This circuit controls an external light that turns on at dusk and off in the morning. The circuit is from a Radio Electronics from October 1987.
The frequency of this traditional crystal oscillator (XTAL) depends only on the used crystal,...
This circuit was found in a 73 amateur radio magazine from the 90s. An LED extends the scale from 0...
The inverter circuit shown in the figure provides a voltage of around 110 V with a rectangular waveform...