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.
I got this circuit from an English magazine from 1977. It can still be easily assembled, as the...
The configuration shown allows to obtain a high voltage gain for FETs. FETs can be BF245 or...
This circuit controls a heating element using a triac. Triac must be fitted with a heat sink. We...