This high voltage circuit was found in a 1970 documentation. The integrated one is of the time and modern equivalents can be tested. The resistors of the voltage reducing system must be calculated.
This double tone generator uses a specific integrated circuit, having been found in a 1977 CMOS...
This circuit is used to test PNP or NPN transistors giving the status indication through LEDs. The...
This dimmer for incandescent lamps was obtained from an American 1990s documentation. The circuit...