TF46
Portable
Super Cricket
Ttansistor/FET Tester
Operation, Application and Maintenance Manual
TF 46 PORTABLE
S UPER C RICKET
TRANSITOR & FET TESTER
IN CIRCUIT CRICKET TESTER & OUT OF CIRCUIT PARAMETER TESTER
S E N C O R E
PUSHTO OPEN
SENCORE
3200 Sencore Drive, Sioux Falla, SD 57107
WARNING
PLEASE OBSERVE THESE SAFETY PRECAUTIONS
There is always a danger present w hen testing electronic equipm ent. U n e x p e c te d high voltages can be p re s e n t at unu sual locations in defective e q u ip m e n t. Every pre c au tio n has b e en taken in th e design
of your in stru m e n t to insure that il is as sate as possible. However, safe o p e ra tio n d e p e n d s on you, the
operator. B ecom e familiar with the e q u ip m e n t you are w orking with, a n d observe th e following safe ty precautions:
1. |
N ever exceed the lim its o f this instrum ent as given in the specifications section a n d the additional |
special w arnings in this m anual. |
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2. |
A severe shock hazard can result if the chassis of th e e q u ip m e n t b e in g serviced is tied to the “h o t” |
side o f th e AC line. An isolation tra n sfo rm e r sh o u ld always be used with hot-chassis e q uipm e nt. Also,
be sure that the top o f your w o rkbench an d th e floor u n d e rn e a th it are dry a n d m a d e o f non-conduc- tive materials.
3. R em ove the circuit power b efore making connections to high voltage points. If this can n o t be
do n e , be sure |
to avoid con tact with o th e r e q u ip m e n t o r m etal objects. Place o n e h a n d in vour pocket |
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a n d stand o n |
a n insulated floor to re d u c e the possibility of shock. |
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4. Discharge filter capacitors (after rem oving power) |
b efore c o n n ec tin g to any part of the circuit |
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re quiring pow er to be rem oved. |
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5. Be sure your equipm ent is in good order. Broken |
or frayed test leads can be extrem ely dangerous |
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a n d can expose you to d a n g e ro u s voltages. |
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6. |
R em ove the test lead im m ediately after the test has b een c o m p le te d to red u c e th e |
possibility of |
shock. |
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7. |
D o not work alone w hen working on hazardous circuits. Always have a n o th e r pe rson close by in |
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case o f an accident. R em em b er, even a m in o r shock can be the cause o f a m o re serious accident, such |
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as falling against the e q u ip m e n t, o r co m ing in contact with high voltages. |
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8. |
Im proper Fuse(s) V oid Warranty. Fuses are for your protection, so always replace |
fuse with p ro p e r |
type a n d c u rre n t rating. T h e p ro p e r fuse |
type description is m a rk e d n e a r the |
fuse |
h o ld e r a n d in the |
m anual. Always: |
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|
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A. Be sure you are replacing the right fuse. O n units with m o re th a n |
o n e |
fuse, be sure you are |
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placing the p ro p e r fuse value in |
the fuse holder. |
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B. Have the proper size replacem ent fu se in stock. W ith each new instrum ent, be sure to u p d a te your fuse inventory with any special value fuses your in stru m e n t may require .
9. Explanation o f symbols.
This m a rk ing indicates that the o p e ra to r m ust refer to an ex planation in the o p e ra tin g instructions.
A term inal at which |
a voltage with respect to a n o th e r term inal o r part exists or |
may be adjusted to |
1,000 volts o r more. |
TF46
Portable Super Cricket
Transistor/FET Tester
Operation, Application and
Maintenance Manual
SENCORE
3200 Sencore Drive, Sioux Falls, SD 57107
TABLE OF CONTENTS
S afety R e m in d e r ...................................................... |
Inside Front Cover |
D e sc rip tio n |
|
In tro d u c tio n ........................................................................................... |
3 |
Features .................................................................................................. |
3 |
S pecifications......................................................................................... |
4 |
Controls..................................................................................................... |
6 |
O p e ra tio n |
|
In tro d u ctio n ........................................................................................... |
8 |
B attery Installation/Replacem ent...................................................... |
8 |
Battery Test.............................................................................................. |
9 |
Auto-Off C irc u it.................................................................................... |
9 |
Meter Z eroing ....................................................................................... |
10 |
Lead C onnections................................................................................ |
10 |
39G85 Touch-Test P ro b e .................................................................... |
12 |
T est P ro c e d u re s |
|
In-or Out-of-Circuit Cricket Gain T e s t .......................................... |
13 |
Out-of-Circuit Leakage T e s ts ........................................................... |
14 |
Key Leakage T e s t ................................................................................ |
15 |
Extended Leakage T e sts .................................................................... |
16 |
Locating L e a k a g e ................................................................................ |
16 |
Out-of-Circuit Param eter Test........................................................... |
18 |
Determining Transistor T y p e s ........................................................ |
18 |
Determining Transistor Basing........................................................ |
19 |
Diode Testing......................................................................................... |
20 |
Special FET T e s ts ................................................................................ |
21 |
Protection For Transistors Under T e s t.......................................... |
21 |
Testing SCRs......................................................................................... |
22 |
C ircu it D e sc rip tio n |
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Theory of O p eratio n ........................................................................... |
23 |
Block Diagram and Functional D escription ................................. |
23 |
M a in te n an c e a n d S ervice |
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Introduction........................................................................................... |
28 |
Checking for Broken Test L eads...................................................... |
28 |
D isassem bly ......................................................................................... |
29 |
C a lib ratio n ........................................................................................... |
29 |
A p p licatio n T i p s .................................................................................... |
32 |
S erv ice a n d W a rra n ty ............................................. |
Inside Back Cover |
2 |
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DESCRIPTION
INTRODUCTION_________________________
The transistor is one of the most common active electronic compo nents in use today. The number of transistors used outnumbers tubes, as well as integrated circuits in most types of electronic design, includ ing home entertainm ent, industrial, and maintenance equipment. A high-accuracy, easy-to-use transistor tester th at allows both inand out-of-circuit transistor testing can make any technician more effi cient in troubleshooting today’s solid-state circuits.
