y increas ed in t he p as t few y ea rs and t he for e ca st is for

even a g re a te r usage. The t ra n si st o r has g i v en wa y to

the IC, b u t due to t he n at ur e and c o n s tr uc t io n of the

cap ac ito r an d th e inductor, t hes e are n o t re pl ac ed with

ICs. The more ICs t h at are use d, the mo re ca pa ci tor s and in du cto rs t h at will be used. The tol era nc e of the capa cit or used to be 20%, b u t today, y o u will find

circu it s h av ing 5% to lerance capa cito rs as s tan d ar d.

The use of ele ctrolytic c apa cito rs has als o d ra stic all y increased as well as the capaci ty range. Lyti cs of

10,000 uF can be found in m an y c on su m e r electronic items. Now more t h an ever, the need to measure cap ac ity value, leakage of the capacitor, i n d u ct o r value and q ua li ty of the in duc tor has become v er y impor ta n t. W i th ou t a good measur e of these i mpo r t a nt pa ra  me t e r s, pr o pe r ci r c u i t o p e r a t i o n b e comes m o re difficult. Sencore has met the challenge head -on with its all new, a u to ra ng in g “ Z ME T ER”, t h e LC53. Now cap aci to rs can be checked for value a nd fo r l eak ag e a t th e r at e d w o rk ing vol ta ge on a d i gi tal r ea d o ut .

Ind u ct o rs can be checked for induc ta nc e a nd for qua li ty wi th the p a te nt e d Sencore rin g i ng test. The

LC53 is tru l y the firs t co mplete ca pac itor a n d in du cto r analyzer.

FEATURES

SPECIF IC A TIO NS

DIGITAL RE A D O U T

TYPE: .5 ” , 7 seg m e n t LED . ACCURACY: F un c ti o n accuracy ± resol utio n error . RE S OL U T IO N : 3 sig n ific ant di gi ts ±2 cou nts on 3rd

digit (3Vi d ig i ts on capaci tor s of 100,000 uF to 200,000 uF).

A UT OR ANGING: Ful ly a ut omat i c d e ci mal

placement. On e o r two place holding zeros a d d e d as needed (does n ot affect accuracy) to provide st a n d ar d value read o u t s of uF, pF, u H, or mH .

RAN G E IN D IC A T O RS :

Type: LE D . Operation: C ontr olled by t he au to r an g in g circui ts .

CAPAC IT ORS (O u t of Circuit):

Dynamic t e s t of capa ci ty value dete rm ine d by me a s ur  ing one RC tim e co n s ta n t when ca paci tor is ch a r ge d to +5V through :

10 Megohm s for 0-9000 pF. 10 Kilohms for 9000 pF-90 uF.

100 Ohms for 90-199,900 uF.

ACCURACY: ±1% of re adi ng + re solu tion erro r.

±5% of re a d in g + resolutio n err or for c a ps over

1000 uF.

RAN GE : 1.0 pF to 199,900 uF in 10 a ut oma tic a ll y

selected ran ge s.

The Sencore LC53 “Z METER” f e a tu r e s adva nce d Digi tal Logic circuits t h a t provide a u t o r a n g in g of the me te r when checking the values of c ap a c it y or ind uc tance. Si mply hook u p the c apac itor o r th e inductor, pre ss the prop er VA L UE bu tto n, and re ad t h e value on the large dig ital readout.

The “Z METER” also checks c ap aci to rs for leakage

wit h two selectable cur re nt range s at the r ate d work ing volta ge from 3 Volts to 600 Vo lts. An L ED

(located b etw een th e L E A K A G E bu t t on and the

A P PLI ED V O LTA GE switch) will flash on an d off as a safe ty rem in der when th e leakage t es t v o l ta ge is set

to 50 Volts or above.

Th e Sencore p a te n t ed rin g in g t e st c he c k s coils, deflection yokes, a nd non-iron core t r a n sf o r m e r s with an a c cu ra te c heck of good or bad. Th ere ar e six sw itch

selectable impedance m at ch in g po sit ion s t o m a t c h the

coil to th e t e s t circ uit from 10 u l i to 10 I I. Good coils

will show 10 or more rin gin g cycles on t h e d igit al d is play while bad ones will show less than 10.

A special L E A D ZERO control lets you balance out

the cap aci ty or i nductan ce of the t es t lead s I'or those

acc u ra te readin gs of the very small capa ci to rs and

coils th a t you may encoun ter. The “ Z ME TER” is also

pro te cte d a ga i ns t accide ntal app licatio n of vo lta ge s to

the tes t leads by a front panel repla ceab le fuse an d a

special relay inside the inst rum e nt.

CAP ACIT O R LE AK A GE

ACCURACY: ± 5% 4- reso luti on error. RANG ES : 0 to 99.9 uA an d 0 to 9.99K uA in two

switch selec tab le ranges.

VOLT AG ES : 12 s electable DC vo lta ges from 3 VDC

to 10 VDC filtered and from 1.5 VDC to 600 VDC, non-filtered. Availabl e at t e s t leads only when LE A KA GE pu s h b u t to n is depressed. Cap a ci to r is aut om a tic al ly di sch arg ed when b ut t on is released.

IND U C T A NCE (In- or Out-of Circuit)

Pa te n t pe nd in g dyn am ic te s t of in du cta nce va lue determ ined by m ea su ri ng t he E MF caused by a con sta nt ly vary i n g cur re nt throu g h t he coil u n de r test . Current ra t e s are:

10 mA/usec - 0 to 90 uli . 1 mA/usec - 90 to 900 uli .1 mA/ usec - 900 ul i to 9 mH. .01 mA/u sec - 9 t o 90 mil .

1 uA/usec - 90 to 900 m il .

.1 uA/usec - 900 to 9,990 m il .

ACCURACY: ±2 % of reading -*■ resolution error.

RANGES: 1.0 uli to 9,990 mil in 6 auto m a tic a ll y

selected range s.

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RINGING TEST

Dynamic te s t of inductor q u al ity d ete rmi ned by c ou n t ing the number of cycles the in d u ct or rings before reaching a p re se t dam pi ng po i n t af te r a given exc itin g pulse has been applied. (US pat e nt 3,879,749).

ACC E S S O R I E S (Optional)

39G85 T ouch Te st P robe

GENE R A L

EX C IT I N G PUL SE AMPL I T U DE : App rox im atel y 7

Volts peak.

ACC UR AC Y : ± 1 c ount from r ea d i n g s of 8 to 13.

ACCES S OR IE S (S up plie d)

39 G 143 Te st Leads * 39G144 Te st Lead A da pt or

39G145 Test B u tt o n Hold Dow n Rod (2 supplied) ' 64G37 Test Lead M o unt in g Clip 68G34 Allen Wrench 44G20 Spare 1 A m p Slo-Blo F u se

“Specifica tions su bje ct to cha ng e w it h o u t not ice.”

T E MPERAT URE RAN G E S (Typical): Calibr ated at

70 °F. Rated accuracy range: 50-90 °F, Opera ting rang e: 32-130°F.

PO W E R: 105-130 VAC, 60 Hz, 25 Wa tt s . T E S T L E A D INP UT: Fuse p r o te c te d with in-line 1

Am p 3AG Slo-Blo fuse. SIZ E : 6” x 9” x 11.5” (15.24 cm x 22.86 cm x 29.21 cm) W E I GH T: 7.75 lbs. (3.56 Kg).

CONTROLS

1. Front panel digital readout, fi r s t th re e d igit s read

the value of capacity , inducta nce, l eak ag e curr en t or ring ing test values, las t two di g it s are plac e holders and only indicate 0 on larger va lue s of ca paci ty, ind uc tance, or leakage c u rre nt so all rea di n gs are given as

pF, uF, uH, or mH.

2. a. Indic ato r LED, lights up when capa cito r re ad  ing is in picofarads (pF).

b. In dica tor LED, ligh ts up w hen capa cito r re ad 

ing is in microfara ds (uF).

c. Indicator LE D, light s up wh en c ap acito r leak age reading is in microamps (uA). d. Indica tor LED, light s up wh en ind uct or rea d ing is in m icrohe nrys (uH). e. Indicator LED, lights up whe n i nd uct or r ea d ing is in millih enrys (mH).

3. I M PE D A N C E MATCH s w itch , r o t a te d thro ug h

th e l as t 4 t es t po sitio ns when m a k i ng the r in gin g te s t on yokes and flyba cks and thr o u gh all 6 positions when te st ing ot her induct ors. A r e a d in g of 10 or more indi ca tes a good inductor.

4. Power ON-OFF switch, co n tro ls th e AC line vol

tag e to the “Z M ET E R”.

13. LE A KA G E RA NG E switch, us ed to se lec t the desired range of capacitor leakage current, 0 to 100 u A or 10K uA .

14. APPLI ED VOLT AG E SWIT CH , used for selecti n g the desired test v olta g e when ma kin g capaci tor leakag e tes t s.

REA R PANE L

15. Rear panel meter zero adjust. A d just to zero

digital readout with all buttons out.

16. 39G145 T es t Button Hold Down Rod mounting

clip.

17. 39G144 Test Lead Ad aptor mou nt ing clip.

18. Cord wrapper for stori ng AC line cord and t es t

leads.

5. RINGIN G TE S T pushb utto n, depre sse d when

ma ki n g the p a te n te d Sencore rin g in g t e s t on induc tors , yokes, an d flybacks to check the quality. Use IM P E D AN C E M ATC H switch (3).

6. Tes t Lead Input jack. U nscre w j ac k for access to

in p u t protectio n fuse.

7. Inductor VALUE push bu tton , d ep ress ed when

te s ti n g induct ors for value of induct anc e.

8. Capacitor VA L U E p u s h b u tt o n , de pre ss ed when

tes t i n g capacitors for capac ity value.

9. Leakage chart on pull out.

10. LEAD ZERO adjust, u sed to balance ou t the

small value of capac ity or in d uc tan ce in t h e t e s t leads when maki ng precise m ea su re m en ts of s mall v alues of cap a ci ty or inductance.

11. LE A KA GE test pu shb utton, depress ed when

te s ti n g capa citors for leakage a f te r t he AP PL I ED VO LT A G E switch (14) has been set to th e wor king vol tag e of t he c apac itor a nd L EA KAG E RA N GE switch

(13) is s et to th e pr ope r value as i nd ic a te d in th e leak

age c h a rt (9).

12. Cautio n ind ic at o r LED, bl i n k s when the

A PP LI ED VO LTA GE switch (14) is se t to 50 Volts or hig her as a warn ing to th e user. Vol ta ge is only pres en t on te st leads when L EAKAGE b u tt o n (11) is depres sed .

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Fig. 1 — Loc a t io n o f c on t ro ls a nd feature s of the LC53.

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SUPPLIED ACCESSORI E S

22. 64G37 Tes t Le ad Mo un tin g Clip.

19. 39G145 Te s t Bu t t on Hold Down Rod. U sed to hold L E AKA GE (11) but t o n d epres sed when ref or m  ing lytics. (2 s up plie d — 1 in m ou n tin g clip, 1 in spare par ts bag.)

20. 39G144 T e s t Lead A da p t o r, Used to a d ap t t es t

lead (21) clips to large screw term ina l lytics.

21. 39G143 Te s t Leads. Special low capa city cable

with E-Z Hook® clips. Co nn e ct to T es t Lead Inpu t

jack (6).

23 . 68G34 Allen Wrench. Used to t ig h t e n knobs.

24. 44G20 Spare Fuse . 1 Amp, Slo-Blo.

OPT IO N A L A CC ES SO R IES

25. 39G85 Touch Te s t Probe for in-circuit t es ti n g of

coils from foil side of P.C. board.

Not es

OP ER AT IO N

INTR OD U CT IO N

Before usin g y o u r LC53 “Z ME TER” for the fir st time, take a few min u t e s to read thr ou gh the o pe ra  tions an d ap p li ca ti on s s ectio n of t he manu al carefully to ac q u a in t y o ur se lf w it h the featu res of th e LC53. Once you are familiar w it h the general operation s, m os t t e s t s can be p erf or me d with the info rma tion p ro  vided on t h e LC53 fro n t panel.

POW E R CO NN EC TION

The LC53 is design ed to be op erate d from 105-130 VAC (50/60 Hz). If 210-230 VAC operatio n is required, the un it m ay be modifie d (at additi onal cost) by t h e Sencore Service De pa r tme n t, 3200 Sencore Drive, Sioux F alls , SD 57107.

To ope ra t e th e LC53 from t he AC line:

1. Co nn ec t t h e AC line cord to a 117 VAC (or 220

VAC for modified uni ts) outl et.

2. T u r n t he power sw it ch on.

3. The LC53 is im m ed ia tel y rea dy to mea sure ca p a  city or ind uc tan ce . If prec ise m ea su re me nt s are to be made, th e u ni t sh ould be allowed to opera te for at l ea st 5 m i nu t e s to allow th e cir cu its to stabilize.

BLOW N FUS E CON D I T I O N S

FU S E

Test Lead

Inp u t

TE S T L E AD INP U T F USE RE P L A C E ME N T: The fuse for the te s t lead i n pu t is lo cat ed behind the BNC input jack. The fuse holder ma y be removed by tu rni ng the BNC connecto r c o u n te r clockwise a nd u nscre wing the connector until t h e fu se is free. The BNC connector of a s et of test leads ma y b e us ed a s a “ W re n ch ” to aid in the removal of th e fuse holder. W hen r eplacing the fuse holder, m ake sure t h e holder is screwed in t igh tly to pr ev en t t h e c onnect or fr o m tur ni ng wh en connecting an d d is co nn ec ti ng t e s t leads. Replace the fuse w ith a 1 A mp Slo-Blo 3 AG fuse only.

)L Q CAP ACITOR tU HA ND DURIN G >0 L ARITY AND VOL TAGE RATIN G .

FUSE

TY P E CO ND I T I O N S

1 Amp 3 AG Slo-Blo

No Lea k ag e rea di ng s Ca p ac i ty re ad s a sma ll neg ative

valu e un c h an g ed b y L E AD ZE R O a dj u s t me nt

In d u ct a n ce sh ow s fla shing 888

wi th 0 following ind ic ati ng open.

No indica ti o n on Rin g ing Test.

M O OE L LCJ

FUSE RE P L ACE MEN T

AC FUS E : T he LC53 does n ot use an AC line fuse. Th e unit is pr o te c te d by a special th erm al sw itch in the power tra ns fo rmer . If th e power tran sf or m er is o v er  loaded, the ther m a l sw itc h will open the prim a ry, rem ov in g t he vol tag e from the unit. Simply allow th e unit to cool down a nd the ther mal switch will close, app ly i ng powe r to t he p ri m a ry and allowing the un i t to ope ra te ag ain. If y o ur u n it goes off, allow it to cool down and tur n it on before any troubl es hoo tin g is st a r te d to allow the th er m a l switch to close if it h as opened.

WAR N I N G

Alw a ys re pla ce t h e f use in th e t e s t lead with a 1 Amp , 3 AG, Slo-Blo ty pe. Any o th er ty p e or c ur  ren t ra t i n g m ay c au se in te rn al dam age to the un it and will void all warr an ti es .

TES T L E AD F U S E : A 1 Amp, 3 AG, Slo-Blo fuse is used in the te st lead inp u t on the “ Z M ETER”. Th is pr o te c t s th e in p ut of the uni t from voltag e applied to the i n p u t ac cid entl y. Replace with a 1 Amp, 3 AG, Slo-

Blo ty p e only.

Fig. 2 — The 1 Amp , S AGC Slo-Blo fuse is located behind th e t e s t lead inp ut ja c k.

TEST LEADS

39G1.43 T E S T LE AD S: The t e s t leads (supplied with the meter) use a special low c ap aci ty cable. The use of any oth er cable will add e x tr a ca pa city to the meter and may be out of range of th e L E A D ZE RO control. If the t e st le a d s ev e r n e e d re p l ac ement , it is recommended th at new leads (39G143) be ordered directly from the Senc ore Service De pa rt me nt , 3200 Sencore Drive, Sioux- Falls, SI) 57 107.

TEST LEAD M O U NTI N G CLIP

The special Tes t Lead M o u n ti n g Clip (64G37), included in th e sp are pa rts , m ay be mo u nt ed on the top of the “Z M ETE R”, on the side of the han dle or on you r work bench. The clip can th en be us ed to hold th e t es t leads

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out of the way, b u t ready for use a t any tim e. To m ou nt the t e s t lead clip, simply peel off the ba ck in g , place on the s p o t to be mounte d, and p res s firmly.

NOT E: Do not mo u n t the T e s t L ea d Clip to t h e sid es o f

the “ Z M E TER" as it will interfere w i th t h e mov eme n t

o f the handle.

Fig, 3 — Th e special T e s t Le a d Mo u nt i n g Clip holds the t e s t leads o ut of th e way, bu t ready fo r use at a n y time.

CAP A CIT O R TESTING

The “Z M ETER ” checks cap aci tors for th eir actual cap a ci ty with 6 au tom a tica lly selected ra ng es . Simply con ne ct the capacito r to the tes t leads, pu sh the

VA L U E b u tt o n under CAPA C IT O R S an d read the value on the d igit al read out.

bu t void th e wa r r a n t y as well. I f grounded, out let is unavailable, us e a g r o u n d in g a d ap to r a nd c o n n ect the third wire pi gt ai l to a go od ea rt h gro un d suc h as a waterpipe.

2. The “Z METER ” has been d es i gn e d to give accu

rate re a d in g s of cap a ci to r v a lue o ut of circuit. Im p ed a n c e s f ou nd in the circu it will up s e t the “Z MET ER'’'1 rea din gs. Capacitors c a n n o t be checke d in-

circuit wi t h any degree o f accuracy or re liab ili ty w it h any k n o w n te st m et h od .

3. Re mo v e t he powe r from the cir cui t if a cap ac it o r is to be c he ck ed t hat has one en d re mov e d bu t t h e oth er end stil l c o n n e c t e d to the circuit. I f the un it u n d e r te s t

is AC oper ated , r e m o ve the AC line cord from t h e AC outlet . W he n ev er poss ib le , r e m o v e the c a p ac i to r

com pl et el y f r o m th e circuit.

CAP A C IT Y MEA S U R E M E N T ACC U RA C Y

The Sencore “Z ME TE R” has been designed to p ro vide acc ur ate me a su r em e n ts (within 1% of reading) of capacity usin g the mo st accura te method available. The “Z ME TER” me asu re s the RC c ha rgin g time of

the capacito r w i t h a precision c ha rgi ng resisto r. This

gives a t r ue a nd ac cu ra te c ap ac ity me asu rem en t. The readi ngs of the ‘‘Z METE R” m ay or may no t be the same as tho se of a n o th er i n st ru m e n t using a dif fe ren t

meas ur ing sy st em. Th e bridge, for example, use s an AC signal a n d mea s ur es capac itiv e reactan ce, no t the actua l c ap aci ty . Two b ridge s wit h different frequ enc y signals will giv e different ca pac ity readings b ecau se the capaci tive reac ta nc e c hang es with frequency. The hig he r the freq u e nc y , the lower th e cap a c i ti v e reactanc e a n d the lower the capa city readi ng. The Sencore “ Z ME TER” will pr ovide a true me as u re of

capacity.

E

3V

; JOOV

/ 490V

10V

CAPACITORS I INDUCTORS

LEAK AGE VALU E I VA LUE R INGI NG T E ST (0}

Fig. 4 — Jus t co nn e ct th e capac itor to the t e st leads, dep re s s th e VAL UE b utt o n, and read th e ca p a c it y on

the d isp la y; the re are no range switc h e s to set.

S PECIAL NOTES ON C APA CIT OR TESTING:

1. Be f o re op e ra ti n g t he “Z M E TE R ”, be sure to co n n e ct th e AC line cord to a p r op er ly g r ou n de d AC outl et . The third wire g r o u n d on the “Z ME T E R ” pr o v i d e s mor e accurat e rea ding s of low le ve l capacito rs (below 1000 pF) w i th the third wire s hie l di ng . Defea t  ing th e t h ir d wire gr o u nd will n o t only re su l t in lower acc u ra cy value read ings on capacito rs belo w 1000 pF,

-WA R N IN G

When ch ec kin g c ap acitor s, conn ect the ca pa ci to r to the te st le ads before d ep ress ing the V A L U E or LE A K AG E p u s h bu t to n .

To Check Capa ci to r s for Capacity Value

1.. Connect t h e t e s t leads to the capacitor to be tested. P ol a rit y of t he t e s t leads is only imp o r ta n t if checking a polar ized capa cito r such as an ele ctrol ytic capacitor. W h en checki ng a polarized lytic, the red lead mu st be con n ect ed to th e posit ive terminal.

