This is the simple On-Off Touch Switch Circuit Diagram with CA3240. This circuit uses a CA3240 dual BiMOS op amp to sense small currents flowing between the contact points on a touch plate. The high input impedance of the CA3240 allows the use of 1- resistors in series with the touch plates to ensure user safety. A positive output on either pin 7 (ON) or pin 1 (OFF) of the CA3240 actuates the CA3059 zero-voltage switch, which then latches the triac on or turns it off. The internal power supply of the CA3059 powers the CA3240.
On-Off Touch Switch Circuit Diagram