Using operational amplifiers of the time, we found this circuit in documentation from the 90s. The configuration can be adapted to use modern operational amplifiers.
This circuit was taken from a Popular Electronics from the 1990s. The circuit triggers a relay that...
The transformer inf this circuit is a 6 or 9 V unit and diodes 1N4002. The filter capacitor is 2...
This circuit causes a relay to oscillate generating a signal that turns into high voltage in a...