Application Notes
AN1006
2002 Teccor Electronics
Thyristor Product Catalog
AN1006 - 5
http://www.teccor.com
+1 972-580-7777
Figure AN1006.4
V
FM
= 1 V at I
PK
= 20 A
SCRs
SCRs are half-wave unidirectional rectifiers turned on when cur-
rent is supplied to the gate terminal. If the current supplied to the
gate is to be in the range of 12 μA and 500 μA, then a sensitive
SCR is required; if the gate current is between 1 mA and 50 mA,
then a non-sensitive SCR is required.
To connect the rectifier:
1. Connect
Anode
to
Collector Terminal (C)
.
2. Connect
Cathode
to
Emitter Terminal (E)
.
Note: When sensitive SCRs are being tested, a 1 k
resistor
must be connected between the gate and the cathode, except
when testing I
GT
.
To begin testing, perform the following procedures.
Procedure 1: V
DRM
, V
RRM
, I
DRM
, I
RRM
To measure the V
DRM
, V
RRM
, I
DRM
, and I
RRM
parameter:
1. Set
Variable Collector Supply Voltage Range
to appropri-
ate
Max Peak Volts
for device under test. (Value selected
should be equal to or greater than the device’s V
DRM
rating.)
2. Set
Horizontal
knob to sufficient scale to allow viewing of
trace at the required voltage level. (The
100 V/DIV
scale
should be used for testing devices having a V
DRM
value of
600 V or greater; the
50 V/DIV
scale for testing parts rated
from 300 V to 500 V, and so on.)
3. Set
Mode
to
Leakage
.
4. Set
Polarity
to (+).
5. Set
Power Dissipation
to
0.5 W.
(
0.4 W
on 370)
6. Set
Terminal Selector
to
Emitter Grounded-Open Base
.
7. Set
Vertical
knob to approximately ten times the maximum
leakage current (I
DRM
, I
RRM
) specified for the device. (For
sensitive SCRs, set to
50 μA
.)
Note: The CRT screen readout should show 1% of the maximum
leakage current if the vertical scale is divided by 1,000 when
leakage current mode is used.
Procedure 2: V
DRM
, I
DRM
To measure the V
DRM
and I
DRM
parameter:
1. Set
Left-Right Terminal Jack Selector
to correspond with
location of test fixture.
2. Set
Variable Collector Supply Voltage
to the rated V
DRM
of
the device and observe the dot on CRT. Read across hori-
zontally from the dot to the vertical current scale. This mea-
sured value is the leakage current. (Figure AN1006.5)
WARNING: Do NOT exceed V
DRM
/V
RRM
rating of SCRs, triacs,
or
Quadracs
. These devices can be damaged.
Figure AN1006.5
I
DRM
= 350 nA at V
DRM
= 600 V
Procedure 3: V
RRM
, I
RRM
To measure the V
RRM
and I
RRM
parameter:
1. Set
Polarity
to (–).
2. Repeat Steps 1 and 2 (V
DRM
, I
DRM
) except substitute V
RRM
value for V
DRM
. (Figure AN1006.6)
.
Figure AN1006.6
I
RRM
= 340 nA at V
RRM
= 600 V
Procedure 4: V
TM
To measure the V
TM
parameter:
1. Set
Terminal Selector
to
Step Generator-Emitter Grounded
.
2. Set
Polarity
to
(+)
.
3. Set
Step/Offset Amplitude
to twice the maximum I
GT
rating
of the device (to ensure the device turns on). For sensitive
SCRs, set to
2 mA
.
4. Set
Max Peak Volts
to
15 V
. (
16 V
on 370)
5. Set
Offset
by depressing
0
(zero).
500
mV
PER
V
E
R
T
DIV
PER
H
O
R
I
Z
DIV
PER
S
T
E
P
IT
VFM
2
A
()k
DIV
9m
PER
DIV
100
nA
100
V
PER
V
E
R
T
DIV
PER
H
O
R
I
Z
DIV
PER
S
T
E
P
VDRM
IDRM
()k
DIV
9m
PER
DIV
100
nA
100
V
PER
V
E
R
T
DIV
PER
H
O
R
I
Z
DIV
PER
S
T
E
P
VRRM
IRRM
()k
DIV
9m
PER
DIV