This circuit is from American documentation from 1970. It can be designed with a BC558 and for the operational, we can use equivalents. The FET can be the BF245.
This circuit was found in the June 1991 issue of Radio Electronics magazine. The circuit uses two...
The MOSFETs are of the type of power and the resistors have their values between 1 k and 10 k for...
In the figure we have the way to use an LED to increase the voltage of a zener. The increase...