This two-port monostable of the 4001 was suggested by an article in the April 1988 Radio Electronics magazine. The timings are given by C1 and R1.
In this 2002 circuit, we have the activation when the reservoir is empty and shutdown when full....
This circuit was found in a 2001 documentation. It is a test of zener diodes that uses a voltmeter or...
The output current is of the order of 100 mA maximum, but the transistor used can be changed for...