This circuit lets through the 300 Hz to 3kHz range that corresponds to the human voice. We found it in the Radio Electronics magazine of February 1990. The circuit uses both parts of the LM381.
Figure bellow shows how n flip-flops can be associated to perform a shift register. Data is...
This simple unregulated power supply with half-wave rectification is for small appliances that do...
This circuit was obtained in an old Elektor and can be adapted to use white power LEDs. The...