This Power supply sources from 500 to 1,000 mA according the transformar and was found in a publication of the year 1958. The diodes can be now the 1N4004 and the transistor should be mounted on a heatsink.
This circuit was obtained in a 1984 publication, but it can be assembled using BC548 for TR1 and...
This circuit was found in an American documentation from 1969. The circuit memorizes when a...
This counter was found in the November 19983 issue of Radio Electronics magazine. The power supply...