FEATURES______________________________
The TF46 Portable Super Cricket provides the Sencore patented Cricket Gain test, which allows inor out-of-circuit Good/Bad testing of transistor gain. No basing information is required, as all possible basing combinations are tested with a rotation of the Perm utator test switch. This test is backed up with the Super Cricket Param eter Test for determ ining the engineering param eters of transistors for matched push-pull circuits, critical gain circuits, and transistor design applications.
All six transistor leakage paths are tested for locating transistors th at are ju st starting to go bad. A special I D S S leakage test is also available for grading FETs. In addition to these tests, the TF46 will provide complete basing information of an unknown transistor to allow a replacem ent transistor to be chosen when no cross-reference informa tion is available, or to test a transistor in-circuit to be sure it is installed properly. An exclusive Auto-Off circuit saves batteries by turning the TF46 off autom atically-even if the power switch is left on.
3
SPECIFICATIONS
Cricket Good/Bad Gain Test:
Test Method: |
Detects ability of transistor to invert a square |
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wave (Sencore patent 3,898,559) |
Test Frequency: |
2 kHz |
Test Voltage: |
VCE = ±4.0 VDC |
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VgE = 7 VPP on zero reference |
Test Currents: |
= 12 mA maximum |
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2-3 mA average continuous |
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Ig = 7 mA maximum |
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3 mA average continuous |
Bi-Polar T ransistor B eta Test:
Test Method: |
Dynamic Beta |
Test Frequency: |
2 kHz |
Test Voltage: |
VCE - ±4.0 VDC |
|
VB E = ^ VPP on zero reference |
Test Currents: |
IQ - (Sig Trans) 25 mA maximum |
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IQ - (Output Trans) 150 mA maximum |
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Ig - (Sig Trans) 50 uA maximum |
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Ig - (Output Trans) 300 uA maximum |
Beta Range: |
0-500 |
Bi-Polar L eakage Tests: |
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Test Method: |
Key test m easures reverse collector-base leak |
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age (ICBO). All other paths tested with rota |
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tion of perm utator test switch (IEBO, IBEO, |
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ICEO, IECO, IBCO). |
Test Levels: |
VC B - ±3-5 VDC (em itter open) |
Leakage Range: |
0-2500 microamps |
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4 |
F ield E ffect T ransistor Gm Test:
Test Method: |
Dynamic m utual conductance |
Test Frequency: |
2 kHz |
Test Voltage: |
VDg = ±4.0 VDC |
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VGS = 0 Volts |
Signal Level: |
.4 VPP |
Gm Range: |
0-25,000 micromho |
FET L eakage Test ( I G S S ): |
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Voltage Level: |
±3.5 VDC (source open) |
Leakage Range: |
0-2500 microamps |
Zero B ias D rain C urrent Test ( I D S S ): |
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Voltage Level: |
Vpg= ±4.0 VDC |
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vGS@o |
ID S S RANGE: |
0-50 milliamps |
General: |
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Test Leads: |
Connected, term inated in color-coded E-Z |
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Hook® connectors.A14 |
Batteries: |
Six alkaline, carbon zinc, or rechargeable “AA” |
Power Consumption: 11 mA, current at idle, 120 mA maximum. |
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Meter: |
4lA", 100 uA, 5%, mechanical shock protected. |
Size: |
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10” x 5 V2” x 3 V2” (25.4 cm x 13.8 cm x 8.9 cm) HWD
Weight: 4 V2 lbs. with batteries (2.0 Kg)
Optional Accessories: 39G85 Touch-Test Probe
(Specifications subject to change without notice.)
