We found this circuit in the May 1996 Electronics Now magazine. The relay must have a voltage according to the circuit power supply and a trigger current of no more than 50 mA.
This circuit, from an old 1988 publication, generates bars on the screen of an old analog TV for...
This circuit was found in a 90s EDN. In it we have the use of LEDs and diodes to stabilize the supply...
This bidirectional optical switch detects the direction of movement of an object that passes...