This circuit appeared in the June 1990 issue of Radio Electronics magazine. Integrated circuits must be equipped with heatsinks. Current and voltage depend on the ICs used.
The critical components for this 1970s project are transformers. The original transistors are made...
Found in a 90s Popular Electronics, this circuit keeps an LED on when a phone is in use. Can be...
We found this frequency meter circuit in a 1974 documentation. The circuit is powered by 12 V and...