This sonic key or vox was found in old English documentation. The operational admits equivalent as well as the transistors. The microphone is crystal.
In the figure we have the way to use a 555 with hysteresis. The circuit is from old documentation and the...
Direct current motors from 5 to 12 volts and currents up to 2A can be controlled with this...
This circuit uses a NAND port to convert rectangular signals from 50 kHz to 1 MHz into triangular...