With this circuit it is possible to use a pair of old telephones in a wired communication system. The circuit is from a Popular Electronics from the 90s.
This 1995 circuit uses interruption sensors or NC connected in series in any quantity. With the...
The integrated circuit used in this amplifier is not common today. The circuit is from a...
This circuit turns off a load after an interval of 8 to 80 seconds adjusted on the potentiometer. The...