Self powering technique for integrated switched mode power supply
US5014178A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 14, 1990 |
| Grant date | May 7, 1991 |
| Priority date | — |
| Expiry date | May 14, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/0006
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A regulator circuit is connected to a transformer. The transformer has a primary winding connected to a rectified D.C. voltage signal and has a feedback winding. A feedback capacitor is coupled across the feedback winding of the capacitor. The regulator circuit includes a high voltage switching transistor, a pulse width modulator which controls the high voltage switching transistor and a high voltage power up transistor. At power up, the high voltage power up transistor connects the single high voltage pin to the feedback capacitor allowing the feedback capacitor to begin charging. When the feedback capacitor has charged past a first threshold voltage the pulse width modulator alternately turns the high voltage switching transistor on and off. When the high voltage switching transistor is turned on, the high voltage pin is connected to ground and current passes through the primary winding of the transformer, and thus current is generated through the feedback winding into the feedback capacitor. Additionally, when the high voltage power up transistor is on, the gate of the high voltage power up transistor is connected to ground turning the high voltage power up transistor off. Once …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.