This tone recognizer circuit that relies on R5 and C1 was found in the December 1994 issue of Electronics Now. The circuit operates on voltages from 6 to 12 V typically.
This dimmer for incandescent lamps was obtained from an American 1990s documentation. The circuit...
We found this decoder in a 1966 General Electric publication. It makes use of general purpose...
The frequency produced by this oscillator depends on the temperatire sensed by a thermistor. The...