Electronic ballast with lamp current correction circuit
US5519289A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 1994 |
| Grant date | May 21, 1996 |
| Priority date | — |
| Expiry date | Nov 7, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention features a gas discharge lamp electronic ballast that uses a frequency-dependent control circuit. The lamps are all energized by means of a single electronic ballast, including an electronically regulated power supply, a power oscillator/driver circuit, an output coupling circuit and a feedback circuit that provides frequency-to-voltage conversion for controlling the output voltage of the power supply. In this way, constant lamp current is maintained, regardless of the number of lamps connected. Since the remaining lamps are operated at their specified, correct lamp current, lamp life is preserved. Another feature of the circuit is its ability to dim the lamp output continuously over a limited range to reduce energy usable in circumstances in which full lamp illumination is not required. Such dimming can be controlled by a suitable external control signal such as from a potentiometer, switch, light monitoring device or a motion detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.