CONTROLS
1.Handle/Tilt Bail with slip-proof cushion allows unit to be easily car ried or used as a tilt stand on a service bench.
2.Good/Bad meter scale used for Cricket Gain test and battery check.
3.Gain meter scales give direct readout of transistor Beta or FET transconductance.
4. Leakage meter scales for all leakage tests, including FET Id ss,
5.Polarity Indicators for determining the polarity of an unknown transistor or FET.
6.Color Indicators for determining the basing of a transistor by relat
ing the colors of the test leads to the transistor elements.
7.Basing Indicators provide full basing information of an unknown transistor.
Test Selector Switches:
8.Gain (Lead ID) button used for parameter tests and lead ID testing.
9.Leakage (Diode) test button used for inter-element leakage testing and diode testing.
10. I D S S leakage test button for industrial culling of FETs.
11.Permutator Test Switch tests all possible basing configurations when rotated through all positions.
12.Power Switch controls unit, and resets Auto-Off.
13.Lead Storage Compartment.
Parameter Gain Test Switches:
14.Enhancement FET selector for reading the transconductance of a positive-biased FET.
15.Normal FET selector button for measuring the transconductance of a normally biased FET.
16.Output Transistor selector button for measuring the Beta of a power transistor using the parameter gain test.
17.Signal Transistor selector button for measuring the Beta of a small signal or RF transistor using the parameter gain test.
18.Sliding M eter Cover protects meter during transportation.
19.Battery Test Switch (inside lead compartment) reads battery condi tion on Good/Bad meter scale.
20.Speaker Switch allows speaker to be turned off when meter only testing is desired.
21.Battery Compartment (rear panel) for 6 “AA” batteries for portable operation.
22.Meter Zero (rear panel) for setting mechanical meter zero.
Optional Accessory:
23.39G85 Touch Test Probe (optional) allows in-circuit transistor test ing from foil side of printed circuit board.
6
OPERATION
INTRODUCTION_________________
The following instructions explain the use of the TF46 in various types of applications. Each section gives details of how a test is to be performed. At the beginning of each test is a simplified front-panel drawing showing the control setup and which m eter scale to read. If a control is required for the test, it is m arked on the drawing. If a con trol is not needed, the label is not shown, and it may be left in any position without changing the test results. Several tests refer to Applications Tips. These tips are located on the last pages of the m an ual. These tips provide information on special testing applications th a t may be encountered in using the TF46. Once the operations of the TF46 are understood, the Applications Tips may be used for answer ing questions during routine testing.
BATTERY INSTALLATION/
REPLACEMENT
The TF46 requires 6 “AA” cells for operation. Standard alkaline, carbon-zinc, or rechargable Nickel-Cadmium cells may be used.
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Fig. 2: Installing batteries |
To install or replace batteries: |
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1. |
Remove the screw at the top of the battery compartm ent cover on |
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the rear of the TF46. |
2. |
Install 6 “AA” cells, observing proper polarity as m arked in the b at |
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tery com partm ent and as shown in Fig. 2. |
3. Replace the battery compartm ent cover and replace the cover screw.
BATTERY TEST
The condition of the batteries may be easily tested by using the test switch in the lead storage compartment. The condition of the batter ies will be read on the “Good/Bad” scale of the meter.
Fig. 3: Operating battery test switch.
To test battery condition:
1.Turn the TF46 on.
2.Slide the right-hand switch in the lead storage compartm ent to the right. (See Fig. 3.)
3. Read the condition of the batteries on the “Good/Bad” m eter scale.
4.If the battery test reads in the red “bad” portion of the scale, the bat teries should be replaced or recharged.
AUTO-OFF CIRCUIT_____________________
The TF46 contains a battery-saving Auto-Off circuit. This circuit will autom atically tu rn the TF46 off after 15 m inutes of operation.
To reset the Auto-Off circuit:
1.Turn the PUSH ON-OFF switch off.
2.Turn the PUSH ON-OFF switch ON again.The TF46 will now oper ate for an additional 15 minutes.
9
METER ZEROING
Proper calibration of your TF46 requires th at the m eter movement be properly zeroed. An adjustm ent screw is provided through an access hole in the rear of the unit. To adjust the mechanical m eter zero:
1.Turn the TF46 off.
2.Check th at the m eter is reading zero.
3.If the m eter is not zeroed, use a narrow blade-type screw-driver to adjust the m eter zero adjustm ent through the hole in the rear of the case. (See Fig. 4.)
x'--'
V
Fig. 4: Adjusting Mechanical Meter Zero.
LEAD CONNECTIONS
WARNING: Be sure power to the transistor to be tested has been removed and filter capacitors are discharged before con necting test leads.
. 4,-
Fig. 5: Opening E-Z Hook® Connector.
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