
Application Notes
AN1006
2002 Teccor Electronics
Thyristor Product Catalog
AN1006 - 13
http://www.teccor.com
+1 972-580-7777
Procedure 11: I
H(Forward and Reverse)
For these steps, it is again necessary to connect the 
Trigger 
to 
MT2 
through a 10
 
 resistor. The other connections remain the 
same.
To measure the I
H (Forward and Reverse)
 parameter:
1. Set 
Power Dissipation
 to
 50 W.
2. Set
Max Peak Volts
 to 
75 V. 
(
80 V
 on 370)
3. Set 
Mode
 to
 DC
.
4. Set 
Horizontal
 knob to 
5 V/DIV.
5. Set 
Vertical
 knob to approximately 10% of the maximum I
H
specified.
Note: Due to large variations of holding current values, the
scale may have to be adjusted to observe holding current. 
6. Set 
Terminal Selector
to 
Emitter Grounded-Open Base.
Procedure 12: I
H(Forward)
To measure the I
H (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
 to maximum 
position (
100
).
Note: Depending on the vertical scale being used, the dot
may disappear completely from the screen.
4. 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 changes to 
a dot, represents the I
H
value. (Figure AN1006.21)
Figure AN1006.21 I
H (Forward)
 = 18 mA
Procedure 13: I
H(Reverse)
To measure the I
H (Reverse)
 parameter:
1. Set 
Polarity
 to (–).
2. Continue testing per Procedure 12 for measuring I
H (Reverse)
.
Sidacs
The sidac is a bidirectional voltage-triggered switch. Upon appli-
cation of a voltage exceeding the sidac breakover voltage point, 
the sidac switches on through a negative resistance region (simi-
lar to a diac) to a low on-state voltage. Conduction continues until 
current is interrupted or drops below minimum required holding 
current.
To connect the sidac:
1. Connect 
MT1 
to the
 Emitter Terminal 
(E).
2. Connect 
MT2
 to the 
Collector Terminal 
(C).
To begin testing, perform the following procedures.
Procedure 1: (+) V
DRM
, (+)I
DRM
, (-)V
DRM
, (-)I
DRM
Note: The (+) and (-) symbols are used to designate the polarity 
of MT2 with reference to MT1.
To measure the (+)V
DRM
, (+)I
DRM
, (-)V
DRM
, and (-)I
DRM
 parameter:
1. Set 
Variable Collector Supply Voltage Range
 to 
1500 Max 
Peak Volts
.
2. Set 
Horizontal
 knob to 
50 V/DIV.
3. Set 
Mode
 to 
Leakage
.
4. Set 
Polarity
 to (+).
5. Set
Power Dissipation
 to 
2.2 W
. (
2 W
 on 370)
6. Set
Terminal Selector
 to
 Emitter Grounded-Open Base
.
7. Set 
Vertical
 knob to
 50 μA/DIV.
 (Due to leakage mode, the 
CRT readout will show 50 nA.) 
Procedure 2: (+)V
DRM
 and (+)I
DRM
To measure the (+)V
DRM
 and (+)I
DRM
 parameter:
1. Set
Left-Right Terminal Jack Selector
to correspond with 
the location of the test fixture.
2. Increase 
Variable Collector Supply Voltage
 to the rated 
V
DRM
 of the device and observe the dot on the CRT. Read 
across horizontally from the dot to the vertical current scale. 
This measured value is the leakage current. 
(Figure AN1006.22)
Figure AN1006.22 I
DRM
 = 50 nA at V
DRM
 = 90 V
5  
mA
5  
  V
PER
V
E
R
T
DIV
PER
H
O
R
I
Z
DIV
PER
S
T
E
P
()k
DIV
9m
PER
DIV
IH
50
nA
50
V
PER
V
E
R
T
DIV
PER
H
O
R
I
Z
DIV
PER
S
T
E
P
()k
DIV
9m
PER
DIV
VDRM
IDRM