Gas discharge lamp ballast circuit with reduced parts-count starting circuit
US5426346A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 9, 1994 |
| Grant date | Jun 20, 1995 |
| Priority date | — |
| Expiry date | Mar 9, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed is an electronic ballast circuit for a high pressure gas discharge lamp with a reduced parts-count starting circuit. The circuit comprises an arrangement for supplying d.c. voltage from a d.c. source, and a main inductor for receiving energy from the d.c. source and supplying the energy to the lamp. The main inductor has a plurality of windings. A first winding of the inductor is coupled to receive energy from the d.c. source. Further included is a current-switching arrangement conductive during periodic first part cycles for transferring energy from the d.c. source to the main inductor, and non-conductive during periodic second part cycles. A first part cycle is followed by a second part cycle in successive periods of switching operation of the current-switching arrangement. The first winding of the main inductor has impressed across it substantially the d.c. source voltage during the first part cycles, and reflects substantially the lamp voltage during the second part cycles. The circuit further includes a starting circuit for providing a pulse in excess of 15,000 volts across the lamp to facilitate starting the lamp. The starting circuit comprises a spark gap device, a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.