This nice analog indicator circuit was found in the January 1974 issue of Radio Electronics magazine. The circuit has 8 scales with individual adjustments. The instrument is rated at 50 uA.
Suggested by an American documentation for 1969 neon lamps, this circuit provides SCR control with...
This circuit is designed to measure very weak currents, in the order of picoamperes. We found it...
The 709 integrated circuit is not common today. The circuit is from American technical...