2. Depress the VAL U E bu t to n under the CA PA  CITO RS se ctio n of the pu s h b u tt o n switch.

3. Read th e v al ue of the cap aci tor on the f ron t panel readout. The va lu e of ca pa cit y will be in m ic rof ara ds (uF) if the L E D in f ro nt of the u F indica tor is lit. The capacity is in picof ara ds (pF) if the LE D in fron t of th e

pF indic ator is lit.

13

NOTE: Mo s t capa cito r values will read v e r y qu ic k ly , but e xtr e me l y large electr olytic capacitors (ove r 50,000 uP) m a y take a f ew seco?ids to come up to a r e ad in g level. For example, a 50,000 uF will tak e abou t 5 se co n d s before a reading is seen on the d i gi ta l readou t. An extr em ely large (100,000 uF) co m p ut e r -t y pe lyti c m ay ta k e 10 secon ds before the value is d i s p l ay e d on th e readout. If the value does no t read in th e ti me list ed abov e, then the capacitor is either s h or t e d or v ery leaky. In eith er case, it is p ro ba bl y defective. Rec h e c k th e v alu e ag ain jus t to be sure.

the aut or a n gi ng circ uit . Values below 2 pF can be read, however, by us in g th e L EAD ZE RO control to o ffs et the met er zero.

To Read Cap ac it or s Le ss Tha n 2 pF

1. Place t he t e st le ad s (with no c ap aci to r conne cted)

on t he work are a in such a way t hat th ey will no t be

moved when the cap ac it or to be test ed is connected. Be sure t ha t the t e s t leads are not on a m etal surf ace or

near AC power or an AC oper ate d device.

Th is pro cedu re pr ovides ac cur ate readings on t h e c ap a  cit or s being test ed. Small value readings (2 p F to 1000 pF) m a y be off sligh tly due to the capaci ty of t h e t e s t leads. T his ca pac ity can be ba lance d out for ex tr em e ly hig h ac cur acy r ead ing s wit h t he LE A D ZE R O co ntr ol. The L E A D Z ER O control is auto ma tica lly switc h ed out of circu it for capacity values above 10,000 pF.

TO ELIMINA T E TES T LEAD CAPA C IT Y

1. P lace t he te s t leads (with no capaci tor con necte d)

on th e work area in such a way t h a t they will no t be

moved when the c apac itor to be teste d is conn ect ed. Be sure tha t the t e st leads are not on a met al s ur fa c e or nea r an AC power o utle t or AC operated device. St r ay AC ma y aff e c t the r e a d i n g of small v a l u e s of

capa ci tor s.

2. D ep re ss th e VA LU E bu t to n and ad ju s t t h e L EAD ZE R O control un til the me ter reads 00.0, with n eg a ti ve sign a p pe ar in g occasionally.

3. Ca refully connect the capa citor to be t e s te d to the Lest leads. D epre ss the VALU E b ut ton an d re a d the act ua l value of the capacitor on the meter.

2. Depre ss th e V A L U E b u t t on and a d j u s t the L E AD ZERO control u nt il t he m et er read s a positive n u m b er such as 2.0 pF. A n eg a ti ve nu m ber can be obt ain ed on the reado ut b u t will give an incorrect reading.

3. Connect the c a pa ci to r to th e t e s t leads wi th o u t

dist ur b in g the ir p os iti on on the work area.

4. D epr ess th e VA L UE b ut to n to obta in a read ing on the meter. S ub t r a c t t h e se tt in g of ste p 2 from th e r e a d ing to get the actu a l value of t h e capacitor. F o r

example, if t he re a d in g o bt ain ed wa s 2.6 and the se t 

ting in s tep 2 was 2.0, t h en the ca pa ci tor value is 2.6 minus 2.0 or 0.6 pF .

INTERPRETING “ Z METER” VALUE READINGS

Some capac ito r d ef ec ts r esu lt in a r ea di ng much lower th a n the tole ranc e specified for t he capacitor. D et ai ls on determ inin g t h e to leranc e of common capa cito rs a re included in th e Appe nd ix section at the end of t he manual. If th e rea d i ng is outsi de this tolerance, the capacito r sho uld be consider ed bad.

Some capacito rs, especially aluminu m electrolytics, may show an o v e rr a ng e indic ation (flashing 888). T h is read ing indica tes that th e cap acito r is defective.

Fig. 5 Tes t lead capa cit y can be zeroed o u t for

ex t r em ely acc ura te readi ngs on sm all value capacitors.

CH E CKI N G CA P A C IT O R S BELOW 2 P I C OFA R A D S

The a u t o ra n g in g circuit in th e “ Z MET ER” will ofte n show a “0 0 .0 ” r ea do ut for ca pacito rs less tha n 2 pF . This is du e to the “zero win dow ” t h a t is ne ce ss ary for

The LC53 au to ma t i c a ll y dis pl ay s the two m o s t common capa cit or va lue s of picofara ds (pF) and m ic ro  farads (uF). C a pa c it or s from 1 p F to .089 uF will show as “ pF” , a nd c a p ac i to rs over .09 uF will show as “uF” . You m ay en c ou n te r s ome capa cito rs t h a t are m ar k e d with the op po sit e multiplier. Some companies, for example, will m a r k the value of a gi ven c apa cito r as

“.047 uFM, while ot h er s may m ar k the same t yp e of capac ito r as “ 4700 p F " . Th e following table will explain how to ea sil y conv ert one rea din g to an o th er . This conversion ch a r t also appe ar s on the pull-o ut cha r t on th e bo t t o m of the “Z M E TER ” for you r convenience.

CHANGE TO

FROM MICROFARAD S

NANOFARADS Mov e de c i ma l

PICOFARADS Move d e c i m a l

MIC RO FAR ADS NANOFARA DS PICOFARADS

3 pla c es lef t

6 pla c es lef t

Move d ec i ma l 3 pla ce s r i gh t

Move d ec i m a l 3 pl ac es le f t

Move d e c i m al

6 places r ig h t

Move de c i mal

3 places r ig h t

Chart 1 — Ca pa cito r mul ti pl ie r conver sio n chart

14

TESTING LARGE SCREW T ERMIN A L LYTI CS

Some lytics, especially in in d us tr ia l ap plic atio ns, use

rat he r large screw terminals rat h er than the conven

tional solder terminals. The 39(1144 TES T LEA D

Ada p to r (supplied with the LC53) should be used to con ve rt the small E-Z 1 look “ clips to large alligato r clips to fit the large screw te rmin als . A special clip is moun ted on the back of the LC53 to s to re the 39 GI4 4 when it's not in use.

Fig. 6 — The 39G144 Tes t L e ad a d a ptor allows even

the large screw te rm in a l ca pacito rs t o be co n ne ct ed to the LC53 for testing.

To Use the 39G144:

1. Connect the Red E-Z Hook" on the LC53 te s t leads to the red term inal of the 39G14 4 T ES T L E A D ADAP TO R. Co nnect t he Black clip to the other terminal.

2. Connect th e Red alligator clip of the 39G.144 to the posit ive screw term inal and th e Bla ck all iga tor clip to the n egativ e termina l.

3. Tes t the cap aci tor in the u su al m an ner .

NO T E: The red area, o f the APP LIED VOLTA GE

sw it c h s ho u ld be observed. Voltages in this area are 50

Volts an d above and could cause a shock hazard. The

blin k i ng L ED is an extr a r emin d er th at the APPL I ED

V OL TAGE switc h is set to 50 Volts or greater. A l w a y s obse rv e the red area o f the sw i tc h in case the extr a remi n de r L ED is burned out.

Fig. 7 —- T he LC 53 can te st ca pacitors for L e ak a ge at

the ra t e d w o r ki ng volta ge of the capacitor. Just set, the APPLIED V OL TA GE swit ch, set the LEAKAG E

R ANGE , a n d dep ress the LEA KAGE b u t t o n an d read

the leak a ge on the displ ay in microamps .

To Check a Capacitor for Leakage

1. Conne ct the capac itor to be test ed to the test leads. I f th e c apacit or is polarized, such as an e lectro lytic cap a ci to r , c on ne ct the p o si ti ve en d of the cap ac ito r to t he red lead a nd t he neg at iv e end to the black lead.

2. Se lec t t he desired leakage rang e with the LEAKA GE R A NG E switch. The AL L OT H E R CA P A C IT O R S (100 uA max) range is used for mo st small ly tics, paper, mica, film, and ceramic capacitors. The L A RG E ALUM. ELE CT R O LY T IC S (100K uA max) ra n ge is used for large lytics. Consult th e leakage ch ar t t o d eterm ine which range should be used. It is

CHECK ING CA PA C IT O R S FOR LEA K AG E

Capa cit ors will often read the co r re ct value b u t e xhibit

leakage which may affect th eir op e ra tio n in th e circuit. The “Z MET ER” will check cap a ci to rs for this leak age a t their ra ted working volt ag e up to 600 Volts. Ther e are two leakage c urr en t ra n ge s , 0 to 100 uA and 0 to 10K uA and 12 vo ltage s from 3 Vo lts to 600 Volts

DC. The volta ge is applied to th e t es t le ads only when the LE A KA G E bu t to n is depre sse d. The cap aci tor is au t oma t i c a l l y d i sc h a r g e d w he n th e LEAKA GE BUT TO N IS RE L EA S ED .

|

---------------------------

1 This in st ru m en t is to be opera ted by a technically

trained p erson only — who und e rs t a n d s the shock hazard of up to 600 Volts applied to th e t es t leads during the capac ito r leakage test. DO NOT hold the capacitor in you r h an d or touch the tes t leads or capacit or leads whe n m akin g the leakage tes t with 50 Volts or more.

W ARNI N G

------------------------------

Fig . 8 — Si mp l y c on su lt the leakage ch a rt on the pu ll ou t ta b unde r the LC 53 or the leaka ge ch a r t in this man u a l for the ma x i m u m allowable leak ag e of a l um i  num a n d t an t al u m lytics.

15

bes t to s t a r t with the hi gh est range (Large Aluminum

Electro lytic s) if you are not sure which r an ge to use. If the display shows “000", then s w it ch to the other

rang e. You can switch ran ges of the L E A K AG E

RA N G E switch while holding the L EAK AGE bu tto n

in if you have selected the wr ong ran ge or merely wish

to sw itch ranges.

3. Select the normal DC working vo l ta g e of the ca pa 

cit or to be tested w ith the A PPLI ED VOLTA G E

switch . If the normal wo rking v oltag e of th e ca pacito r falls between the range s on the switc h, select the nex t

low e r range. For example, if the wo rk in g vol tag e of the ca pa c it or to be test ed is 35 Volts, s ele ct th e 25 Volt pos it io n of the APPL I ED VO LT A GE switc h.

4. Depress the L E A K A G E bu tt o n and read the

valu e of leakage cu rr ent in m icroamps on the display. Cap ac it or s will take a specific a m o u n t of time to cha r ge and give an a ccu ra te reading of th e leakage

cur re nt . Consult t he typ e of ca pacito r you are t es tin g

in the following listing for time require d to show a

display.

CER AM I C, PAPER, M ICA, AND FILM TY P ES:

Us e the ALL OT H ER CA P AC I TO R S posit io n of the L E AKAGE R ANG E switch when t e s t in g t hes e c ap a cit or s for leakage. The leakage r ea d i n g should take only 2 to 3 seconds for an a ccu ra te dis pla y. In some case s, w ith a very large value of c ap ac ity , a low leakage

re ad i n g may appear in the first second o r two and th en cha n g e to 00.0. This is a normal cond itio n and merely sho w s the capacitor is charging . If a re ad in g is still pr e s en t after about five seconds, the cap ac ito r has exces siv e leakage and should be conside red defective.

circuits. Wh en a lytic is fully ch arged, th e rea d in g will change in small st ep s up and down showi ng th e ca p a

citor is charg ed . T he se small step s s impl y in di ca te t h a t the c a p ac i to r und er tes t is a t te mp t in g t o filter small

changes in th e AC power line voltage. I t is not neces

sary, in mo s t ca ses, to wai t un til t he ca p ac it o r is fully

charged to de ter m ine if it is good. Just d e p re ss the

LE AKA GE b u t t o n until the leakage d ro ps below the max im um allo wable level as shown on t he c h a r t in the

manu al or o n the pull out table on the bo t t o m of the “ Z

M ETER”.

If th e LAR GE ALUM . EL E C T RO L Y T IC (L0K uA max) r an g e is used first a nd the rea din g d r o p s to 000, simply c h an g e t he L E A K A G E RAN G E s w it ch to the

ALL OTH ER C A PA C IT OR S (100 uA max) range while de pr e ss i ng the LEA K A G E b ut to n. Ignore the first tw o r e ad i ng s a ft er ch ang ing ra ng es a s the rang e switch ing cha ng es the series imped ance which in tu rn causes a m o m e nt ar y cha nge in the charg ing ra te .

130

S PECIAL NOTE O N L OW V OL TAGE C ER AMI CS :

Ceram ic capacitors of 50 wo rk in g vol ts or gre at er hav e a ver y high insulation re sistan ce an d s ho u l d no t sh ow a n y leakage on the lea kage test. Ceramic capacitors

w i t h a lower w o rki ng voltag e tha n 50 Vo lt s have a

m u ch lower i nsulat ion resi sta nc e a n d m ay shoiv lea k age on the leakage test. The act ua l in su l a ti o n r esi s

tan c e va ries fro m m a n uf a ct ur e r to m an uf a ct ur e r, bu t a gen e ra l rule o f th u m b is: 16 wo r ki ng vo lt capacitors

ma y sho w as muc h as 16 u A o f lea ka ge and be w it hi n

tolerance. 25 Volt ceramic capacit ors m ay show up to

2.5 u A of leakage. It is b es t to m a k e a com p a r is o n test,

i f po ss ib le, with a kn o w n g o od ca p a ci to r a n d the su s  p ect ca pacit or wh en in doub t I n most cases, t he se low

vo lt a g e capacitors will on l y be u s e d in circu its where th is hig h leakage will not u p s e t th e cir c u it operation.

AL UM INU M LYTICS:

Th e alu min um lytic charg ing time will v a ry w ith t he ca pa c it y and th e applied leakage vo ltag e. On larger lytic s, the m eter will overra nge (showing flas hing 888) un ti l the c hargin g cur re nt drops b elow 10 mA. The ty pi ca l amo un t of time tha t the m et e r will o verr ange can be determined from cha rt 2. The d ispl ay will

usu al ly begin a t a high leakage r ea d in g an d then drop wi t h each u pda te of the digital di spla y. Th is show s the c h argi ng ac ti o n of th e ca pa ci t or thr ough th e imp ed an ce of the APP L I ED V O L TA G E power sup ply

Capacity (u F)

Chart 2 — Me t er overrange tim e ve rsus c ap ac it or value and app li e d v olt a ge .

NO T E: S ome lyt i cs may sho w a good value reading and a lo w l eak ag e reading a nd be a q u es t io n a b le co m 

ponent. If th e value is rechecked a fte r the leak age is

chec ked an d the capacit y is lowe r than f i r st chec ke d and b eg i n s to increase to wa rd the original value, the lytic is e x hi b i t i n g dielectric abs orption. T h is ge ne rall y occurs w h en the electrolite in the lyti c begin s to d ry out. Th e capa c ito r does n ot c o m p le te ly d is ch a rg e and the re sid u al volta g e reduces th e c h ar gin g time ma k i n g

the ca p ac it or appear to be a smalle r value. I f a capa citor ex h i bi ts dielectric absorption, try r e fo r m i n g the capacitor as ex p la in ed in “Ref o rmi n g Ly t ic s on the “Z

METER ” or ‘ Ref o rmin g L yti c s with a Po w er S u pp l y ”

covere d l a t e r in t hi s manual. I f the ly ti c stil l sh o w s dielectric ab so r pt io n a fte r reforming, the l y t i c s h ou ld

be con si de r ed defect ive.

TANTALU M LYT IC S :

Ta n ta l u m ly tics have a much lower l eaka ge comp ared to alum in u m lytic s for the sa me cap aci ty and working voltage. T a n t al u m lytics should, in mo s t cases, be checked on the AL L O TH E R C A P A C IT O R S r ang e of the L EAKAG E RA NG E switch. T a n t al u m l ytics will give a leak ag e rea di ng in a very s h or t peri od of time,

ju s t a ma t t e r of 2 to 5 seconds.

16

LEAKAGE CHARTS

The following leakage c h a r t s ar e the s ame ch a rt s t h a t you will find on the pull ou t t ra y on the LC53 *'Z

vIETER". They show the ma x imu m allowable leakage

of common lytics and t a nt a l u m lytics. Note t h a t these

figures are t he wors t case c on di tio ns as specified by the Ele ctronics In du st ry As so ci at ion (El A) s ta n da r d s ItS-345, and m an y lytics will show leakage values well below these figures.

MA XIM UM A L LOWABLE LEA K AGE (in micro a mps)

Sta n d a r d Al uminu m Electr o l y tic Ca p a c it o r s Stand a rd T a ntal um Ca p acit ors

Capacity

in ijF

1,000 1,500 400 2,000 470

5,000 740 10,000 Ί 20,000 1470

50,000 1700 100,000 3300 200,000

3V

1 3

5 10 5 15 20 5 25 5 30 35 6 40 6 50 8 70 11

100 150 2"0 250 300 45 400 200 500 230 750 290

40

340

1040

4650 6600 8 500

15 22 30

1 0 V 1 5V

6V

5

5 5

5

5 5 5 5 5 8

5

5 8 13

10 15

6

13 20

8

5

9 15 25

10

18 12 20 15 25 40 20 35 190 30 50 230

45 230 280 200 270 330 230 300 250 330 290 38D 470 330 4 20

520 640

400 470 600 740

740 900

570 660 850

1040 1340 1470 1900 2320 2070 26 80 3290

2340 4 24 0 5200

4650 6000

50 V 10 0V

25 V

5

5 5

5

5 8

6 13 13 25 50 270 20 40

5Π

25 30 220 300 420 40

230 330 460

28

45 250 360 500

30

190

270 380 210 300 420 250 350 500 300 420 600 850 370 520 730 420 600

370

470 670

400

S20 730 660 850 1200 1700

520

670 950 1340 1900 820 1160 950 1340

1160 1640 2320

1040

1340 1900

1640

2120 3000 3000

424Θ

6000

4240

9500

6700

7350

9500

200 V

5 15 30 25 50

230 270

1040 850 1200 950 1340

1040 1470

1640 2320 1900 2680

3286

2700 4240

300 V

15 20

10

45 200 below 230 270 330

330

400 4 60 460 540

380

520 600 570 660 620

540

660 760

600

730 850

710

870 1000

1040 1200 1300 1470 1470 1640 1800 2Q8Q 2320 2450

Non-polarized lytics should be m ea s ur e d for leakage in bo th directions. Make the leak a ge t es t, then reverse the te st leads an d r e pe at the te s t. Some non-polarized lytic s have one lead connec ted to the case. The allowable leakage on these ty p es is twice t h a t of a reg u la r lytic of the same cap aci ty a n d v olta ge r at in g in bo t h directions.

400 V

380 3.3

700

1550 220

Capacity

in u F

1.5 and

2.2

4.7

6.8 10 15 22

33 47

68 100 150

330 470

680

3V 8V 1 0 V

ALL CAPA CITOR S IN THI S A RE A SH OUL D J>hUW IMU L EA KAGE

1.5

2.5

1.5 2 3.5

1.5 3 5 2 4.5 7

14

22

10

20

3 6.5 5 10 15 7

10.5 20 15

20

1 5 V 25V 50 V

1.5 2 3.5

2 2.5

2.5 4 6

3.5

5.5 10

8.5

5

7.5 12 20 11 15 16 20

14

20

1.5 2

2.5

5

Use LARGE ALU M I NUM ELECTROLYTICS

Use ALL OTHER CAPACITORS Range

Range

Chart 3 — Max i mu m a llo w a b le lea kage for Al umi nu m and

IDENT IF Y IN G CA P AC ITOR TYPES

The capacito r ha s i ncreased in use tr em endo us ly in the pa s t few yea rs. M any new type s and i mproved versions are now in use. The following info rma tion is orovided as a guide to aid in th e identif icatio n of the

,ype of cap ac ito r a nd its valu e. Th e color code ch a rt s

cover mo st of t he v ar ia tio n s t hat will be encou ntered.

There may be oth er s not cov ere d here an d in those

cases, c on su lt t he m a n u fa c t u re r of the eq ui pm e nt for

information.

Tan t a l um ly ti c s per El A sta n dar ds .

