Found in Radio Electronics from the 90s, this thermometer uses an integrated circuit that is unusual today. The sensor is a thermistor or NTC.
This simple CMOS metronome circuit can be mounted in a small box, providing both sound and light...
Although indicated in the original publication of the 1980s as a capacitance switch, the circuit...
In the figure below we have a simple way to do chroming, silvering or another type of...