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I am driving an inductive load and have a situation where an SCR will be forward biased but conduct in reverse. Can it do that if I strobe the gate the entire time I want it to conduct in reverse?

Update: I edited the question to stipulate significant conduction, as opposed to leakage. I assume the device will leak a small amount when reverse biased.

James Strieter
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    Provide more details. you question need clarification. terms bias and strobe should be explained. – user263983 Feb 23 '23 at 09:41
  • Bias refers to anode-cathode junction. So forward biased means there is positive potential from anode to cathode. Strobe means provide a current pulse through the gate. – James Strieter Feb 23 '23 at 10:58
  • You can use the SCR to short a bridge or use two SCRs back to back. – Gil Feb 23 '23 at 21:39

2 Answers2

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The simple answer to your question is that an SCR will not conduct in reverse, ever.

As user263983 says, you need a triac if you want to conduct both ways.

Also remember that once its triggered, it will continue conducting until the current flow drops to zero.

Useful description here:

https://eepower.com/technical-articles/an-introduction-to-triac-basics/#

OXO
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  • There is always current in reverse, even if just leakage. – Tim Williams Feb 23 '23 at 13:09
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    @TimWilliams I think what OXO's saying is that an SCR cannot conduct far more than leakage current in reverse. For example, if the device has a leakage current of 1 uA, it cannot conduct 1000 A backwards. If you agree, can you kindly remove the down vote? – James Strieter Feb 23 '23 at 13:24
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Yes. Leakage current will flow, and some of the free charges created by the G-K bias, bleed through the anode layers, increasing leakage.

See: Should I gate SCRs on when reverse-biased?

Tim Williams
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