
AN1006
Application Notes
http://www.teccor.com
+1 972-580-7777 
AN1006 - 6
2002 Teccor Electronics
Thyristor Product Catalog
6. Set 
Rate
 by depressing 
Norm
.
7. Set 
Step Family
 by depressing 
Rep
 (repetitive).
8. Set 
Mode
 to 
DC
.
9. Set 
Horizontal
 knob to 
0.5 V/DIV
. 
10. Set 
Power Dissipation
 to 
220 W
 (
100 W
 on 577).
11. Set 
Number of Steps
 to 
1
. (Set steps to 
0
 (zero) on 370.)
12. Set 
Vertical
 knob to a sufficient setting to allow the viewing 
of 2 times the I
T(RMS)
 rating of the device (I
T(peak)
) on CRT.
Before continuing with testing, note the following:
(1) Due to the excessive amount of power that can be 
generated in this test, only parts with an I
T(RMS)
 rating 
of 6 A or less should be tested on standard curve 
tracer. If testing devices above 6 A, a Tektronix model 
176 high-current module is required.
(2) A Kelvin test fixture is required for this test. If a 
Kelvin fixture is not used, an error in measurement of 
V
TM
 will result due to voltage drop in the fixture. If a 
Kelvin fixture is not available, Figure AN1006.3 shows 
necessary information to wire a test fixture with 
Kelvin connectors.
13. Set 
Left-Right Terminal Jack Selector
 to correspond with 
the location of the test fixture.
14. Increase 
Variable Collector Supply Voltage
 until current 
reaches rated I
T(peak)
, which is twice the I
T(RMS)
 rating of the-
SCR under test.
Note: Model 370 current is limited to 10 A.
WARNING: Limit test time to 15 seconds maximum after the 
Variable Collector Supply
 has been set to I
T(peak)
, After the 
Variable Collector Supply Voltage
 has been set to I
T(peak)
, the 
test time can automatically be shortened by changing 
Step 
Family
 from repetitive to single by depressing the 
Single
button.
To measure V
, follow along horizontal scale to the point where 
the trace crosses the I
T(peak)
value. The distance from the left-
hand side of scale to the intersection point is the V
TM
 value. 
(Figure AN1006.7)
Figure AN1006.7
V
TM
 = 1.15 V at I
T(peak)
 = 12 A
Procedure 5: I
H
To measure the I
H
 parameter:
1. Set 
Polarity
 to 
(+)
.
2. Set 
Power Dissipation
 to 
2.2 W
. (
2 W
 on 370)
3. Set 
Max Peak Volts
 to 
75 V
. (80 V on 370)
4. Set 
Mode
 to 
DC
.
5. Set 
Horizontal
 knob to 
Step Generator
.
6. Set 
Vertical
 knob to approximately 10 percent of the maxi-
mum I
H
 specified.
Note: Due to large variation of holding current values, the
scale may have to be adjusted to observe holding current.
7. Set 
Number of Steps
 to 
1
.
8. Set 
Offset
 by depressing 
0
 (zero). (Press 
Aid
 and 
Oppose
 at 
the same time on 370.)
9. Set 
Step/Offset Amplitude
 to twice the maximum I
GT
 of the 
device.
10. Set 
Terminal Selector
 to 
Step Generator-Emitter Grounded.
11. Set 
Step Family
 by depressing 
Single
.
12. Set 
Left-Right Terminal Jack Selector
 to correspond with 
location of test fixture.
13. Increase 
Variable Collector Supply Voltage
 to maximum 
position (
100
).
14. Set 
Step Family
 by depressing 
Single.
 (This could possibly 
cause the dot on CRT to disappear, depending on the verti-
cal scale selected.)
15. Change 
Terminal Selector
 from 
Step Generator-Emitter 
Grounded 
to 
Open Base-Emitter Grounded
.
16. Decrease 
Variable Collector Supply Voltage
 to the point 
where the line on the CRT changes to a dot. The position of 
the beginning point of the line, just before the line becomes a 
dot, represents the holding current value. (Figure AN1006.8)
Figure AN1006.8
I
H
 = 1.2 mA
Procedure 6: I
GT
 and V
GT
To measure the I
GT
 and V
GT
 parameter:
1. Set 
Polarity
 to (+).
2. Set
Number of Steps
 to 
1
.
3. Set 
Offset
 by depressing 
Aid
.
4. Set 
Offset Multiplier
 to 
0
 (zero). (Press 
Aid
 and 
Oppose
 at 
the same time on 370.)
5. Set 
Terminal Selector
 to 
Step Generator-Emitter Grounded.
6. Set
Mode
 to 
Norm
.
7. Set 
Max Peak Volts
 to 
15 V
. (
16 V
 on 370)
500
mV
PER
V
E
R
T
DIV
PER
H
O
R
I
Z
DIV
PER
S
T
E
P
IPK
VTM
2
A
()k
DIV
9m
PER
DIV
100
mA
20
500
 A
PER
V
E
R
T
DIV
PER
H
O
R
I
Z
DIV
PER
S
T
E
P
IH
()k
DIV
9m
PER
DIV