We found this circuit in the September 1971 Radio Electronics magazine. The SCR can be any of the 106 series and the buzzer can be replaced by a relay according to the supply voltage.
September 2017 - The new LDOs of STMIcroelectrinics LDLN025 for currents up to 250 mA and 1.5 to...
We found this circuit, which should only be used with incandescent lamps. In the Motorola Linear...
This version operates in the opposite way to the previous one, triggering when light falls on the...