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.
Found in an old American publication, this circuit is intended for audio experiments. The...
This battery-powered micropower supply was shown in Radio Electronics magazine in 1991. The...
This power supply for model railroad was found in a February 1961 Radio Electronics Magazine. The...