The selected circuit was found in GE's 1977 semiconductor manual. 3N84 is a controlled silicon switch and SCRs support equivalents. The transistor can be a BC558, depending on the supply voltage.
We found this circuit in a 1982 documentation. An intercom to be good must be sensitive and have...
This Star Trek red alert circuit was found in the July 1990 issue of Radio Electronics magazine. The...
The circuit shown in the figure is suggested by Microchip (www.microchip.com), being built around...