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Keithley 445 Service manual

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INSTRUCTION MANUAL
Automatic Ranging Digital Picoamneter
Model 445
COPYRIGHT 1974, KEITHLEY INSTRUMENTS, INC.
PRINTED JULY,
1978,
DOCUMENT NO. 29105
CLEVELAND, OHIO U. S. A.
ILLUSTRATIONS
iLLUSTF.ATIONS
Fiu. No.
1 2 3 4 5 6
7 8 9
10 11 12 13 14 15 16
17
1B 19 20 21 22 23
lb 25 26 27 25
:i 31 32 33 ::
Title
Front Panel. Front Panel Conrrols. Rear Panel. Triaxial Receptacle. Reading Time. Digital Display. Prfnter/Control ConneccLr.
Timing
Diagram. Feedback titer. Range Calibration. Overall Block Diagram. Autoranging Block Diagram. A-Lo-D Converter Diagram. Delay Hold Diagram. Integrator Block Diagram. zero cro**ing DetacLor.
Model 4401 Buffer stage. Chassis, Top View. PC Board Locationa. Componanr Layout, PC-207. cMnponenc Layout, PC-208. COmponent Leyout, PC-209. Component Layout, PC-212. Component Layour. PC-214. cmponent Layout, PC-217. Colnponent LayoUr, PC-218. component Layout, PC-219. component
Layout,
PC-221. corQpon.nt Layout. PC-229. Componenr Layout, PC-230.
Mechanical Assembly. Test Equipment Set-up for A/D Calibration.
AID
Converter Zero Adjuetmenrs
Test Cover Template, Top Panel.
Teat
Cover Template, Bottom Panel.
Page
1 2 2 3 4 5
9 10 11 11 12 13 14
15 15
15
17 19 20 21 21 22 22 23
23 24 24
25 27 27
31 54 55 57 58
0714
MODEL 445
GENERAL DESCRIPTION
SECTION 1. GENERAL DESCRIPTION
1-1.
GENERAL. The Model 445 is B sensitive Automatic
Ran
ing Digital Picoammeter with eight ranges from
8
lo-
to 10-2 ampere plus 100% cwerranging.
l-2.
FEATURES.
a. Stability. Zero drift with time is less than 1 digit per day; drift with temperature is less than one digit per O/C, making frequent adjustment unnecessary.
b. Overload Protection.
A transient overload of
1000 volts at up to 20 r,A will not damage the instru-
nlent.
C. Damping. A front panel FILTER Switch selects additional damping of noisy signals on the 10-7. lo:*. and 1O-g amp& r&es. - -
d. Digital Display. The digital display provides
3 digits with lo-= ampere resolution.
e. Variable Dieplay Kate. A front panel DISPLAY
RATE control adjusts from 24 readingslsec. to 1 read-
ing/Z eec, to accommodate the mode of data retrieval.
f. Autorsnning. Autorange circuit sense8 the in­put current and automatically selects the proper range far each meaeurement.
g. Complete BCD Output and Control Lines. Binary­Coded-Decimal Outputs are provided on a rear panel connector for significant digits, range, polarity, overrange, and zero check. Cantrr,l lines are also provided for remote control of ranging and A/D conver­*ions.
,
Control
POWER witch (S102) ZERO CHgCK (S1204) ZERO ADJUST (R1207)
FILTER Switch (S1201)
RANGE-HOLD/AUTOMATIC (51203)
RANGE - lo-Z/DOWN (51202)
DISPLAY FATE (R1237)
0971
TABLE
l-l.
Front Panel Contr018.
Functional Description
Controls power to instrument. Selects Zero Check Made.
Adjusts the zero offset.
Selects additional filtering. Selects HOLD or AUTOMATIC modes. Permits manual range selection.
Adjusts the AID conversion rate.
Paragraph
2-3, B 2-3, b 2-3, c 2-3, d 2-3, a 2-3, f
2-3, 8
1
MODEL 445
OPERATION
SECTION 2.
OPERATION
LOW
CASE
1NPUT
HIGH
OPERATION
MODEL 445
Accurecv. The accuracy is specified in terme
!L
of a
percent of reading on esch range. A” addition-
al 2
1 digit is specified since the A/o conversion
has-e” inherent 2 1 digit uncertainty. Noise and
saurce~resistance conditions should be evaluated es additianal meeeurement considerations.
a. Source Resistance.
The value of eowce resist-
ance can affect the measurement if the loading effect
of the picoammeter is significant. To avoid a de-
gradation of zero drift, the picoammetee range should be selected so that the range feedback resisrar is much lesa than the e~urce resistance. The zero drift
epecificseio” is valid only for e~urce voltagee greaf­er the” 2 volts.
f. Overloads.
A unique input circuit provides complete overload protection with feet recovery. The maximum overload is 1000 volts using e current limit­ed supply (up to 2OmA) such as Keithley Models 240.4,
245, or 246.
Instantaneous input current mwt “ever exceed 125 milliamperes. With a” input voltage up to 1000 volts use e current limited supply or a ser­ies limiting resistor (8000 ohms minimum).
TABLE 2-1.
Typical Reading Time With Filter “OUT”.
g. Reading
Time.
The time interval for a new reading to take place depends on the Model 445 front panel Settings as well as the chareceeristics of the input signal. The various time intervals which co”­etitute the total reading time are described es follows. The intervals are graphically shown in Figure 5.
1. T1 = A/D Conversion Time until first range change.
2. T2 = Total Time for all successive range changes.
3. Tj
= A/D Conversion Time to first an-scale reading.
4. Tq = Total Settling Time until reading is final.
h. Off-Ground Measurements. The Model 445 can be used far off-ground meeeurements with the circuit low floated up to 100 volts with respect to chassis ground. Circuit low to chassis ground isolation is greater then 106 ahms shunted by .02 microfarad. When making off-ground meeeuremente discannect the LO to GND shorting link on the rear panel. A triaxial cable should be used to maintain noise shieldine and to provide ueer safety., The BCD autputs are”co”“ected to circuit low and therefore muet be used with de­vices which ce” be Operated off-ground.
Input
Signal
10-9
10-g
Initial Sampling Range Ranging Final Range
Range
A 10-2 A .042 7
10-2 (1)
A A
Time Tl Sec.
.042
(1)
A 10-2 A .042 (1) 5
10-7 10-6 10-5 10-4
10-2
A A .042 (‘1) 4 A 10-2 A .042 (1) 3 A 10-2 A .042 (1) 2
:;I; ; .042 .042 (1) 0 1
(1)
Changes
6
Time T2 Sec. Time Tg Sec. Time Tq Sec.
Settling Total
.120 (3) .498 (12)
.294
(7) .042 (1)
.252
(6)
,042
(1) .210 (5) ,042 (1) .168 (4) .042 (1) .126 (3) ,042 (1) .084 (2) .042 (1)
,042 0 (1) ,042 ,042 (1)
,060
(3) .OlS (3) .312 ,015 - .267 (6) ,012 - .222 (5) .003 - ,171 (4) ,003 .003 - - ,129 ,087 (3)
(0) (1)
Time Sec.
.396
(11) (10)
(2)
4
PIGoRE 5.
Reading Time.
0971
OPERATION
TABLE 2-2.
Output Information and Controls.
lode1 4401 Printer Output Cards: Provide SCD outp"t
and external control of Model 445; may be purchased
installed or separately for field installation (no
wiring required).
Printer Outputs: SC0 pwitive o"tp"t represents each of the four digits, exponent, range, zero, polarity and averrange. Standard code is l-2-4-8. "O"< +0.4 volt; "1" 5 +lO volts at up to one milli­ampere; O=OOOO. Print Command: Positive pulse of 14 volts from a 2200-ohm source with 1 volt per microsecond rise time, 100 microseconds minimum pulse width. Remote Controls:
Hold #l: Closure to ground inhibits A to D conver-
sion at that iridtant.
Hold 82: Closure to ground inhibits A to D canver-
sion after reading has been completed. Trigger: Closure to ground initiates one conversior
when in Hold 112. Integration period starts 8.3 ms
(10 ms on SO-Hz models) after
"Trigger"
or release of Hold i/Z. Connector: SO-pin Amphenal Micro-Ribbon mounted on
Model 445.
Output mating connector supplied with
4401.
MODEL 445
NOTE
The term "Closure to Ground" or "Grounded control
line" means a short to commn directly or a saturated NPN transistor (VC, <
+0.4V).
the "COMMON" as supplied at the PRINTER/CONTROL connector should be used for closures to ground.
TABLE
2-3.
Full Scale Magnitude.
Connector Pi" No. Output
1
2 26 27
3
4 28
29
5
6
30
31
.l x 10" 1
2
x 10" 4 x 10" 8 x 10"
1 x 101 1
2
x 101 4 x 101 8 x 101
1 x 102 1
2 x 102 4 x 102
8
102
x
Decimal Digits
2 4
8
2 4
8
2
4
8
through
Only
0971
MODEL 445
OPERATION
2-6. A!JTORANGING. The sutomatic ranging feature of the Model 445 permits rapid measurements of B wide range of currents.
a. AUTOMATIC Mode. In this made the Model 445 will automatically select the full-range that permits a display from 0.100 to 1.999. The Model 445 changes
range in decade steps from .a less sensitive range to
a mare sensitive range. This process is defined as
“down-ranging”. If the input current causes the dis-
play to exceed 1.999, the” the Model 445 will a”to­matically change to “10-2” range and “down-range” until the display Is between 0.100 and 1.999.
1. DOWN Range Control. The “se of Switch S1202
permits manual range changing. This switch is a
momentary-contact type switch. Each time the switch
is depressed to “DOWN” position, the range will “down-range” from a less sensitive range to a more
sensitive range.
When the 10-V range is reached, actuation of the switch will cause the range to go to 10-2 or “reset” position.
10-2 Range Control.
2.
When switch 51202 is set to “10-Z” position, the range will be “reset” to the lo-2 range regardless of the current input. Once the switch is released the Model 445 will re-
vert to normal operation.
b. HOLD Mode. When switch 51203 is set to “HOLD”
position, the full range of the instrument will hold regardless of the input current. This switch posi­tion inhibits the operation of the DOWN/lo-2 switch.
NOTE
If the input current exceeds 1.999 for the range in “HOLD”, the display tubes will
blank indicating a” overload on that range.
If Switch 51203 is set CO “AUTOMATIC” the
Model 445 will change to 10m2. Then if the
input current does not exceed 1.999 on the 10-2 range, the display will indicate
normally when the final range is selected.
b. Output Codes and Levels. The PRINTER/CONTROL
0ut”uts are Sinarv Coded Decimal sianels with l-2-4-
8 S&da-d Code. .
The Standard signal levels are as
follows:
Logic “0” < +0.4 volt Logic “1” > +lO volts at up to 1 milliampere.
c. Output Information. The various Output Informa-
tion and Controls sre surmnarized in Table 2-2.
1. Full Scale Magnitude. The Magnitude of the reading is indicated by SCD o”tp”ts which corres­pond to the three front panel display lights (three significant digits) as shown in Table 2-3.
2. Overrange Indication. Overrange is indicated
by the fourth (from the right) display light and
corresponding SCD output as shown in Table 2-4. Overload is indicated by a blanked display and corresponding BCD output. The output at pin 33
will be a logic “1” while the magnitude will be
represented by logic “0” as shown in Table 2-4.
TABLE 2-4.
Overrange and Overload Outputs
Connector Decimal
Pi” NO. output Digits
7 8
1 x 103
Gammon 0 32 COSDIIO” 33
Polarity and Zero Check Indication. The
3.
Overload (8 x 103) 8
1 0
polarity is indicated automatically by the Polarity
indicator and corresponding BCD output as shown in
Table 2-5. Additional BCD levels are available at
pins 14 and 39 for use with some printers. The zero check mode is indicated by a BCD o”tput from pin 38.
TABLE 2-5.
Polarity output
ANALOG OUTPUT. The analog OUtput on the rear
2-7. panel (51218) provides a voltage of 1.05 volts corres­ponding to 1.000 o” any range. Since this output has a source resistance of 499 ohms, the recording device
must have a load resistance greater than 10 kilohms
to obtain 1.000 volt for full range.
If a recorder such as the Keithley Model 370 is available, an Isola­tion Amplifier (such as Keithley Model 399) must be used to provide up to 1 milliampere current for full range.
2-8. DIGITAL OUTPUT.
8. General. The Model 445 has o”tp”t buffer print-
ed circuit boards which provide Binary Coded Decimal
(BCD) outputs.
A factory wired SO-pin PRINTER/CONTROL connector is provided on the rear panel (51214). A spare cutout is provided on the rear panel for instal­lation of an additional PRINTER/CONTROL connector.
bnnector ‘in No.
13 14
38
output
Polaritv +15v . Zero Check
Decimal Digits
39 + 15v
4. Range Indication (Exponent). The range or
exponent has a corresponding BCD output as shown
in Table 2-6.
TABLE 2-6.
Lange or Exponent Indication
onnector
Pi” No. output
9 10 34 35
1 x 10 Range 2 x 10 Range 4 x 10 Range 8 x 10 Range
Decimal Digits
1 2 4 8
7
OPERATION
MODEL 445
5.
Ranging Signal.
A single binary signal is available at pin 49 which corresponds to 8. ranging signal.
The logic level is “1” whenever range
changes are occurring so as to indicate invalid
readings.
d. External Control.
1. General. To obtain aptim~ system perform-
ance, Ft is often desirable t” “perate the Model
445 synchronously with other digital equipment such as printers, paper tape punches, computers, and other data handling devices.
2. Applications. Several approaches may be used
in designing the overall syetem contra1 scheme.
The Model 445 can be used to provide master
*).
control of external devices so that maximum poss-
ible conversion rates ca” be obtained.
An external device can be used far master
b).
control; such as a high speed printer.
A completely independent “master clack”
Cl.
can be used for system caner01 for maximum flex-
ibility.
3. Description, “HOLD 1”. This control inhibits A to D
=). conversion at the instant a closure to ground is made.
The conversia” cycle will resume immediate-
ly when the “HOLD 1” line is opened.
“HOLD 2”. This control inhibits A to D
b). conversion after a complete reading cycle. Further conversions are inhibited as long as a closure to ground is made. The conversion cycle will resume
immediately when the “HOLD 2” line is opened.
“TRIGGER”. This control initiates one com-
Cl. plete conversion when “HOLD 2” line is grounded.
Closure t” ground may be momentary or any longer duration to initiate a conversion.
“PRINT COMMAND A”. This control provides
d).
* positive going pulse of 14 volts after * corn­plete A to D conversion is made and all data out­puts are final readings.
No change can take place (except Zero Check) for 25 milliseconds. This “Print Command” signal is present regardless of the mode (ADTOMATIC or HOLD).