TANTA LU M LYTIC S :

Ta n t a lu m l ytic s are be ing f ou nd in m or e electronic cir cui ts th a n ever before. Its low leakage curr e nt and sma ll er phys ical size has m a de it a st a n d o u t for solid- st a t e circuits. The tan t a l u m lyti c s can be m ade to tigh t e r tolerances tha n alum in um lytics. Tan ta lu m s are no t mark ed as such and th e sche m ati c generally does n o t indica te t he lytic as a t a n talum . The ta n t al u m lytic is smaller (abou t one-half or less) tha n t he same

ca pa c it y a nd voltage a lum i nu m lytic. The ta n ta lu m

17

comes in m an y sizes and s ha p es as shown in figure 9. Some use a color code like t ha t s h ow n in figure 9. No te th a t the color coding can show the p ositi ve lead. Some tan t al u m s are m ark ed with t h e v al ue a nd a + on the posit ive lead. Oth e r t a n ta l u m s use th e shape of the lead or a r ou nd in g of a corner to indic a te the p ositiv e lead.

Typ i c a l Physical Sha pe s of

Commo n Ta n t a l u m C apaci t ors

FILM TYP E S:

The s e are th e h a r de s t to identify as t o t h e t yp e of film bei ng used. The typ e of film is no t ge ne ral ly m ark ed and i t could be any one of at leas t five t ype s. On these

cap ac it or s, you will have to cons ult t he ma n u f a ct u r e r ’s

service infor ma tion for t he co rrec t typ e. It shou ld be no t e d t ha t a Mylar® ca pacito r is not a universal rep la ce m en t for any film typ e cap ac ito r. Ea c h film has diff e ren t cha rac te ris tic s a nd m u s t be r ep lace d wi th the

sa m e ty pe of film used in the circuit. T hi s is especially

tru e in t ho se a rea s of s che ma tics that are de sign ed as

“ S af e ty C riti ca l” .

TE S T I N G FOR DIELECTRIC A B SORPT I O N

Dielectri c abs or pt ion is the inab ili ty of a cap aci tor to com ple te ly d ischa rge to zero. This is s o me ti m es called

“ba t t e r y a c ti o n ” or “c apa cito r me mo r y ” a n d is due to the dielectric of th e c apac itor r e t a in i n g a c harg e. All ca pa c it or s have some dielectric ab s or p t io n , b u t electr o lytic ca pa ci tor s have th e hi gh est a mo u nt an d will often affe c t cir cuit op er atio n if it b eco mes excessive. You can c heck lytics for dielectric a b s o rp t io n d u r in g the no rm a l t e s t for c ap aci tor value an d lea ka ge by simply ree he ck ing th e valu e of th e ca p ac ito r a f te r the lea kage

te s t in th e following man ner.

Fig. 9 — T a n ta l u m lyt ics co m e i n all size s a nd shapes.

The m o s t co m mon shap es are s ho wn here for identifi~

catio n o f the pos i ti ve lead.

CE R AMIC DISCS:

The ceramic disc is well-known an d c an be identified by its round sh ape and generally b r o w n color. Some cer a

mic discs come in different co lors such as blue and green due to a different co a t i n g materi al on the outside. M o st ceramic discs a re m a r ke d wit h the value

and the tolerance. T he m ost c o m m on wo rkin g vol tage

(500 Volts) is gene rally not m a r ke d , b u t a n yth in g dif

ferent is normally found on t he cap ac i to r body. Th ere

are ot her marki ng s such a s NP O , GMV, N1500, or similar. These a re th e t e mp e ra t u re coefficients or how muc h the ca pa ci tor will ch a ng e with a change in tem pe ra tu re. W he n repla cing a ce ram ic disc, be sure to use the s ame ex a ct type t ha t w as use d in the original circuit. NPO s t a n d s for Ne gativ e-Pos itive-Z ero or no

chang e in capaci ty. GMV is Guar a nt ee d Minimum

Value and th e a ctu al value could be muc h higher. Th e

let te r N in dicate s tha t the ca p a c i ty will decrease wit h

an increase in t em p er at ur e, an d if yo u find one w it h a

let te r P, t h a t one will incre ase in capacity with an

increase in tem p er at ur e. Fu r the r information will be

found in t he sectio n on “ C a p ac i to r Theory and th e ‘Z

METER’ ” a nd in the G lo s sa ry at the back of the

manual.

1. Co nne ct t he cap ac ito r to t he t e s t le ad s a n d t e st for the c a pa ci tor value in the n ormal ma nn er . Note the valu e of the capacitor.

2. T e s t the ca pac itor for l eakage a t t he ra te d work  ing v o lta g e of the capa citor. Allow t h e le aka ge c urr ent sho w n on th e display to dro p to th e max i m um allow able lea kage or below as shown on th e l eaka ge c h ar t in

the ma nu a l or on the pull out t ab u n de r t he meter.

3. Re lease t he L E A KA GE bu t t o n a n d allow th e d is play to dro p to 000 and then i m m ed ia te ly depr es s the VAL U E b u t t o n and note th e ca pa ci to r reading.

a. If th e c apa ci ty re ad ing is wi th in 5% of the origi nal value and the re adi ng i nc re ase s slowly upward tow a r d the original value, or th e re is no difference in t h e r eading s, th e ca pacito r ha s v ery l ittle dielec tric abs or pt ion and is good.

b. I f th e value re adi ng difference is gr ea t er th a n 5% b u t less tha n 15%, the capa c it or m ay require refo rm in g a s desc ribed later. So me of th e dielectric oxide h as de te rio ra te d a nd r ef or m in g t he lytic m ay br in g it back to a us eful life. R e ch eck for dielectric abs or pt io n o ften a tt e m p t in g t o re for m t he capacitor.

c. If the valu e rea din g difference is gr ea t er than

15% and the rea din g c ha ng es u p w a rd rapidly tow a rd th e origin al value, t h e ca p ac it or has exc es sive dielectric ab sorp tio n. E le ct ro l yt ic capac itor s exh ib iti ng t his much dielectric a b s o rp t io n may be refor me d in some cases. If th e c a pa c ito r exhibi ts simi lar dielectric abso rpt io n a f ter reform in g hai been a tt e m p te d , it s hould be r epl ace d as it will give tro ub le in the circuit.

N OT E: If a mi ca or film ty p e cap a ci to r s h o w s any dielectric absorption, i t can be cons id e re d “b ad” an d sho u ld be replaced.

18

REF O R M IN G L Y TIC S ON THE “ Z ME TER ”

Alum in um lyti cs will ofte n show low value or hi gh leakage if th e y hav e been s i tt in g on a shelf for a long period of time. Ge ner al ly any alum inu m electrolytic capac ito r sit t i n g on the shelf for over one year will

show up in this m a nn e r. This is caused by a loss of

some of th e oxide c o at in g t h at forms the dielectric of

the capa cito r. In m a n y case s, th e oxide coatin g may be reformed with the a pp li ca tio n of a DC volta ge for a

period of time. The “Z METER” can reform the dielectric m a te ri al by u si n g t he same DC power sup ply

tha t is used for leak a ge tes ting . R eform in g ma y require m ore th a n an ho ur before the c ap aci to r r et u r ns

to its no rm al cond itio n. The 39G145 T E S T B U TT O N

HOL D D O W N R OD is includ ed with the “Z M E TE R” to hold the LEAK AGE b u tt o n down for re form ing

lytics. A spe cial clip is mounted on th e rear of th e

in st r u m e n t for s t o ra g e of t h e 39G145 when it is no t in use.

W A RN I NG Use the 39G145 wi th extre me caution! Do not touch the t e s t le ad s or t he capacitor leads while the 39G145 is being used. Make su re tha t the

cap ac ito r being re fo rm e d will not to uch any metal or come in co n t a ct with any me tal object while it is being re fo rm ed . The vo lta ge from the A PPLI ED VOL T A G E switch is pr es en t on the te s t lea d s when the LE AK AG E b ut ton is depres se d.

S PECI AL N OT E : This met hod of hold i n g the L EAKAGE but to n in pro vid es a greater degree of saf e ty than a “lat c hing " typ e of s w it c h . A lway s observ e ex tr eme cau tion when y ou see the handle in fro n t of the s wi tch es as t h i s will tell you voltage is being ap plied to the test leads and. capacitor. Neve r at t e mpt to operate any o t h e r fun ct io n pus hb u t t o ns when the 3 9 G145 is being used.

iAPACITORS | INDUCTORS

w um'tiT o w n I ftN w our w fjn c iim

LEAKAGE V AtU t I VALUE RINGING TEST (G)

Fig. 10 ~ Th e 39G145 Tes t bu t t on H o l d D ow n R o d can be used to k ee p the LE A KAG E bu tt on depressed when refo r mi ng a lytic on th e “ZM ETER".

REFORM ING LYTICS WIT H A POWER SUPPLY

NO T E : Ob s er v e th e red area on the APPLI ED

V OLTAGE sw i tc h . This i7idicat.es a voltag e of 50 to

600 Vol ts DC an d can be dangerous. The specia l LED

will also blink on a n d o f f to indicate th a t the APPL IED V O LTAGE s w i t c h is se t to 50 to 600 Volts bu t rely on t h e red area of th e s w i tc h in case th e LED burns out.

To Use the 39 G145 Te s t B u t t o n Hold Down Rod:

1. C onn ect the lytic to be reformed to the t e s t leads

obse rvin g pol ari ty ,

2. Select t h e pr o p er vo lta ge with the AP P L I ED VOL T A GE sw itc h. O b s er v e the above w arn ing when using 50 Volts or more.

3. Dep r e s s th e LEAK AGE but ton , a n d wh ile

holding th e b ut ton in, plac e th e 39G145 on th e b u tt on . Bring th e h an dl e to t he fr on t of th e mete r and wedge the 39G145 b et we en th e hand le and the LEA K A G E bu tt o n so that the rod holds t he L E AK AG E butt on

depress ed.

4. A fte r the c a p ac i to r h as been refo rmed for at le ast one hour, i t s ho uld be allowed to d isch arge an d sit for ab ou t 30 min ut es . T he n rechec k the value and t h e leak age to see if th e r ef or m in g pr ocess ed ha s impro ved the capacito r.

A s ep a ra te DC power s up p ly ma y be used to reform a capacitor. The power su p pl y mu s t have a vol tage ou t p u t equal to the c ap a c ito r s working voltage, and should be ad ju sta bl e from zero to allow the vol tage to be increas ed slowly. The po we r supp ly should also have a DC cu rr en t m e ter or an e xt er na l m eter m u s t be used to mo nit or the ch a rg in g curr en t.

■CAUTION·

Always use a series li m it in g r e si st or when apply* mg v olta ge from an ex t e rn a l po wer su pply. This will prev en t th e c ap ac ito r fro m cha rgi ng too f as t which may cause p e rma ne n t dama ge to the

capacitor.

-W A R N ING - Voltag es from 50 to 600 Vo lts can be dangerou s. Do not to uch th e leads fro m th e power sup ply or the leads of th e capa cito r. Do n o t allow the ca pa  citor to come in co nt ac t wit h m et al or any metal object while the vo lta ge is be ing applied. A w a rn  ing sign shou ld be place d on or n ext to the unit while the capacitor is bein g reformed.

19

To Use the E x t e rn a l Po we r Su pp ly to Reform Lytics:

1. W it h the power su p p ly turn e d OFF, connect the

positive power sup pl y t er min al, t hr o ug h a 1000 Ohm, 5

Wa tt re sis to r and the ex te rn al cur ren t met er (if required) to the p o sit iv e term ina l of th e lytic to be reformed.

2. Connect th e ne g ati ve te rm ina l oi' the power supply

to the negativ e ter m ina l of the lytic.

3. Set the ou t p ut vo lt a ge contr ol on the power supply

to minimum.

4. T ur n t he po wer s up p l y to ON and slowly increase

the volta ge while w a tc h in g the c ur re nt met er. Do not allow the ch ar gi ng c u r re n t to go above 50 mA. If the meter re ad s h ig her th a n 50 mA, stop in cre asing the voltage until th e cu r re n t dro ps below th is level. Then slowly i ncrease t he vol tag e aga in while w atc hin g the

current me ter unti l the DC working v olta ge of the capacitor is reached . Allow the ca pac itor to rem ain a t its full rated wo rki ng vol ta g e for at least 30 m in ut es to one hour.

5. After one hour, t u r n the power supply off and allow the capa ci to r to di sch ar ge . After th e cap acito r has disch arg ed for at l ea s t one hour, recheck t he value and leakage on the “ Z M ETER ” to see if further reforming is necessa ry.

LEAKAGE IN CERA M IC, P AP E R , FILM, AND

MICA C A P AC IT O R S

Ceramic, paper, film, and mica t y p e c ap aci tor s should not show any lea kage at all. T he m a xi mu m allowable leakage is below the s e ns it iv it y of the m ea sur ing circuit. If any of thes e t ype c a pa c it o r s e xhibit leakage, they are defective.

CHEC K ING FOR LEAKAG E B ET W EE N SEC T IO N S OF A M ULT I-SEC T I O N LYTIC

Multiple section lytics are co m m on in m an y power supplies. Lea kage so me tim es d ev elo ps b etw een two or more sections of a multiple secti on type. This leakage may be due to an i nte rn al sh o r t circ uit , or a build-up of

di rt between the term ina ls on the outside of the capacitor. This t yp e of leakage is p a rti cu la rl y difficult to tro ubl esho ot bec ause th e s ig na l f rom one section of the ca paci tor is coupled to the o th er section which res ul ts in multipl e sym p t om s in the o pe ratio n of the device in which the capac itor is used.

An ohm m et er will often fail to show this leakage

because it only occurs at or nea r the capaci tor 's ope ra tin g voltage.

The “Z M E TE R” will quickly lo cate thi s type of leak  age while p erfo rmi ng the st a n da r d leakage test. The sections t h a t are n o t b ein g t e sted for leakage are simply shorte d out while t he leak age of the first section is being m onit ore d wi th the LC53 cu rre nt meter. An increase in l eakage in di ca te s interna l leak age between sect ions and a bad c ap aci tor.

Fig. 11 — A lyt i c ma y be refo rm ed with an externa l

pow er s u p ply bein g sure to us e a series re sis tor a n d a

current m e t e r to m on it o r t he r efo rm in g cu r r e n t

CAPACITOR TEST ING APPLICATION TIPS

NO VALU E REA D ING ON SM A LL VALUE CAP ACI T ORS

A sh ort ed cap a ci to r will n orm ally give a 000 read out. However, th ere a re some capac itor s, generally below

1000 pF, th a t are not s ho rt ed , bu t will still give a 000 readou t on c ap ac it or VA L U E . If the leakage of these capacitors is measure d, it will be discovered a low value leak age c u rr e n t is pr ese nt. This small' value of leakage cur re n t will u p s e t the capacity measuring circuit of the ” Z METE R” and cau se the 000 readout.

----------------------------

The following procedure sh ou ld only be per formed by a qualified pe rso n who un de rs ta nd s the potential hazar d of up to 600 Volts being applied to the te s t leads while mak in g the leak age test. Do not touch th e R ed te s t lead clip or the capacitor term inal it is conn ect ed to du ring the

tes t or while the LE A K A G E b u t t o n is depressed.

To tes t for leakage be tween s ect io ns of multi-section capacitor:

1. Connect one section of the cap aci tor to th e tes t

leads observing polarity.

2. Set the APP L I E D v ol ta ge swi tch to th e proper voltag e for the sect ion being t es te d . Be sure to use the correct vo lta ge as ma ny multi- se ctio n ca pacit ors have different voltages for each section.

3. Dep ress the L E AK AG E b u t t o n and obs erve the

leakage curren t read ing on the display.

4. Using a s ho r t jum per, con ne ct one end to the common terminal of the c ap ac it or and th en while depre ssin g the LE A K A G E bu t to n , connect the other end of the ju mp er to one of t h e o th e r term inals of th e capacitor not connected to th e t e st leads. A good lytic will show no ch ange in the lea kag e r eading. A ca paci tor with leak ag e be tw ee n s e ct i o n s will show an

W ARNI NG

-----------------------------

20

incr ea se in l eaka ge when the sh o rt is ap plied to the

unt e s t e d ter mina l.

NOTE : Be su re to te s t all th e terminal s of the mu l t i- se c ti o n lyti c a ga in s t each oth e r for leakage b e t we e n sect io n s.

Fig. 12 — Te s t the l eakage of one sect ion an d then sh or t one o f t h e oth e r se cti ons to ground. An incre as e in l ea k ag e c u rr e nt s h o w s l eak age b etw e en th at s e c ti o n

and t h e one u n d er test.

LARG E F L U C T UAT IO NS IN LYTIC LEA KAG E R EAD IN GS

often be refor med to i ts o rigin al ca pac ity wi th the “Z

M ETER” or powe r supply or when placed in the

circuit and allowed to ru n for a period of time.

LOW VALUE LYT I CS USED IN HIGH FREQUENCY CIRCU IT S

Low value ly tics (1 u F to 1000 uF) used in high fr e quency filtering ap pl ic at io n s s uc h as switc hing powe r supplies and AGO ci rc uit s in television can develop an above normal i nt er na l series res istanc e. In these app li  cations, the series re si sta nc e will interfere with the filtering action of th e capa ci tor and imprope r ci rc uit action will result. I n th ese rare occasions, the c ap aci to r could be p ut to u se in a con ven tion al 60 H ertz pow er supp l y an d funct ion n or mal l y . B e c a u s e thes e

capacito rs will fun ct io n norma lly at 60 Hertz, t hey may no t show up a s b ad on the “Z ME T ER” . In fact,

the leakage of th e h ig h in ter nal series r esis tan ce c a p a  citor m ay even be lower th an a good capacitor. If th is is the case, conne ct a scope us in g t he Lo Capaci ty probe across the capa c ito r an d observe the ripple waveform when che ck ing leakage. If the waveform ha s

tips, as shown in F ig ur e 13B, the ca pacito r has a series inte rna l r esis tan ce t hat will in terfere with circuit o p er  ation an d should be replaced. If no tip s are ob served,

as shown in F i g ur e 13A, then the cap aci tor ha s ve ry

low or normal inter n al series resistanc e.

Lea k a ge rea d in gs on lytics will normally st ar t at som e hig h va lue and then de crease a s the c apac ito r c ha r ge s up. When t he ca p ac ito r is fully cha rged, th ere will be a sma ll var ia tio n in the l eakage rea ding i nd ic at in g t h at

the ca p ac it or is tr yi n g to filter out the small v a ri a ti o n s in t h e line volta ge. When th e va ria ti on s bec ome r a th e r la r g e a n d c ha n ge in la rg e jump s , s us pect an in t e r mi t t e n t lytic. Lytics t ha t e xhibit this s y mp t o m will give tro ub le in the circuit an d should be rejecte d.

LEA KAG E M E A S U R E M E N T S OF NO N-P O LAR I Z E D LYTICS

Le a ka g e m e as u r eme n ts on non-polarized ly ti cs mu s t be ma d e in b o t h di rectio ns. Simply make th e lea ka g e te s t, note the leakage c urre nt, and then reve rs e the lea ds and ma ke th e le akage t e s t again. If bo t h e n d s of th e no n-polar ized lyti c are i ns ul at ed from th e c ase, th e ma x imu m allowabl e leaka ge is the sam e as lis ted in t h e leak a ge c ha rt . If o ne end is co nnect ed to the c ase, the allow abl e le ak ag e is doubled.

LY TICS SIT T I N G IN S TO CK

Ly t i c s t h a t hav e been s it ti ng on the shelf ma y show high leak age whe n checked. Th ese lytics should be re form e d accor di ng to the inform atio n in this ma n u al un d e r “Refo rm ing Lytics with the ‘Z M ET ER ” ’ or

“ R ef o rm i n g L yt ic s with a Po wer S u pp l y” . G en era lly , a

lytic t ha t h as been s it ti ng a nd is checked for valu e a nd th en le aka ge m a y i ndic ate a larg er capac ity v al ue wh en the valu e is rec hecked. For example, the l yt ic m a y m ea s u re 1000 u F when tes te d before p er fo rm i ng th e lea ka g e check. W hen the va lue is checked a f te r the leak a ge t est , t h e value may now be as high as 1100 uF . Th i s ind ic at es th a t the lytic was p art ial ly refor me d whe n the lea ka ge wa s t est ed. This type of ly tic c an

Good 2 .2 uF leakage rip pie .BV /Pi v.

Defective 2u F leakage r ipp le ,5V /0 iv.

Fig. 13 — T he sc o p e wa v ef o rm sh o w n in A is a g oo d capacito r w it h no i nt e r na l series resistance. B sh o ws a def ec ti ve c apac itor wit h inte rn al series resis tan ce as det e c te d by the s p i ke s a t the top of the waveform.

INTE R M IT T EN T C A PACITORS

Occasionally, a cap ac i to r can become i n te rmit te n t. A

poor weld of t h e lead to the foil or oth er m echanica l

malfunctio n ca n c a us e t he ca pac ito r to opera te in a rand om fashion. Th e leads of t he susp ect ed capac ito r should be moved a ro u n d or pulled on when m ak ing t he Value te st. A ch a n ge in cap ac ity indic ates an int e r m it te n t problem.

