what is happening when we apply voltage to gate terminal in scr? Is the avalanche breakdown voltage decreases?If yes how.....

 

what is happening when we apply voltage to gate terminal in scr? Is the avalanche breakdown voltage decreases?If yes how.....

Look carefully at the figure attached. It is an scR with transistors.

 

Actually i thought that (when considering the transistor equivalent of scr) the gate voltage turns-on lower npn transistor which in turn turns-on upper pnp transistor. So breakdown does not happens. But in many books i read that applying gate vaoltage decreases "breakdown" voltage of reverse biased junctions.

 

Actually i thought that (when considering the transistor equivalent of scr) the gate voltage turns-on lower npn transistor which in turn turns-on upper pnp transistor. So breakdown does not happens. But in many books i read that applying gate vaoltage decreases "breakdown" voltage scr.