Originally indicated as an alarm alert in a 1990s US publication, this circuit can be used as a shield to control a strobe lamp. The sensor is a optocoupler with LDR.
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...