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 interrupts the power supply when grounding is missing. The circuit is from an old...
ON Semiconductor MC74VHX1Gx Logic ICs The Mouser Electronics series 74 Logic ICs are available for...
This circuit uses a sensitive reed relay to control external loads. The time delay is given by the...