This circuit provides a 5 V negative voltage from a positive input voltage. Found in old American documentation, information on the used integrated circuit was not provided. Probably an oscillator.
Found in an Electronic Design from the 90's, this circuit uses common components. The circuit is...
When the sensor receives light, the relay closes its contacts and remains so even after the light...
This circuit produces pulses of 90 V at intervals that can reach 5 minutes. The circuit is from a...