This circuit was found in Electronics Today International of the 80's. The circuit uses still common components, providing the indication through LEDs.
This circuit for igniting gas flames was found in a 1967 Electronic Design. The SCR firing device is a...
We found this circuit in a 1966 US documentation. It simulates a variable capacitor that can vary...
Found in Radio Electronics, this circuit is intended to activate the lighting system of garages...