An SCR/TRIAC tester

[Guest]

I found this circuit on a site and decided to put it here. Its simplicity caught me.

TO TEST AN SCR :-

When Kathode is closed,lamp does not light.
When Gate is also closed, the lamp lights to full intensity.
Then when Kathode is opened, even momentarily the lamp does not close again when Kathode is closed.
This is the ON & OFF operation of SCR.

TO TEST AN TRIAC :-

Hookup the TRIAC as; Kathode as MT1, Anode as MT2,Gate as Gate
Execute the tests same way as a SCR.
Lamp should be on only when Kathode switch is ON and Gate switch ON momentarily.
In any other case the lamp should be off.
If not the TRIAC is defective.

View attachment 35299

 

[Kevin Weddle]

Has anybody seen the circuit with the PUT across a capacitor across an opamp. This generates a sawtooth. A rapid discharge of the capacitor. I think these 5 layer devices pose a serious physics debate. You know the construction lends itself to PN voltages even though we treat them as a short. There is some serious doping going on with these devices.

 

[ante1]

Kevin,
I have not seen this circuit you are referring to where can I find it, seems interesting.

Ante :