Found in a 90s American documentation, this circuit mimics the Enterprise warning signal from the movie Star Trek. The signal must be applied to an amplifier.
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...