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 circuit is from old documentation. The operational amplifier is uncommon nowadays. The...
This memory flip-flop must be powered by 5V voltage. The circuit stores 1 bit. ...
This simple preamplifier was published in Radio Electronics magazine in February 1958. The battery...