With this circuit it is possible to obtain a higher voltage from a zener diode. The circuit is from a 1970’s EEE. The device used as a constant current source is uncommon today.
In the original 1992 application, this passive circuit was intended for use in the car. At that...
This 1995 circuit uses an audio amplifier that is no longer common today. However, other...
This circuit is from an 80's documentation. The integrated circuit is from the time and the...