Electronic ballast deriving auxilliary power from lamp output
US6023132A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1998 |
| Grant date | Feb 8, 2000 |
| Priority date | — |
| Expiry date | Oct 12, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An ballast includes a variable frequency boost circuit and a driven half-bridge inverter having a series resonant, direct coupled, parallel output. A control circuit includes a variable frequency driver section, a multivibrator section, and a sensing section. The variable frequency driver changes frequency smoothly, i.e. without discontinuities. The multivibrator section acts as a switch that is enabled or disabled by the sensing section for controlling the frequency of the inverter. Lamp current is required for continued operation of the control circuit. The multivibrator section controls starting by causing the inverter to produce an output signal having a trapezoidal envelope. In the event of an arc, the control circuit quenches the arc and the multivibrator periodically pulses the lamp to attempt to re-start the lamp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.