Found in an American documentation from 1969, this astounding circuitry makes a relay operate on 3 Hz cycles. The relay is of the high voltage type of the time.
This traditional configuration can provide high voltages for an electric fence, for science...
We found this filter configuration in an old documentation. It is one of many possible ones that...
This circuit measures the conductivity of a saline solution, which is affected by the electrolysis effect....