Circuit for measuring in-circuit resistance and current
US5804979A · kind A · utility
40Cited by
4References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 13, 1997 |
| Grant date | Sep 8, 1998 |
| Priority date | — |
| Expiry date | May 13, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/16
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit for measuring alternating current (a.c.) and direct current (d.c.) in a conductor without breaking the conductor is provided. A modulated current source is coupled in parallel with a segment of the conductor to inject a test current. A synchronous demodulator is also coupled in parallel across the segment to separate the test voltage drop induced by the test current from the voltage drop due to the current in the conductor. The test voltage drop and the voltage drop are measured by a voltmeter and the resistance of the segment and the current flowing through the segment can then be calculated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.