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 for signals up to 30 MHz can improve your reception in the medium and short-wave...
This circuit can be used as a shield for transmitting the temperature of a sensor. The circuit is from...
This astable multivibrator follows the traditional configuration for use as a signal injector, found in...