This circuit was found in Radio Electronics from the 90s. The CMOS integrated circuit is a PLL not easy to obtain today. The output stage can be exchanged for another one with greater power.
This circuit deactivates devices powered by the power grid so that when the power returns, they do...
The trigger signal for this circuit is an audio tone. Tones up to close to 100kHz can be used. The...
Found in the March 1974 Radio Electronics magazine, this circuit is designed to measure the level...