“PRINT COMMAND 8”
This control is similar toe)‘Print Command A” except that na signal is present if the instrument is changing range.
f). Zero Check. This control places the Model
445 in Zero Check and prevents automatic range
change when a closure to ground is made.
Range Hold Control. This control prevents
9).
automatic range change when a closure to grand is made.
10e2 Range Hold Contral. This contra1
h).
causes the range t” change to low2 when a closure to ground is made.
The range is held until the
line is released.
i). High and Law References. Two reference
voltages are provided t” define the “HIGH” and
“LOW” digital output states far external printers
or other devices; “HIGH”** +Bv, “LOW” = +2v.
Summary of Digital 0”tp”ts and Controls.
e.
Standard Output Codes and Levels. The sta”-
1.
dard output code for Model 4401 Printer Output Cards
is l-2-4-S Binary Coded Decimal (BCD). A binary coded decimal digit is represented by a four-bit binary code as shown in Table 2-7.
TABLE 2-7
Decimal Number
0 1
2 0 0 3
4
bit 3 bit 0 0 0
0
0 0
2
bit
0 0
1 0 1
1 bi,
4 0 1 0
5
6 0
7
8
9
0 1 0
1 1 0
0
1
1 1
0
0 0
1 0 0
Refer to Figure 17 for a circuit diagram of the
Model.4401 Standard Printer 0”tput buffer stage.
0 1
1
0
1 1 1
TABLE 2-8.
Typical Digital Outputs.
Fr”“t Panel Digital Display
+ 0.275 + 1.347
- (blank) + (blank) +
- 0.023 0 023 3 0 - ,023 x 10-3 A + 1.962 10-6 +
- 0.586 10-4 0 586 4
Range
Exponent Polarity or overload gag.
10-5 10-9
+ 0
* 1 10‘2 10-7
10-3
Sign. Digit
Range
EXP.
275 5 0 + ,275 x 10-5 A 347 9 0 + 1.347
8 000
8 000 7 0
1
962 6
Ranging
Signal Interpretation
2 0
negative overload positive overload
1 ranging 1 ranging
8
x 10-V A
I
0971
MODEL 445
OPERATION
in No.
1 1 x 100 2 2 x 100
2 1 2 x x 101 5
6
7
8 Caman 9
10
Output
1 x 102
2 x 102 1 x 103
1 x 100
2
x 100
11 Blank
12 Common
13
14
1 x 100
+ 15"
15 Blank 16 Blank
101
PRINTER/CONTROL Connector Pi" Identification.
TABLE 2-9.
F"llCtiOll
oata Data
Data
Data oata
oata oara
Range
Range
---
--_
P&WiQ
___ ___
___
Pin No. Output
26
27
28 29 30
31 32
33 34
35 36
37
38
39 + 15v
40
41
4 x 100 8 x 100
4 8 x x 101 101 4
x 102
8 x
102
Comon 8 x 103
4
x 100
8 x 100 Common
cormnon
1 x 100
Blank
Blank
Function
mea oaea
Data Data
oata oata
___
Overload
Range
Range ___
___
Zero Check ___
___
-_-
17 + 15v
18
19
20
21
22
23 24 + BV
25 + 2"
+ 3.6V
Grounded Grounded
Grounded
"lank
+ 14"
Pulse
___ ___
Remote Zero Check Remote w2
Remote Range Hold
--_ Print Command A
Hi Reference
Law Reference
42 43
44
45
46 47
48 49
50
- 15"
COllllTlO"
Grounded Grounded
Grounded
Blank
+ 14"
Pulse
1 x 100 Blank
___
_-_
Hold ii 1 Hold ii 2
Trigger
___ Print Command B Ranging Signal
0971
FIGoRE 7.
Printer/Control
connector.
OPEBATION
MODEL 44s MODEL 44s
PRINTER/CONTROL Connector. The PRINTER/CON-
2. TROL Connector used on the Model 445 provides for connectiom to 50 ~,ins as shown in Table 2-9. The
mating connector supplied is an Amphenol Part No.
57-30500 or Keithley Part Number CS-220.
3. Analog-to-Digital Conversion Cycle, The analog-to-digital conversion cycle
a).
can be initiated in any one of three ways.
1. DISPLAY RATE Control Set at MAX. With the DISPLAY RATE Control set at MAX, the end of one complete conversion triggers a second
conversion to obtain the maximum conversion
rate of 24 readings per second.
2. DISPLAY SATE Control Set at Other Than
MAX. With the DISPLAY RATE Control set at some position other than MAX, (uncalibrated control setting) the end of one complete con­version triggers a second conversion which is delayed by a specific time interval (DELAY). The time delay is a function of the position of a continuously variable control to provide a conversion rate from 24 readings per second
to 2 readings per minute.
3. ‘HOLD 2” With TRIGGER Control. With the ‘TlOLD 2” camand grounded, a closure to ground of the “TRIGGER” command initiates one complete
conversion cycle. A second convereion will
fallow only if the TRIGGER command is removed
and reapplied a second time. The maximum con­version rate using an external trigger is 24
readings per second.
Conversion Cycle Timing. The Conversion Conversion Cycle Timing. The Conversion
b). b).
Cycle is composed of three timing periods, namely Cycle is composed of three timing periods, namely Integrator Zero, Integrator Sampling, and AD Integrator Zero, Integrator Sampling, and AD Counting period. Counting period. Refer to Timing Diagram Figure Refer to Timing Diagram Figure
1. Integrator Zero Period (ZERO). When a trigger pulse initiates a new conversion cycle, the Integrator circuit is zeroed for a period
not to exceed 8.33 milliseconds for 60 Hz oper­ation. (The Integrator Zero Period is 10.00 milliseconds for 50 Hz operation).
2. neegratOr sampling Period (INTEGRATE).
The Integrator Sampling Period follows automat-
ically the Integrator Zero Period and lasts for the duration of 16.67 milliseconds for 60 Hz operation. The Integrator Sampling Period lasts for B duration of 20.00 milliseconds for 50 Hz
operation.
3. AD Counting Period (COUNT). The AD Count­ing Period is initiated immediately following the Ineegratar Sampling Period. The actua$ counting time duration will depend on the actual integrator voltage up to a maxilll”m Of 2000 clock pulses of 16.67 milliseconds. Following the counting period a Buffer/Storage command is automatically generated in order to store the
new reading in the output registers.
2-9.
117-234V LINE POWER OPERATION. The Model 445
is shipped far use with 117V ac line power unless ordered for 234V operation. TO cO”“ert any inserunlent for either 117V or 234V operation, use a screwdriver to set the 117-234” Switch on the rear panel. The
10
0971
MODEL 445
CIRCUIT DESCRIPTION
SECTION 3.
CIRCUIT DESCRIPTION
3-l. GENERAL. The Model 445 consists of three sec-
eions packaged together in one chassis: a sensitive picoameter, an automatic ranging circuit, and an an­alog-to-digital converter.
a. Picoammeeer. The picoammeter is a linear dc amplifier connected as a feedback anmxeter with eight current ranges.
b. Autarangina Circuit. The autoranging circuit
senses the magnitude of the display so 88 to trigger the range changing circuits and cycle from 10-2~ through lob9 amperes full scale.
C, Analog-to-Digital Converter. The A/D converter
is a dual slow, integratina t”Pe converter with med­ium conversion &ace, cold cathi& readout tubes, BCD
outputs end optional external controls.
3-2. PICOAMMETER.
a. Operation. The picoammeter consists of a linear dc amplifier with a 1 volt full scale
mensitivity.
The amplifier provides an analog output up to Z~volts for 100% overrange display. The RANGE resistors are con­nected across the feedback of the amplifier.. A sim­plified diagram of a feedback ammeter is shown in
Figure
9.
b. Circuitry.
The
amplifier input stage is a pair
of insulated-gate, field-effect transistors (IGFET)
designated 91201 and Q1202 connected in a differential
configuration. The circuit designated 234308 is a spedlal overload
protection
circuit
on
the Input PET
board. The gate,of Q1201 is connected to the input
through 10 Megohms while the gate of Q1202 is refer­enced to ground.
Potentiometer R1238 is an internal
COARSE ZERO adjustment. Potentiometer R1202 is an
internal BALANCE control. Transistors Q1203-Q1204 form a second differential amplifier stage. Potentio-
meeer RI207
is a front panel ZERO adjustment.
TrZl”S­istors Q1205 and Q1206 (emitter-follower) provide sufficient gain for the analog output and A/D can”eT­ter. The analog output is connected through R614
(499CL)
R1215 and 01212).
to the dc amplifier output (the junction of
The full scale current sensitivity is determined by the RANGE resistor connected across the feedback. The RANGg resistance RP is composed of a fixed resistance 81 plus a calibration adjustment resistance K2 as shown in Figure 11. The RANGE re­sistors are arranged in “parallel” such that, an the
“1O-2’1
range, all eight RANGE resistors are connected.
Range selection and zero check are performed using
reed relays which are electrostatically shielded from the high impedance circuitry to preve?f.coupling of switching transients. The FILTER Switch
“ides additional damping on the 10-7, lo-
51201) pro-
$
, and 10-9
ampere ranges with an additional 40 dB rejection of
60 Hz frequency.
With the FILTER Switch set to “IN”,
the A/D conversion rate is set to 1 reading per second
max inlum .
3-3.
AUTORANGING.
a. operation.
FIGURE 9.
FIGURE 10.
Feedback Ammeter.
Range Calibration.
The autoranging circuit operates
from the BCD outputs of the A/D converter. If the reading is less than O-l-O-0, then an “Under-range” command is generated and the range relays are operated to “Down-range” to a more sensitive range. If the reading is greater than l-9-9-9, then an “Over-range” command is generated and the range relays are oper­ated so as to “reset” and then “Down-range”.
If the
HOLD/AUTOMATIC Switch is set to “HOLD”, the autorang-
ing circuit is inhibited and the range will hold re­gardless of the current being measured.
b. Circuitrv. Integrated circuits QA703, QA704A, and QA704B code the BCD outputs to generate “Under­range” and “Overrange’! c,ommsnds. The “Buffer-stare”
command is delayed for approximately 5 microseconds by Mono stable gates QA705A and QA705B, to allow
signals to settle. The range counter gates (QA801,
QA802) is a three-bit binary counter (“000” corres-
ponds to 1O-2, “111”
corresponds to 10-9 ampere). The
output of the range counter is decoded by gates QA803,
QA804 and QASOS into an “eight-line” code. The eight-
lines are encoded by gates QA806 and QA807 to yield BCD range information. Gates QA809 and QAEIO store the range information. The range display tube is driven by transistors Q901 through Q908. Gates
QA902
and QA903 drive transistors 9909 through Q915
QA901,
to operate the read relays.
0971
11
CIRCUIT DESCRIPTION
MODEL 445
ANALOG-TO-DIGITAL CONVERTER OPERATION.
3-4.
a. General,
cO”“erter is shown in Figure 13.
digital converter aperates using a dual slope inte-
gration technique which has inherent line frequency
noise rejection. The analog signal is applied to the
integrator far one complete line frequency cycle. The analog signal is ehen removed from the integrator
input. to zerc, to complete the voltage-to-time conversion. The time interval to reach a “Zero Grassing” is count­ed and displayed on the “Readout” in proportion ta the original analog signal. The sequence is then re­peated for a second reading. A Timing Diagram is
shown in Figure 8.
major circuits which perform the analog-to-digital
conversions and provide various control commands.
pulses at a rate of 120 kilohertz for Electrometer using 60 Hz line power. (The 50 Hz units have e pulse rate of 100 kilohertz).
The voltage on the integrator is then driven
b. Circuits.
1. Oscillator or Clock
2. BCD counter
3. Delay Hold
4. Program/Decoder
5. Integrator zero crossing Detector
6.
7. Buffer/Storage Register
8. DecaderfDriver
9. Numerical Readout
C. Oscillet~r or Clock.
A detailed block diagram of the A/D
The analog-to-
The A/D Converter is composed of nine
The Oscillaear praduces
d. BCD counter.
pulses with a Wea.1 range of 5000 c~unte. The C~unec
is composed of 4 individual cwnters designated 1, 10,
100, and 1000,
e. Delay Hold. The Delay Hold circ”it controls the DISPLAY BATE function and external Hold and Trigger commands as shown in Figure 14. It determines ehe length of time between A/D conversions when the front panel DISPLAY RATE Control is set t0 any position other than MAX. The clock is stopped at the beginning of the ZERO (2) period for a time determined by the rotation of the DISPLAY RATE Central. If eneures thee
when the Hold 2 Fe grounded the conversion in process will be completed and new data will be stored in the
output storage register.
hibited at ebe beginning of the ZERO period (2). The
instrument will remain in this condition indefinitely
until Hold 2 %s released or until Trigger is shorted
to ground. After cowersian, the instrument will again be inhibited at the beginning of the period (2). If both Switches Sl and S2 are closed, the canversion cycle works in the following manner. After the pre­vious conversion has been completed, the leading edge of the program co,+,nd (2) reeete the flip-flop.
In this new condition Q is high and, therefore, the
clack gives no output. At that time, the unijunction
timer begins its cycle and, after the appropriate
time, produces e pulse that sets the flip-flop. This
changes Q to a low state and a new converslan cycle begins.
(2) command again reeets the flip-flop and the timer
again issues a new pulse to set the flip-flop.
After the reading has bee,, completed, the
The BCD Ccuneer counts the Clock
Then the clock will be in-
12
INPUT+
r
FEEDBACK
PICOAMMETER
rc
b A-TO-D CONVERTER OUTPUT
AUTO RANGE
RANGE
DISPLAY
FIGURE 11.
DIGITAL
DISPLAY
T ’
a---
RANGE
overall Black Diagram.
0971
1 .-
-
CONVERTER
MODEL 445
CIRCUIT DESCRIPTION
f. Program/Decoder.
The Program/Decoder circuit
produces event canrmands to control the overall se­quence of events for a complete A/D conversion.
g. Integrator. The Integrator circuit operation
is composed of three periods.
1. Zero Period.
During this period the integra-
tor amplifier is zeroed by the closure of switch Sb,
Switches S,, S,,
and Sd are open to prevene inte-
grator charging es shown in Figure 15.
2. Integration
switch Sb, S,,
Period. During this period,
and Sd ere open. Switch S, is closed to permit charging by the analog voltage for a per­iod of one line cycle.
Discharge Period. During this period, switch
3.
S, is open to prevent further charging by the ana-
log signal. Either switch S, or Sd is closed to drive the Integrator voltage to zero. A reference current of opposite polarity to the input current
is applied through either switch SC or Sd. The Discharge Period ends when the Zero Crossing De­tector circuit detects a zero Integrator output.
h. Zero Crossing Detector. The Zero Crossing De-
tector circuit provides a “High” or “Low” level out­put depending on the polarity of the detected input. Refer to Table 3-l for e description of voltage out­puts.
