Remote current sensor
US4376247A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 26, 1981 |
| Grant date | Mar 8, 1983 |
| Priority date | — |
| Expiry date | Feb 26, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/15
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
To detect a change of current flow in a conductor, a current transformer is coupled to the conductor for generating a voltage corresponding to the rate of current change. A liquid crystal device is connected to the transformer and its optical state changes when the transformer generates a voltage. The liquid crystal device is incorporated in a fiber optic circuit illuminated at one end for controlling the light emission from the other end. If the monitored circuit carries direct current, the light emission will change state briefly when the current is turned on and off or makes other rapid changes. Where the monitored circuit carries alternating current, the emitted light will be on or off depending on whether the alternating current is on or off.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.