Turning off the thyristor using a tank circuit

When connected to a direct current DC supply, the thyristor can be used as a DC switch to control larger DC currents and loads. When using the Thyristor as a switch it behaves like an electronic latch because on. So we must reduce the anode current below the thyristor holding current Ih. That is the only way to turn it off. In our circuit this job is done by the normally closed off push button shown as S2. So when we press S2 then it opens the circuit and cuts current flow to zero.What is a thyristor firing circuit?YouTube [pdf]
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