FIGURE 14.
Delay
Hold Diagram.
Zero Crossing Detector Output Levels.
TABLE 3-l.
0” 0”
-0.5v
+3.5v
+1.5v 0” 0”
+1.5v
i. Buffer/Storage Regisfer. The Buffer/Storage
Register is composed of “flip-flops” arranged to copy
the states of the various BCD counters. The Buffer/
Scarege Register requires e Buffer Store command be-
fare any information can be transferred. The “flip­flap” circuits provide coded information for Decoder/
Driver and the BCD outputs.
j. Decoder/Driver. The Decoder/Driver circuit Qe-
codes the BCD information from the Storage Register
into ten-line decimal code. The Driver circuit then drives the proper numeral in each of the Numerical Readout tubes,
k. Numerical Readout. The Numerical Readout con­sists of four numerical indicators and one polar,ty indicator driven by the Decoder/Driver, Polarity ad
Overload Drivers.
FIGURE 15.
Integrator Block Diagram.
1. Summery of Operation. The operation of the A/D
Converter ten be described by considering a typical
conversion cycle.
1. The
Oscillator or Clock provides pulses at a
rate of 120 kilohertz.
0971
FIGURE 16. Zero Crossing Detector.
CIRCUIT DESCRIPTION
2.
The Delay Hold circuit gates the output of
the Oscillator depending on the state of the "RS flip-flop" and elle "Hold 1" control line. A uni­junction timing circuit provides a delay period
before a conversion is initiated. The time delay
is selected by the front panel DISPLAY RATE Control.
3. The BCD counter serves as a master timing
control for the A/D conversion cycle. The timing
is accomplished by the "1000" co"neer which has
five
coded
4:
states, namely 0, 1, 2, 3,
The
Program/Decoder controls the sequence Of
and
4.
commands based an the coded etatee from the BCD counter. shown in Table 3-2.
The decoded commands are described as
the "2"
command initiates the
integrator ZERO period which removes any residual charge on the integrator capacitor. The "3,4" CO",­mand initiates the
INTEGRATE
period which permits
an integration of the analog signal. At the end of
the INTEGRATE period, the "0,l" command initiates
the COUNT period.
TABLE 3-2.
Command
F""ction
MODEL 445
ANALOG-TO-DIGITAL CONVERTER CIRCUITRY.
3-5.
a. General. The circuits described in this aectio
are located on the various Sub-Assemblies listed beloh
and in Table 7-2 of Section 7.
1. Oscillator Board, K-217.
2.
Integrator Board, K-219.
3. Display/Overload Board, X-241.
4.
Readout Board, PC-229.
5.
Polarity Board, K-207.
6.
Output Buffer Board, X-218.
7. Output Buffer Board, X-209.
b. Oscillator Board.
The Oscillator Board contains
portions of three circuits: the Oscillator (clock)
circuit, the Delay/Hold circuit, and the Discharge-
Voltage CUrrent source circuit.
1. Oscillator Circ"if.
Transistor Q501, crystal Y501, and phase shift capacitors C501, and C502 farm a "Colpitts"
C504
are used for trimming the oscillator frequency.
type oscillator. Capacitors C503
and
The output is taken from the collector of transistor Q510 which is a common emitter gain stage'used for squarLng the output.
Transistor
Q507 serves as an
emitter-follower to reduce output impedance.
2
3,4 031
When the "3,4" command is given, the integra-
5.
ZERO
INTEGRATE COUNT
tor is charged by the analog signal for B period of 1 line cycle of 16.67 milliseconds.
6,
When the "O,l" command is given, the analog
signal is removed and the integrator output is driv-
en to zero by a reference current. The Zero Cross-
ing detector senses a zero crossing of the Ineegra­tar output and removes the reference cuxene. The Detector provides outputs as shown in Table 3-1. The +1.5 volt levels are provided for control of the Integrator and Polarity Storage Register. A pulse command is also produced to initiate a Buffer/Store and Print Command o"tp"t.
7. When the Buffer/Store command is given, the Buffer/Storage Register copies the BCD COUnterStateS at that instant of time.
The BCD coded information in the RegFster is then available for the Decoder/ Driver and external printout.
The
8.
Decoder/Driver decodes then Buffer/Storage
output and drives the'Numerica1 Readout for a digit-
al display.
9. The RCD Output information is available at the
Model 4401 Buffer Card o"tp"ts in the form of posi-
tive (+lO volt) tr"e logic (l-2-4-6 BCD Code).
The conversion cycle is completed when the BCD
10.
Counter reaches 2000 co"nt~ and the Program/Decoder
provides a "2" command to initiate a new con"ersFon cycle.
The Unijunction Timing Circ"it will initiate
11. the ZERO period after a present time delay controlled by the front panel DISPLAY
RATE
Control.
2. Delay/Hold Circuit. There are three major
components in ehe Delay/Hold circuit: an "RS" type
flip-flop circuit, a "Unijunction" timing circuit
and a "Hold" gate circuit.
"RS" Type Flip-Flop Circuit. The flip-flop
a).
gafes ehe output of the clock depending an the input8 Bt pins R and S.
The RS flip-flop is con­structed of gates QA5OlB and QASOlC. The pins are identified as shown in Figure 16.
"Unijunction
b).
tion timing circuit determines the time delay be-
" Timing Circuit. The "nijunc-
tween conversion cycles to obtain the desired con­version rate as determined by the front panel DIS-
PLAY RATE Control.
The circuit is composed of transistors Q513 and 0514, timing capacitor C507, and timing resistors R532 and R1269 (DISPLAY RATE Control potentiometer located on the front panel.
"HOLD" Gate Circuit
C).
for identification of switches Sl and S2). The
. (Refer to Figure 16
"HOLD" gate circuit is composed of gates QA501A, QASOlD, and QA502 (A, B, C, and D). Switch Sl is gate QA501A and is controlled by eirher~the "HOLD
2"
external line or the "MAX" position on the DIS-
PLAY RATE Control.
Switch S2 is transistor Q513
which is controlled by either the "Q" output of
the flip-flop or the "HOLD 2" external line. The
"HOLD
1" circuit is composed of gates
QA502B
and
QA502C.
3. Discharge-Voltage Current Source Circuit.
The positive current source composed of transiseors Q502 and Q506 delivers a constant current of ~7.5 milliamperes to drive a 9-volt zener diode D602
(located on the Integrator Board, W-246) "hen +REF Terminal (Pin 13) is greater than +0.7 volt. The negative current source composed of transistors QSOS and Q509 delivers a constant current of -7.5 milliamperes to drive a g-volt zener diode ~601
(also located on the Integrator Board, X-219).
16
0971
MODEL 445
CIRCUIT DESCRIP’fION
C. Integrator Board.
The Integrator Board consists
of two major circuits: the Integrator circuit and the
Zero Crossing Detector circuit.
1. Integrator Circuit.
The operation of the In-
tegrator is controlled by the positions of switches
s,, sb, SC> and sd.
Switch S, is transistor Q605. Switch Sb is transistor Q606. Tranststors Q601 through 9604 are control circuits arranged to turn
off the proper FET switches depending on the signals at pins 11 and 12. The integrator amplifier consists
of transistors 9607 and Q608 and integrated circuit
QA601. The feedback capacitor is C603. Switches S,
and Sd (located on the Oscillator Board, PC-217)
control the current for 9-volt zener diodes D601 and
0602. Resistors R602 through R611 are full-scale calibration resistors.
2. Zero Crossing Detector Circuit. (Refer to
Figure 18).
The high gain amplifier is composed of
cascaded amplifiers QA602 and QA603. The zero ad-
justment network consFsts of resistors R645, R646,
R648, R649, and R650, and diodes D611 and D612. Transistor Q609 and other components form a 6-vole supply far QA603 and the zero circuit. The level­splitter circuit consists of diodes 0613 and D614, resistors R651, K652, and R653 and gates QA604 (A,
B, C).
d. Display/Overload Board. The Display/Overload Board contains a BCD Counter (“1000” counter), a Pro­gram Decoder circuit, and an Overload Control circuit.
1. The BCD Counter L8 composed of “J-K” flip-flop
circuits QA301 and QA302.
2. The Program Decoder circuit is composed of
gates QA303C and qA303D (3.4 Cownand) and QA304A, QA304B, QA304C, QA304D, QA305A, QA305B, QA305C, QA305D, QA303E, QA306A, QA306B. and QA306C (0,l &
2 Commands).
f. Polarity Board, The Polarity Board contains various circuits which are controlled by signal “B” and “C” from the Zero Crossing Detector signal as shown in Figure 16.
1. Polarity Indicator Control Circuit. This circuit drives the Polarity Indicator DS201 to pro­vide a Polarity display. QA201A and QA206.4 are J-
K Flip-Flop circuits which control transistors Q201
and Q202,
2. Polarity Print Signal Circuit. The Polarity Print signal is determined by the Q output of J-K flip flap QA206A.
3. Discharge Voltage Polarity Control Circuit,
The +REF Control signal is determined by QA201.4 and
gate QA204A.
The -REF Control signal is determined
by QAZOZA, QA203A, QA203B, QAZOZB, QAZOZC, QA203C,
QA203D,
and QA204B.
4. Buffer Store Command Circuit. The Buffer Store coormand is provided by J-K flip QAZOIB and gates’ QA204C and QA207A.
5. Overload Blanking Circuit. A portion of the
Overload Blanking circuit QA204D, QA206B, and QA207B
is located on the Polarity Board. The remainder of
the circuit is located on the Display/Overload Board
PC-241.
g. Output Buffer Board, PC-218. This board con­tains 15 buffer circuits to provide BCD Data and Over­load and Polarity Print signals. Buffer circuits “A”
through
“P”
consist of transistor buffer stages as
shown in Figure 17.
3. The Overload Control circuit provides an over-
load signal if a zero crossing does not occur in the
Discharge Period (0,l).
It controls the Numerical
Blanking circuit and provides an Overload Print
eiglL¶l. e. Readout Board.
The Readout Board contains Dec­ade Counter circuits, Buffer Storage clrwlts, and Decoder Driver and Display clrcults.
1. Decade Counter Circuits. Each decade co”nter
is composed of four J-K flip-flops. Circuits QA401
through QA406 are Dual J-K Flip-Flop integrated cir-
cuits.
Buffer Storage Circuits. The Buffer Storage
2. register is composed of Dual J-K Flip-Flop integrated circuits qA409 through QA414.
3. Decoder Driver Circuits. QA415, QA416, and QA417 are Decimal Decoder Driver integrated circuits.
4. Display Circuits. V401, V402, and V403 are
Readout Tubes for Units,
Tens,
and Hundreds respec-
tively.
CIRCUIT DESCRIPTION
MODEL 445
h. 0”tp”t Buffer Board, X-209. This board con­tains six buffer circuits and various gate circuits to provide Print Cornnand and Range Signal Print signals.
1. Buffer Circuits. Buffer circui~ts “A” through
“E” provide BCD Range information.
2. Print Command Circuits. Buffer circuits com-
posed of transistors Q1101, Q1102, Q1104, Q1105,
Q1106, and 91107 provide Print Cooanand signals as
determined by gates QAllOl (A, B, C, and D) and
QA1102 (A, B, C, and D).
3. Range Signal circuit. Translseors QllOS,
QllOV, end QlllO comprise a Range Signal Buffer
stage controlled by the Range Signal.
4.
Reference Voltages. A High and Low Reference valtage is provided by resistor divider R1114, R1115, and R1116. The voltages are +S volts (High) and +2 volts (Low),
POWER SUPPLIES. (Schematic 234483).
3-6.
a. h.15 Volt Supply. The +I5 volt supplies tap ac
power from a secondary of transformer T101. Diodes
D103, D105, D107 and DlOS and capacitors Cl04 and Cl05
compose a fullwave rectifier with filtering. Trans­istors Q114 and Q115 form a differential amplifier
which campares the voltage at R115 with the voltage of
zener diode D110. The difference voltage is amplified by transistor Q109 and fed to Darlington transistor pair, Q106 and Q107, which series regulate the output voltage. amplifier which compares the voltage at R123 with re­spect to lo. transistor 9113 and fed to Darlingtan transistor pair, QllO and Qlll, which series regulate the -15 volt o”t­put. rent ‘CO about 200 milliamperes.
Transistors Q116 and 4117 form a differential
The difference voltage is amplified by
Transistors QlOS and 9112 limit the output cur-
b. C3.6 Volt Supply. The +3.6 volt supply taps ac
power from a secondary of transformer TlOl. Diodes
DlOl and D102 and capacitor Cl01 farm a full-wave rec-
tifier with filtering.
difference between the +3.6 volt output and a refer-
ence voltage derived from the +15 volt supply and de-
termined by resistors R103 and R104. The difference voltage is amplified by transistor 9104 which drives a Darlington transistor pair, QlOl and Q102. The Dar-
lington pair series regulates the +3.6 volt output.
Transi.stor 9103 limits the o”tp”t current to about 3
*lllp*i-6% .
c. +170 Volt Sup”ly. The t17OV supply taps ac power
from a secondary of transformer TlOl. Diode Dill and
ca”acitor Cl12 form a half-wave recitifier with filter-
Transistor 9119 amplifies the voltage developed
ini.
by the resistor divider R12S and R129. The output of
Q119 controls the w-3 regulator transist?r QllS to
maintain the +170 volt output. When the electrometer
is overloaded, and overload signal drives transistor Ql20 which in turn controls the voltage at the base of transistor QllV. transistor Q120, and resistors R130, R131 and R132
reduces the +170 volt output to +SO volts when over-
loading occurs. Grounding the off transistor Q120 causing diode D112 to conduct and drive QllV. The reduced +SO volt o”tp”t causes blank-
ing on all Numerical Readout Tubes connected to the
+170 volt supply.
d. +210 Volt Output. The CZlO volt supply is an unregulated voltage supply “sing the half-wave filtere, voltage at diode Dill and capacitor C112.
e. t17 Volt Supply. The cl7 volt supply is an “n-
regulated voltage “sing the half-wave filtered voltage at diode 0113 and capacitor C113.
Transistor QlO5 amplifies the
The circuit composed of diode D‘l12,
overload
input turns
1s
0971
MODEL 445 DIGITAL PICOAMKETER
SERVICING
I
FIGURE 20.
+ TP (S&ape Trigger)
Component Layout, PC-20%
I
0171
FIGURE 21.
Component Layout, PC-208.
21
SERVICING
MODEL 445 DIGITAL PIC@WMETER
FIGURE 22.
component Layout, PC-209.
22
FIGURE 23.
component Layout, PC-212.
0171
MODEL 445 DIGITAL PICOAMMETER
SERVICING
FIGURE 24. Component Layout, PC-214.