21

An in t e r mi t t e n t c au s ed by a ba d weld can s om etim e s

show up as f las hin g 888 on the meter. This is due to th e cap aci ty c h a n g in g a t t he time the V A LU E b u tt o n is depr es se d a n d the m e te r can no t lock in on a range.

INTERNAL CONSTRUCTION OF

ALUMINUM ELECTROLYTIC

Ins ula t o r

Posi tiv e

Lead

Tab C o n ne c ted

To An o de Foil

Tab We ld e d To Lead

Paper

Impre gn a te d

With

Elec tro ly te

Tab Conn e cte d

Rolled

to Other Foil

Foil

Alum in um Lead

Case

Tab Wel de d to

Alum i n u m Case

Neg a t iv e

Fig. 14 — A lyt i c can be come i n t e rmit t en t if the wel d is not pr oper on e i th e r tab or becomes corroded a f t e r a long peri o d o f use.

TIM E REQU IR ED TO OBTAIN A VALUE READ IN G ON A C A PACIT O R

Cap ac it or s of 1000 u F and below will read almo s t ins ta n ta n e o us l y. More t ime is required for c ap aci tor s above th is value. Th e a ctu al time dep end s upon t h e RC time c o ns t a n t of t h e capacitor. For example, a 50,000 uF will re a d in only 5 seconds an d a 100,000 u F ta k es only 10 secon ds. The meter will re ad 000 until the cou n ti ng c ir cu it h as reac hed the pro per level a nd the n the ca p a c it y re ad i ng will app ear on the display.

soldering iron or h e a t g un , the te m pe ra tu re va ria tion can be seen. If the c a p a c it o r is ma rke d COG or NPO, for example, the ca pa c it y sh ould no t chan ge or cha nge only slightly. If t he c a pa c it or is mar ke d with an N, such as N1500, t hen th e c ap a ci ty will decrease as long as the h ea t is applied un ti l the lower limit is reached. Capacito rs m ark ed wi th th e lette r P (not in common usage) will increase ca pa c it y with th e application of heat.

CHECKIN G FILM TYPE C A P ACIT ORS FOR TEMPERATURE SEN S I TIV I TY

Fil m ty pe c a pa ci t o rs ca n bec o m e t e mp er at ur e sensitive and cause pr o bl e m s in the circuit. By con

necting th e su spe ct c a p ac it o r to t he “ Z METER” and

tes tin g the capa city whil e a pply in g he a t from a sold er

ing iron or he at gun or s p r a y in g w ith a “freeze spr a y ”, the change in capacity c an be seen. Mo s t film ty pe cap  acitors should change very little in capacity. If a dras ti c change is seen, t he capa cito r has become

tem pe ra tu re sen sitive an d sho uld be replaced. A word of c autio n here — do no t to u ch the sold ering iron to the capacitor. The heat c an da m a g e the sens itive plastic

film used as a dielectr ic and mak e the capacito r useless.

TESTIN G C A P A CITY OF SIL IC O N DIODES

AND TRA N SIS T OR S

The “ Z ME T E R " can me as u re the cap acity of silicon diodes and tr an si st or s. T h e reverse leakage paths aroun d t he tra ns is to r a n d diode can also be measu red within the limits of th e le ak a ge power supp ly of the “Z M ETER”. The c on ne ctio ns to m easu re capacity and leakage are the s ame a n d th e prope r lead connections

are shown in figure 15. i f th e rea do ut shows 000 when

tes t in g for ca pac ity or fla shin g 888 when t es tin g leakage, the leads a re rev ers ed. No p rec auti ons are necessary when t e s ti n g ca pac ity , but the following guidelines should be o b se rv e d when te s t in g leakage.

1. Use only the 3 V o lt position of the AP P L IED

VOLT AGE switch wh en t es t i n g Ibeo.

On ver y lar ge c ap ac it or s, generally ove r 100,000 uF , the f ir st r e a d in g m a y differ from l ater read ings by a s mu ch as 10 p er ce nt. This is normal an d cause d by th e dielectric ab so r p t io n f ound in mo s t type s of c ap ac i

tors. Th is s li gh t cha ng e in read ings shou ld c ause no prob le m b e ca us e t h e tolera nces of thes e ca pa cito rs a re gene rall y -20%, + 80% which m ea ns th a t the fi r st

read i ng will be close e no ug h to locate ca pac ito rs t hat have ch a n ge d va lue ou tsi de the tolerance limits. I f you requi re a v ery pr ecise reading, simply leave th e Cap a cit or V AL U E b u t t o n depres sed until the “ Z

METE R” has gone th r ou g h a t l eas t 2 co mplete r e a d  ing cycles.

CH E CK ING CERA M IC CA PA C IT O R S FOR TEM P ERA T U R E SE N S IT IV IT Y

Cer a mi c cap a ci tor s (often called disc ca p a c i to r s

becaus e of the ir phys ical appearance) come in a wide

var ie ty of c ap a ci ty valu es an d t em p e rat u re toleran ces.

By c o nn e ct in g th e ca pac itor to the “ Z MET ER" and

check ing the ca p ac it y and t hen a pply ing he at fr om a

2. Use the setti n g of th e AP PL I ED V OL TAG E switch t h a t m at ch es th e m ax im um applied voltag e to the tr a ns is t or when te s t i n g Icbo or Iceo. Do not exceed the ra ti ng s of the tra n s is t o r. The t r an s is t o r will go into a zener mode and gi ve a n inco rrec t leakage reading. If left in this manner, it could da ma ge th e tra ns ist or.

NO TE : The capac ity of g e r ma n i u m transi sto rs and diodes ca nn ot be m ea u sr e d. T h e high leakage of these devices will up set t h e c a p a c i ty m e a su r in g circuit o f the

“Z ME TER ' ’" and th e re a d o u t will sh ow flas h in g 888 when the V AL UE but t on is depresse d. The leak age o f ger m a n i u m dev ices can be mea s ur e d with the leakage

te s t th e s a me as t he s il ico n devices. D o not exc ee d th e

voltage rating o f the d e v ic e as ge r m a n iu m devic es cun

be dam a g e d quite easily.

22

PNP

Black

ICBO and

B to C Capacity

/

Red

ICE O a n d

*

Red

\

IBEO and

B to E Capacity

' Black·**

E to C Capacity

NPN

^Red-#*.

ICBO and

B to C Capacity

Black

4

Black

\

IBEO and

B to E Capacity

x Red

Bla c k

\

ICEOan d

E to C Capacity

Red

- M - r

Red

Leakage

- and Junction Capacity

Fig. 15 — Capac ity c on ne ct ion s for m e asu r i n g capa ci t y of silicon junc ti on s . Lea ka g e pa t hs are for both silic on a n d ger m a n i u m t y p e jun cti o ns .

Black

2. Be gin wit h the A P PL I ED V O L T A G E s w itc h in

the 50 Volt posit io n and de p re ss the LEAKAGE

butto n.

3. W hile holdin g th e L EA KAG E butt on , incr eas e the AP PLI ED VO L TA G E swi tch one ste p at a tim e until th e di g i ta l displa y shows a lea kage re ad ing . D o

no t increase the Volta ge pa st the po i n t where the digita l readou t be gin s to read. Inc re ase d vo l ta g e m ay

cause too m u c h cu rr e n t to flow which may ruin th e diode.

If you ge t all th e w ay to 600 V o lts and th ere is still no

reading, t h e diod e is open.

4. R elease th e L E AK AG E bu t t o n a nd rev e rs e th e connectio n of the red and black test leads.

5. I nc re as e t h e s e tt in g of the APP LI ED V O L T A G E

switch to t h e 600 Volt position.

6. A ga in d ep r e ss t he LE AKA GE b u tt o n a n d obse rve the di gi tal re a do u t. The d igita l r ea do u t s h ou ld st a y a t “0 00”. An y l ea ka g e c u rr en t in dic at es t ha t t he diode is leaky and s ho u ld be considered defective.

TEST IN G SI LIC O N C ON TR O LLE D RECT IF IER S (SCRS) AND T R IA C S

SCRs a n d T RI A Cs can be te s te d dy nam ic ally on th e “Z M ET ER ” usi ng th e leakage functi on of t h e c a pa  citor te st . SC Rs an d T RI ACs can be t es ted for t u rn on (latched) and t u r n off (unlatched) cond itions a n d a t th e full r a te d wor ki ng voltage of th e device u p t o 600 Volts.

TE STI N G HI GH V O L T A GE DIODES

Hig h v o l ta ge diodes, such as found in TV h ig h v ol tag e and focus volta ge sections, cann ot be t e s t e d on a con ven ti on a l ohm m e ter because th ey r eq u ir e Vo lta ges as high as 200 Volts before the y begin t o condu ct. An oh m m e te r, which typic ally supplies on ly 2 Volts, will

sim p ly show an open c irc uit no ma t te r h ow t he leads are conn ecte d.

The Lea ka ge te st of th e LC53 prov id e s sufficient Vo lt ag e to allow high vol tag e diodes to b e t e s te d for bo th forw ard conduction and rev erse leakag e. The diode sho uld be te st e d for forw ard co nd uc tio n f ir st to confi rm t hat it is not open. Then, it sho u ld be te s te d for rev er s e leakag e.

WAR N I N G The following p roce dur es should be perfor m ed only by a tech nically qualifie d pe rso n w ho u nd er  st a nds the pot ent ial shoc k haz ar d of up to 600 V o l ts app l ie d to th e t e s t le ad s w he n th e LEAKAG E b ut to n is depressed.

To t es t a high Voltage diode:

1. Co nn ec t the red lead of t he LC53 t o th e anode (- end) of t h e diod e a nd t he blac k lead to t he c at ho de ( + end).

—--------------------- W ARNI NG

------------------------- The following procedur es should be p erf orm ed only by a te chn icall y qualified person who un d er  sta nd s t h e pote nt ial shock h az ard of up t o 600 Volt s a p p l i e d to the t e st leads w h en the LE AKA GE b u tt o n is depressed.

NO T E : All t es t s m us t be p e rf o rmed wi t h t h e devic e out-of-c ircu it

TES T IN G SC RS AND TR IACS FOR DC LAT CHING

The following tes t will determin e if the SCR or T R I AC will tu rn on and rem ain latched und e r DC c onditions.

1. C onnect th e Red t e s t clip lead to th e an ode of th e SCR or to ter m in a l 2 (MT2) of the TR I AC. Co nne ct th e Black te st clip to th e cath ode of the SCR or to term ina l 1 (MT1) of th e TR IA C.

2. Se t th e LE A K AG E RA NG E switc h to the LA RG E AL U MI N UM ELEC TR O LY T IC S (10K uA max) range.

3. Set th e A PPLI ED VO LT A GE switch to the 10 Volt position a n d de pres s th e L E A K AG E b u t t o n . The display shou ld show 0000, indicati ng no leakage.

23

a. If th e D is p lay shows an ov erra nge con d iti o n of

888, th e device under te s t is shorted.

NO TE : If t h e wo r king volt ag e is unk no w n , use th e 15

Volt sett ing of the A PPLI ED VOL TAGE switc h.

b. If th e D is pl ay shows a re ad ing o th er t han 0000, the device sho ws excessive leakage a n d sh ou ld be

replaced.

4. Con nec t a n in su la ted jum p e r lead from t he ga te of th e dev ice bein g t es te d to the lead co nne cte d t o the Red t e s t clip (anode or MT2).

5. Dep re ss the LE A K AG E bu tto n . T h e displ ay shou ld show a n o ve rra ng e c ond ition of f la sh i ng 888 if th e device is good or has latched ON. Re move the s ho rt wit h th e LE AK AGE b u tt o n still d ep re s se d. The dis pl ay should stil l show f lashin g 888 i nd i c at in g tha t th e device is lat ch ed a nd will rem ain la tch ed u n ti l t he vo lt ag e is remo ve d by releasing t h e L EAKAG E bu t t o n . If the device does n o t show th e fl a sh i n g 888 when t he s h or t is removed, th e gat e is defective.

6. Release th e L E AK A G E butto n. De p re s s the L E AKAGE bu t t o n ag ain wi th ou t the s h or t a pplied. The d isp la y s ho uld show 0000. Th is in dic ate s t hat t he devic e tu rn e d off whe n th e DC vo ltage was r em ove d. An y oth e r re ad in g indic ates a defective device.

SCR

Red Test Black Test

Clip Clip

2. Connect t h e Re d te s t clip to th e an ode of the S CR or to terminal 2 (MT2) of the TRIAC . Co nne ct the Black tes t clip to t h e ca th od e of the SC R or to te rmin a l 1 (M T l) of the TR IAC .

3. Depress th e L E AKA GE b ut to n . The dis p la y should show 0000, in di ca ti ng no lea kage at th e r at e d voltage. Any leak a ge read in g here i ndica tes t hat the device is defectiv e a n d s hould be replaced.

4. While d e p re s s in g th e LE AKA GE but to n, s h o r t the g at e of th e d evic e being tes te d to the lead con nected to t h e Red te s t clip with an i nsu la ted j u m p e r. Observ e the Wa r n in g notice above. Th e disp lay shou ld show an ove rr an ge co ndition of fla sh ing 888, i n d i c a t ing t he device h a s t u r n ed ON. Rem ove the s h or t and the ove rrang e sho u ld drop to 0000 in jus t a few seconds, indic at in g t h at the device has tu rne d O F F .

NO T E : If t h e SCR or TRI AC does no t show flas h i n g 888 when the g at e is sh o r te d to the a no de or t er mina l 2 (MT2) or does no t dr op to 0000 in jus t a few s e co n d s

when the s h o r t is r e mo v e d fr om th e gate, the d e v i c e is

defe c tiv e and s h o uld be replaced.

DETER MIN IN G T H E LENGTH OF RF CO AX I AL CABLE

Short as Indicate d

in Procedures to Test

for Proper Turn-On

Fi g . 16 — L o ad c on ne cti ons for te s t in g SCRs a nd

T RI ACs.

TES TING SC RS AND TRIAC S FOR A C LATC H AND UNLATCH CONDITIO NS

The fo llowing t e s t will deter mi ne if the SCR o r T R IAC will t ur n on a nd off with t he AC vo ltag e a s it should. Th e p u l s a ti n g DC vol tag es of the LC53 were de si gne d to m a ke t hi s t e st so tha t the SCR and TR I A C wo ul d be op e ra t e d unde r nor mal ope ra tin g cond itions, just like the y woul d be in-circuit.

N OTE : All test s must be p er fo r m ed wi t h the de v ice out-of-circuit..

1. Set t he AP PLI ED V O LT AG E sw itch to t h e w or k

ing vo l ta g e of the device to be tested.

The actual len gth of a piece of coaxial cable or the point at where a b re a k exi st s can be de ter min ed v er y accurately with th e “Z ME TER” . Each type of coax has a nominal amo u nt of ca paci ty per foot of l en gt h.

Simply m ea sur e the capaciLy of the cable unt e rmin  ated and div ide by the cap ac ity per foot to find th e lengt h or th e p o i n t of the brea k in the cable. Th e “Z METER” will m e as u r e the break poin t ca p a c i ty regardless if th e b re ak is in t he shield or the c en te r

conductor. The b r e a k p oi nt c an be found by the s imp le

step s below. If at all possible, m eas ur e from bo th e nd s of the cable to pin p oi n t t he br eak much closer.

1. Measur e th e cap ac it y of t he cable (must be op en and u nt erm i na ted ) w ith th e “ Z ME TER”. C onnec t the red t es t clip to t he ce nte r co ndu ctor an d the bl ack te s t clip to the shield braid.

2. Divide th e rea d in g from the “Z METER” by th e cable cap acity pe r foot. This gives the dis ta nc e or lengt h of the cable from th e me asu ri ng poin t in feet.

NO T E : The accu r ac y of the meas u re men t depend s

upon the cable ca p a c i ty tolerance since the value l i s t e d

is a nomin al fig u re and can v ary sli g h t ly wi th manu facturer. The no r m a l tolerance is wit hi n 2%. If th e

cable has seve ra l locations whe re there is e x c essiv e crim p in g or c la m pin g , the capac ity will chang e at those p o in ts a nd will aff e c t the overall reading. If t he cable is s h o r te d or term ina te d, th e “Z M ETER" wi ll

not be able to read t he capacity . The fo llo wi ng se c t io n indicate s how to lo cat e a short.

24

RF COAXIAL CABLE

50 - 55 Ohm

RG/U C abl e Type

5B/U

8U 52 29. 5

8U Fo am 50 26

8A/U 52 29. 5

10A/U 52

18A/U

58/U

58/U Fo am

58A/U 50 30. 8

58C/U 50 29 . 5

58C/U Foam 50 26

74A/U 52 29 . 5

174W 50 30 - 3 0.8

1

77I U

212/U

213/U

214/U 50 3 0 . 5

215/U 50 3 0 . 5

219/U 50 30

225/U 50 30

224/U 5 0 30

Nomina l

Im p ed a n ce

50 29. 5

52 29. 5

53. 5

50

50 30

50

50 30. 5

No mi na l

Ca p In pF/FT

29 . 5

28 . 5

26

29 . 5

Nominal

Ind uc ta nc e

Char t 4 — Ca pa city of typica l RG C oax ia l Cable.

HOW TO FIN D A S HOR T IN A COAXIAL CAB LE

RF COAXIAL CABLE

7 0- 75 Ohm

Nominal

RG/U Ca b le Typ e

6A/U 75

6A/U Foam

11 u

11U Foa m

11 A/U

12 A/U

13 A/U

34B/U

35B/U

59/U

59/U Foam

59/U Do ub le Shie ld

59/BU

164/U

216/U 75

82 C h a nn e l

Im pe d an c e

75

75 20.5

75

74

75 20

75

73

75

75 17.3

75

73

RF COAXIAL CABLE

90- 1 25 Ohm

RG/U Ca bl e Typ e

62/U

62A/U 93 13.5

63B/U 125 10

71B/U 93 13. 5

79B/U 125 10

Nominal

Im pe da n ce

93

Nomina l

Cap in pF

20

20 5

17.3

20. 5

20.5

21

17.3

20.5

20. 5

17.5

Nomina l

Cap in pF

13.5

Nominal

In d uc t an c e uH/FT

Nomina l

In d uc t an c e uH/FT

A brea k in a co axial cable m ay be loc ated with th e Cap ac it y t es t as ind ica ted in th e p re vi o us section, A sho rt e d cable, however, will n o t re a d on the Capa city test . The Indu ct an ce te s t shou ld be used to loca te a shor t.

The amo un t of ind uct an ce p er foot is generally not publ ish ed by th e cable man u fa ct u re r . T hi s value m ay be deter min ed by u si ng the “ Z METER” to m easur e a known le ngt h of the cable (as exp lain ed in the ne xt section) before pe rfo rm ing the I n d u ct a n ce test . Space has been left in the c h ar ts ab ove for t he ind uc tan ce per foot to be added as you enc ou nte r dif fe ren t cables.

To find the ap pr ox im a te dis tan ce t o a short:

1. M easur e th e induct anc e of t he sh o rt ed cable. The red t e st clip shou ld be co nnected to t he ce nte r co ndu c tor and t he black te s t clip to the sh iel d braid.

2. Divide the r ea din g ob tain ed b y t he ind uct anc e pe r foot t h at you have me asu re d to find th e di sta nc e in feet from th e m ea su ri ng point to the sh o rt .

HOW TO FIN D T H E IN DUC T ANC E PER FO OT O F C OAXIAL CAB L E

A k no wn le ng th of cable should be m ea s ur ed with th e “ Z M ETER ” to find the valu e of in d uc ta n ce p er foot. A le ng t h of a t l ea st 20 to 25 feet is rec omm ende d to obt a in a mor e accu ra te reading. A lengt h of 10 feet

ma y be t oo sh o rt to give a good indu c ta nc e value.

1. Con nec t the known length of cable to the “Z ME TER”, th e c ente r condu ctor to th e red tes t clip, and th e shield brai d to the black t e st clip. S ho rt the cen te r co n du ct or to the shield at th e op p os ite end.

2. M ea su re the inductance . Divi de the reading ob ta in e d by th e len g th of the cable. Re co rd this figure in the c h a r t for futur e reference.

NOTE: Th e indu c ta nc e ma y v ar y sl i ght ly w i t h the

sam e typ e of cable due to the var ia ti on s in m a nu f a c ture. Th e me a su r in g tolerance to the p oi nt of a sh or t

sh o u l d be w it h in 2% in mos t cases. For find i n g a short,

it is reco m men d e d tha t the cable be mea s u re d from both e n d s to pi np o i nt th e sh o rt closer.

25

INDUCTORS

BALAN C I N G OUT LEAD IND U CTA NCE

The “ Z METER” mea su res the ac t u a l in du cta nc e of coils usin g a pate nt -pe nd ing circuit. Simp ly connect

the te s t leads to the coil and de p re s s the V A LU E bu t t o n and read the i nduct ance in u H or m H on the display.

