I understand that one of the method to turn-off an scr is by connecting a transistor parallel to it in order to short it. I would like to turn on the transistor(BC547B)by touching the wires with my finger(see photo) and make the scr turn-off. Through the base the current may be about 8 microamper,so the max hfe will be 1.6mA(X200)and that current will be,only if i will connect the collector of the transistor before the R2(second position).
My question are: Does it enough current(1.6mA)to make the SCR turn-off?
What is the minimum current that i need to pass through the transistor in order to turn-off the scr?
Should i connect the collector wire of the transistor as the 1 position or the second position?(before R2 or after the R2,LED?). Thanks.