Transformer hot spot detection system
US4140999A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 3, 1976 |
| Grant date | Feb 20, 1979 |
| Priority date | — |
| Expiry date | May 3, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08C19/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention is a system for the detection of hot spots, i.e., localized over-heating, in electrical power transformers and the like which utilize one or more telemetric temperature devices that are embedded at preselected locations in the windings of the transformer and that utilize a coil about the windings to obtain an induced voltage power supply that is rectified and drives an oscillator circuit of the device. The oscillator circuit includes a temperature responsive component that varies the frequency of the oscillator output in response to the local, sensed temperature. The output of the oscillator circuit is coupled to a telemetering facility to broadcast by electromagnetic or ultrasonic radiation the temperature-altered signal to a remote receiver, whereby the telemetric temperature device is isolated and "floats" on the voltage potential of the windings at its location.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.