Patent · US Expired

D. C. electrometer

US4063154A · kind A · utility

13Cited by

4References

2Claims

0Family size

Assignee

Xerox Corporation · US

Inventors

Paul G. Andrus · Powell, US
James M. Hardenbrook · Columbus, US

Key dates

Filing date	Nov 26, 1976
Grant date	Dec 13, 1977
Priority date	—
Expiry date	Nov 26, 1996

Classification

Technology area (CPC G)Physics
CPC primaryG01R29/12
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

Feedback circuit for the probe of an d.c. type electrostatic voltmeter to reduce spacing sensitivity thereof. A variable gain amplifier is employed to control the amplitude of the a.c. signal output of a square wave oscillator in response to the potential sensed by the probe. The a.c. signal output drives a high voltage transformer, the output of which is rectified to provide a d.c. signal output matching the potential sensed by the probe. The d.c. output is returned to the probe housing to bias the housing to a potential equal to the potential read by the probe. A sample and hold circuit enables readout of the d.c. signal output.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.