This simple power supply, which is equivalent to 2 AAA or AA batteries, was found in an Elektor from the 90's. The transformer has a 4.5 V secondary with a current of 50 mA or more.
Bis This two-transistor circuit was found in the January 1994 issue of Electronics Now magazine. The...
This receiver for the police band, which at the time was 45 MHz, was found in a publication by...
This circuit is the digital indicator for the previous circuit and can be used with similar...