---------------------------- Do no t connect the te s t leads to a cir c uit hav ing power applied. Be s ure t he power is “OFF” by disconnecting the AC line cord to t he e qu ipm e nt under tes t.

CHE C K IN G INDUCTO RS FOR IN DUCTANCE VALUE

1. Connect the te s t leads to the coil or tr an sf or m e r to

be test ed.

2. Depress the In du ct ors VA LU E b u t to n .

3. Read the valu e of in ducta nce of th e coil or t r a n s  former on the digital display. T he L ED will lig ht in fron t of uH if the value is in mic ro he nry s or in fron t of the mH if the value is in millihenrys.

W ARNI NG

-----------------------------

1. Pl ace t h e t e st l eads on the work are a in su ch a way th a t th e y will not be moved when c on ne ct ing a coil. Be sure the leads a re n ot on a metal surface, n ea r AC

power or a n AC o pe ra ted device. S ho r t th e t e s t lead clips togeth e r.

2. Wi t h th e tes t le a ds sh o rt e d , depr es s the Ind u c ta n ce V A L UE bu tt on a n d a d j u s t the LEAD ZER O contro l u nti l th e display reads 00.0 with the nega tiv e sign a pp ea ri ng occasionally.

NOT E : Adj us t th e LEAD ZE RO contro l sl ow l y as the

LC5 3 re quir es a b o u t 2 se co nds b e tw e en r ea d i n gs whe n

the t es t leads are shorted.

3. C arefu lly con nect th e coil to the te s t lea ds being careful n ot to di st ur b the position of t h e le ads if possible. De pr e ss the I n du ct or s VA LU E bu t t o n and read t he i nd uc tan ce value on the display.

N O TE : A reading o f f la s hi n g 888 w i th a st e a d y zero

indi cates an ope n c irc u i t. Reche ck y ou r lea d conn e cti on s to m a ke sure y ou are c o n n e c te d to the

pro p e r terminals.

The above procedure provides accu r a te readin g s on in du c to r s over 1000 uH . Small val ue indu ct or s betwe en 2 ul i and 1000 uH may be off s lig htly due to

the induct ance of the tes t leads. Th is in du ct an ce ma y be balanced ou t for high a ccuracy r ea d in g s with the LE AD ZE RO control.

3 IR S I I N D U C T O R S

IMPED

(BIN

ALUE I VALUE RINGING TEST (Q)

I

.

i

25 V O L TS IS APPLl

NOT HOLD CAPA ClTOi

SERVE POLARI TY AND

iZERO

Fig. 17 — S i mply c on n ec t the i n d u c t o r to be t es t e d to

the te s t leads, pu sh the V ALU E but t on and read the ind u ct a n ce value on the display. Th e re is no range

sw i t c h e s on the LC53.

Fig. 18 — Th e induct a nc e of the tes t lea d s can be balanced ou t for accurate readings o f sm a l l value induct ors .

CHE C K ING CO IL S BELOW 2 M ICROHE N RYS

The “Z METE R” ma y show a re adin g of 00.0 for coils und er 2 uH in value. Th is is due to the “ zero w in d ow ”

th a t is n e ces sa ry in t he a u to ra n gi ng circui t. Values of

coils below 2 uH can be read by o f fs ett in g the m eter

with t he L E AD Z ER O control.

To Read Value of Coils Below 2 uH:

1. Pla ce t h e te s t leads on the work area in such a way

th a t th ey will no t be moved when the coil is connected.

26

2. Sho rt t h e tes t leads tog et her . Depr ess the Indu cto rs V A L U E b u t to n a nd ad ju s t th e LEA D ZERO con tro l un t il th e d is pl a y shows a re adi ng of 2.0 uH.

NOT E : If the LEAD Z ERO con tr ol is turned in the

ivrong direc tio n , a ne g at iv e s i g n will app ear in fron t of the reading. A djust the LEAD ZE RO control f or a

pos it i ve reading.

3. Unsh ort the t es t leads an d carefully connect the

coil to the tes t leads wi th ou t di s t u r b in g their position.

4. Depress t he In du cto r V A LU E b ut to n and obt ain a

reading on the dig ital display . S ub t ra c t the 2 uH se t up

in step 2 from th e rea din g on t h e di spla y for the actu al inductance valu e of the coil. F or example, if the display shows a rea di ng of 2.8 u H, the actu al value is 2.8 minus the 2.0 or 0.8 uH.

OPEN W I N DIN G IN A COIL

Open wind ings in coils are ea si ly sp o tte d with the “ Z

M E T ER ” . Just hook up th e “Z ME TER ” to check the inductance value. If the disp la y shows flashin g 888 with a s t at i o n ar y 0, th en the coil is open. Check the lead con nectio ns to the coil to be sure. If th e coil is a small wire type , be sure to che ck th e fine wires t h a t go

to the solder lu gs on th e coil for m. The fine wire can be

broken easily from ten sion or ext rem e hea t an d cold

variations.

On large t ra n sf or m er s tha t ha ve several tap s or windings in series, simply che ck from to p to bo tt om for an open. The ac tu al open can be is olate d by moving one lead down t he series of t a p s until the “Z METER” gives an i nd u ct an ce readin g. T h e t a p a bove t his point has the open winding.

NO TE : On m ult i t a p tr a n sf o r m e r s suc h as fly b ac k

transformers, c hec k the t e r m i n a ls the tes t leads are connect ed to. If th e “Z M ET E R” sh ow s an open, y o u ma y be con n e c te d to the w r on g ter m in a ls .

CHECKING IND UC T ANCE IN-CIRCUIT

----------------------------- W ARNI NG ----------------------------- Do not conn ect the te s t le ad s to a circuit ha ving power applie d. Be su re t h e powe r is “ OF F” by disconn ecti ng the AC line cord to the s et under test.

The “Z ME TE R” can check t h e valu e of in du cto rs in- circuit for the ac t u al i nd u ct an c e value. Sim ply con nect

the te s t leads to the coil a n d depre ss t he Induc to rs VAL UE b u t to n an d read th e i n du ct an ce valu e on the display. Circui t im ped anc e will have some affect on the

ladings. Th e va lue s of res is to r s t ha t can be paralleled

with the indu c to r an d d ecre ase th e ind uc tan ce value by only 10% ar eas follows:

2 to 90 uH — 100 Ohms

90 uH to 9 mi l — 300 Ohms 9 mH to 90 mil — I.5K O h ms 90 m il to 900 mi l — 5.K O hm s 900 mi l to 10 II —- 1 OK Ohm s

If t he value of re si sto r is larg er than t h a t listed, the

m ea s ur in g error will be less tha n 10%.

Fig. 19 — In d u c t a n ce values can be c h ec ke d in-circuit w i t h th e LC53 indu c ta nc e test.

Coils in a television or two-way rad io can be checked quickl y and easily for value. If a coil is open and sh un t ed by a resi sto r (so meth ing t hat m i gh t be missed wi t h a n ohmmeter), the “ Z M E T E R ” will not read the cor re ct value, b u t a m uc h hig her value. For example,

th e coils in a CB tr an sce ive r will n or ma lly run around

.2 or .5 uH. If the coil is open, th e “ Z ME TER” will re a d flashing 888 w ith the s t a t ion a r y 0 if t her e is no res i st o r shu n ti ng the coil. If a I K Ohm resisto r is sh u n t i n g the coil, the “Z ME TE R” will read a b ou t 2.8 mH .

TES T I N G INDUCTO RS ON PR INT E D

CIR C U IT BOARDS

On m os t PC bo ards, th e leads to a n y com po nen ts are

ve ry s ho rt which m ay m ake c on ne cti on s difficult. The

E- Z

Hook® clips used w ith th e “ Z ME TE R” will con ne ct to m a ny of th e coils t h at y ou wish to test. When th er e is no lead to co nne ct to, y ou c an use th e Sencore 39G8 5 To uch T e st Pro be (optional accessory) to m ake

co n t a ct w ith th e l eads of the coils. C on nec t the 39G85

to the “ Z METE R" t e s t leads as follows:

1. Connect th e Red clip of th e t e s t leads to the II po i n t on the to p of the 39G85. Co nn ec t the Black clip to t he Y point on the top of the 3 9G85.

NOTE: T h es e are the t w o l o n g es t prob e poi nts a nd will

m a ke it easier to use wh en ch e c k i ng coils.

27

Fig. 20 — The 3 9 08 5 {opti on al a cc ess or y) can be us e d

wit h the “Z M ETE R ” to c h e c k th e inductan c e and ringing o f coils th at are mo un t e d f l a t to the PC board.

VAL UE READINGS ON HIGH RES ISTA N CE COILS

Coils wit h high internal res is ta n ce will cause most ty p e s of inductor te s te rs (including bridges) to read the

ac t u a l i nd ucta nc e value slightly off-value. The special

(patent- pe ndin g) i nductan ce t es t p ro v id ed by the ” Z METE R ” co mp ens ate s for the se ri es resi sta nce of the ma j o r it y of all coils tes ted . T he re a re , however, a few coils whose DC re sista nce is larg er than the range of res is t an c e com pens ation tha t c an be bu ilt into the “Z METE R ” wi thou t affe cting a cc u ra c y on st a nd a rd low res i st a n ce coils.

The following tab le lists the DC re s is ta n c e ne cessary to affect the accuracy of the ”Z METER” reading. No ti ce th a t each of the six a u to - ra n g ed induc tan ce scale s ha s a different correction fa c t o r applied by the

“Z ME TE R” to compensa te for larger resis tanc e val u es on highe r inductance coils. This as su re s the hi g h e st possible accuracy for th e maj or it y of coils tes t e d .

COIL RESISTA N C E E FFE CT ON INDUCT A NCE VALU E R EADIN G

ACCU RACY F O R COI L R ESIS TA NCE

Coil I n d u c t a n c e

2% or B et te r

2-5%

2. Make con ta ct to the p oi n t on the PC boa rd for one side of the coil to be teste d w i th the Red prob e point and apply sli ght pressu re to hold it in place. Th en make c onta ct to th e ot her coil p oi n t with th e Yellow probe point and apply pre s su re to hold the 39G85 in place.

3. Depress the Induct ors VA LU E b u tt o n and read

the inductan ce on the digital disp lay .

MUTUAL INDU CT A N C E

If two or more coils are wou nd on th e same form and

connected eit her internal ly or extern ally, the total

inductan ce mea sur ed from end to end with the “Z M ETER ” will no t be equal to th e mea sur ed ind uct anc e of the individual windings. T he m ea su red value may be higher or lower t h an the mea su re d value of the individual wind ings due to the m u tu al in duc tan ce of the coils. The mea su red value of the t o tal will be affect ed by the s paci ng betw een the wi ndings, the type of windings used, an d th e core mat er ia l used to wind th e coils on. The a c tu a l value ca n n o t be pre-de termine d by simply looking at the coils. The “ Z METER” will measure the a ct u al in du cta nce of th e combina tion of coils just as the cir cuit would see it.

1 uH - 90 uH

100 uH - 900 uH 1 mH - 9 mH 10 m H · 90 mH

100 mH *9 00 mH

1000 mH - 9000 mH

4 Ohms or les s 40 Ohms or less 40 Ohms or le ss

170 Ohms or l e ss

500 Ohms or le ss

1500 Ohms or less

4 -1 0 Ohms 40 - 100 Ohms 40 -100 Ohms

170-40 0 Ohm

500 · 2000 Ohms

1500 -6000 Ohms

Char t s — Acc u r a c y of LC 53 ver s us re si st an ce of coil.

INDU C T O R CODING

In d u c to r s can be found with se v era l different color codes of which the two mo st co m m o n are shown here. The s t ri p code on the posta ge s t a mp coils may also be a serie s of dots. The two codes s h o wn here are by no me an s all the codes t h a t may be en co un ter ed. When a st ra ng e code is found, con sult t h e m an u f a ct u re r ’s service lite ra tu re for the values.

Charts on follow in g pa ge .

T 1000 uH T T 10OOuH j |_100 G uH j J 1000 uH j

2280 uH

(When Mutual In d uct a n c e Adds)

j t

{W hen M u tu al Induc tanc e

1 8 70uH

Subtr acts )

I

Fig. 21 — The in d u ct an c e re ad in g s of the “Z METER" will show the a ct ua l ind uct a n c e of two coils with mu t u a l inducta nce . Mutual ind u c t an c e can eith er ad d or subtra c t for the i n di vi d ua l read in gs of the windings.

28

TUBULAR E NC AP SU L AT ED RF CHOKE S

Back

Mil Spec. I nden t.

Tolerance

; Π

H

1st Fig. (red)

Ex a m p le s h ow n is for 270 uH 10% chok e

Colo r F i gur e Mul t iplier Tol e r ance

Black

Brown 1

Red 2

Orange 3 1,000

Yellow 4

Green

Blue 6

Violet 7

Gray 8 White 9

None Silver 10% Gold 5%

Mu lt ip lie r is the fa c to r by w hic h the two co l o r figures are mul ti pli ed to o b t a in th e in d u ct a nc e value of the cho k e coit in uH.

Mult.

(brow n)

0

5

2nd Fitj.

(violet)

1

10

100

20%

Chart 6 — T y pi c a l I nd uc t or color codes.

$ 1

f 2

CO

1 3

“ PO STAG E ST AMP ” FIXED INDUCTOR S

1st Digit 2nd Digit

Color

Black or (Blank) 0 0 1

Brown

Red 2 2

Orange 3 3 1,000

Yellow 4 4 10,000

Green 5 5 100,000

Blue

Violet 7 7

Gray

White

Gold

Stiver

Values will be in uH.

1st Strip 2nd Strip

1 1 10

6 6

8 8

9 9

Multiplier

3rd Strip

100

X.1

X.01

CHEC K IN G INDUCTOR S FOR GO OD OR BAD WITH THE R I NGI N G TES T

The p a te n te d Hing in g t es t allows you to d eter min e if a coil (without an iron core) is good or ba d w ith an a ccu 

rate b u t easy to p e rfo r m test of the qua lit y or “Q”

fa ct o r. A s p e c i a l imp e d an c e ma t c hi ng ci r c u i t esta bli she s a refere nce for all coils larger th an 10 uH. A good coil sho uld show a rea din g of 10 or more on th e digital displa y. A ba d coil will show less t h an 10 r i n g 

ing cycles.

The R ing ing t e s t m e a su r es th e “ Q” factor by apply ing

a reference pulse to t h e coil and then d igit ally co un ti ng

the n um be r of r in g in g cycles p roduced u ntil t he sign al

is da mp ed to a p r es e t level. A sho rte d t u rn in a coil will

lower its Q an d c au se the ring ing to d am p en fa st er

tha n in a good coil. An open coil will show no ringing.

/h e pa t e n te d S enc or e R ing in g te s t is base d on the Q of the coil, bu t t h e re a di n g s on th e “Z METER” will n o t agree with t h o se o b ta in e d w ith a b ridge or a Q mete r. The r easo n is sim p ly t hat th e Q te s t h as been simpli fied to mak e th e nu mb e r 10 a reference point.

IMPEDANCEMATCH

(BINGING TEST ONLY)

H °M s <$

Fig. 22 - The IMPEDANCE M ATCH sw i t c h is di v id ed in to tw o s ect ions, the fo u r pos i ti o n s in red for

T V y ok e s and fl yb a ck s, or all si x po s it i on s for other type coils an d tra nsf or me rs .

The Rin ging Te st IM P ED ANCE MAT CH switc h is divided into two secti ons. T h e f our positions m ark ed in red are the only p osit io ns tha t sho uld be used for t e s t ing television yoke s and f lyba cks . The se nsi tiv ity of the Ringin g te s t cir cuit s in t he se posit ion s is matc hed

29

to the i mp ed an ce a nd frequ en cy specifications of these special coils.

All six p os iti on s sh ould be us ed for test in g ot he r typ es of coils. T he two pos it io ns m arke d in blue have add i  tional s en s i ti vi t y t o allow small value coils to be tes te d accura tely . Th e four r ed p osit ion s will mat ch prop erly

to la rge v alu e coils.

SP EC I AL N OT E S

1. The R in g in g te s t shou ld be not be us ed on coils and t r an s f o rme r s h av i ng l am ina te d iron cores such a s power tr a ns f or m e rs , a u di o o u tp ut tran sfo rme rs, and

filter chokes. T h e iron c ore in thes e ty pes of tran s fo r m  ers and coils ab s o rb s th e r ing ing energy of the coil and resu lts in low re ad in g s that are unreliable.

2. Good coils below 10 u H in value m ay n ot rin g 10 cycles. T he low indu cta n ce of the se coils generally allows on ly abo u t 2 to 4 cycles. A comparis on t e s t should be m ad e on a kno wn good coil to see if the Q factor re s ul ts are corre ct.

3. So me coils a bo ve 10 uH m a y n ot show 10 or more rings due to the na t u r e of th e c ons tr uct io n or core mate ria l used in the coil. Th es e m ay show 8 or 9 rin gs and still be good. T he q u a li ty of th ese coils m ay be confirmed by a d d in g a “s h o rte d t ur n” a nd rech eckin g

the ri ng i ng of th e coil. I f t he coil is bad, t he nu m be r of

rings will n ot cha n ge or chan ge v ery little, indic ati ng

the coil alre ad y h as a sh o rte d tu rn. If th e numb er of rings drop s off d ra st ic all y, then the coil is good. A good “ s h o rt ed tur n” ca n be mad e from a piece of solder

wrappe d arou nd the coil t ig ht ly and twiste d t og e th er at th e e nds. Small d ia m e t e r wire or stra nd e d wire does

not give the sam e affec t and could give mislea ding results . Be s ure to us e solder or a hea vy g aug e solid wire for the “s ho r ted tur n”.

To Te s t t h e Q ua li ty of a Coil with the Ri nging Test:

1. Conne ct t h e t e s t l ead s t o the inducto r to be tested.

2. D ep res s the R INGI NG TEST but to n. Hold the bu tt on do wn a nd ro ta t e the IM P ED AN CE MATCH switch t h ro u g h all 6 pos it io n s for r eg ul ar in du cto rs or thro u gh the las t 4 positions for TV yok es and flybacks.

3. If a readin g of 10 or mor e a p p e ar s on the display in

one or more positions of th e IMPE D ANC E M ATC H switch, th e indu ctor is good. If a rea din g of less tha n

10 is displayed on all p os i ti o n s of the switch, the ind uc tor is defective. Refer t o the In d u c to r Te st in g Appl i cations an d t he section on t e s t i n g yo kes an d flybacks for furt he r information.

NO T E : The “Z M ETE R ” may s h o w a con t in u o u sl y

chan g ing reading wh en u s i ng the t wo mos t se n s i ti v e pos i ti o n s of the IM PEDANCE M ATCH sw itc h in the presen ce o f high AC p o we r radiati on. T his can occur if:

1.} T he coil is ope n an d near a so u rce of hig h level AC po w e r radiation, 2.} The lea d s are n o t conn ec ted p r o  per ly or conn e ct ed to th e wro ng t er m i n al or not ma k i n g prop er con tac t and picking up AC radiation, 3.) To u ch 

ing the Red test clip a n d inje c t i n g AC into the “Z M E TER”, a n d 4.) De p r e s s ing t he Ringing T e s t b u t to n

wit h the leads no t c o nn e c te d to any t h i ng a nd near a source o f h ig h level A C p owe r radiation. I f the con tinu o u sl y c ha n gin g re adin g occurs, m o v e the coil being test e d to a location a w ay fr om the s ource of AC radia

tion and check the con n e ct i o n s to the coil I f y o u su s p ec t th a t the coil ma y be open or the leads not conn ec ted properly, m e re l y r ech eck the inductanc e

value. I f the readout show s a flas h in g 888 with a

sta ti on a ry 0, the coil is o p en or th e leads are n o t con

necte d properly.

INDUCTOR TESTING

APPLICATIONS TIPS

The p a ten t e d Ring in g t e st on t he Se ncore “ Z

M ETE R” has been d es ig ne d to te s t coils and tr a ns 

formers for an indication of go od or bad. The ringi ng

tes t can be mad e in-circuit a s well a s o ut of circuit for

fast troubleshoo ting. Th e following applicatio n tips

cover special situ at ion s you ma y en cou nter when

test in g in-circuit. Review t h e s e not es carefully before

mak ing an y in-circuit t es t s. The app lica tio ns tips are

divided in to two secti ons, one on general coils and

tran sf orm e rs and the ot h e r d ev o ted to TV flyback

tran sf or m ers and yokes.

Fig. 2 3 — An in d u c t o r can be che ck ed for q u a lit y by simp l y co nn e c t i n g the ind u c to r to the test leads, de

pr e s s i n g th e RI NGI NG TEST but to n a nd ro ta ti ng t he

I MPEDANCE MATCH sw i tc h a n d wa tc hi n g the dis pl ay f o r th e nu mb e r of ring in g cycles.

