This circuit with current up to 100 mA according to the transformer was found in the Radio Electronics magazine of October 1991. The regulation is done directly by the zeners.
Using a capacitor as a sensor, this circuit was found in the 1989 Radio Electronics Experimenter magazine....
Using bipolar, FETs and unijunction this long-lasting timer can reach 10 hours with good quality...
This circuit is found in an American documentation from the 80's. The circuit measures the power of...