Non-intrusive impedance-based cable tester
US5977773A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1997 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Aug 15, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/088
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A non-intrusive electrical cable tester determines the nature and location of a discontinuity in a cable through application of an oscillating signal to one end of the cable. The frequency of the oscillating signal is varied in increments until a minimum, close to zero voltage is measured at a signal injection point which is indicative of a minimum impedance at that point. The frequency of the test signal at which the minimum impedance occurs is then employed to determine the distance to the discontinuity by employing a formula which relates this distance to the signal frequency and the velocity factor of the cable. A numerically controlled oscillator is provided to generate the oscillating signal, and a microcontroller automatically controls operation of the cable tester to make the desired measurements and display the results. The device is contained in a portable housing which may be hand held to facilitate convenient use of the device in difficult to access locations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.