Why does the SCR remain 'ON' even though the gate pulse is removed? I understood the two transistor model but I want to know the bare physics of it. If you remove the gate pulse only the +ve anode w.r.t. cathode remains, thereby making junction J2 reverse biased hence current should fall of to zero value. How does the SCR regenerate the current? Current flows from anode to cathode and electrons from cathode to anode(when it is in forward conduction mode). If we apply the principle of operation of SCR to transistor then when when we switch of base-emitter voltage current should flow but this doesn't happen in transistor and only in SCR.. Any help will be highly appreciated..........!!!!!!!! Thanks.