This circuit multiplies the input voltage by 3 and can work with up to 12 V input. The current is a few mA. We found it in the Radio Electronics magazine of December 1992.
Using bipolar, FETs and unijunction this long-lasting timer can reach 10 hours with good quality...
This 1-transistor circuit for currents up to 50 mA was found in the August 1974 Radio Electronics...
We found this circuit in a 1969 General Electric documentation. The circuit uses transistors of the...