This circuit was found in the September 1997 issue of Electronics Now magazine. The circuit uses two op-amps and includes the symmetrical power supply.
With this circuit, from a 1991 publication, it is possible to regulate the output of a symmetric source...
In this circuit, the transistors are NPN for general use and the phototransistors can be replaced by...
This simple experimental circuit, with a good external antenna can capture distant stations in the...