This sophisticated circuit with two LF411 operational amplifiers appeared in the November 1984 issue of Radio Electronics magazine. The circuit uses a Mallory buzzer as an indicator.
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...