Circuitry to maintain proper current transformer operation
US5610508A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 16, 1994 |
| Grant date | Mar 11, 1997 |
| Priority date | — |
| Expiry date | Jun 16, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit to maintain proper current transformer operation in a resonant transition converter circuit or any circuit having a wide range of reverse current present in a current transformer primary at the beginning of a power pulse. The circuit includes an active clamp which is applied to an extra secondary on the current transformer for the duration of a "on" time of a switch associated with a particular current transformer. A diode of the active clamp is polarized to accept current in the secondary when primary current is reversed or negative flow. Thereby only small amounts of voltage, and thus volt-seconds will be developed on the transformer during reverse primary current, in turn keeping the current transformer out of reverse saturation. A current generator provides a bias current during the on time of the switch associated with the particular current transformer and switches a bias current into the main current transformer secondary during the power pulse to offset the negative primary current which occurs at the beginning of a power pulse.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.