QUALITY TE STING ON GE N E R AL COILS AND TR AN S F OR M E R S

PEAK IN G CO ILS

Coils wound on resisto rs (pea king coils) may not give a good indication on the R in gi ng t e s t due to the da mp ing action of the resistor. The lower the value of the resi s tor, the lower the Ringing tes t will read. For example, a

1.000 u H coil wound on a 10K Oh m resis tor will j u s t

make 10 rings. Th e acti on of th e r es is to r is to da mp en

out the oscillations or rin g in g in t he circuit and it wil do the same on the Rin ging te s t.

30

COIL S IN MET AL S H IELDS

Coils a n d tr a ns fo rmer s th a t are shielded w i th a metal shield may not show good on th e Ringing tes t. The

' net al shield ma y a bs o rb the rin gin g energy dep en din g

on how close t he shield is to th e coil. You should

cons id er a shielded coil good if it shows 10 or more

rings . If th e coil shows less th a n 10 ring s in all posi tion s of the I M P E DA NC E MATCH s w itc h, you shou ld e ithe r remov e th e shield an d rep ea t th e t e s t or mak e a co mp aris on t e s t on a known good s hie lde d coil. Be s ur e the coil is identical to the one in th e circ ui t being t es te d for accur at e resu lts.

FERRI T E C ORE T RANSF ORMERS AND COILS

TUBE SOLID-STATE

Red Lead

Fig. 24 — The “Z M ETER” can be co n ne c te d for a quick-in-circuit ri n g in g t e st in tub e or solid-state.

Coils an d t ra n sf or m e rs t h a t use ferrite core s will n or  mally s how go od r ing in g if th e coil is good. T h e v alue of th e coil or tra n s fo rme r m u s t be above 10 u H t o sho w a ring i ng t es t of 10 or more jus t like regular coils.

TESTI N G T V F LYB AC K T RAN S FOR MER S AND YO KE S WIT H TH E RINGIN G TEST

The p a te n t ed Senc ore Rin ging t e s t allows t h e t e s ti n g

of yokes a nd flybacks in- or out-of-circuit. Simply

con n ec t th e yo ke or flyback to the te s t l eads, de pr es s

the R I N GI N G T ES T pus h b u tt o n a nd rot a t e the IMPE DANC E MA TC H s witch th ro ug h th e fo ur yoke and flyba ck posit io ns (marked in red). A d i s pl a y of 10

or more on any one of th e four po siti ons ind ic at e s a

good yoke or flyback. If the r ea di ng is less t ha n 10 in

dl four positi ons of the IM P E D AN C E M A TC H swi tc h, the R in gin g t e s t will help locate t he ca u se of the low rea ding , a s h or ted t u rn or a circuit l oa di n g t he yok e or flyba ck down.

---------------------------—W ARNI NG----------------------------- Do no t co nne ct t he “Z MET ER ” tes t l ead s t o th e yoke or fly b ack in th e s et un til A L L pow er t o t he se t has been r emoved. F o r yo ur safe t y, di sc o n  nec t the AC line cord to the receiver from t h e AC out le t.

3. I f the se t ha s a h igh vo lta ge rectifier tube, re mov e it as the fi lam e nts m ay a c t as a s h o r t an d cause t he “Z M E TE R" t o giv e a false readin g of less tha n 10.

4. Dep ress th e R I NG I NG T E S T p u s h b u t to n and hold it down while ro t a t i n g the I MPE DANCE MAT C H s w it ch thro ug h the four yoke and flyback positions m ar k ed in red. If t he m e te r reads 10 or more in one or m ore pos it io n s of t he switch, the flyb ack is good. If the di sp l ay sh ows less t h a n 10 in all four p o si  tions of th e sw itc h, a sh o rt or load on the flyback is indicated.

NO T E : The fir st four ste p s will ide nti f y a. good fly ba c k . If a reading o f less than 10 is indicated, the fly b a ck ma y still be goo d b ut a cir cuit co uld be loa ding it Use the re ma inin g s teps to locate th e defect.

5. If the te s t r e s u l ts in t he pr evious s tep s r e s ul t in a rea do u t of less t h an 10 in all four positions, unp l u g or unsold er t h e y ok e lea ds from the horizontal wi nd ing s and rep eat the te s t .

6. If the re a d ou t is sti ll less t h a n 10 on a solid s t a t e set, discon nect on e e nd of the d am p er diode and r e pe a t the Ri nging tes t.

7. I f the re a d o u t is stil l less th a n 10, u nplug th e co n vergence coils an d re p ea t th e Rin gin g test.

IN - CIR CUI T Q U ICK TES T

1. C onn ect th e red clip to: a. Pl ate cap of a tub e set. b. Collector or in p u t to the t rip ler of a s oli d- st ate

set.

2. Co nne ct th e black clip to: a. The ca tho d e of the d am p er tu be or ano d e of the

boo ste d b oo st rectifier or s imilar loc atio ns that is

DC c onn ect ed to th e p lat e cap t hr o ug h t h e w in d

ings of the flyback for a tub e set. b. The B+ i n pu t to the horizontal ou t put t r an

sis to r or to ground. If th e set uses a n iso l at ed grou nd , c on nec t to the B+ in p u t poi nt only.

8. If the rea d o u t is still less tha n 10, sta r t disc o n nectin g the o t h e r coils from the flyback (such as th e AGC winding) one at a time. Perf or m th e R ing ing t e s t each time a lo ad is di scon ne cted until you eithe r find:

1.) the flyback be gi ns to read good, or 2.) all th e le ad s have been re m o ve d f rom the flyba ck a nd it still t e s t s bad. If all the le ad s h a ve been removed a nd th e d is pl ay still shows less tha n JO in all fou r positions, t h e fly back is defective. If, on the o th er hand, the f lyb ack begins to rea d go od a ft er a load h as been remove d, t he flyback itse lf is good. T he las t l oad to be d isc onn ecte d should be test e d as th ere is a sho r t which is loadi ng the ring ing circuit. T he fly bac k m ay be test ed o ut of c ir cuit using th e sa m e procedure.

NO T E : The f l y ba c k will te st “bad ” if: 1.) the coil u n d er te s t is open, 2.} the coil und er t e s t has one or mor e sho r t ed turns, or 3.) an y o t h er coil in e ith e r the pr i ma r y or the s ec on da r y of the transf o rm e r has one or m ore

31

sh o r te d turns. Th is third poi nt is true beca u se a sh o r te d tu rn in a n y coil will lower th e Q o f all t h e o th e r coils th r o u g h mu t u al inductance.

cann ot be checked dir ec tl y w ith th e R inging t est. T h e flyback m us t be ch ecke d from the pr im a r y w inding s to deter min e if it is good or bad.

A coil in the secon dar y m ay occasionally op en r a the r tha n s ho rt . Thi s ty p e of failure will only affec t th e coil th a t is op en an d will n ot aff ect t he other coils. If th e ope ra tio n of t he receiver indic ates th e p oss ibi lity of a n open windi ng, ther e a re two ways to t es t e ach indiv id ual winding. Firs t, y ou can ring each coil se p  arat el y . Second a nd fas ter proc edu re is to leave t h e “Z MET ER” conne cted to th e prim ar y winding an d app ly a s ho r t cir cu it to each of th e oth er windings in the tra ns fo rmer .

An e xt er na ll y applied s ho rt will lower the Q of all the oth er win di ngs , j u st like an intern al sh ort. Si mp ly no te the n u mb e r of r ing in g cycles disp lay ed w ith n o ex t e r  nal s h o r t applied. T h en use a small jump er to s h o r t ou t the se co n da ry you wish to t est. Repeat th e Ringi ng te st wit h the ext er na l sh or t applied. You do n o t n ee d to ro t a te th e IM P E D A NC E M A TC H switch for these add it io n al te st s. Simp ly leave it in t he p osit io n t hat gave th e hi gh e s t num b er of r ing s when t h e coil was tes t e d w it h o u t th e ex tern al sho rt.

If t he sec o nd ar y coil you are tes t in g is open, y ou will not see any c ha nge in the readin g when you dep re s s th e R INGING TE ST p u sh b u t to n when th e e xt er na l s h o r t is app lied. If, on t he ot her hand, t he coil is good, you will see fewer ringin g cycles displayed. Re peat t h is t e s t on all th e seco nd ary coils.

NOT E: I f t he trans fo rm e r has several coils co n nec t e d in series, simpl y co nn ect across the ends of t h e seri es co n n e ct e d coils. An open in an y coil will r e s u l t in no chan ge in t he n u m ber o f ringi ng cycles dis play ed,

SPECIAL N OT ES: A few of the newer yoke s and flybacks hav e been

des ign e d wit h very low indu cta nce for use in ce rt ai n soli d- sta te receivers. These yokes and fl yba cks may not r in g 10 or more times b ut ma y show only 8 or 9 rin gs ev en whe n good. The que sti on of good or b a d can be a n s w er e d qu ickly b y a d di ng a ‘‘shorted tur n” an d rech ec kin g th e n um b e r of rings. If th e n u mb er of ring s does no t ch a ng e or changes only slightly, t he n t h e yoke or tra n s f o rme r rl re ad y ha s a sh or te d tur n . If, t he nu m b er of ri ng s d ro ps off drastically , then th e y ok e or flyba ck is good. This m et hod can be used on a n y su sp e ct e d yoke, flyback, or inductor.

A sim ple “s ho rt ed tur n” is a piece of solder. Sim ply form i t i nt o a loop and pr ess it close to the w in di ng s of the y ok e or w ra p it aro un d t he core or wind ing s of th e flyback. Do no t use a fine wire or strande d wire a s th ey do n o t giv e the sam e affect and could give m is le ad in g res ul ts . Be su re to use solder or a heavy ga u g e solid wire for t he “sh or ted t ur n”.

Some of th e newer fly backs are being made w i t h the Hig h V ol ta ge rectifier diodes bu ilt r ig ht into the fly back itself. The Diodes are included as p art of the t r ans for m er w i n d i n g . Be ca us e of th e reve rs e bre ak d o w n of th e diodes, the high v oltag e wind ing

If there is a lack of high v olta ge an d th e flyback sh ows good ringing, one of th e diodes is open. If the high voltage is se veral t h o u sa n d volts low and the fly ba ck shows good rin gin g, one of th e diodes is shorted. In both cases, th e f ly ba ck mu st be repla ced as the d iod es are not replaceable.

Ring

Fig, 2 5 — Ki ng on ly the pri ma ry a n d th e in di vi d u a l

wind i ng s of the tr an s f or m e r s w i th built-in high vo l ta g e

rectifiers. The high volta ge wi n d in g cannot be run g

because of the br e a kd o wn pot e n t ial of the diodes.

TESTIN G YOKE S WIT H THE RINGIN G TEST

If the flyback checked bad and then checked good when the yoke w as d isc onn ecte d or t he sy mp to m s on the screen indica te a possible ba d yoke, the yoke should be teste d wit h th e Ringin g t e st to be sure.

------------------------- WAR NI NG -------------------------- Do n ot conne ct t h e “Z M ETE R” to the yoke or flyba ck in th e s e t u n ti l A L L pow er to the s et has been discon nec ted. For y ou r safe ty , remove the AC line cord of th e receiver from th e AC outlet.

SP E C I A L NOT E: The yoke shou ld be tes t ed while it is still m oun ted on

the CRT. Occ asionally, there is a s h o r t caused by t he pres sur e of the m o u n t in g of t he yoke. Removing th e

yoke from the CR T will relieve th e pressur e a nd the

shor t m ay dis ap p ea r. The re s ul ts if the yoke is removed before it is tes t ed is a yoke th at is bad when mounte d, b ut te s t s good when off the CRT.

TES T IN G HOR I ZO NT AL YOKE WI ND INGS FOR G OOD OR BAD

1. Disconne ct t he yoke leads from th e circuit. On se ts with a yoke plug, sim pl y pull th e plug. If the leads are soldered to the flyb ack or PC boa rd, carefully un sold er them n otin g where t hey were connected.

2. Connect th e te s t leads from the “ Z ME TE R” to the horizontal win di ng s of the yoke. Depress t he RI N G ING T E S T p u s h b u t ton and hold down. R o ta te the IM P E DAN CE MAT C H s wi tch thr oug h the fou r

32

position s for yoke and flybacks (mark ed in red). A displa y of 10 or more on any one of t h e four positio ns indicate s a good yoke winding. A di s pl a y of less than

10 on all four positions of th e s witch in di ca t es a defec-

;ve yoke.

NO TE : The horizontal wind in gs o f th e y oke can check good an d st ill h ave a b ad y o k e if the v e rt i ca l w in di ng s are bad. B e sure to check both th e v e rt ic a l and the hori zon t a l w ind in gs of the yo ke w ith th e R ing i ng test.

TE ST I N G V ER T I CA L YOKE WI NDI NGS F O R

GOOD OR BAD

1. Di sconnect the yoke from th e circ uit. On se ts with a yoke plug, simply pull th e plug. If the le ads are sold ered to the vertical ou t p u t tr a n sf o rme r or th e PC

bo a rd , uns o ld e r th e m no t in g wh e re t h e y were connected so t h a t th ey m ay be rec on ne ct ed or t he new yoke connected to the prope r points,

2. Check the yoke for dam pi ng re si st or s. Som e yokes use a dam pin g re si sto r across t he v er ti ca l windings. These should be dis conn ected a t one en d a s they will sw amp ou t the ri n gi n g te s t a n d p o s s i b ly give erroneous results .

3. Connect the te s t leads from t h e “Z ME TER” to the ve rtic al win din gs of the yo ke. De pr e ss the RI N G I N G TE S T bu t to n a nd read t he n u m b er of ring ing cycles on the display. A readi ng of 10 or more rings in a ny of the four positions of th e IMP E DA NC E

A ATCH switch for yokes and flyb ack s (m ark ed in red) indicate s t ha t t he yoke is good. A d i sp la y of less th a n 10 in all four positions indicates a defec tiv e yoke.

NOT E : On series con ne ct ed vertical yo ke windi ngs, the w in d in g s sho ul d be te s t e d i n d iv i d ua l ly . I f there is an im bal an ce o f more t ha n 3 ring s or t h e in d u ct a n ce is more tha n 10% di ff e re n t betw ee n th e t w o w in d in g s , th e yok e will gi v e trouble in th e receiver. A go o d y ok e will gi ve a lmo s t iden tica l readin gs on b o t h w i nd i n gs .

33

MAINTENANCE

------------------------ These servi cing in st ru ct ion s are f or u se by qua l

ified personnel only. To avoid elec tric shock, do not p erf orm any ser vic in g o t h e r t h a n t hat conta ine d in the operat ing in s t ru c tio n s unless you are qualified to do so.

WAR NING

--------------------------

INTRODUCTION

Th is Main ten anc e and Service section o f th e m anua l will help you mai nta in your LC53 wit h in th e pub lish ed specifica tions. The schematic, pa r ts list , a n d board lay- ou ts are included on se pa ra t e sheets.

CHECK ING THE LC53 AC C U R A C Y

Th e accu racy of the LC53 should be chec ked ag a in st lab typ e st an d a rd s to insu re th a t t h e acc ura cy is cor- rect. If lab typ e s ta n da rd s are no t availa ble , use sta bl e ty p e capa ci tor s th at have been mea su re d w it h th e “Z ME TER” when it was new an d co mp ar e them on a an nu a l or semi-annual schedule. Do n o t u s e a lum in um elec tro ly tic capacitors as a reference. Thes e will change wi th ag e an d the capaci ty will not be c on s is t an t . Poly  prop yl en e or polystyrene are reco mm end ed as th ey will hav e th e b e st tem p era tur e cha ra cte ris tic s.

NOTE: T hi s is r ec om m en de d only as a ch e ck a n d n ot

as a stan d a r d to be use d for calibration.

ACCE SS / DI S AS S E M B LY

See Wa rn in g on page 37!

Acce ss to the interior of t he LCS3 for recalibra tio n and /or service may be o bta ine d u si ng the following proced ure .

1. Unp lu g the unit from the AC line.

2. Re move the four screws (two on e ach side) a t the

rea r of the instru me nt.

3. Place the uni t on e nd w ith the han dle a nd fro nt pan e l po int in g upward. Pull gen tly on th e han dle while hol di ng th e back porti on of the case. The ca se will now slip from the chass is an d rear port io n e xpo sin g t he pr in t e d circuit bo ards and all the cali bra tio n controls.

Th er e is no need to fu rthe r di sas sem ble th e u ni t unless acce ss to b oth sides of a prin te d c ir cu it board is re qui red for service. If this is the case, th e n proceed as follows:

4. Un plu g all the connectors from bo t h board s. There are several single terminal con nectors t ha t mu s t also be disconnec ted.

bly and p ull aw a y from the front of the un it. Th e two PC boards will come out as an assembly from th e unit.

7. To s e p a r a te th e two PC boards, remove the two screws at t h e re ar of the assembly. Carefully lift the top PC bo ar d from the bo tto m board. Lift care full y so th a t th e pi ns o f the plug conn ectin g t he two b oa rd s are not dam age d.

8. To reassem b le, rever se the order of the procedure.

EQUIP ME N T REQUIRED FOR CAL IBRAT I O N

The following equ ip m en t is rec omme nded for use in cali bra tin g t h e ”Z METER”. T hes e are hig h ac cur acy

sta nd a r ds a n d will allow the calibra tion of the m e te r to the specific atio ns in the fro nt of the manua l. Lower

accuracy s t a nda r ds will reduce th e accura cy of the ” Z

MET E R” . If cap ac it or s and ind uct or s of know n value s

are available, th e y m ay be used for calibration.

if known valu es of capa citors and induc tor s or the following equ i pme n t is not available, the m e te r m ay be

retur ned to t he Sencore Service D e pa rt m e nt for check out and rec a lib ra ti on for a small service charge.

/οι ··

GenRad model I491 G Sta n d ar d I ndu cto r (covers all

range s exc ep t the 100 u H range of the “ Z ME TE R”).

Hewle tt P a ck a r d model H P 16 48 1A 56 uH S t a n d ar d

Ind uc to r. 0 R » iu;;

Hew l et t Pa c k a r d model 4440B St an d a rd Ca pac ito r

Decade (covers all ranges except the 800 uF for the top ran g e of the “ Z MET ER” ).

800 u F film t yp e c apac itor (can be made up of 20 - 25

uF film ca pa ci to rs a n d the n checked o u t by a cali

bra tio n lab). Digital Vo l tm e te r such as the DVM37 or DVM 38. Voltage so u rce capable of outp u t s of .09 an d .9 Volts

DC.

1000 He r tz sine wave signal source vari ab le to 4.0

Volts peak-to-peak.

Calibra ted Scope such as the PS29 or PS 163 to

mea su re t h e amp li tud e of the 1000 Hertz signal.

METER CA L IBRA T I O N

See W a r ni n g on pag e 37! The inte rn a l me ter (readout) calibratio n should be

checked an d a d j u st e d if necessary before cali br at io n of any of the ra n ge s of the ” Z METER”.

NOT E: D o n o t dept'ess a ny o f the pu s hb ut t o ns on the

”Z METER w h en a d j us t in g the m e te r zero on the

rear or the me t e r calibration controls.

1. T ur n the ”Z ME T ER” 0 1 1 an d allow a 10 to 15

minute w arm - up period.

5. Remov e the four screws (one at each corner) of the

top pr int ed board.

6. Ca refully lift the rear of th e pr in te d bo ard a ss em 

2. If the re a d o u t does not show 000 with the ne ga tiv e sign ap pe a r in g occasionally, a d j u st the rear panel meter zero co ntr ol until the ne gati ve sign is just off or appears in t e rm i tt e nt ly .

34

See Warning on page 371

3. With the o u t p u t contr ol of the I)C sup ply se t to

minimum, c onn ect t he posit ive lead to the u ngrou nded

end of R1082. Co nnect t he neg ati v e lead to the

grounded end of I I I 082. C on nec t a DVM such as the

VM37 or DVM38 to the s am e points. A d ju s t the

power supply for a reading of 0.9 Volts DC across

R1082.

4. Ad ju s t R1035 on the “ Z METER” for a read o ut of

900 on the display.

5. Reduce t he power supply ou t p ut to 0.09 Volts DC

and ad j us t R1031 for a read o ut of 089 on the display.

6. Repe at s te ps 3, 4, and 5 two or th ree tim es as t he

control s will have some inter act io n.

INPUT PRO TE CT IO N R ELA Y TRIP POINT A D JU S TM E N T ^ > i o m O

The inpu t pro tecti on relay tri p p oin t ad j u st m e n t should be made before c al ib ra ti n g th e o th er r ang es of

the LC53. The following pro ce du re sets up the trip poin t at which the relay will open th e in pu t to the LC53 when an external volta ge is applie d to the te s t leads.

