Touch on-off switch
Posted on Aug 18, 2012 11849
A Touch On/Off Switch is desired, this circuit fills the bill. Two sensitive gate SCRs are interconnected, so that when one of the devices is turned on, the other (if on) is forced off. That toggling effect gives an on/off circuit condition for each of the LEDs in the SCR-anode circuits. To turn LED1 on and LED2 off, simply touch the `A'' terminal, and to turn LED1 off and LED2 on, the `B` pick-up must be touched. It is possible to simultaneously touch both terminals, causing both SCRs to turn on together.
To reset the circuit to the normal one-on/one-off condition, momentarily interrupt the circuit's dc power source. Additional circuitry can be connected to the anode circuit of either or both SCRs to be controlled by the on/off function of the touch switch.