An Electronic A.C. Differential Voltmeter
L. A. Rosenthal, H.S. Zablocki · Review of Scientific Instruments · 1950
An electronic a.c. differential voltmeter capable of giving a direct reading of the percentage change in voltage in the region of ±10 percent for voltage levels from 1.5 to 150 volts and frequencies between 20 and 200,000 cycles, is presented. The instrument is stable in operation, and simple in design. Experimental observations and circuit details are included.