This circuit allows the use of an electret microphone with a 1.5 V source. We found it in the Encyclopedia of Electronic Circuits volume 5 from 1995.
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...