The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 17, 1998
Filed:
Jan. 17, 1996
Noel Verbiest, San Jose, CA (US);
Lyle Nelsen, San Jose, CA (US);
Steven B Heymann, San Jose, CA (US);
Noux Corporation, San Jose, CA (US);
Abstract
An electrometer that is able to measure the potential difference of an electrostatically charged body without causing a rapid discharge of the subject charge. The electrometer has an input impedance that is in excess of 100 gigohms. The input impedance is created by an active voltage divider. The active voltage divider is a unique circuit which instead of the typical voltage divider that utilizes a passive resistive divider and an op amp in a voltage follower configuration, uses an amplifier configuration that attenuates its input signal. One result of this configuration is that the input line can then be guarded. This allows the device to be supplied with probes that are not subject to typical elements of degradation of the input signal with distance from the circuit, e.g. parasitic capacitance and bandwidth limitations. The device operates with two channels: a first channel recognizes the presence of a charged body in the proximity of the device, while the second channel measures the magnitude of the potential difference on a charged body examined by a probe. The device includes alarms that are activated when charge levels exceed a chosen level. A display tower allows a user to visually demonstrate to trainees the magnitude of ESC events.