The circuit shown was obtained in American documentation from 1968. MOSFETs can be replaced by equivalents. The circuit dissipation is less than 0.5 mW.
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...