This circuit was originally suggested in a 1968 publication to generate a white mark (frame) on a film at regular intervals to serve as a time reference.
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...