1. Connect a DVM to th e s ix t h pin from the fro nt panel on the LEAK AG E p u s h b u tt o n , on the side of the switch closest to th e outsid e of t h e in st ru m en t. This is accessible from the side of the in s tr u m e n t.

5. S h o r t t he t e s t leads t oget her, d ep r e ss th e VAL UE but t o n an d ad j u s t th e front pane l L EA D ZERO contr ol for a rea dou t of 000 wit h the negativ e sign ap pe a r in g occasionally.

6. Con nec t the t es t leads to a s tan da r d 80 uH coil.

^ j A d j us t R1019 for a reado ut of 80.0 uH.

it )

C, 7. C onn ec t th e t es t leads to a s t a n dar d 800 uH coil.

U S'

> ,, Adj us t R1021 for a rea d ou t of 800 uH.

8. Con nec t the tes t leads to a s tan da r d 8 mH coil.

A dj u s t R1023 for a read ou t of 8.00 m H .

9. C onn ect th e t e st l eads to a s t a nd ar d 800 m H coil.

A dj u s t R1027 for a read ou t of 800 m H .

10. C on nec t the te s t leads to a st an da r d 8 He nry coil.

A d j us t R 1029 for a readou t of 8000 mH .

RINGING T E S T CALI BRAT ION

The c ali bra tio n of the R ingin g t e s t is d ep en d en t upon the a ccu ra cy of the scope used to m ea su re th e 1000

H e rt z sine wave i np u t on the secon d half of the

proced ure .

1. S h o r t th e t e s t le ads to ge t h e r a n d set the

IMPE DAN CE MAT CH switch to any one of the

BLUE p osition s.

2. Connect a power supp ly s e t t o 7 Volt s DC cap able

■f delivering 250 mA of cur r e n t to the tes t leads. Connect th e po sitiv e lead to th e r ed t e st lead, t he n eg  ativ e to the black te s t lead.

3. A d ju s t R1107 cou nte rclo ckw ise so t h a t t he DVM read s plus 7 V olts DC. Slowly rot a t e R1X07 clockwise until the relay opens and t he D V M reads 0 Volts. The n ad j u s t R1107 c ounte rcloc kwis e u nt il th e voltage jus t retu rn s.

IND UCT AN CE CA LI BRA TI ON

The following proc edure req ui re s th e use of s ta n d a r d indu ctor s or i nd uct or s of kn ow n value. The i nd uct or s of known value m us t be close to the values shown in the procedur e to insure tha t th e pr op er rang e is cali brat ed . Ea ch time a c ontrol is to be adju st ed , t he VAL U E pu s h b u tt o n mu st be de p re sse d on the front

panel.

^0 /

1. Set all i nd uct anc e cal p o t s to midra nge (R1019,

R1025, R1023, RI 027 , 1U029, and R1070).

2. Connect the te s t leads to a stan d a r d 80 m H coil.

A d j u s t R1025 for a rea d ou t of 80.0.

3. Connect th e t e s t leads to a st a n d a r d 10 m H coil.

\dj us t R1070 for a reado u t of 10.0.

4. R epea t s te ps 2 and 3 a t l ea s t tw o to th ree tim es as

the controls will int er a ct wi th ea ch othe r. This s et s th e

lineari ty of all th e in du c ta nc e rang es of the “Z

M ET ER” and cali br ate the 10-100 mH range.

2. C on nec t a DVM to the collector of TR217.

3. D e pr es s t he R ING I NG T E ST but t o n and a d j u s t

R1081 for a 6.0 to 6.5 VDC reading.

4. U n s h o rt the t e s t leads. Set th e IMPE D AN C E MAT C H s witc h to any one of th e RE D {Yoke & Flyb ack ) positions . Conne ct the ve r ti ca l in p u t from a scope a nd th e ou t p u t of an audio g e n er a to r to the in put of the “Z M E TER ” . The inp ut of the scope an d the ho t lead of t h e ge ne ra to r a re co nnect ed to t he red tes t clip an d t he gro un d leads to the black tes t clip.

5. Se t t h e audio g e ne ra to r to sin e wave a nd the fre que n cy to 1000 Hertz.

6. De pr ess the R INGING T E S T b ut to n an d a d ju s t

th e o u t p ut of the audio gene ra tor for 3.6 Volt s peak-to- peak.

7. Adj u s t R1054 with the R I NGI N G TE S T b ut to n

dep re s se d so the fro nt pa nel d i sp la y on the “ Z METER” is counting. Slowly back off u ntil the c o u nt  ing a pp e ar s to be i n t e rmi tt e n t o r th e rea d ou t shows som e num ber . Th e actua l n um be r is m ean in gle ss and only sho ws t h at you have reache d t h e pr o pe r t rip po int in t h e ri ng in g circuit. Carefully ch eck t hat t he p oin t is th e corre ct one by ad j u st in g the contro l above an d below t he poin t to see t ha t th e c o u n tin g s t a r t s and sto ps .

35

In du ct a nc e Cal Pot s

w y R i *.

-CD -

Negative lead of power supply and DVM for meter cai.

δ δ δ δ ΰ δ δ δ δ δ ί ό δό δ δ ό ό ό ό

Posit i ve le ad o f Pow e r S upply a nd D VM f o r M e te r Cal .

C ap acito r Cal Con t ro l s

M e t e r C a l Contr ol s

f Ri n ging T e i t f

A dj us tmen ts

Pig, 26 — Co m p on e nt view of th e 1000 board, 43B149 s h ow i n g the loc at io n of the calibrati on c o ntr ol s a n d th e p oi n t of conn e ct in g th e DVM for the i nput relay trip po i nt adj u st m e nt .

CAPA C IT O R CAL IB RA TIO N

Use of the sta n d a rd s listed in the be gin ni ng of the pro cedure are recommended. If c al ib ra ti o n mu st be done

with known value ca pacito rs, be sure that the three

the n e ga tiv e sign ap pea rin g o ccasionally. Do not touch the fr on t pa nel L EAD ZE RO a ga in u n ti l a fte r th e ne xt step.

capac itor s are close in value to t h e one s recommended.

Calibrate the meter to read th e va lu e of th e cap acitor used re gard less of the value listed for the mo st accu rat e readings.

2. Open the test leads and d e p re ss the VALU 1C b u t t on under CA PA C IT OR S an d a dj u st the internal capa cit y- ind uc tan ce balance control R133 until the rea d o u t shows 000 with the ne ga ti ve sign a ppe arin g

1. Short th e t es t leads to g e th e r an d depress the

VA L UE bu t to n under IND U CT A N C E . Check to see

th at the me ter is zeroed. If no t, re s e t th e fron t panel

occasionall y. This p u ts the i nd uc ta nc e an d capa cita nce lead zero a t the same point on t he f ro nt panel LICAD ZE R O control.

LE A D ZERO control until th e r e a d o u t shows 000 with

3. C onne ct a s ta n d a r d 8000 p F c a pa c ito r to th e test le ads a n d de pr e s s t h e VALUE b ut ton u n d e r CA PA C IT O R S.

4. Ad j u s t R1083 for a reado ut of 8000 pF.

5. C onne ct a sta n da r d 0.8 uF c a p ac it or to the te st

le ads an d d e p r e s s th e VALUE butt on un d e r

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Pig. 27 — Co m p on e nt view of t h e corner of the 100

board sh o w i n g the location o f th e lead zero balance contro l R1 3 3 and in dic a tin g the fron t of the unit or disp l a y board for a reference.

;C2 8'

6. Ad j u s t R1088 for a reado ut of .800 uF.

7. Conne ct a s ta n d a rd 800 uF ca p ac it o r to the te st le ads a n d de pr e s s t h e V A LU E bu t t on u n d er CA PA C IT O R S.

8. Ad j u st R1090 for a readou t of 800 uF.

36

Notes

-------------------------

Avoid shock hazard when the case is removed. Raw AC line vo l ta g e i s present in some areas and vol ta g e s to 600 Vo l t s in others. Avoid cont act with: 1. All termina ls of the Applied Leakage

switch, 2. The module of the Leakage pushbutton

located behind t he m ain switc h assem bl y, 3. All wiring on the back panel, especially t hos e covered with th e plas tic shiel d, and 4. Wiring connecting

to the AC power sw it c h . Make certain that the plastic shi el d on t h e ba ck panel is in place before the instrum e nt i s re*assembled.

WARNI NG--------------------------

37

APP EN DI X

CAPACITO R THE ORY AND THE

“Z ME TE R”

The ca paci tor is one of t h e m os t comm on c omp onents used in electronics, b u t less is known a bo ut it t h an the other c om po n en t in electronics. T he following is a brief expla nati on of t h e cap aci to r, how it works, a nd how the "Z M ETE R” m ea su res t h e i m p o r ta n t p ar am e te rs of the c apacito r.

The basic ca pac ito r is a p a ir of met al plat es sepa ra ted by an i ns u la ti ng m a te ria l ca lled the dielectric. The size of the p late s, th e typ e of dielectric, an d the thic kn es s of the dielectric de te rm in es the capac ity. To increase capacity, you can increase th e size of the plates, increase the n u mb er of plate s, u se a diffe rent dielectric or a th in ner dielectric. T h e closer the plates, or the thinner the dielectric, the lar ge r the capacit y for a given size plat e. Be ca u se flat pl ate s are rat he r impractical, ca pa cit or s a re genera lly mad e by p u t ti n g an ins ul ati ng mat er ial b etw e en two foil str ip s and rolling the com bi nati on in to a ti g h t pack age or roll.

sto re d in the dielectric mat erial. Wh en th e c apac ito r is

discha rged , the electric dipoles bec om e re oriented in a

rand om fashion, dischar gin g th e ir s to re d energy.

1

| 1

Η H

C HAR GE D C APAC I T O R

Fig. 29 — When a p ote n t i a l is ap p l ie d to a capacitor,

the dielectric dipoles in th e d ie le c tr ic line up in the directio n of th e ap pl ied p o te n ti a l. When the capacitor is discharged, th e dip oles ret ur n to a ran do m order and are not lined up.

When a ca pac itor is c onn ecte d to a vo ltage source, it does n ot become fully cha rge d instan ta ne ou s ly , bu t

tak es a definite a m o un t of time. T h e tim e r equired for the capa citor to charg e is de te r m i n ed by the size or

capa cit y of the capa citor and t h e r e s is t o r in series with

the capa citor or its own i nte rn al s erie s resis tance. This is called RC time and is c a p a c it y in Fara d s times resi sta nc e in Oh ms equa ls tim e in seconds. The curve of the charge of th e cap aci tor is t he RC charg e curve.

U NC H A RG ED C APA CITO R

Fig. 28 — Mos t c apac itor s are m a de up o f layers o f foil separa ted by a dielectri c an d then rolled into a ti g h t

package.

The old e xpla na tio n of how a c ap aci tor works had th e electrons pi ling u p on one pla te forcing th e electrons off of the o th er to c harg e a ca pac ito r. Th is m ade it dif ficult to ex pla in othe r acti on s of the capacitor. Fa r a d a y ’s t h eo r y more closely a pp roa ch es the way a capac itor really works. H e s t a t e d t ha t t he ch ar ge is in the dielectric mat er ia l a n d not on the plates of the capacitor. Insid e the ca p a c i to r ’s dielectric mater ial, there are tiny electric dipoles. When a volta ge is a p  plied to t he plat es of t he capacito r, the dipoles are stre ss ed and forced to line u p in rows crea tin g stor ed energy in t he dielectric. T he dielectric h as und erg one a physical c ha ng e similar to tha t of s oft iron when ex  posed to c u rr en t t hr o ug h an i nd u cto r when it becomes

a mag net . 1 f we were able to rem ove th e dielectric of a charge d ca p ac it or an d t h e n me a su re the vo ltag e on the plates of th e capac itor , we would find no voltage.

Rein ser ting the dielectric and the n meas ur ing the plates, we would find th e vo ltag e tha t the capacito r had been c ha rg e d to before we had removed the dielectric. The charge of the capacito r is actually

Fig. 30 — A capacito r do es no t charge up “inst a nt -

eou sly”, it requires time. The tim e and rate of the charge is the RC charge t ime who s e curv e is s ho w n here.

The “ Z METER” m akes use of this charge curve to meas ure the ca pa ci ty of a c ap ac ito r. By a pply in g a

38

pu l sa t i n g DC v ol tag e to the ca pac ito r under te s t a n d

m e a su r i n g the tim e on it s RC c harg e curve, th e c a p a

cit y of th e ca pa ci t o r can be de te r mi n e d ve r y

acc ur ate ly .

Pape r an d mic a were for ye ars the stan d a rd diele ctr ic mat e ria l s for c ap ac it or s. Ceramic b ecame po pul ar du e to its s ta b il it y an d controlled chara ct er ist ics and lower cost ove r mica. T od ay , there are m any new diel ectr ics with d if fe re nt r a t ing s and uses in ca paci tors . P a p e r is still u sed tod ay . It is imp re gn ate d with a wax or special oil t o reduce the air po ck ets and the m o i st u re

abs o r pt i on o f the paper.

Pla st ic films of Po ly est er , Pol yca rbo nate , Po ly sty re ne , Poly pr op yl en e, and Polysulfone are use d in ma n y of the n ew er l ar g e v alue, small size cap acitors . Ea c h film has i ts own sp ecia l c h ar ac te ris t ic s a nd is chosen to be used in t h e c ir c ui t for th is special feature. Some of th e pla st ic films a re also m etaliz ed b y v ac uu m p l at in g t he film with a me ta l. Th ese are generally called self- heal in g typ e cap ac i to rs and should not be re pl ac ed with an y o t h e r typ e.

Ceramic diel ect ric is t he mo st vers at ile of all. M a n y va ri a ti o n s of ca pa c ity can be cre at ed by alte ri ng th e ceram ic mate r ia l. C apa cit ors th a t increase, stay th e sam e value, or decrea se valu e wi th temp e r a tu r e cha n ge s ca n be m ade. If a ceramic disc is m ar ke d w it h a l e tt e r P s u ch a s P100, t h en th e va lue of the c ap a c it o r will in cre as e 100 p a r t s per million p er degree cen t i gra d e in cre ase in tempe ra tu re . If t he capaci to r is

na r k e d N P O or COG. the n the value of c ap ac it y will

rem ai n co ns t a nt w ith an incre ase in the tem p e rat u re.

im p o rt an t in m any c ir cu it s s uch as the tu ned circui ts of the radio and te lev is ion IF. The t em p er at u re coef ficient of an in du cto r is pos itiv e and the induct anc e will increase as the t e m p e r a t u r e rises. If the tuning capac ito r across the coil is a n eg at iv e coefficient, th en the net re su lt will be a zero or very little change.

55 45 3 5 2 ‘ )5 5 5 15 25 35 45 55 6 5 75 85 9 5 105 115 11 5

TE M P E R A T U R E C

Fig. 32 ~ Te m p er at ur e c ha ng e v er su s ca pa city change of N750 to N5600 Tem p e r at u re com p en s at ed ceramic disc capacitors.

General t yp e ceramic di sc s a re o fte n m ark ed with suc h lett er s a s Z5U, Z5F, Y5V, X5V, and so forth. This indicate s t he ty pe of te mp e r a tu r e curv e for tha t p a r ti  cular capacitor . C era mi c cap ac ito rs t h a t are no t NPO or r at ed with N o r P type c ha ra cte r ist ics will have wider te m p e ra t u re v a r ia ti on s an d can vary bo th p osi

tive an d n eg ativ e w it h t emp e r a tu r e changes. The Z5U

prob abl y has th e gr ea t e s t chan ge and will only be

found in non-critical a pp lic at io ns such as b yp as sin g of B + points. These ty p e of cap ac ito rs should not be used in critical appl ic at io ns such as oscillator and timin g circuits.

TE M PE R A T U R E "C

Fig. 31 — Te m p e r a tu r e ch ang e v ers us ca pac ity ch a n ge jf P I00 to N 7 5 0 Te mp e ra tu re com pe ns a ted ceram ic

disc ca pacitors.

Ceram ic disc cap ac i to rs mar ke d with an N such as

N1500 will de c rea s e in ca pa ci ty as the tem p e ra t u re

incr eas es. T h e ne ga t iv e t e m p er a tu r e coefficient is

A ceramic capac ito r m a r k e d GM V m eans tha t the marke d va lue on the c ap a c ito r is th e G ua ra nte ed Mini mum Value of cap ac i ty at roo m tempe rat ure . The actua l valu e of th e c a pa c it or c an be much higher. Thi s type of ca pac ito r is u se d in b y p as s a pplic atio ns where the actu al value of c ap a ci ty is not critical.

Ceramic c ap ac ito rs ha v e been th e mo st po pul ar c a pa  citor s in electronics b ec aus e of t h e v er sa ti lit y of th e different te m p e ra t u re coefficients and the cost. When

replacing a ceramic d isc cap acito r, be s ure to replace

the defective c ap ac it or w i th one h a vi ng the same c ha r

acte ris tics an d vol ta ge rat in g .

The alu m inu m elec trol yti c ca pa ci to r or “L y ti c ” is a

very pop ul ar c o mp one nt . A la rge value capa city in a

small case ca n be o b t ai ne d qu it e easily. Th e alu minum

lytic is used in power s u pp l y filtering, audio, an d video

coupling and in by p a s s ap pli cati on s. An ywhe re a large

39

UJ

TEMPERATURE *c STABLE TYPES

LU

te m p e ra tu re - c SEMI-STABLE TYPES

TEMPERATURE °C

Fig. 33 — T e m p e r at u re ch ang e v ersu s ca pac ity cha ng e of N on -T em pe ra tur e c om p e n sa te d ceramic disc capacitors.

value of c a p a ci t y is re quir ed with a small space a v a il ability, t he ly tic fits r igh t in.

The a lu m i nu m lytic is m ade by us ing a pur e alu m inu m

foil wo und wi th a p a p er soa ked in a liquid ele ctroly te. When a v o lt a ge is app lie d to the combi nation, a th in layer of ox ide film forms on t he pure al um in um formin g the dielectric. As long as the ele ctr oly te rem ain s liquid, th e cap aci tor is good or can be reformed a f t er s it t ing for a while. Whe n the ele ctr olyte dry s ou t, th e le aka ge goes up and th e cap acitor loses capa city . Th is can h ap p en to alum inum lytics j ust s i t  ting on t h e shelf. W h en an al um in um lytic s t ar t s dry in g out, the cap ac i to r begins to show dielectric abso rp tio n .

Alth o ug h the al um in um ele ctrolytic is very p op ul ar, the tan t a l u m lytic is ga in in g ground. Just a sho rt tim e

ago, th e t a n t a l u m lytic wa s very high in cost c om par ed

to the al umi nu m lytic, b u t m ass produ ctio n te chno logy has br o u g h t the cost down on t a n ta lu m lytics. Th e leakage in t h e alu m in um lytic is very high due to th e

na tu r e of i ts c o n st ru c tio n . Th e t an ta lu m , on the o t he r

hand, is ver y low in leakage and can be c o ns tr u ct e d

with m uch t i g h t e r tole ra nce s th an th e al umin um lytic. The t an t a l u m is also mu ch smaller in size for the s am e cap ac it y a n d w or ki ng vol tag e th a n an al um inum lytic.

Ta n ta lu m l y tic s have become very pop ula r in ti m in g circu its a n d for critica l co upling where high ca pac it y is

req uir ed wi t h low leakage. The ca pa ci ty of the

ta n ta l u m ly ti c is lim ited and for extr eme ly large v alu es

of c ap a c ity for po wer supp ly filtering, t he al um in um

lytic is still th e firs t choice.

GENERAL PURPOSE TYPES

There are many dif fe re n t type s of capacitors , using different typ es of diele ctric s, e ach with its own best capability. When repl ac in g capacitor s, it is best to replace with a c a pa c ito r hav ing not only the same

capac ity an d tolerance, but the s am e type of dielectric and tem p er atu re ch ar a c te r is ti c s as well. This will

insure of continued p er fo rm a nc e equal to the original.

t

Fig. 34 — The tan ta l u m lyti c , s h ow n on the righ t, is

muc h smaller in size th a n the al u mi nu m l yti c for the same capac ity and w o r k i n g voltage.

The “ Z M E TER” will m ea s u re leaka ge in the dielectric of a c apacito r and will als o show dielectric absorp tion. The DC leakage is me as u re d in t wo range s with the value displayed on the d ig it al rea d ou t in microamps.

