This 1977 circuit only allows the solenoid to energize if the right combination of switch positions is selected. The relay is 6 or 12 V depending on the low voltage supply used.
We found this circuit at Modern Electronics in January 1991. The magazine no longer exists, but...
In this circuit, a jack with a diode activates a relay in a security system. The circuit is from a...
September 2016 - Supercapacitors of 10F to 100F in 3 V from Eaton can now be purchased from Mouser...