The figure shows the equivalent circuit for the LM381 audio preamplifier IC. The circuit was found in the February 1990 issue of Radio Electronics magazine.
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...