40

Dielectri c ab s or pt io n will show up m ostl y in lyt ics as a ch a n g in g c ap ac it or value, if the ca pac itor is ch ecked for le ak a g e a nd the n checked for value, th e m e te r will show a lowe r value capacitor a t f irs t an d t h en th e read-

ig will increase slowly upward. This in dic at es t hat the electric dipoles in the dielectric are resi s t in g the dis ch a rg e of t h e ca pacito r and remain ing pol ari zed in th e d ie le ct ri c. This is diele ct ric ab s o r pt ion and some time s called capacitor memory. I t can also be referr ed t o as b a tt e r y action of a c apac ito r. Wha t is act ua lly ha pp e ni ng is t h at the small v ol ta ge from the diele ctric a bs o rp ti on is ch an gi ng the EC c h ar g e cu rve and ma k i n g th e m ete r see a smaller value of ca pac itor . As t h e t e st c ontinue s, the dielectric c harg e or me m ory is slowly d is si pa te d in th e ch ar ge and rec ha rg e of the cap ac ito r , in cre as ing the len gt h of the RC cha r ge curve and allow ing th e meter to read a higher a n d higher valu e capa ci tor . This ind icate s tha t th e ele c tro l yt e is dry i n g out in an electrolytic ca pac itor whi ch will indi ca te a f ut u re prob lem with t hi s c om pon en t. Dielec tric ab s o r p ti o n will not nor mal ly show u p in film or ceram ic ca p ac ito rs , bu t if it does show up wi th th e “ Z METER", then the capac itor is a su spe ct. This will gene rall y be asso ci at ed with a high leakage a s well.

Ca p ac i to r s c an c hange value. On some mu lti- la yer foil cap a ci to rs , poor welding or so lder ing of t h e foil t o t he leads can cau se an open to one of the foils a t a la ter da te due t o stre s s of volta ge o r t emp er a tu re . These

type can lose a lm o st one-half of thei r r at e d or m ar ke d cap a cit y. Cera mic disc c apa cito rs can als o chang e val ue by a small value or a large value de p en d in g up on

here a fis sure or crack is located. Small fiss ur es or cra c k s in th e ceramic in su l a ti ng ma te r ia l can be cre a te d by th er m al st re ss or expo sure to he a t a n d cold. Som e t im e s v ery small fissu res ca n be cre at e d a n d t he n not e ffec t t h e capa cito r un til m uch later. N o te t ha t th e crac k will reduce the capacit or to a smalle r value. Al th o u g h the ceramic is still conne cted to th e leads, the act u a l value of capa city could be a ve ry small por ti on of th e original value depen din g u po n wh ere th e cra ck occurs. The “Z M ETER” will let you kno w w h a t the v alu e of t he capa cito r is regar dle ss of it s mark ed value.

□ OP ENS

C

Fig. 36 — On mu lt i-la ye r foil capacitors, a break in one of the foil connect io n s to the lead can cause a, reda ctio n o f capacity.

Ou te r Co a t in g

Ce ra mic Di e lect r ic

Ca p a c i t o r Plate

Cra c k

(Fis su re )

Lead s o l d e re d to c a p ac i to r plate

Fig. 35 — A ceram ic disc is m ad e up of th e ceramic

dielectric c o ate d with silver for the p l a te s and, then

;)vered wi t h a pro te c ti v e coating. So met imes a crack or f i s su r e can occur in the dielectric m at e ria l large eno u g h to reduce th e value of capacity.

41

Color

Rated

Voltage

Capac

1st

Figure

Pico

Dipped Tanta lu m Capacit ors

tance in a rads

2nd

Figur e Mu l t i plie r

Black

Brown Red Orange

Yellow

Green Blue

Viole t 50 7 7 Gray Whit e

4

6 10 15 3 20 4 25 5

35

_

. „

.... 9’

0

1

2 2

6

8 8

~

...

9

0

1

3

4 5 100,000

6 1,000,000

...

.

— — — —

10,000

10,000,000

~

—

Cer a m i c Disc Capacitors

Man u f a c tu r e r’s

Code

Capacity

Value

Tole ran c e

‘ W ork ing

Voltage

Tem p e ra tu r e

Range

Low

Temp. + 1 0 ° C Z + 45°C

-30 °C

•55 “C X + 85°C

Letter

Symbol

High

Temp.

Y + 65°C 4

+ 105a C + 125X 7 ± 4.7% E

Te m p e r a t u r e Ra ng e Identif icat ion of

Cera m ic Disc C apacitors

Typ i c a l Ce r a m i c Disc Cap ac ito r Mark ing s

5 F 1 0 0 J

Numerical

Symbol

2 + 1.0% A 5 ± 1.1% C

6 ± 3.3% D

Max. Capac. Change Over Temp. Range

± 1.5%

±7.5%, F ± 10.0% P ± 15.0% R ± 22.0% S

+ 22% , -33% T + 22% , -56% U + 22% , -82% V

If No Voltage M ar ked ,

Generally 500 VDC

Letter

Symbol

B

1st & 2nd

Fig. of

Capaci tanc e

I

Mult i plier

1,000 3

10,000 4

100,000 5

.01 8

.1 9

Numer ic a l

1 0

10 1

100

Symbol

2

— —

Capac it y V a l ue a nd Tole ra nc e of

Tolerance on

Capacit an ce

±5% J ± 10% ±20%

+ 100%,- 0 % P + 80% , -20% Z

Lette r

Symbol

K

M

42

Film Typ e Capacitors

Ceramic Feed Through Capacitors

Mult ip lie r

Tol e r a n c e

MULTIPLIER

For the

Number Multiplier

0 1

1

2

100 D

3 1,000 4 10,000

5

100,000 H

TOL E R A N C E O F CA P AC IT O R

Letter 10 pF or Less

B

10 C

p

±0.1 pF ± .25 pF

± 0.5 pF ± 1.0 pF

G ± 2.0 pF ± 2%

J

8 0.01

9 0.1 M

EXAMPLES:

152K = 15 x 100 = 1500 pF or .0015 uF, ±10% 759 J = 7 5x 0 . 1 = 7.5 pF, ± 5%

K

Over 10 pF

±

1%

± 3% ± 5%

±10% ±20%

Sig n i f ic a n t f 1st fig u r e \ 2nd

Signifi- Toleranc e

Color

Biack Brow n

Red Orange

Ye llow Green

Blue Viole t 7

Gray 8 0.001 0.025 pF White

Gold Silver

cant

Figure Multiplier

0 1

2 3

4 5

6

9

_ _ — — — —

1,000

10,000

0.1

10 pF

or Less

1102 pF

0.1 pF

100

_ _ — — ---

_

5 pF

1 PF

_

Te mp e r at u r e co ef f ic ie n t

Over

10 pF

20%1%0

2%

2.5%

5%

_

---

10% + 120 to -750

_

Temp era tu re

Coefficient

N30

N60 N150

N220 N330

N470 N750

P30

(RETMA )

+ 500 to -330 (JAN)

P100 Bypa s s o r co upl ing

NOTE: The letter “ R ” may be used at times to signify a decimal point; as In: 2R2 = 2.2 (pF or uF).

Postage S t amp Mica C a p a c i to r s

Mica ca pa cito rs-B lack (A WS pape r capaci tors- silver)

Characte ristic

AWS and JA N f ix e d c a pa cit o rs

(Fir s t d o t silve r o r b l a c k )

First

significa nt figure

Sc eo nil significa nt fi gu re

First

signifi ca nt figure I

(No t silve r -

or b ia c k) c

Vol ta g e rating

J

o o o

Firs t

sig ni fi ca n t figu re

Sec o n d sig ni fi ca n t fi g ur e

Dec i m a l m u lt i p li e r

To l e r an c e

Dec imal

mult i p l ier

Se co n d sig ni fi ca n t fig ur e

Thi r d

o

sign i fi ca n t figur e

*

i— D e c im a l m u l t ip l ier

Tol e ra n c e

Colo r

Black Brown

Red 2 Orange 3 Yellow 4 Green 5 Blue 6 Viole t Gray 8 100,000,000 White 9 Gold Silver - 0.01 No color

Si gn i f i ca nt

Fig u r e Mult i plier

0 1

1

7

1,000,000,000 9 900

-

~

100 2 200

1,000 3 300

10,000

100,000 5 500

1,000,000 6 600

10,000,000

0.1 5 1000

—

Tolerance V o l tage

(%)

„

10 1 100

4

7 8

10 2000 20 500

Ratin g

—

400

700 800

43

Standa rd Button Mica

1 st DOT

Identifier

2nd an d 3

Capa ci ta r

rd DOTS

ic e in pF

1st & 2nd

Blac k Black

N O T E : I d e n t i f i e r is o m it te d i f c a p a c it a n c e m u s t b e s p e c i f i e d t o

t h r e e s i g n i f i c a n t f i g u r e s .

Color

Bro wn Red

Ora n g e Ye l l ow

Green

Blue

Vio let Gray

W h i t e Gold

Silve r

Sig. Figs.

0

1

2

3

4

5 6

7

8 9

Radial or Ayia! Lead C e ra m ic Capa c it or s

(6 Dot or Band Sys te m )

4th DOT 5th DO T

Multiplier

Cap a c it a n c e

Tole ra n c e

Percent

1 10

100 1000

± 20 % ± 1%

± 2% o r ± 1 pF

± 3%

0.1

± 5 % J

±10 % K

Te mpe r at u r e coe ffi ci en t

6th DOT

Temp.

Characteristic

Letter

Symbol

F F

G or B

H

+ 100

-20 PPM /° C

above 50 pF

±100 PPM / ° C

below 50 pF

5 Dot or Band Cera m ic Cap ac ito rs

A- F l r s t significant figur e

8-Second si gn ifi c an t figure

C De cim al mu l ti p l i e r □ C ap acit ance tole ra n ce

Temp. Coefficient

T.C.

Cotor

P100 P030

NPO N030

N080 N150

N220 N330

N470 N750

N 1500 N2200

N3300 N4200

N4700

N5600

N330

± 500 W hite

N750

± 1000 Gray

N3300

i. 2500 Gray

Red Green

Black Brawn

Rert Orange

Yellow Gres;n

Blue Vioiiit

Orange Yellow

Green Green

BiiiO Gfeen

DOTS OR

BANDS

Nominal Capacitance

Capacitance

2nd

Color

Violet Blue

Orange Orange

Orange Green

Orange

Biack

1 st and

2nd Stg.

Multi

Fig.

plier

0

1

2

100

3

1,000

4510,000 Yellow

6

7

.01.1Gray

8 9

Color

110Black

Brown Red

Orange

Green ±0.5 pF

Blue

Violet

White

1st

To)era nee

10 pF

or Less ±2.0 pF

±0.1 pF

± 0.2 5 p F +8 0% - 20%

± 1.0 p F ± 10 %

Over to pF

± 20% ± 1%

±. 2%

:t 3‘it

+ 100%-0% Yellow

± 5% Green

Color

Black Brown

Red Ora ncje

Blue Violet

Gray White

Color

Blac k Bro w n

Red Ora n g e

Ye llow Green

Blue Viole t

Gray W hite

Black

Fi x ed ce rm ic capac ito rs, 5 d o t o r bau d s y s t e m

Color C o de for Ce ra m ic Ca pa cit ors

Capacit a nc e

1st & 2nd

Significant

Figure Multiplier

0

1

2 100 3 1000

4 5

6 7

8 0.01 9 0.1

1 ±2 0%

10 ± 1%

Tolerance

Over

10 pF

± 2%

± 5%

± 10%

...-

10 pF

or Less

2.0 pF

0.5 pF

0.25 pF P 30

1.0 pF

- - - - - -

Temp.

Coeff.

0

N30

N80

N150

N220 N330

N470 N750

P500

44

Notes

GLOSSARY

Aging — op era tin g a c om p on e nt or in st r um e n t a t con

trolled cond itions for tim e an d te m pe r at u re to screen ou t weak or defective u n i ts and , a t t he same time, stabilize the good units.

Anode — the positive electrode of a capacitor. Capacitan ce ~~ t he m easu re of th e size of a capacito r.

Usually expressed in micr of ar ad s and picofarads. Determined by the size of the p l a te s , a nd the dielectric material.

Capacitive re acta nc e — the op p os iti on to t he flow of a

pul sat in g DC voltag e or AC vo ltag e. Measu red in

ohms.

Capacito r — an electronic com p on e nt co nsist ing of two metal plate s s ep ar ate d by a dielect ric. Can store a nd release electrical energy, b lock th e flow of DC cu rr en t

or filter o ut or bypa ss AC cu rr e n t s.

Catho de — the neg ativ e ele ctr ode of a capacitor.

Charge — the q u a n ti ty of ele ctr ic al energ y store d or held in a capacitor.

Clearing — the rem ova l of a flaw or weak spo t in the dielectric of a metaliz ed cap ac ito r. The stor ed energy in t he capacitor vaporizes the m a te ri al in t he imme  diat e vicinity of the flaw. Also called self-healing or self-clearing.

COG — same as NPO. Very s ma ll c apa city ch arge for large tem pe ra tur e changes.

Coil — an inducto r wound in a spiral or circular fashion. Can be wound on a fo rm or wi th ou t a form such as an air coil.

Dis c capaci tor — a small single la y er ceramic capa cit o r co nsi st ing of disc of ceramic i n s u la t o r with silvei de p os it e d on both sides as the plat e. The ceramic m at e ri al can be of diffe rent co mp o si tio n s to give dif fer e n t t e m pe ra tu re curves to the ca pac it or.

Di ss ip a ti on factor (DF) — the r at io of the effective

serie s re sis tan ce of a capa cit or comp ar ed to its rea c ta n ce a t a given frequency, genera lly given in perc en t.

El ec t ro l y te — a curre n t co nd u c tin g liquid or solid bet we e n t h e pla tes or electro des of a capa ci tor with a t le a s t one of the plate s h avin g a n oxide or dielectric film.

El e c tr o ly t i c c ap ac it or (alum inum ) — a c ap aci tor co n s i s t in g of two con d uc ti ng el ec t ro d e s of pure alu m in u m , the anod e ha ving an o xi de film which a cts as the dielectric. The ele ctrolyte se p a r a te s th e plates.

Equ iv a l e n t series res ista nce (ESR) — used in capac ito r calc ula tion s. All inte rn al series re si s ta n c es of a c ap a cit o r ar e lumpe d into one res ist or an d t re a te d a s one re s is to r a t one point in the capa cito r.

F a r ad —■ th e mea sure or unit of capa ci ty . Too large for

electr on ic use and is generally measu re d in micro

fa ra d s or picofarads.

Fi s su r e s — cracks in th e ceramic diel ectr ic m ateri al of disc capa cito r, m o st often caus ed by therm al shock.

Som e sm all fissu res m ay not c au se failu re for a period of ti m e u ntil exposed to g re at t h e r m a l shock or mech anic al v ib ra tio n for a period of tim e.

Fix e d ca pa ci tor — a capaci tor d es ig n ed wi th a specific

valu e of capacitanc e t h a t canno t be cha ng ed.

CV p ro du c t — th e ca p a c i ta n c e of a ca p a ci t or multiplied by i ts working vo lt ag e. Us ed when dete r  minin g the leakage allowable in electroly tic cap acitors.

The CV pro d uc t is also eq ual t o the charge th a t a

capacitor can sto re at its m a x im u m voltage. Dielectric — the ins ul ati ng or no n-con duc ting m ateri al

between the p lat es of a c apa cito r. Typical dielectrics include air, im pr eg na te d pap er, p l as t ic films, oil, mica, and ceramic.

Dielectric a bso rpt ion — the m e a su r e of the re lucta nce of a capacitor to completely disc ha rg e. The cha rge t h a t rema ins after a determin ed d is c ha rg e time is expre sse d in a pe rc enta ge of the original charge. Can also be called “Ca pacito r Me m ory " or “B a tt e r y Ac ti on ”.

Dielectric c o ns ta n t — th e ra ti o of c apac itance between a capacitor h avin g a dry air d ielectric and th e given material. A figure for d e te rm i n in g the efficiency of a

given dielectric mate rial. The l arg e r the dielectric con

stan t , the g r ea ter th e capac ity w it h a given size plate.

Gim mic k — a c apac itor formed by tw o wires or other con d u c tin g m ateri als twi sted t o g et h e r or br ou g ht into

close pr ox im ity of each other.

GM V — Guar an te ed Minimum Value. The sm alles t valu e this ceramic ca pacito r will have. I t s value could be muc h higher.

He n r y — The u ni t of t he mea sure of ind ucta nce . Also exp re s se d in microhenry and millihen ry.

In d u c t o r —- a device co nsis ting of one or more wind

ing s with or withou t a magne tic ma te ri al core or

int r od u c in g inductan ce into a circuit.

In d u ct a n ce — the p ro p er ty of a coil or tra ns fo rm er wh ich indu ces an elec trom agn etic force in t h a t circ uit or a neig hbo ring circuit upon ap pl ic ati o n of an al te r  na t i n g curre nt.

In d u ct iv e r eac tanc e — th e oppo siti on of an in duc tor to

an a lt e r n at i n g or pu ls at in g curren t.

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Imped anc e — th e t o ta l opp osit ion of a circuit to the flow of an a lt e r n a ti n g or pu ls a t in g current.

Insu lati on r es i st a nc e — th e ratio of the DC working

>ltage an d th e re s u lt i n g lea kage cu rr en t t h ro u gh the

Aiiectric. Gener all y a min im um value is specified,

usually in the s ev era l t h o u sa n d megoh ms range.

Iron core — the c e n tr al p o rti on of a coii or transfo rm er.

Can be a p ow de red iron core as in small coils us ed in

RF to the large iron sh e et s use d in power trans form er s.

Time co n st an t — the nu m be r of se con ds requ ired for a capac ito r to reach 63.2% of its full charge after a

voltag e is applied. The time cons t a nt is the cap aci ty in

fara ds tim es th e resi stan ce in o h m s is equal to seconds (T=RC).

Trim me r — a low value v ar ia bl e cap aci tor placed in parallel w ith a fixed c ap aci tor of hi gh er value so t h a t the to ta l c apac ity of the ci rc u it ma y be a d ju st ed to a given value.

Leak age cu rr e n t — st r ay dir ec t c u rr e nt flowing thro ug h t he d iele ctr ic or a ro u nd it in a capa ci tor when

a voltage is applied to i ts term ina ls. Metalized c ap a ci to r — one in which a thin film of metal

has been va cu u m plate d on the dielectric. When a breakdown occurs, the m e t a l film ar ou nd it im med i ately bur ns away. S om e t im e s called a self-healing capacitor.

Monolithic ceramic ca pa c ito r — a small capacitor ma de up of sev e r a l la y e r s of cerami c d iel ect ric sep ar at ed by prec io us m e t a l electrodes.

Mutu al indu ct an c e — th e common p ro p er ty of two indu ctor s whe re by th e indu ced voltag e from one is induced into t he o the r. The ma gn it ud e is d ep end en t upon the spa cing.

NP O — an ult r a sta b l e temp e ra tu r e coefficient in a

'ra m ie disc ca p a c i to r . Derive d from “nega tive - ^o s it i v e - z e ro” . D o es n ot c h a ng e c ap a c i ty wi th tem p er at ur e ch an ge s.

Pad d e r — a hi gh c a pa c it y vari ab le cap aci tor placed in series with a fixed c a p a ci to r to v ar y t he to ta l cap acity of t he circuit by a sm all am o un t .

Variable c apa cito r — a c a p ac i to r t ha t can be cha nged in value by v ary in g the di st a n c e b etwe en th e pla tes or the useful area of its plates.

Voltage ra ti ng - - see working vo lt ag e. We t (slug) t a nt a lu m c a p ac i to r — an electrolytic

capa ci tor havin g a liquid catho de .

Wor kin g vol tag e — the m a x i mu m DC vol tage t ha t can be applied to a capac itor for co n tin u ou s ope ration at the m axi m um rat e d t emp er a tu re .

Power f acto r — t he r a ti o of the effective resist an ce of a capac itor to its i m pe da nc e.

Reacta nce — th e o p po s iti o n of a c apac itor or ind uctor to the flow of an AC c u r r e n t or a pu ls at ing DC current.

Se lf -h e a li ng — t erm u s e d wit h m e t a l ize d foil capacitors .

Solid ta n t al u m cap a c it o r — an ele ctrolytic ca paci tor with a solid t a n t al u m ele ctr ol yt e inst ead of a liquid. Also called a solid ele c tr ol yt e ta n ta lu m capac itor.

Surg e v oltag e — th e ma x im u m safe voltag e in peaks t o which a cap ac it or ca n be s ub jec te d to an d rem ain within the op e rat in g specifications. This is not the working volta ge of th e capac ito r.

Te mp e r a tu r e co e f fi c ie n t (TC) — th e cha ng es in capa ci ty per d eg r ee c h an g e in tem p era tu re . I t can be

ositive, negat iv e, or zero. Exp r es se d in par t s per

million per degre e c e n ti g ra d e for linear typ es. F or no n linear ty pes , it is expr e ss e d as a per ce nt of room tem pe ra tu re .

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Not es

Sencore LC53 Service manual

Specifications and Main Features

Frequently Asked Questions

User Manual