FIGURE 25.
0171 23
Component Layout, PC-217.
SERVICING
MODEL 445 DIGITAL PICOAMMETER
FIGURE 26.
Component Layout, PC-218.
24
FIGURE 27.
component Layout, PC-219.
0171
MODEL 445 DIGITAL PICOAMMETER
SERVICING
FIGURE 29.
Component Layout, PC-229.
0171
FIGURE 30. Component Layout, PC-230.
27
MODEL 445 PICOAMMETER
REPLACEABLE PARTS
REPLACEABLE PARTS
4-l.
REPLACEABLE PARTS LIST.
SECTION 4.
This section contains a list of components used in this instrument for "ser reference. The Replaceable Parts List describes the individual parts giving Circuit Designation, Descrip­tion, Suggested Manufacturer (Code Number), Manufac-
Abbreviations and Symbols
TABLE 4-l.
A
ampere
F
Fig. Cb"ar cero Cer Trimmer COtlIP
DCb oesig.
EAL
ETB ETT
Carbon Variable ceramic Disc ceramic Trimmer Composition
Deposited Carbon Designation
Electrolytic, Aluminum Electrolytic, tubular Electrolytic, tantalum
CCb
k
I-I
M Mfr. MtF
MY NO.
turer's Part Number, and the Keithley Part Number.
Also included is a Figure Reference Number where
applicable. The complete name and address of each
Manufacturer is listed in the CODE-TO-NAME Listing
following the parts list.
farad
n
ohm
Fig"t-e
pica (10-12)
Class enclosed Carbon
;c Poly
Printed Circ"if Polystyrene
kilo (10-3)
Ref. Reference
micro (104)
TC" Tinner Capperweld
leg
(106)
M**“f*Ct”PSr
" "Olt Metal Film l.fyl*r
Number
w NW WW"*r
watt Wirewound Wirewound Variable
4-i. ELECTRICAL SCHEMATICS AND DIAGRAMS. Schematics
and diagranls are included to describe the electrical circuits as discussed in Section 3. Refer to Table
4-2 which identifies all schematic part numbers in-
cluded.
4-3. HOW TO "SE THE REPLACEABLE PARTS LIST. This
Parts List is arranged such that ehe individual types of components are listed in alphabetical order. The parts far the i"str"ment's Main Chassis are listed
folrzed by printed circuit boards and other sub-
assemblies.
4-4. HOW TO ORDER PARTS.
a. Replaceable parts may be ordered through the
TABLE 4-2.
CirC"it Description
Main Chassis
power supply Polarity Board Thousand Board Readout Board
Oscillator Board
Integrator Board Range Control Board Range Counter/Decoder Tube & Driver Board Output Buffer output Buffer
Sales Service Department, Keithley Instruments, Inc. or your nearest Keithley representative.
b. When ordering parts, include the following in-
formation.
1. Instrument Model Number.
2. Instrument Serial Number.
3. Part Description.
4. Schematic Circ"it Designation.
5. Keithley Part Number.
C. All parts listed are maintained in Keiehley
spare parts Stock.
Any part not listed can be made akilable upon request; -Parts identified by the Keithley Manufacturing Code Number 80164 should be ordered directly from Keithley Instruments, Inc.
Schematic Pare No
PC-221
234883 PC-221 234483 PC-207
PC-208
PC-229
234490
234501)
23451E
PC-217 234520 PC-219 234533 PC-214 23454E PC-212 234553 PC-230
23456D
PC-218 234570 PC-209
234813
0971
29
REPLACEABLE PARTS
MODEL 445
r
Series
100 200 300 400
500 600
700 800 900
1000 1100
1200
PC Board Designation Series
Description
Power Supply
Polarity
Board Thousand Board Readout Board
08cillator Board Integrator Board Range Control Board Range Counter/Decoder Tube & Driver Board Output Buffer Board Output Buffer Board MEIF" Chsssis
TABLE 4-3.
Designation Connector
PC-221
PC-207
PC-208
PC-229 PC-217 PC-219 PC-214 PC-212
PC-230
PC-218 PC-209
51204 51205 J1206/51207 41
J1208
51209 51212 51211
51210
.J1216
51202
PC-221
Page No.
37 39
40
i: 46 46 47
i," 33
30
0971
MODEL 445 DIGITAL PICOAMMRTER
REPLACEABLE PARTS
TABLE 4-4.
Mechanical Parts Lisa.
Item No.
1
2
Description
Top Cover Assembly
Cover
Fastener
Bottom Cover’ Assembly Cover Fastener
Angle, Rack Assembly
Screw,
Slotted, 10 - 32
Front Panel
Chassis
x l/4
Quantity Per Assembly
Keithley Part No.
17958C 17162C
FA-54
17960C
17957c
FA-54
146248
23000C 230038
0171
FIGURE 31. Mechanical Assembly.
31
s (I
j
MAIN CHASSIS PARTS LIST
(“1200” Series, E-221)
CAP.4CITORS
REPLACEABLE PARTS
Circuit
msig. Value Rating
Cl201
Cl202 10 @ 20 v
Cl203 10 p 20 "
Cl204 ,004, fl 600 " Cl205 .047 NF 200 "
Cl206 ,022 fl 400 " Cl207 .022 p 400 v
Cl208
Cl209 1000 pP 500 v
Cl210 390 pF 500 v Cl211 .033 p!s 600 "
Cl212 150 pF 500 " Cl213 3600 pF 500 " Cl214 22 PF 500 " Cl215 10 PF 500 "
CU.16 .Ol pF 600 "
Circuit
msig.
.l1201**
5 pF 60" "
.Ol @
600 "
DWXiptiO”
Plug-in contacts
Mfr. Mfr.
TYPe
CerD 72982 ED-5 C22-5P 28 ETT 17554 TSDZ-20-106 C179-10M 28 ETT 17554 TSDZ-20-106 C179-10M 28 CerD 72982 ED-.047 C22-.0047M 28 MY 13050
MY 1305D SMlA C73-.022&l 28 MY 13050 cerD 72982 ED-.01 C22-.OlM 28 POlY 71590 CPR-1000J C138-1OOOP 28 POlY 71590 CPR-3903 C138-39OP 28
MY Poly 71590 cm-15OJ C138-15OP 28 Poly 71590 CPR-3600J Cl38-3600P '28
POlY 71590 Poly 71590 cm-1O.T C138-IOP 28
cem 72982 m-.01 c22-.OIM 28
CONNECTORS
Code
56289 CPS-550 C62-.033M 28
Mfr.
Part NO. Part NO.
SMlA
SW.4
CPR-22J
Mfr.
Code Part NO.
80164
Keithley
C143-.047M 28
C73-.022M 28
C138-22P 28
Keithley Part NO.
Fig. Ref.
see FET Lnput
Fig. Ref.
28
Card
PI201
51202
51203 .I1204
51205
J1206
51207
51208
51209
Printed circuit contacts, mate
of n201
Receptacle, 44 pins, Rear Card of 0”tput Buffer Stage PC-209
Not Used
Receptacle, 15
Board PC-207
pins, Polarity
Receptacle, 15 pins, Thousand
Board PC-208
Receptacle, 6
Board PC-229
Receptacle, 15
Board PC-229
pins, Readoue
pins, Readout
91662 02-005-113-6-200
09922
09922
09922
73690 02-006-105-6-200
73690 02-015-105-6-200
09922
09922
09922
09922
PSC 4DD22-12
PSC 45515-12
PSC 4SS15-12
PSC 4SS15-12
PSC 4SS15-12
PSC 4ss**-12
PSC 4SS22-12
m-199
CS-205
cs-175 28
cs-175 28
CS-223 28
CS-222 28
cs-175 28
cs-175 28
CS-182 28
cs-182 28
28
28
0971
33
REPLACEABLE PARTS
MODEL 445 DIGITAL PICOAMMETER
MAIN CHASSIS (Cont'd)
CONNECTORS (Cont'd.)
Gil-C"it. rlesig.
51212
51213
---
51214
__-
51215 51216
51217
---
51218
__-
P1202
Description
Receptacle, 22 pins, Range
Mfr.
Mfr.
code Part NO. 09922 PSC 4SS22-12 CS-182
Keithley Part No.
Control Board PC-214 Receptacle, triaxie1, INPUT
95712
Plug, triaxisl, mate of 51213 95712 Receptacle, 50 pins, PRINTER/
02660
33050-2-m-34
30197-l
CS-181 m-141
57-40500-1 CS-221
CONTROL Connector
'Plug, mate of J1214
02660
57-30500-l CS-220
Binding Post, LO 58474 DF21BC BP-11B
Receptacle, 44 pins, Front
09922 PSC 4DD22-12 CS-205
Card of Output Buffer Stage, PC-21Q Binding Post, GND 58474 DFZlGC BP-116
Shorting Link for LO & GND Posts 24655 938-L BP-6
Receptacle, Microphone, ANALOG
02660
SO-PCZF CS-32
OUTPUT
Plug, mate of 51218 (Supplied) 02660 SO-MCZM CS-33 1 pin connector, mete to .I501
80164
CS-185 lx-185
FFg. Ref.
28
3
3
3
28
Circuit
Des&.
TYPe
Mfr. Mfr.
Cade
Part No. PaIT NO. Ref.
Keithley Fig.
L!lZOl Silicon 01295 lN64.5 RF-14 28 D1202 Silicon 01295 lN645 RF-14 28
D1203 Silicon 01295 lN645 RF-14 28 ~1204 Silicon 01295 1~645 RF-14 28 01205 SilkOIl 01295
D1206 D1207
D1208
~1209
01210
DlZll Silicon
D1212
01213 Silicon
D1214
01215 Silicon
D1216 SiliClXl
01217 SiliCOl?
Dl218 Silicon
Silicon 01295
SFliCOlI
Silicon
Silicon
Silicon
01295 01295 01295 01295
02735
Silicon
02735 02735
zener
84970 VR47 01295 113645
01295 02735 02735
1~645
lN645 18645 lN914 lA645
lN3255 lN3255 1133255
1~645 lN3255 IN3255
RF-14 28 RF-14
28 RF-14 28 RF-14 RF-28 RF-14
RF-17 RF-17 RF-17 DZ-30 RF-14
RF-14 RF-17
RF-17
28
28
28
28
28
28
28
28
28
28
28
LAMPS
circuit
Desig. DS1201
Description
Range Changing Pilot Light,
Mfr. Mfr.
Code Part No. Part NO. Ref. 91802 2100 series
Keithley
PL-46
Fig.
2
34
MODEL 445
REPLACEABLE PARTS
MAIN CHASSIS (Cont’d)
RELAYS
~1201(A K1202 (1
8. B) Reed
K1203 ‘1 K1204 PI K1205 ”
K1206
” K1207 ta K12OS ”
circuit oesig.
23430B
PC-207
Mfr. Cade
Relay Reed Relay Reed Relay Reed Relay Reed Relay
Reed Relay Reed Relay
Reed Relay
27682
27682 27682 27682 27682
27682 525-0002 27682 27682
PRINTED CIRCUIT SUB-ASSSMBLIES
Description
Input FET P.C. Board, with components. Polarity P.C. Board, with componenes.
less components.
Mfr.
Part No. 525-0002
525-0002 525-0002 525-0002 525-0002
525-0002 525-0002
Eceithley Part No.
RL-34 RL-34 RL-34 RL-34 RL-34
RL-34 RL-34 RL-34
Fig. Ref.
28 2s 28 2s 28
28 28 28
lceithley Part NO.
23730B
PC-207
22875B
PC-208
PC-209
PC-212
PC-214
PC-217
PC-218
PC-219
PC-229
PC-230
Thousand P.C. Board, with ccqmnents.
Output Suffer P.C. Board, Model 4401, vith components.
less components.
Range Counter/Decoder P.C. Board, with components.
less companencs.
Range Control P.C. Board, with components.
less components.
Oscillator P.C. Board, with components.
less components.
Output Buffer P.C. Board, Model 4401, with components.
leas components.
Integrator P.C. Board, with com,,one”ts.
less componenes.
Readout P.C. Board, with coqmnents.
less components.
Tube & Driver P.C. Board, with components.
less camponents.
PC-208
2287SB
Iv-209
228828
PC-212
22892B
PC-214
22895B
PC-217 230618
PC-218
23065B
PC-219
230bSB
PC-229
23628C
PC-230
23633B
0971
35
REPLACEABLE PARTS
MAIN CHASSIS (Cont'd)
RESWI'ORS
MODEL
445 DIGITAL PICOAMMETER
R1201 R1202 R1203** R1204 R1205
R1206
R1207 R1208 R1209 R1210
R1211
R1212
R1213 R1214
R1215
R1216
R1217
R121S
R1219
R1220
R1221
R1222
R1223
R1224
R1225
Value
10 MO
10 kn
100 kR
15 kn 100 n
18.2 ki, 500 n
18.2 kn
22 kn
4.7 kn
4.7 kfl 680 0
3.3 k0 100 n 470 n
100 R
116.67 il
4.75 kR
1.1667 kfl
11.667 ki7 115
k0
1.15 Mn 10 Mn
1.5 Mn
100 Mil
Rating
l%, l/2 W
20%, 2 w lO%, l/4 w
l%, l/0 W
lO%, l/2 w l%, l/8 w
?20%, 2 w
1%.
1/a w lO%, l/4 w lO%, l/4 w
lO%, l/4 w lO%, l/4 w
lo%, l/2 w lO%, 2 w lO%, 2 w
lO%, l/2 w O.l%, 1 "
l%, l/2 w O.l%, 1 w O.l%, 1 w
l%, l/2 w
l%, l/2 w
l%, l/2 w
l%, l/2 w
l%, 2 w
Mfr.
Type DCb
Code
91637 WWVtW 71450 camp
MfF
camp
MW
Cermet
MtF
camp
07716
01121
07716
71450
07716
44655
COl"p 44655 camp
COIBP COlllp COtlIP CO¶V
COtlIP
ww
MU WI?
ww
MtF Mm
DCb DCb
DCb
44655 44655
01121
01121
01121
01121
01686
07716 01686 01686
07716
07716
91637
91637 91637
Mfr.
PBrt No. DCF-l/2
INS 115 CEA
EB CEA
551 CEA RC07
RC07
RC07
RC07 EB
HB HB
EB
7040
CEC
7040 7040
CEC CEC DCF-l/2 DCF-l/2 DC-2
Keithley
Part No. RlZ-10M
RPSO-1OK
R88-15K
Rl-100 R88-18.2K
RP72-500 R88-18.2K R76-22K R76-4.7K
R76-4.7K R76-680 Rl-3.3K R3-100 R3-470
Rl-100 R70-116.67 R94-4.75K R70-1.1667K R70-11.667K
R94-115K
R94-1.15M RlZ-10M RlZ-1.5M
R14-100M
Fig. Ref.
