Suggested by General Electric in a 1970 documentation, this circuit makes use of some components of the time, in the case of transistors. The circuit detects smoke by the transparency changing of the air.
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...