Electronic ballast
US7279844B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 2004 |
| Grant date | Oct 9, 2007 |
| Priority date | — |
| Expiry date | Feb 2, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/295
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to a ballast for low-pressure discharge lamps, comprising a controllable inverter circuit for the generation of a high-frequency supply voltage for a discharge lamp (1), a lamp inductance (L1) connected to the inverter circuit, a lamp parallel capacitor (C1) which is serially connected to the lamp inductance (L1) and connected in parallel to the discharge lamp (1), and a preheating circuit supplying heating current to the electrodes (2, 3) of the discharge lamp (1). In order to minimize electrical losses and to enable universal use of said ballast for various types of discharge lamps the invention proposes that current is supplied to the preheating circuit via an auxiliary winding (7) arranged on the lamp inductance (L1) with said auxiliary winding (7) being connected with the preheating circuit via a controllable switch or a parallel resonant circuit (9).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.