The idea of this circuit is that when the device in SO1 is turned on, the device connected to SO2 automatically receives power. The circuit is from Radio Electronics from January 1985.
The circuit presented may use any general purpose transistor. The indicator is an LED and...
The operational amplifier used in this project no longer exists, but the circuit can be adapted to...
This car battery monitor was featured in the January 1988 issue of Radio Electronics magazine. The circuit...