Inverter power source
US5333104A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 1993 |
| Grant date | Jul 26, 1994 |
| Priority date | — |
| Expiry date | May 19, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/338
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An inverter power supply includes a DC supply providing a DC voltage from an AC mains, a transformer having primary, secondary, and feedback windings, and a self-excited oscillator energized by the DC supply to generate a high frequency voltage across the primary winding and induces across the secondary winding an output AC voltage for driving a load. The oscillator comprises an FET connected in series with the primary winding. A biasing capacitor is connected in series with the feedback winding across a source-gate path of FET for providing an offset voltage which is additive to a feedback voltage at the feedback winding to give a bias applied to a gate of FET so as to alternately turn on and off FET for self-excited oscillation. Also included is a bias stabilizing circuit which lowers the offset voltage by discharging the biasing capacitor through FET being turned on, thereby driving FET turned on only for substantially a constant ON-time period irrespective of an increase in the DC voltage within a limited range. The power supply is characterized to include a compensation circuit which produces a negative voltage to be superimposed to the offset voltage of the biasing capacitor,…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.