This circuit detects smoke by changing the light falling on the sensor. The circuit was found in the Electronics Experimenter's Handbook of 1991. Optical devices must be used.
This transmitter was found in a 1993 documentation, but it can be assembled with operators like...
This transistor tester was found in a 1980 publication. The transistor can be the BC548 and the...
This circuit is from an Electronics Now from the 90s. The circuit uses a power integrated circuit...