28 28
28 28
28
28 28 28 28
28
28
28 2s
28
28
28
28 28
28
28
2s
28
2s
28
R1226 R1227
R1228 R1229
R1230
R1231 R1232 R1233 R1234
R1235
R1236 R1237
R1238
circuit
Desig. s1201
-_-
51202
S1203 S1204
15 lm 109 n
4.75 kR 250 kfi
5 kO
50 kfl 500 kfl
560 0
1 k0 1 kn
249 kiZ 500 kfl
1 kR
l%, 1 w +3-O%, l/R W l%, l/2 w ?20%, 2 w 20%, 2 w
220%, 2 w *20%, l/4 w
10%. l/2 W
20%, 2 w 20%, 2 w
lO%, 112 W
120%, 114 w 20%, 2 w
DeSCriptiO"
Rotary Switch, FILTER
Knob Assembly, Filter Switch Toggle Switch, RANGE 10-2/DOWN
Toggle Switch, RANGE HOLD/AUTOMATIC Toggle Switch, ZERO cHEcK/OPmATE
DCb GCb MtF
C~~llWt
wvar
91637 80164 07716
71450 71450
CetXEt 71450 CbVar COIl?p
71450
0,1121 WW"X 71450 WWVU
MtF
CbVar
wwvar
SWITCHES AND CONTROLS
71450
07716
71450 71450
DC-1
230928 CEC 550 INS 115
550
Type-45
EB INS 115 INS 115
CEC GC45 INS 115
Mfr.
R13-15M
230928 R94-4.75K RP79-250K AP50-5K
RP74-50K RP73-500K Rl-560 RPSO-1K
RPSO-1K
R94-249K
RP75-500K
RPSO-1K
Keithley
Code Part No.
80164
SW-280
80164 209338 80164 80164 80164
SW-277
w-236
88-236
28 28 28 28 28
28 28 28 28 28
28 28 28
Fig.
Ref.
2
2 2 2
** R1203 is part of FET I"p"t Card
36
0971
MODEL 445 DIGITAL PICOAMMETER
REPLACEABLE PARTS
MAIN CHASSIS (Cont'd)
SWITCHES AND CONTROLS (Cont'd.)
circuit
Desig. 51205
Rotary Switch, DISPLAY RATE (see
Description
also R1237)
-._ __-
circuit Desig.
QlZOl** Q1202**
Knob Assembly, Display Rate Control Screwdriver Adjust potentiometer,
ZERO
ADJUST
(81207)
Mfr. Code
80164 80164
Q1203 07263 Q1204 07263 Q1205 04713
41206 71279
**Transistors Q1201 and Q1202 are matched
TRANSISTORS
Mfr.
Part NO.
S17638 S17638 2133904
ES-5321
POWER SUPPLY PARTS LIST
("100" Series, PC-221)
CAPACTTORS
Mfr.
Keithley Fig.
code Part NO. Ref.
71450 RP75-500K 2 80164 71450 RPSO-1OK
Keiehley Part NO.
2 2
Fig. Ref.
28
28 TG-33 TG-33 TG-47
TG-54
28
28
2s
28
Keithley Part No.
C93-ZOOOM czz-11OOP
Fig. Ref.
28
28 C22-150P 28 C177-ZOOM 28 C177-ZOOM 28
C177-ZOOM 28 C177-ZOOM 28 C179-1.2l.l 28 C22-5P 28 C3-125M
C3-125M C173-15M
2s
28
28 C94-500M 28
Value klti*g
Cl01 Cl02 Cl03 Cl04 Cl05
Cl06 Cl07
2000 fl
100 pF
150 pF 200 pF 200 fl
200 p 200 @J
Cl08 1.2 pE Cl09 Cl10
Cl11 Cl12
Cl13 Cl14
5 PF
125 ,iF 15 v ETB 73445 C42b
125 (IF
15 pF 500 plJ
68 PF
Mfr. Mfr.
Type
15 v
600 " 600 V 35 v 35 v
35 v
EAl Ce?Sl CerD EAl EAl
BAl
35 " EAl 20 " ETT
Code
72982
72982
90201
90201
90201 90201 MTVZOON35PDN 17554 TSDl-20-125
Pat-t No. 36-750-ZOOO-15C
ED-100
ED-150 MTVZOON35PDN MTVZOON35PDN
MTVZOON35PDN
600 V CerD 72982 ED-5
15 v
300 v 25 V
ETB 73445 C42b
EAl
90201 PTC-015-N-300-P-3-E
EAI 56289 89D234
DIODES
CiX”it
Deeig.
‘fw
Mfr. Code
Mfr. Pare NO.
Keithley
Fig.
Part N". Ref.
DlOl Silicon 13327 1134139 RF-34 28
0102 Silicon 13327 lN4139 RF-34 28 Ill03 Silicon 01295 lN645 RF-14 28 0104 Silicon 01295 lN645 RF-14 28
D105 SiliCO" 01295 lNb45 RF-14 28
0106 SiliCO" 01295 lN645 RF-14 28
II107 Silicon 01295 lN645 RF-14 28
0108 Silicon 01295 lN645 RF-14 28
D109 Silk"" 01295 lN645 RF-14 28
DllO zener 04713 lN936 m-5 28
0971
37
REPLACEABLE PARTS
MODEL 445 DIGITAL PICOAMMETER
POWER SUFTLY (Cont'd)
DIODES (Cont'd.)
CirCUit maig.
Dill 0112 D113
CitXUit
msig. FlOl (117V)
FlOl (234V)
--_
PI01
SlOl 5102
TlOl
Type
Silicon Silicon Silicon
Mfr.
Code 02735
01295
01295
Mfr.
Part NO.
183255 113645 lN645
MISCELLANEOUS PARTS
Mfr.
Mfr.
Description Code Part No. Part NO. Ref.
Fuse, slow blow, 3/8 A
71400
Type
MDL Fuse, quick acting, zoom.4 75915 361.200 FU-24 Fuse Holder 75915
Cord Set, 6 feet
Slide Switch, 117-234V Toggle Switch, POWER
Power Transformer
93656
80164 80164
80164
342012 FH-3
4638-13
SW-151 SW-265 SW-265
TR-114
RESISTORS
Value
Rating
TYPO
Mfr.
Code Part NO. Part No. Ref.
Mfr.
Keiehley
Part NO. RF-17
RF-14 RF-14
Keithley Fig.
FU-18
co-5
SW-151
TR-114
Keithley
Fig. Ref.
28 2s 28
3 3
3
I3
2
19
Fig.
RlOl 6.8 kC R102 R103 R104
RI05
0.2 n *lo%, 4.25W TCU 10 kC
1.1 kR 1 kR lO%, l/4 W camp 44655 RCO7
R106 100 n R107
RlOS RI09 RI10
Rlll
150 a 33 kC 30 l%, l/2 W 680 a
3.3 kfl
lO%, l/4 w CCX&P 44655 l%, l/8 W Mm
l%, l/S W MtF
l%, l/S w l%, l/8 W
MtF MtF
lO%, l/4 W
DC%
lO%, l/4 W
COlllP
IO%, l/4 w R112 4.7 kfl 10%, l/4 w R113 3.3 kR R114 R115
R116
R117
4.75 k0 2 kR
8.06 kC 15 kC lo%, l/4 w COlllp
RllS 7.5 kC l%, l/8 W
lO%, l/4 w
l%, l/8 w
20%, 2 w
l%, l/8 W MW
MtF R119 33 kR lO%, l/4 w COUV R120
R121 R122 RI23 R124 RI25
RI26
3n 33 kR
33 kC
7.32 kR 82 n 1 Mn
100 k0 RI27 56 kfi R128 80.6 kR
l%, l/2 w lO%, l/4 w
lO%, l/4 W l%, l/8
W
lO%, l/2 w lO%, l/4 w
lO%, l/4 w IO%, l/4 w 1%. l/2 w
DCb
camp
MtF-
camp camp
camp
91637 CW-2 R151-0.2
x07 R76-6.8K
07716
CEA
07716 CEA
R88-10K R88-1.x
28 28 28 28
R76-1K 28
07716 07716 44655 91637
CEA CRA RC07 R76-33K DCF-l/2
44655 RCO7
44655
RC07 R76-3.3K
44655 RC07 R76-4.7K
R88-100 28 RES-150
28
28 RlZ-3 28 R76-680 28
28
28
44655 RCO7 R76-3.3K 28
07716 CEA REE-4.75K
71450 INS 115 RP50-2K 07716 CEA RES-8.06K
44655 RC07 R76-15K 07716 CEA REE-7.5K 44655 RC07
R76-33K
91637 Lxx-l/Z RlZ-3 44655
44655 07716 CEA 01121 44655 RC07
44655 RCO7
RC07 R76-33K
RC07 R76-33K
R88-7.32K
EB
Rl-82
R76-1M
R76-l00K 44655 RC07 R76-56K 07716
CRC R94-80.6K
28 28
28 28 28 28 28
28 28 28 28 28
28
2s
28
0971 38
MODEL 445 DIGITAL PICOAMMETER
REPLACEABLE PARTS
POWER SUPPLY (Cont'd)
RESISTORS (Cont'd.)
circuit Desig.
R12Y R130
F.131 R132 R133
"8lW Rating
7.32 kn l%, l/8 W
1.5 kR 1 kn
lo%, l/4 W
lO%, l/4 w 12 k12 lO%, l/4 w 10 kn lO%, l/4 w
TYW MW
cow COUlP
COUlP camp
Mfr. Mfr. Code Part NO. Part NO. Ref.
07716 CBA K88-7.32K 44655 KC07
44655
RC07 44655 RC07 R76-12K 44655 KC07 R76-10K 28
Keithley Fig.
28
~76.1.5K 28
R76-1K
28 28
TRANSISTORS
CirC"it Desig.
q101 q102 "103 a104 Q105
Q106 07263 QlO7 02734 QlO8 07263 q109 07263
QllO
Mfr. Mfr.
Code
Part No.
2N3565 40317 2133565 2N3565
07263
S1763S
Keithley Fig.
Part NO.
TG-68 lx-54 z-39 TG-39 TG-33
TG-39
Ref.
28 28 28 28 28
28 TG-43 28 m-39 28 m-39 28 TG-33 28
Qlll 02734 40319 TG-50 28 q112 07263 517638 TG-33 28 Q113 07263 517638 TG-33 2s q114 07263 2N3565 x-39 28 q115 07263 2N3565 x-39 28
Q116 07263 517638 u-33 28 Q117 07263 S17638
q11*
4119
02735 40346 x-44 28 02735 40-346
TG-33 28
TG-44 28
Ql20 07263 2N3565 TG-39 28
POLARITY BOARD PARTS LIST
("200" Series, X-207)
CAPACITORS
Circuit
msig. C201
"EllW Rating
150 PF 600 " CerD 72982
TYV=
INTEGRATED
Circuit tlesig.
QA201
QA202 quad 2 Input Gate 04713 MC724P IC-5 20 qA203 Quad 2 Input Gate 04713 MC724P IC-5 20 QA204 qua* 2 Input Gate 04713 MC724P ic-5 20 QA205 Quad 2 I"p"t Gate 04713 MC724P K-5 20
qb.206
QA207 Dual 3 InpUt suffer, non-inverting 04713 MC788P IC-6 20
Dual J-K Flip-Flop
Dual J-K Flip-Flop 04713
Description
.wr.
Mfr.
Cc& Part NO. Part NO. Ref.
ED-150 C22-15OP 20
CIRCUITS
Mfr. Mfr. Keithley Fi,S.
Code Part NO. Part NO. Ref.
04713
MC79OP n-8
MC790P IC-8
Keithley
Fig.
20
20
0971
39
REPLACEABLE PARTS
MODEL 445 DIGITAL PICOAMHSTER
POLARITY BOARD (Cont'd)
LAMPS
circuit Deaig.
DS201
cirlxit
DeSig.
R201 R202 R203 R204
circuit uesig.
Q201 Q202
circuit Desig.
Description
tpolarity Pilot Light
Value
270 C
2.2 kC
1.5 kR
1.5 kC
RattIll:
10%, l/4 w lO%, l/4 w lO%, l/4 w lO%, l/4 w
Mfr. Code
02735 02735
Description Code
Mfr.
Code
91802
RESISTORS
Mfr.
Type COlllP
COUIP
COUIP COUIP
Code
44655 44655 44655 RC07 R76-1.5K 20 44655
TRANSISTORS
Mfr.
Part No. 2N5184
2N5184
THOUSAND BOARD PARTS LIST
("300" series, PC-208)
INTEGRATED CIRCUITS
Mfr.
Mfr.
Part No. 2330 Series
Mfr.
Part No. Part No. Ref. RC07 R76-270
RC07 R76-2.2K 20 RC07 R76-1.5K 20
Mfr. Keithley Part No. Part NO. Ref.
Keithley Part NO.
TG-67 TG-67
Keithley
Part NO. PL-43
Keithley
Fig. Ref.
20
Fig.
20
Fig. Ref.
20
20
Fig.
QA301 QA302 QA303 QA304
Cil?C"i+Z rlesig.
R301 R302
circuit Desig.
Q30
Dual J-K Flip-Flop
Dual J-K Flip-Flop
04713 04713
MC79OP MC79OP IC-8
Ouad 2 positive logic Nor Inpur Gate 04713 MC724P
Hex 1nverter
04713
MC789P
LAMPS
Description
Mfr.
Code Part NO.
Mfr.
Pilot Light, front panel thousands tube 80164 PL-42
RESISTORS
Value
1.5 kfl 100 kC
Rating
lO%, l/4 w lO%, 1 w
Type COtlIP
COlllp
Mfr.
Code Part NO. Part NO. Ref. 44655 RCO7
01121
Mfr.
GB
TRANSISTORS
Mfr.
Code 02735
Mfr.
Part No.
2N5184
Keithley
Part No. TG-67
IC-8
21
21 IC-5 IC-7
Keithley
21 21
Fig.
Part NO. Ref.
PL-42 21
Keithley Fig.
R76-1.5K
RZ-100K
21 21
Fig. Ref.
21
40 0971
MODEL 445 DIGITAL PICOAMMETER
REPLACEABLE PARTS
RFADOUT BOARD PARTS LIST
(“400” Series, PC-229)
CONNECTORS
circuit Desig.
P401 P402
CiK"it msig.
