
AN1006
Application Notes
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+1 972-580-7777 
AN1006 - 12
2002 Teccor Electronics
Thyristor Product Catalog
7. Set
Terminal Selector
 to
 Emitter Grounded-Open Base
.
Procedure 5: V
BO (Positive and Negative)
To measure the V
BO (Positive and Negative)
 parameter:
1. Set 
Left-Right Terminal Jack Selector
 to correspond with 
the location of the test fixture.
2. Set 
Variable Collector Supply Voltage
 to 
55 V
 (
65 V
 on 
370) and apply voltage to the device under test (D.U.T.) 
using the 
Left Hand Selector Switch.
 The peak voltage at 
which current begins to flow is the V
BO
 value. 
(Figure AN1006.19)
Figure AN1006.19 (+)V
BO
 = 35 V; (-)V
BO
 = 36 V; (±)I
BO
 < 10 A
Procedure 6: I
BO (Positive and Negative)
To measure the I
BO (Positive and Negative)
 parameter, at the V
BO
 point, 
measure the amount of device current just before the device 
reaches the breakover point. The measured current at this point 
is the I
BO
 value. 
Note: If I
 is less than 10 μA, the current cannot readily be seen 
on curve tracer.
Procedure 7:
 
V
BO (Voltage Breakover Symmetry)
To measure the 
V
BO (Voltage Breakover Symmetry)
 parameter:
1. Measure positive and negative V
BO
 values per Procedure 5.
2. Subtract the absolute value of V
BO
 (-) from V
BO
 (+).
The absolute value of the result is:
V
BO 
= [ I+V
BO
I - I -V
BO 
I ]
Procedure 8: V
TM (Forward and Reverse)
To test V
TM
, the 
Quadrac
 must be connected the same as when 
testing V
BO
, I
BO
, and 
V
BO
.
To connect the 
Quadrac
:
1. Connect 
MT1
 to 
Emitter Terminal 
(E).
2. Connect
 MT2
 to 
Collector Terminal 
(C).
3. Connect 
Trigger Terminal
 to 
MT2 Terminal 
through a 10
 
resistor.
Note the following:
Due to the excessive amount of power that can be generated in 
this test, only parts with an I
T(RMS)
 rating of 8 A or less should be 
tested on standard curve tracer. If testing devices above 8 A, a 
Tektronix model 176 high-current module is required.
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 volt-
age drop in fixture. If a Kelvin fixture is not available, 
Figure AN1006.3 shows necessary information to wire a test 
fixture with Kelvin connections.
To measure the V
TM (Forward and Reverse)
 parameter:
1. Set
Terminal Selector
 to
 Emitter Grounded-Open Base
.
2. Set 
Max Peak Volts
to 
75 V
. (
80 V
 on 370)
3. Set 
Mode
 to 
Norm
.
4. Set 
Horizontal
 knob to 
0.5 V/DIV
.
5. Set 
Power Dissipation
 to 
220 watts
 (
100 watts
 on a 577).
6. Set 
Vertical
 knob to a sufficient setting to allow the viewing 
of 1.4 times the I
T(RMS)
 rating of the device I
T(peak)
 on the CRT.
Procedure 9: V
TM(Forward)
To measure the V
TM (Forward)
 parameter:
1. Set 
Polarity
to (+).
2. Set 
Left-Right Terminal Jack Selector
 to correspond with 
the location of the test fixture.
3. Increase
Variable Collector Supply Voltage
 until current 
reaches rated I
T(peak)
, which is 1.4 times the I
T(RMS)
 rating of 
the triac under test.
Note: Model 370 current is limited to 10 A.
WARNING: Limit test time to 15 seconds maximum.
4. To measure V
TM
, follow along horizontal scale to the point 
where the trace crosses the I
T(peak)
 value. This horizontal dis-
tance is the V
TM
 value. (Figure AN1006.20)
Figure AN1006.20 V
TM (Forward)
 = 1.1 V at I
PK
 = 5.6 A
Procedure 10: V
TM(Reverse)
To measure the V
TM (Reverse)
 parameter:
1. Set
Polarity
 to (–).
2. Set 
Left-Right Terminal Jack Selector
 to correspond with 
the location of the test fixture.
3. Increase 
Variable Collector Supply Voltage
 until current 
reaches rated I
T(peak)
.
4. Measure V
TM(Reverse)
 the same as in Procedure 8. (Read mea-
surements from upper right corner of screen).
50
 A
10  
 V
PER
V
E
R
T
DIV
PER
H
O
R
I
Z
DIV
PER
S
T
E
P
()k
DIV
9m
PER
DIV
 VBO
 IBO
+VBO
+IBO
500
mV
PER
V
E
R
T
DIV
PER
H
O
R
I
Z
DIV
PER
S
T
E
P
IPK
VTM
1
A
()k
DIV
9m
PER
DIV