I have this chart from 1973 seems this is all the SCR's they had what I wanted to know is when it says typical gate trigger current is this the minimum needed to turn it on or is the maximum it can handle? I built this sound to light converter. What I can't figure out is it says SCR's latch on when turned on and you need to disconnect power to turn them off does that mean gate? If this sound to light converter where used with 12 volts DC bulb instead of 120 volt AC would this unit with this SCR still work? I also found the buzzer picture on line would not pushing the switch turn on and off the buzzer?