QA401 QA402 QA403 QA404
QA405
QA406 QA407 QA408 QA409
QA410
QA411 QA412 QA413 QA414 QA415
QA416 QA417
DeSCt+tiO" Code mug, 6 pins, connects to 51206 Plug, 22 pins, Connects to J1207 73690 02-015-105-6-200
DeSCripCiO"
Dual J-K Flip-Flop Dual J-K Flip-Flop Dual J-K Flip-Flop Dual J-K Flip-Flap Dual J-K Flip-Flop
Dual J-K Flip-Flop Quad 2 Input Gate Quad 2 Input GBL~ Dual J-K Flip-Flop Dual J-K Flip-Flop
Dual J-K Flip-Flop Dual J-K Flip-Flop Dual J-K Flip-Flop Dual J-K Flip-Flop Decimal Decoder/Driver
Decimal Decoder/Driver Decimal Decoder/Driver
Mfr. Mfr.
73690
INTEGRATED CIRCUITS
02-006-105-6-200
Mfr. Code
04713 04713 04713 04713
04713
04713 04713 04713 04713 04713
04713 04713 04713 04713 07263
07263 07263
Part NO.
Mfr.
Part NO.
MC791P MC791P MC791P MC79OP IC-8
MC790P
MC79OP IC-8 MC724P MC724P IC-5 MC79OP “C790P
MC79OP MC79OP MC79OP MC790P U6B996079X
U6B996079X
U6B996079X n-3
Keithley
Part NO. c-223 a-222
Keithley Part NO. Ref.
IC-9 IC-9 IC-9
IC-8
U-5 IC-8
IC-8 IC-8
IC-8
K-8 E-8 xc-3
E-3
Fig!.
Ref.
29
29
Fig.
29 29 29 29 29
29 29 29 29 29
29 29 29
29
29 29
29
READOUT TUBES
CirCUie
Desig. v401
“402 v403
Value
R401 10 ksl 5%, l/2 w COlllp
~402 10 kn 5%, l/2 w R403 10 kn 5%, l/2 w
Circuit Desig. Rating
c501 .0022 c502 ,001 pF 100"
c503 4.5-25 pF 500" c504 22 pF 500" c505 470 pF 600”
Description
"nits Readout Tube Tens Readout Tube Hundreds Readout Tube
Rating
p
100"
OSCILLATOR BOARD PARTS LIST
("500" Series, W-217)
POlY 13934 E3FR-222-1-C C152-.0022M P"ly 13934 E3FR-222-1-C C152-.OOlH 25 cer Trimmer 71590 82282 C76-4.5-25P 25
Mica 84171 DM15-220J c21-22P 25
CerD 72982 ED-470 CZZ-470P 25
Mfr. Code
80164 80164 80164
RESISTORS
TYP
COUlP 01121 EB R19-10K 29 COtlIP
CAFWITORS
Mfr. Part NO. Part ND.
___
-__ _-_
Mfr. Code Part NO.
01121 EL3
01121 E" R19-10K 29
Mfr. Mfr. Keithley Code
Mfr.
ParI2 NO. Part NO. Ref.
Keithley
E”-841 29 E”-841
E”-841
Keithley Pal-t NO. Ref.
R19-10K 29
Fig. Ref.
Fig.
Fig.
29 29
25
0971
41
REPLACEABLE PARTS
OSCILLATOR BOARD (Cont'd)
CAPACITORS (Cant'd.)
MODEL 445
DIGITAL
PICOAMMETER
Cil-CUit Desig.
C506 c507 C508
Circuit
Desig. D501
D502 0503
J501
QA501 QA502
y501**
Value 220 pF 600"
4.7 tlF 2OV 10 P 2ov
Diode, Silicon, lN645 01295 RF-14 25 Diode, Silicon, lN645 01295 RF-14 25 Diode, Silicon, lN914 01295 RF-28 25
Varicon Contact 73690 02-001-113-6 m-224 25 Quad 2 positive logic Nor Input Gate
Quad 2 positive logic Nor Input Gate Crystal, 60 Hz 80164 CR-1 CR- 1 25
Rating
Type
CerD 72982 ED-220 czz-22OP 25 ETT 05397 K4R7JZOK CEO-4.7M 25 ETT 17554
MISCELLANEOUS
Description Code Part NO. Pat-t No. Ref.
Crystal, 50 HZ 80164 CR-2 CR-2 25
RESISTORS
Circuit Desig. Value Rating Type
R501 3.3 ksl
R502
33 kfl R503 68.1 0 R504 4.99 k!l R505
1 kfi
lO%, l/4 w C‘XIIP 44655 RC07 R76-3.3K lO%, l/4 w COlDp 44655 RC07 R76-33K l%, l/8 W I%, l/8 W
MtF 07716 MW
lO%, l/4 w COUlP 44655 RC07
Mfr.
Mfr.
Keirhley
Code Part NO. Part NO.
TSD2-‘JO-106
Cl79-IOM 25
PARTS
Mfr. Mfr.
04713 04713
Mfr.
Code Pare NO. Part NO. Ref.
MC724P U-5 MC724P IC-5 25
Mfr.
CEA
07716
CEA
Keithley Fig.
Keithley Fig.
R88-68.1
R88-4.99K R76-1K
Fig. Ref.
25
25 25 25 25 25
R506 R507
1 kR
1 kR
lO%, l/4 w
l%, l/8 w
R508 470 a lo%, l/4 W R509 4.7 k0 lO%, l/4 W R510 56 kfl
R511 4.7 k0 R512 470 n R513 680 0 ix514 470 R R515 237 n
R516 1 kfl R517 4.99 kfi
R518 56 kfi R519 237 0 R.520 3.3 kG.
R521 6.8 k0 R522 1.5 kfl R523 1 kfi R524 1 kR R525 10 kfi
R526 1 kn R527 3.9 k0 R528 3.9 kR
R529 330 a R530 1.5 kn
lO%, l/4 w
lO%, l/4 IJ
lO%, l/4 iJ
10%) I/ 4 w
lO%, l/4 w
l%, l/8 w
l%, l/8 W
l%, 118 W
lO%, l/4 w
l%, l/8 W
IO%, l/4 w
lO%, l/4 w
lO%, l/4 w
lo%, l/4 w
lO%, l/4 W
lO%, l/4 w
lO%, II4 w lo%, 114 w lo%, l/4 w IO%, l/4 w
lO%, l/4 w
COlllP 44655
MtF
07716 CCXUP 44655 COl?lP
COtlIp
44655
44655 COmp 44655
C‘Xlp 44655 COlllP 44655 COlilp 44655 MW 07716
MtF 07716
MC? 07716 COUIP 44655 MtF 07716 COUtP 44635
camp 44655 COUIP 44655
camp 44655 c olnp 44655 COmp 44655
CLXV 44655 COtlIp 44655
COUIP 44655
COmp 44655
COtlIp 44655
RC07 CEA
R76-1K
R88-1K RC07 R76-470 RC07
X76-4.7K
KC07 R76-56K RC07 R76-4.7K
RC07 R76-470
RC07
R76-680 RC07 R76-470 CEA
CEA CM
R88-237
Rfm-1K
R88-4.99K RC07 R76-56K
CEA
R88-237
RC07 R76-3.X
RC07
R76-6.8K
RCO7 R76-1.5K RC07 R76-1K RC07 R76-lK RC07
RC07 RC07
R76-10K
R76-1K
R76-3.9K
RC07 R76-3.9K RC07 RC07
R76-330 R76-1.5K
25 25 25
25
25 25
25 25 25
25 25
25 25
25 25
25 25 25 25 25
25 25 25 25 25
42
0971
MODEL 445 DIGITAL PICOAMMETER
REPLACEAULE PARTS
OSCILLATOR BOARD (Cont'd)
RESISTORS (Cont'd.)
circuit
Desig.
R531 R532 R533
R534 R535
Value
5.6 k0
4.7 k0 10 0
1.5 Id7 1 kn
R536 47 n K537 K538
circuit oesig.
33 n
4.02 k0 l%, l/8 W MU 07716
Q501 Q502 4503 Q504 Q505
Q506 Q507 Q508 Q509 4510
Q511 Q512 Q513 Q514
Kating
lo%, l/4 w lo%, l/4 w lo%, l/4 w lO%, l/4 w l%, l/S w
lO%, l/4 w lO%, l/4 w
Mfr.
Code
07263 07263 07263
07263 07263
07263 07263 07263 07263 07263
07263 07263 07263 03508
Mfr. Mfr.
Type camp
camp camp camp MCF
CO"p camp
Code 44655 x07 R76-5.6K 25
44655
RC07 R76-4.X 25 44655 RC07 R76-10 44655 07716
RC07 K76-1.5K 25
CEA 44655 KC07 R76-47 25
44655
RCO7
CEA
Mfr. Keithley
Part NO. Part NO.
2N5134 'X-65 2N5134 Z-65 2N5134 m-65 2N5134 X-66 2N5134 X-65
m5p9 W-66 2N5134 X-65
2N5139 W-66 2N5134 W-65 2N5134 TG-65
2N5134 TG-65 2N5134 TG-65 2N5134 W-65 2N2646 m-52
Keithley
Fig.
Part NO. Part NO. Leaf.
25
K88-1K
K76-33
25
25
R88-4.02K 25
Fig.
Ref.
25 25 25 25 25
25 25 25 25 25
25 25 25 25
C601 C602 C603 C604 C605
C606 C607 C608 C609 C610
C611 C612 C613 C614
Value Rafing
100 pF 600V 10 pF 5oov
0.082 @ 1oov 10 @J 2ov
220 pF 600~ 220 pF 600V
.0047 ,lF 600V
0.1 I*F 250v 10 w 2OV
22 pP 1000"
0.1 I*F 250V 10 ,.F 2ov 10 ,lF 2ov
22 ,9 1ov
INTEGRATOR
("600" Series, PC-219)
BOARD PARTS LIST
CAP*CITORS
Mfr.
TYW
Code
cero 72982 ED-100
Mfr.
Keithlfy
Part NO. PaIT NO.
C22-1OOP 27 Poly 71590 cm-1OJ C138-LOP 27 l%ly 13934
E3FR-222-1-C ETT 17554 TSDZ-20-106 CeHl 72982 ED-220
cero 72982 ED-220
CerD 72982 ED-.0047
73445 C280AEfPlOOK
ETT 17554 TSiX-20-106
certl 56289 56AQ22
73445 C280AED100~
C152-.082M 27 C179-10M 27 czz-22OP 27
CZZ-22OP 27 CZZ-.0047M C178-.lM 27 C179-10M c72-22P
c17z3.m 27 ETT 17554 TSDZ-20-106 C179-10M 27 ETT 17554 TSDZ-20-106
ETT 17554 TSDZ-10-226
C179-10M 27
C180-22M
Fig. Ref.
27 27
27
27
0971
43
REPLACEABLE PARTS
MODEL 445 DIGITAL PICOAMMETER
INTEGRATOR BOARD (Cont'd)
circuit
Desig.
0601 0602 0603 D604 0605
D606 0607 ~608 D609 ~610
Type
7.ener
7.ener Silicon Silicon
Silicon
Silicon SiliCOll Silicon Silicon Silicon
Mfr. Mfr.
Code Pa-C No. 04713 lN936
04713 07263 07263 2N3565
01295 lN645
01295 01295 01295 01295 01295
0611 Silicon 01295 0612 SiliCCXl 01295 D613 Silicon 01295 D614 SiliCO" 01295 0615 Silicon 01295
INTEGRATED CIRCUITS
Description
QA601 QA602 QA603 QA604
Integrated Circuit
Integrated Circuit High Speed Differential Comparator Quad 2 InPUt Gate
DIODES
Keithley
Fig.
Pat-t NO. Ref. m-5 27
18936
2N3565
DZ-5 27 w-39 27 TG-39 27
RF-14 27
1~645 lN914 lN914 lN645 lN645
lN645 lN645
lN914
lN914 lN645
Mfr.
Code
Mfr.
Part NO.
RF-14 27 RF-28 27 RF-28 27 RF-14 27 RF-14 27
RF-14 27 RF-14 27
RF-28
27 RF-28 27 RF-14 27
Keifhley Part NO.
Fig. Ref.
12040 LM-201 xc-2 27
12040 m-201 x-2 27 07263 04713
65B771039X
MC724P
IC-4
IC-5
27
27
CilTUilZ Desig.
~601
R606 R607 ~608 R609
~610
R613 R614
R615
R616
R617
R618
Ml9
R620
R621
R622
R623 4.7 kfi R624 49.9 kfi R625
Value Rating
10 lin 10%. l/4 W
10
kfl
*
7.5 kil
7.5 kfi
7.5 k*
Not Used
499 0
49.9 ksl 680 C?
680 fi 33 kR
4.7 kIl 33 kn
4.7 kn
4.7 k*
l%, l/S w I%, l/8 W l%, l/S w
l%, l/8 l%, l/S w
lO%, l/4 w lo%, l/4 w
lO%, l/4 w 1056, l/4 w lO%, l/4 w
lO%, l/4 w 10%. l/4 w
10%; l/4 w l%, 1/a w
100 kO lO%, l/4 w
* Nominal value, factory selected.
..,
W
RESISTORS
Mfr.
Type Code corn
44655 MtF' 07716 MtF 07716
MtF MU
07716
07716
cermet 73138
MfF 07716
Mm 07716
MtF 07716 MW 07716
i%L%let 73138 COtlIp
44655
MtF 07716 MtF 07716
camp 44655 camp 44655
COUlp 44655 camp 44655 COlllp 44655
COtlIP 44655
COWI 44655
COIMP 44655 MtF 07716
COllp 44655
RC07 CEA
CEA
CEA CEA
77PRlOK CEA cm
CEA CEA
77PRlOK
RCO7 CEA
CEA
RC07 RCO7 RC07 ix07 RC07
RC07 RCO, RC07
CEA
RC07
Keiehley
Par? No.
R76-10K
R88-*
R88-7.5K
R88-7.5K
R88-7.5K
RP64-1OK R88-*
Fig.
Ref.
27 27 27 27 27
27
27 R88-7.5K 27 RS8-7.5K
27 R88-7.X 27
RP64-10K
27
R76-10K 27
R&x3-499 27 R88-49.9K 27
R76-680 27 R76-680 27 R76-33K 27 R76-4.7K 27 R76-33K 27
R76-4.7K 27 ~76-4.7K 27 R76-4.7K 27
R88-49.9K
2.
~76-1OOK 2,
44
0971
MODEL 445 DIGITAL PICOAMMETER
REPLACEABLE PARTS
RANGE COUNTER/DECODER BOARD (Cont'd)
INTEGRATED CIRCUITS (Cont'd.)
Circuit wsig.
qA804 QA805
QA806 QA807 QA808
QAEOV
QASlO
Description
Triple 3 Input Gate 04713 Triple 3 Input Gate
Dual 4 Input Gate ma1 4 Input Gate 04713
Hex 1lwereer 04713
Dual J-K Flip-Flop 04713 Dual J-K Flip-Flop 04713
TUBE
& DRIVER BOARD PARTS LIST
Mfr. Mfr.
code
Part NO. Part NO.
MC792P
04713
MC792P IC-10
Keithley Fi.S.
