Found in Popular Electronics from the 90s, this circuit uses a reed switch on the rails as a sensor. Instead of lamps, in a modern version, LEDs can be used.
In the 110 V network, capacitors of 200 V or more and in the 220 V network, capacitors of 400 V or...
This circuit makes use of older operational amplifiers, but can be designed on the basis of modern...
This 12 V incandescent lamp switch with time delay can be found in old documentation. The SCR can...