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 capacitor for small capacitances is based on the tuning of a receiver circuit. The variable is...
This circuit is from the Motorola LinearDatabook of 1990. It shows how it uses the LF355, 356 and...
We found this circuit in an American publication from 1977. Combining a monostable with a...