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SCRs (THYRISTORS)
Make sure the Voltage Control is at the zero position (fully counter clock-wise) before turning the unit
on. Connect the Anode, Gate and Cathode leads to the device to be tested. DO NOT MIX UP THE
ANODE AND CATHODE LEADS OR HIGH VOLTAGE WILL BE APPLIED TO THE GATE!
Place the function switch in the PRV position and press the “TEST” button.
Slowly raise the Voltage Control while observing the Peak Voltage and Peak Leakage Current on the
panel meters. In a properly functioning device, the rated voltage should be reached before the current
starts to rise rapidly, (the “break-over point”). If the break-over point is reached before the rated volt-
age, the device is marginal. UNDER NO CIRCUMSTANCES MUST THE RATED VOLTAGE
OF THE DEVICE BE EXCEEDED!
Return the Voltage Control to the zero position
Place the function switch in the PFV position, depress the “TEST” button and repeat steps 3 and 4.
Place the function switch in the GATE position and press the “TEST” button.
Slowly raise the Voltage Control while observing the “TRIGGER INDICATION” light. The Gate Volt-
age and Gate Current will be displayed on the panel meters. The meter reading should be taken just prior
to the trigger point to avoid incorrect readings due to a gate impedance change after turn-on.
Return the Voltage Control to the zero position and disconnect the device.
DIODES
Make sure the Voltage Control is at the zero position (fully counter clock-wise) before turning the unit
on. Connect the Anode and Cathode leads to the device to be tested.
Place the function switch in the PRV position and press the “TEST” button.
Slowly raise the Voltage Control while observing the Peak Voltage and Peak Leakage Current on the
panel meters. In a properly functioning device, the rated voltage should be reached before the current
starts to rise rapidly, (the “break-over point”). UNDER NO CIRCUMSTANCES MUST THE DE-
VICE’S RATED VOLTAGE BE EXCEEDED!
Return the Voltage Control to the zero position
NOTE : Diodes only have to be tested in one direction. In certain instances you may find it easier to
hook up a diode with the leads reversed in which case you would then test with the function switch set
to PFV.
TRANSISTORS
The procedure for testing transistors is basically the same as for SCRs, with the exception of terminolo-
gy:
Cathode = Emitter, Anode = Collector, Gate = Base.
All types of transistors can by tested, such as, Darlingtons, IGBTs, and bipolar transistors.
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