This 1988 circuit makes a back-and-forth of LEDs whose speed is controlled by P1. All components used are common and the circuit can be powered by voltages from 6 to 9 V.
This simple circuit can be used to power a simple communication system using ordinary telephones....
This circuit cuts the audio spikes. It was found in an English publication from the 1980s....
This circuit consists of an echo or reverberation chamber for sound systems and must be...