Found in old documentation, this circuit has only the most difficult component to obtain the PUT. The sensors are electrodes placed in the reservoir. The circuit directly controls an AC power load.
We found this circuit in the October 1992 Radio Electronics magazine. The frequency is given by C1...
This conventional LED flasher circuit has a configurable multivibrator configuration with PNP...
This extremely slow circuit produces one pulse per month and can be used in a timer. We found it...