This circuit with two operating modes was found in the September 1989 issue of Radio Electronics magazine. Other operational amplifiers can be used. The power supply must be dual.
This circuit is from the documentation of Radio Shack 1975. It can be mounted with 12 V relays,...
Using an optocoupler this circuit turns on the light in a bedroom for a set amount of time when...
This circuit is used for remote current monitoring. In the original version of the 80s a lamp is...