This oscillator for frequencies up to a few tens of kilohertz was found in a 1970s documentation. The transistor can be of general use. For the component values used, the frequency is 250 Hz.
The energy that powers this radio's amplifier circuit is obtained from the signal itself. The coil...
Based on the BA1404 integrated circuit, this circuit was found in the July 1992 issue of Radio...
This circuit can linearly control the temperature of showers, taps or heaters up to 2 500 W. The...