Transformer over-current protection with RMS sensing and voltage fold-back
US6873142B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 14, 2004 |
| Grant date | Mar 29, 2005 |
| Priority date | — |
| Expiry date | May 14, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY04S20/222
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for selectively enabling flow of current to a load from an alternating current supply signal connected to the load is presented. The method includes storing a first time passing between a zero-crossing of the supply signal, the first zero-crossing indicating a leading edge of the signal, and a second zero-crossing of the supply signal, the second zero-crossing indicating a trailing edge of the supply signal. The method further includes sending a first signal enabling flow of the current according to a desired conduction angle when a subsequent zero-crossing indicating the leading edge of the supply signal does not occur within a second time, the second time being at least as long as the first time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.