Circuit for measuring the ground resistance of an ungrounded power circuit

US4066950A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Gerhard Rumold · Bubenreuth, DE
• Georg Russ

Key dates

• Filing date: Sep 9, 1976
• Grant date: Jan 3, 1978
• Expiry date: Sep 9, 1996

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R27/18
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A measuring circuit for measuring the ground resistance of an ungrounded power circuit, particularly a d-c system supplied from a converter circuit in which a series circuit including an a-c voltage generator, a measuring resistor and a coupling member is connected between the object of the measurement and ground and an evaluation circuit including a phase sensitive rectifier circuit forms the unknown ground resistance by dividing the active component of the current driven by the generator voltage through the series circuit into the voltage between the measurement object and ground.