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Well, this was a bit more complicated than it should have been, but it was worth finally getting what I expected after a lot of scrapping. Anyway, the circuit consists of 2 transistors connected to each other to form a thyristor. The interesting part about this is that 2 major circuits are used here to control the thyristor, which are the turn ON mechanism, and the turn OFF mechanism which uses a forced commutation - class A circuit.
First off, a thyristor is a device which acts like a switch, mainly used in power electronics. When a voltage supplied to the anode is greater than the cathode, conduction barely happens, with the dispensing of leakage current through the device. However, once the gate is applied, the device turns ON, which cannot be turned back OFF, unless the cathode voltage is made more positive than the anode, OR unless the anode voltage becomes 0V.
In order to turn on the circuit, a Turn ON gating circuit is used here, which is made up of a negative voltage and some diodes and resistors. The diodes are connected in such a way as to avoid reverse voltage/current. Also, the resistances act as current limiters.
Since thyristors cannot be turned off on its own, commutators are used. There are mainly 2 types of commutators, which are natural and forced. Natural does not require any circuitry (can allow the thyristor to turn off if an alternating signal like sinusoidal wave is applied at the anode - negative half cycle), while forced requires a circuit to switch it off.
The Turn OFF forced commutation circuit in this is made up of a parallel RLC Load.
*Note: To simulate, keep the 3 sided switch connected to the push switch and press the push switch. To turn off, press the 3 sided switch to the RLC Load. If you wish to turn it on again, wait for a second, and then switch it back to the push button and repeat.
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