We found this circuit in the March 1992 issue of Radio Electronics magazine. The circuit has a range from 1.25 V to 1 kV. The formula for the voltage values is given.
We found this circuit in documentation from the 1970s; The circuit uses Japanese transistors of...
This circuit goes into operation producing a sound on a small speaker when the supply voltage...
Suggested by Harris in documentation from the 80s, this circuit uses components from that time. It...