IC-10
04713 MC725P U-11
W725P
IC-11 MC789P IC-7 MC79OP
EC-8 23 MC79OP IC-8
("900" Series, W-230)
CAPACITORS
Circuit Desig.
CVOl CVO2 c903 c904
Value Rating
2.2 p
1.2 $@
1.2 UF
2ov ETT 2ov ETT 2ov ETT
1.2 ;IF 2ov
c905 1.2 p 20"
TYPO
ETT ETT
Mfr. Mfr. Code Part No.
Keithley
PBCC No. Ref.
17554 TSDl-20-225 C179-2.2 pF 17554 TSDl-20-125 c179-1.2 )LJ 17554 TSDl-20-125 C179-1.2 UF 17554 TSDl-20-125 17554 TSDl-20-125
c179-1.2 I*F C179-1.2 p.F
C906 1.2 p 2ov ETT 17554 TSDl-20-125 c179-1.2
CONNECTORS
circuit
msig.
Description
Mfr. Mfr.
Code Part No.
Keithley Part No.
I~~~
iJE
Ref.
23 23
23 23 23
23
Fig.
30 30 30 30 30
30
Fig. Ref.
.I901 5902 5903 5904 305
5906 5907 J908 .I909
circuit Desig.
qA901
QA902 QA903
Circuit Llesig.
"901
contact Pin
contact Pin contact Pill contact Pi" contact Pill
contact Pin contact Pill Contact Pin contact Pill
Description
Quad 2 Input Gate
Quad 2 Input Gate quad 2 input. Gate
80164 IX-69 80164 TE-69 80164 TE-69 80164 TE-69 80164 TE-69
80164 TE-69 80164 m-69 80164 m-69 80164 TE-69
W-69 m-69 TE-69 IT-69 TE-69
TE-69 TE-69 m-69 TE-69
30
30 30 30 30
30
30 30 30
INTEGRATED CIRCUITS
Mfr. code
04713 04713 04713
Mfr.
Keithley
Fig.
Part No. Part No. Ref.
~c724P x-5 30 m724P IC-5 30 MC724P IC-5 30
READOUT TUBES
Mfr. Mfr.
Keithley
Fig.
Code Part NO. Part NO. Ref.
80164
_--
E"-841
30
47
REPLACEABLE PARTS
MODEL 445 DIGITAL PICOAMMETER
circuit Deal.*.
R901 R902
R903 R904
R905
R906 R907 R908 R909
Value Raring Type
820 0 820 n 820 0 lo%, l/4 w 820 0 820 0
820 ~7 820 iI 820 0 22 k0
R910 820 0 R911 820 a
R912
820 R R913 820 0 R914 820 a R915 820 0
R916 820 52
R917 R918
560 0
1 k$l R919 1.5 kfl R920 1.5 k0
R921 1.5 kR R922 1.5 kR
8923 1.5 kf, R924
560 0
TUBE & DRIVER BOARD
RESISTORS
lO%, l/4 w camp IO%, l/4 w
camp Camp
lO%, l/4 w
Camp
lO%, l/4 w ccmp lO%, l/4 w
lO%, l/4 w
lO%, l/4 w
5%, l/2 w lO%, l/4 w
lo%, l/4 w
lo%, l/4 w lO%, l/4 w lo%, l/4 N lO%, l/4 w
lO%, l/4 w lo%, l/4 w lO%, l/4 w
lO%, l/4 w
lO%, l/4 w lO%, l/4 w
lo%, l/4 w lo%, l/4 w lO%, l/4 w
Comp 44655 RC07 Camp
COltlP
camp 01121 Camp 44655 RC07 R76-820
COUlp
COlUp COllp CLXIlp COttIP
camp Camp COTOP COllp camp
Camp Camp CLXtlp COmp
(Cant'd)
Mfr. Mfr. Code
44655
Part NO.
RC07 R76-820 44655 RC07 44655 RC07 44655
RC07 R76-820 44655 RC07
44655 RC07 44655 RC07
Keithley
Pat-t NO.
R76-820
R76-820 R76-820
R76-820
R76-820 30 R76-820 30
EB R19-22K
44655 RC07 R76-820 44655 RC07
R76-820 44655 RC07 R76-820 44655 44655
44655 44655 44655 RC07
44655
44655 RC07 44655 RC07
44655 RC07 44655 RC07 44655
RC07 RC07
RC07 RC07
RC07
RC07
R76-820
R76-820
R76-820
R76-560
R76-1K
R76-1.5K
R76-1.5K
R76-1.5K
R76-1.5K
R76-1.5K
R76-560
Fig.
Ref.
30
30
30 30
30 30
30 30
30 30 30 30 30
30
30
30 30
30
30
30 30 30
circuit
IMsig. q901
q902 q903
4904 Q905
Q906 Q907 9908 q909
q910
Q911
q912
0913
6914
Q915
Q916
Mfr.
Code 02735
02735 02735 02735 02735
02735 02735 02735 04713
04713
04713
04713
04713
04713
04713
04713
Mfr.
Pare NO.
2N5184
2N5184 2N5184 2N5184 2N5184
2N5184
Keith&
Part NO. W-67
TG-67
TG-67
TG-67
TG-67
TC-67 2N5184 Z-67 2N5184 2N3904
X-67
TG-47 2N3904 TG-47
2N3904 2N3904 2N3904
lx-47 TG-47
TG-47 2N3904 TG-47 283904 x-47
2N3904 TG-47
MODEL 4401 OUTPUT BUFFER BOARD PARTS LIST
("1000" Series, PC-218)
On schematic diagram 234571) there are 15 buffers labeled 'A' through 'P' not including 'I'. Each buffer is composed of 4 resistors and 3 transistors.
left hand corner of the schematic.
Pollowing is a sample replaceable pares list for each buffer.
A sample buffer circuie is given in the lower
buffer.
Fig.
Ref.
30 30 30 30
30 30 30
30
30 30 30
30 30 30 30 30
30
48
097j
MODRL 445 DIGITAL PICOAMMETER
REPLACEABLE PARTS
BUFFER RESISTORS (A thru P)
Circuit Desig.
RlOOl 81002 R1003 R1004
CiPZUit Desig.
QlOOl Q1002
q1003
CirC"lf Desig.
Cl101
Cl102 Cl103 Cl104 Cl105
Value
180 kn
3.9 kfl 120 kG 10 kfl
value
.OOl @ .0033 @F .OOl @
0.1 @ 100 pF
Mfr.
Raring Type Code
lo%, l/4 w COltlp 44655 lO%, l/4 w lO%, l/4 w camp
COtlIp
44655 RC07 R76-3.9K 44655 RC07 R76-120K 26
Mfr.
Part No. Part
Keithley
No.
RC07 R76-180K
lO%, l/4 w camp 44655 RC07 R76-10K 26
SW'FER TRANSISTORS (A thru P)
Mfr. Mfr.
Code 07263
07263
Part No. 2N3565
2N3565
07263 2N3565
Keithley
Part
No.
TG-39 TG-39 TG-39
MODEL 4401 OUTPUT BUFFER BOARD PARTS LIST
("1100" Series, PC-209)
CAPACITORS
Rating 600V
600" 600" 250V 600V
Type Code
Mfr.
cem
72982 cem 72982 CerD 72982
73445 CerD 72982
Mfr.
Part No.
ED-.001
ED-.0033 ED-.001 C280AEIPlOOK ED-100
Keiehley
Part NO. Ref.
CZZ-.OOlM
CZZ-.0033M C22-.oom
C178-O.lW c22-1OOP
Fig. Ref.
26 26
Pig. Ref.
26 26 26
Fig.
22 22 22 22 22
Cl106 Cl107 Cl108
Cl109 ClllO
100 pF 470 PF 470 PF
22 P 10 ilp
600V 600V 600V 1OV 2ov
CerD 72982 CerD 72982 CerD ETT 17554 ETT
INTEGRATED CIRCUITS
Cik-C"iC Desig.
QAllOl QA1102
RESISTORS
circuit msig. Value Type
RllOl R1102 R1103 R1104 R1105
R1106 R1107 R1108 RI109 RI110
1 kfl
3.3 kR 1 kR
3.3 kfi
120 kn 10 kn
180 k0
2.2 k0 1 kR 10 k0
lO%, l/4 w lO%, l/4 w lO%, l/4 w lO%, l/4 w lO%, l/4 w
lO%, l/4 w lO%, l/4 w lO%, l/4 w lO%, l/4 w lo%, l/4 w
COmp camp camp camp camp
camp COIIIP camp COmp GXQp
72982 17554
ED-100 ED-470 ED-470
~502-10-226
TSDZ-20-106
czz-1OOP C22-470P
CZZ-470P
C180-22M 22 c179-1OM
Mfr. Mfr. Keithley Fig.
Code 04713
04713
Mfr.
Code
Part No. MC724P IC-5
MC724P IC-5
Mfr.
Part No.
Part No.
Keithley
Part No.
44655 RC07 R76-1K 44655 RC07
R76-3.3K 22 44655 RC07 R76-1K 44655 44655
44655 44655 44655 44655 44655
RC07 RC07
RC07 RC07 RC07 RC07 RC07
R76-3.3K 22
R76-120K 22
R76-10K
R76-18OK 22
R76-2.2K R76-1K R76-10K 22
22 22 22
22
Ref. 22
22
Fig.
Ref. 22 22
22 22
22
Rllll R1112 R1113
0971
120 kfl 180 kR
2.2 k0
lO%, l/4 w lO%, l/4 w lO%, l/4 w
camp camp camp
44655 44655
RC07 RC07
R76-120K R76-180K
44655 RC07 R76-2.2~
22 22 22
49
REPLACEABLE PARTS
RESISTORS (Conf'd.)
MODEL
445 DIGITAL PICOAMMETER
CitX"it
Deeig.
R1114 R1115
R1116 R1117 R1118 R1119 R1120
circuit
rJesig. QllOl
Qll02 Ql103 Q1104 Q1105
Q1106
Value
6.98 kfi
6.04 kR 2 kn
120 kn 10 k0 180 kn
3.9 k0
Mfr.
Code
07263 07263
Not Used
07263 07263
07263
Q1107 07263
QllO8 Q1109 QlllO
07263 07263 07263
Rating
l%, l/8 W l%, l/8 W
l%, l/S w lO%, l/4 w lO%, l/4 w lO%, l/4 w lO%, l/4 w
Type MW
MtF MtF
COmp COUIP camp camp
TRANSISTORS
Mfr.
Part No.
2N3565 2N3565
2N3565 2N3565
2N3565 2133565 2N3565
2N3565 2N3565
NOTE
Mfr.
Code 07716
07716 07716
44655 44655 44655 44655
Mfr.
Part No.
CEA
CEA CEA
RC07 RC07 RC07 RC07
Keithley
Part No.
TG-39 TG-39
TG-39
TG-39 TG-39
TG-39 TG-39
TG-39
TG-39
Keithley
Part No. R88-6.98K
R88-6.04K R88-2K
Fig.
Ref.
22 22
22 R76-l20K 22 R76-10K 22 R76-180K R76-3.9K
22
22
Fig. Ref.
22
22
22
22
22
22
22
22
22
on schematic diagram 234813 there are 6 buffers labeled 'A' through 'F'.
5 resistors and 3 transistors.
A sample buffer circuit is given on the schematic. Following below
is a sample replaceable parts list for each buffer.
BUFFER RESISTORS (A thru F)
CiXUit
Desig.
R1121 R1122 R1123 R1124 R1125
Value
10 kfi 120 k0 10 kn 180 kR
3.9 kn
Rating Type
lO%, 114 w
camp lO%, l/4 w COIUP lO%, l/4 w
camp 44655 RC07 R76-10K lO%, l/4 w camp lO%, l/4 w COTJ
Mfr.
Code
44655 44655
44655 RC07 44655
BUFFER TRANSISTORS (A ehr" F)
CirCUit Desig.
q1111
Q1112 Q1113
Mfr.
Code 07263
07263 07263
Mfr.
Part No. 2N3565
2N3565 2N3565
Each buffer is composed of
Mfr.
Keithley
Part No. Part No.
RC07
RC07
R76-10K R76-120K
R76-180K
RC07
R76-3.9K
Keiehley
Part No. TG-39
TG-39 TG-39
Fig. Ref.
22 22 22 22 22
Fig.
Ref.
22 22 22
50
0971
"ODEL 445
r
CALIBRATION
SECTION 5. CALIBRATION
5-l.
GENERAL.
This section contains i"formneio"
neceseary to calibrate the inecrument. 5-2. REQUIRED TEST EQUIPMENT. Recommended teet
equipment
for
checking end adjusting the instrument
is given fn Table 5-1.
5-3. ADJ"Sl%-WT/CALIBSATION PROCSD"PX.
NOTE 1.
To obtain rered accuracy, perform calibration at the ambient temperature of end "se eree, otherwise temperature coefficient correction factora muet be used (see specificatio"e). During calibration, the ambient temperature should be co"efe"t within *l'C. Relative humidity should be within range from 20 to 60%.
NOTE 2.
The top end bottom covers should be iastalled for
A/D
Converter and Picoamater calibration. It is reconrmended that epecial punched top and bottom covere be fabricated. See Figures 34 end 35 for templates for co"ere. Alternr rely, the top cover may be removed for short
periods of tie. After edjwrment, replace
cover end allow
instrument
to stabilize for
e few minutes before the cal. procedure $8
conti"ued.
Recomnended.Teet Equipment for Calibration.
TABLE S-1.
NOTE 3.
Care must be taken to minimize stray "awe during calibration. Current sources should
be isolated
(flOati”g)
from ground. Model 445 should be also isolated. D'iM should be grounded (except where noted).
a.
Power Supply Adiustment.
(Top and bottom
cover8 m,tsf be removed for this adjustment).
1. Set LINE Switch to 117V or 234V if higher
line voltage is only availeble.
(Switch 5101.)
2. connect voltage of 115v -c3 volts. or 234V
t6 volts, 60 Hz (or 50 Hz, see note).
NOTE
If instrument is 50 HZ version, oscillator circuit should have 1OOkH.z crystal instal-
;;d2" PC-217.
(Y501, Keithley Pert No.
3. Turn on power (Switch S102).
4. Remove bottom cover and measure dc voltage et +15V test point on mother board on tape side of PC-221 wing DVM CC).
5. Adjust potentiometer Rll5
6.
Check remaining regulated voltages es shown
for
+15.000 i5Om".
in Table 5-2.
I
0774
Item
A
B
cvrrent Source, Ranges: Current Source, Ranges: il x 10-2A to 1 x *O-lo,
Nlnimum
Performance Required Mfr.
