Using an LDR as a sensor, this circuit is from the Radio Electronics magazine of December 1984. The operational amplifier is the 741 and the source must be symmetrical.
This circuit, which can be used as a shield, has its time determined by RA and C connected at the...
This circuit was found in a Linear Technology documentation from the 90's. The integrated circuits are...
The basis of this circuit is a National Semiconductor operational amplifier that functions as a...