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.
This is a two-input audio switching circuit. The operational can be of any type and more entries can...
We found this amplifier for automotive use in the Philips integrated circuit manual from 1990. The...
Found in old English documentation this circuit can be made with a BF245 or equivalent. Coils are...