Found in a 90s Popular Electronics, this circuit aims to find the voltage of a zener diode up to approximately 20 V. The transformer may have a lower current.
This circuit for signals around 4.5 MHz for old analog TV was found in the September 1992 Radio...
The circuit shown is a commercial electronic voltmeter sold in Japan in the 1960s. The circuit is fully...
This 80's circuit can be implemented with modern equivalent FETs with lower on resistance. The...