Variable from 1 x lo-6A to 1 x lo-SA Keithley
Accuracy: +0.02X, from 1 x 10-2A to 1 x lo-4A
*0.05X.
from
1 x 10-5A LO 1 x 10m6A tO.ZX, 1 x lo-'A tO.3%, from 1 x lo-SA *0.5X, 1 x
(Source must have
output
to 1 x
lo-1OA
capacitance less than 1OOpP)
10-gA
(Positive end "egetive tracking meet be within one-half
the rmxlmum tolerence.)
C
D I
Digital
Digital Counter, 1OOkxz or 12OkKz tlik
*2ov.
Voltmeter
ACCUIC3Cy:
(DVM). 5-l/2 digire, f10 microvolts
*0,02X of reading.
E OscLlloecope (meinfrme)
Amplifier Plug-i", lmV/Div, DC to 5OOkBz Tima-Base
F Null Detector, flOuV to SO!', t2X accuracy, 101217 isolation
Plug-in, 5ms/Div
IX
. .
to
Model
261
Keithlev
190
1 Eldorado ( 1507B-
Tektronix 561B Tektronix Tektronix
Keithley
3A9
2B67 155
1
51
CALIBRATION
power Supply Voltage Verification.
TABLE
5-2.
.
MODEL 445 -~
e. Picoammeter Ranxe Calibration.
IMPORTANT
b. Zero Adjust. (Top cover must be removed for
these adjustments.)
1. Set front panel Zero Adjust (R1207) to mach-
anical center of adjustment span.
2. Set Display Rate to MAX.
3. Set Ran,,e to 10-2A.
4.
Select ZERO CHECK, with no input signal co,,-
netted.
5. Set Filter to
OUT.
6. Connect Null Detector (F) to Model 445 ANALOG
OUTPUT (51218).
7. Co"nect DV" (must be floating) across reaia-
tar RI.206
(16.2kG).
8. Adjust Coarse Zero (R1238) for II f 2 milli-
volts *t ANA!.xx OUTFm (51218).
9. Adjust Balance (Rl7.02) for 5.2V f O.lV.
10. Repeat steps
6 throush
9 until both readings
are obtained simultanedualy.
Ihe range calibration must
start
on the lo-'A range and prograes towards the 10-2A range since calibration of higher current ranges
depends
Care
on calibration of all lesser ranges.
must
be exercised BQ as to avoid ovar-
loads on the lesser cutrent ranges when in
RANGE HOLD.
1. Set Display Rate to "AK.
2. Set Filter to OUT.
3. Place Range in HOLD.
4.
Select 10-qA range by d-ranging using the
"DOW??' switch.
5.
select ZERO CHECK.
6.
Conned DVH to ANALOG OUTPUT of Model 445.
7.
Verify
OUtpUt
of 0 t o.lmv.
Connect Current Source to Model 445 INPUT
(Jh3).
9. Apply +l x
10.
Adjust lo-'A Cal. (R1235) to obtain
1O-qA.
.t O.lmV at ANUOC OUTPUT (51218).
11. Complete remainder of current range call-
bration in
accord
with Table 5-3.
-1.05V
-.
11. With Null Detector
(F)
connected, adjust
front panel Zero Adjust (R1207) for 0 zt O.lmV at
ANALffi OUTPUT (51218).
C. Clock Adjust. (Top cover must be removed for
this adjwtment.)
1. set Display Rate to MAX.
2.
Set Filter Co OUT.
3. Connect Counter (0) between "CLOCK" test
point on printed
circuit
board PC-217 and "GND"
test point on PC-219.
4. Adjust Frequency Adjust (C503) on PC-217 for
a Counter reading of 120kHz t 1 HZ.
is 50
HZ veraion, set frequency
NOTR
(If Model 445
for
1ookHz ? 1 HZ.)
Capacitor C504 (22pF) may be added or removed to extend the adjustment range of trtoxner
c503.
d.
Stabilization. Make carrain internal shields
and
top/bottom co"ara are installed. With power on,
allow
the Model
445 to stabilize in the calibration
area for two houre.
f.
A/D Zero
1. set
Adjustment.
rasplay Rate
at
pux.
2. Set Filter to OCT.
3.
Cwnect Oscilloscope as ehowa in Figure 32.
4. Connect DVM to analog output of Model 445.
5.
Set ren~e
6.
Place Modal 445 in ZERO CHECK.
7. Adjust
0 t O.lmV
to
10-7A and HOLD.
front psnal Zero Adjust .(Rl207) for
et ANALCC
OUTPUT (51218).
8. set Oscilloscope to following: With INTZGRATOR
a).
test
point
connected to
vertical input, set vertical gain to 5mV/div.,
dc coupled.
With EXT. TRIGGER
b).
horizontal input,
8.t
te.t
point
horizontal gain to Srrmldiv..
connected to
ac couplad.
set triggar to EXT. +.
c) .
52
L.
0774
i
MODEL 445
CALIBRAT:[ON
TABLE 5-3.
Current Range Accuracy Calibration.
Rmxe
1 x 10-qA*
1 x LO-gA
1 x 10-7A
1 x 10-6A**
1 x lo-'A**
Input
Zero Check
+l x lo-'A
Zero Check
+I x IO-*A
-1 x
lo-gA
+l x IO-'A
-1 x 10-qA Zero Check
+l x 10-7A
-1 x 10-7A
+l x lo-gA
-1 x lo-'A Zero Check**
+1 x lo-6A
-1 x 10-6A
+l x 10-7A
-1 x
10-7A
Zero Check**
+l x 10-5A
-1 x 10-5A
Output Reading 0 t O.ImV
-1.05v t O.lm"
+1.05v * 0.3%
-0.105v * 0.8% +O,lOSV * 0.8%
0 fO.lmV
-1.05v ? O.lmV +1.05v + 0.3%
-0.105V t 0.6% +o.l05V + 0.6%
0 + 0.1mv
-1.05v + O.lmV c1.05v ? 0.2%
-0.105v f 0.5%
+o.l05V * 0.5% 0 '-o.luv
-1.05v * 0.1mv
+l.O5V * 0.06%
-0.105V + 0.25% +0.105V * 0.25%
0 i O.lmV
-1.05v * O.lmV +l.O5V * 0.06%
AdJustment/Verificatian _
Verify Adjust lo-' CAL. (R1235) Verify Verify Verify
Verify Adjust lo-* CAL. (Rl234) Verify Verify
Verifv
Verify
Adjust 1O-7 CAL. (R1232) Verify Verify Verify
Verify Adjust 10-6~~. (R1231) Verify Verify Verify
Verify Adjust 10-5 CAL. (lu221) Verify
I
1 x 10-4A**
Zero Check**
+l x 10-4A
-1 x 10-4A Zero Check**
+l x 10-3A
-1 x 30-3A Zero Check**
+l x 10-2A
-1 x 10-2A
*If calibration of 10sqA ran e la not possible, the problem may be a result of excessive offset currant (less than *2 x lo-
19
A
at factory calibration).
0 *o.ld?
-1.05v ? 0.2% +1.05v * 0.2%
0 t o.lmv
-1.05v f 0.2% +1.05v * 0.2%
0 * 0.1mv
-1.05v * 0.1mv +1.05v * 0.03%
Verify Verify Verify
Verify Verify Verify
Verify Adjust 10-2 CAL. (Rl.229) Verify
**Remove input SOWCB on these ranges when verifying zero.
_~
0774
53
CALIBRATION
MODEL 445
TOP VIEW
___---__----
arr.mn 7.7 ,n--_ * _..,_ -_-_ c_* .._ Z^_ A,?. *^lll.-.clnn
OSCILLOSCOPE
IN
VERTICAL
PLUG-IN
MODEL 445
FLOATING
5 MS/DIV
EXT
TRIG
+AC
O
HORIZ.
PLUG-IN
9. Adjust INTEGKATOR ZERO (R632) to minimize
wave-form amplitude as shown in Figure 33.
Adjust
10.
mize wave-form amplitude 8s shown in Figure 33. Increase 0scilloscope vertica+ sensitivity a* necessary (to lmV/div, dc coupled).
If range of adjustment of INTEGRATOR ZERO
(~632) is insufficient add ar remove jumpers
acr”s~ realstars R630 and R631.
Set vertical oscilloscope input
11. AC/DC/GND witch) to set reference “0” position. Switch to DC and verify that RESET position coin­cides with “0”.
With RESET edjuated on oseilloac”pe grid
12. line, adjuet INTEGRATOR ZERO to
waveform within tO.lmV of RESET position.
Adjust ZERO CROSSING ADJ. (R649) to obtain
13. a zero reading on the Model 445 display such that the polarity indicator flashes + and -.
Remove Oscilloscope and other leads from
14.
!lodel 445.
8. A/D Linearity Adlust.
ZERO CROSSING A0.l. (R649) t” mini-
NOTE
to
GND (using
set
“Integrator”
5. Adjust + REF. Control (R611. PC-219) for a
Model 445 display flashing between +1.999 and bla”k.
NOTE
Add or remove jumper wire8 which shunt rasis-
tore R608, R609, or R610 (on printed circuit board PC-2191 t” extend the range of adjust­ment on potentiometer R611. Resistor R607 may be changed if “eceasary.
6. Apply a minus input curre”t to Model 445.
7. Adjust
“eces88ry far ANALOG OUTPUT reading of +2,0995V *
o.lmv.
8. Adjtw - REP. Control (R606, PC-2191 for B
Model 445 dieplay flashing between -1.999 and blank.
Add or remove jumper wires which shunt reais-
tars R603, R604. or R605 (on printed circuit board PC-219) ta extend the range of adjust­ment on potentiometsr R606.
m8y be changed if necessary.
Current
Source and front panel zero as
NOTE
Resistor R602
1. Connect Current Source (A) to Model 445 INPUT.
2. Open ZERO CHECK.
3. Apply 8 positive input current to Model 445.
4. Adjust Current Source and front panel zero as necessary for ANALOG OUTPUT reading of -2.0995V f o.lmv.
54
Remove Current Source.
9. Place Model 445 in ZERO CHECK.
10. Adjust front panel Zero Control for ANALOG
11.
OUTPUT of 0 f O.lmV.
Model 445 display should indicate rOO0.
12.
_.
0774 __
MODEL 445
NTEGRATE DISCHAR
_
"0" REFERENCE
0
INTEGRATOR
ZERO
CALIBRATION
I
I
I I I
- I ZERO
FIGURE 33.
OSCILLOSCOPE
SETTINGS
VERT HORIZ - 5MS/DIV SYNC - + EXT TRIG
A/D Converrer Zero Adjustments.
- lmV/DIV
-
0774
55
CODE-TO-NAME LIST MODEL 445.
CODE-TO-NAME LIST.
CC& List oe Suggested Manufacturers. (Based
on Federal Supply Code
for
Caceloging
Handbook H4-1):
01121 Allen-Bradley Corp. 13050 Potter co.
01295
01686
02660
02734
02735
03508
1201 South 2nd Street
Milwaukee, Wis. 53204 Texes Inatr”mnts, Inc.
Semiconductor-Components Div.
13500 No. Central Expressvey
Dallas, Texas 75231 RCL Electronics, Inc.
195 McGregor street
Manchester, N.H. 03102 Amphenol Corp.
2801 South 25th Avenue
Broadview, Ill. 60153 Radio Corp. of A-rice
Defense Electronic Products Camden, N.J.
Redlo Corp. of Annrice Conne+rcial Receiving Tube and Semiconductor Division Somerville, N.J.
Generel Electric Company Semicaaductor Prod”cta Dept. Electronics. Perk Syracuse, New York 13201
13327
13934
17554
24655
27682
44655
56289
Highway 51 N. wesson, Miss. 39191
Solieron Devices, Inc.
‘256 Oak Tree Reed
Tappen, N.Y. LO983 Widvee Corp.
602 Mein Oehkosh, Nebr. 69154
components ) Inc. Smith Street Biddeford, Maine 04005
General Radio Co. 22 Baker Avenue
West Concord, Mess. 01781. Hethavey Inetru~nts, Inc.
5800 E. JewalL Avenue
Denver, Colorado 80222 Ohmite MES. CO.
3601 Hoverd Street Skokie,~Ill. 60076
SpreSua Electric Co. North Ademe, Meee.
13138
73445
13690
75915
80164
83594
84171
Recksen 1natruments, Inc.
Helipot Division
2500 Herbor Blvd.
Fullerton, Cal. 92634 Amperex Electronic co.
Dtv. of North American Philips co. Inc.
Hicksville, N.Y.
ELCO Resistor co.
1158 Broadway
New York, N.Y. Littlefuse, Inc.
800 E. Nocthwest Hwy.
Dee Pleines, Ill. 60016 Keithley Instruments, Inc.
28775 Aurora Road
Cleveland, Ohio 44139
Burroughs Corp. Electronic Componente Div. Poet Office Box 1226 Plainfield, N..,. 07061
Arco Electronics, Inc. community !-xiv* Greet Neck, N.Y. 11022
1
04713
55397
17263
17716
19922
12040
Motorola Semiconductor
Products Inc. 5005
Eest
McDowell Rd.
Phoenix, Arfz. 85008
Union Carbide Corp. Electronics Division
270 Peck Avenue
New York, N.Y. LOO17 Fefrchild Cem*re end
1netru@mnt Corp. Semiconductor Division 313 FronteSe Road
Mountain View. Cal.
IRC, Inc. 2850 Mt. Pleasant BurlinSton, love 52601
0uendy carp. Richards Avenue Norwelk, Coon. 06852
National Semiconductor Corp.
colm@arcs Drive
post
Office Box 443
Danbury, Coon. 06813
58474
71279
71400
71450
7L590
72982
Superior Electric Co. ,Tha 383 Middle St. Bristol, Coon. 06012
Cambridge Thermionic Corp. 430 concord Avenue CembridSe, Mess.
Buarnn!S,m ME& Div. of McGraw-Edison Co. 2538 W. University St. St. Louis. MO.
CTS Corp.
LL42 W. Beerdelay Ave.
Elkhert. Ind.
CentreLeb nlviaFon OE Globe-Union, Inc.
932 E. KeeEe Ave.
Mflweukea, Wls. 53212 Erie Technologicel
Products, Inc. 644 W. 12th St.
Erie, Pa. 16512
84790
91637
9L662
91802
93656
95712
nure corporetion
Implement Division Post Office Box 231 Zenesvflle, Ohio 43702
Mallory Capacitor 3029 East Washington Post Office Box 372
Indienepolia, Ind. 46206 Dele Electronice, Inc.
P.O. &ox 609 Columbus, Nebr. 68601
ELco Corp. Willow Grove, Pa.
Industrtal Devices Lne. 982 River Rd. Edgewater. N.J. 07020
Electric Cord Co.
1275 Blowfield Ave. Caldwell, N.J.
DeSe Electric Co., Inc. Hurricme Road Frenklfn. Indians
56
-.
0774
-
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