Based on the LF256 operational amplifier, this circuit was found in the September 1989 issue of Radio Electronics magazine. The indicator is analog, and the power supply must be symmetrical.
This class B push-pull amplifier circuit with a few hundred milliwatts of power was found in an...
In the figure we have a window detector that uses only a voltage comparator. The circuit can use...
This circuit was found in an old American documentation. The operational used is of the...