This circuit designs for control DC Motor 12Volt. By use the touch once Motor as a result turn go to once. When use a finger touches the metal makes Schmitt Trigger Circuit take a signal from Oscillator Circuit and make a signal goes out Trig SCR Bias Current the DC Motor 12V then turn follow want. For power supply type of DC Motor this must be AC 12Volt Only. because of make SCR not bias during negative current there. And this circuit works not heavy DC motor, turn ? do not turn ? Then don’t have to stick heat sink give SCR1 for DC motor you will may use motor at use in an automobile all right. Request enjoy please, sir.