Electronic ballast for gaseous discharge lamps
US4415839A · kind A · utility
Inventor
Key dates
| Filing date | Nov 23, 1981 |
| Grant date | Nov 15, 1983 |
| Priority date | — |
| Expiry date | Nov 23, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/2828
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic ballast for energizing one or more gaseous-discharge lamps and for regulating the power consumed thereby, the ballast including a power supply for providing a source of DC power between a pair of outputs, a pair of transistors connected as switches in series between the power-supply outputs, the transistors for selectively coupling to the juncture thereof positive and negative potentials, a voltage-conditioning and current-limiting network for energizing the lamp from the potential developed between the transistor juncture and a power-supply common, and a pulse generator for developing pulses for driving each of the transistors in turn whereby a potential is developed at the transistor juncture which alternates as positive-going and negative-going pulses each separated by a dead time, the pulse generator for monitoring the power consumption level of the lamp and responsive thereto operative to vary the frequency and/or the width of the transistor driving pulses whereby the lamp consumption is regulated. Also included is a third harmonic trap for coupling the power supply to the AC power line to improve the power factor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.