Found in a 90s Popular Electronics, this circuit checks if a remote-control transmitter is emitting signals. The sensor is a general-purpose type found in many electronic devices.
Using the 2N2646 this circuit was found in a Radio Electronics magazine from July 1968. The...
The purpose of this circuit found in a 1990s Popular Electronics is to increase the current...
Found a documentation for PC from 1992, this circuit is indicated for the English power grid of...