We found this circuit in the November 1984 Radio Electronics magazine. The base frequency is given by C1. The power supply can be between 3 and 12 V.
This multiple switching power supply was found in the April 1991 issue of Radio Electronics...
We found this circuit in an old documentation. Its purpose is to turn on warning lights when the...
This Power supply sources from 500 to 1,000 mA according the transformar and was found in a...