This circuit was found in a 1967 General Electric manual. It shows a SCR control with unijunction and zener diode. The triac depends on the controlled load.
This circuit detects frequency modulated signals that are not received by a photo sensor. The...
T Found in a 1992 Popular Electronics, this sophisticated circuit uses two speakers on a different...
This direct conversion receiver circuit was found in Radio Electronics from the 90s. The...