This circuit was found in a 90s Popular Electronics. The sensor can be any phototransistor.
This inverter can reach a power of 300 W depending on the transformer used. In this case, a...
This circuit causes an instrument needle to oscillate to signal an event. The circuit is powered by...
This circuit converts signals from the 350 kHz to 500 kHz longwave (VLF) band to the 4.35 to 4.6...
