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.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...