This circuit triggers an LED when the input signal exceeds the peak, or the value set in RV1. The transistors can be the modern equivalents BC549.
This circuit can serve as the basis for a small FM transmitter with varicap. We found it in a...
This circuit was obtained from the Radio Electronics magazine of August 1962. It is a tandem...
This 10 A solid state relay was found in a 1980s documentation. It can work as a shield and...