Method and circuit to operate a low-pressure discharge lamp, particularly compact fluorescent lamp
US5122712A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 21, 1991 |
| Grant date | Jun 16, 1992 |
| Priority date | — |
| Expiry date | Feb 21, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/05
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
To decrease the losses in the starting circuit for a compact fluorescent p, a positive temperature coefficient (PTC) resistor (KL) is connected in a resonance circuit of the lamp and also connected to the power supply of the lamp through a diode, polarized in blocking direction with respect to direct current, so that, before the lamp fires, a-c provided from an inverter (INV) can pre-heat the electrodes (E1, E2) of the lamp (LP), which will also cause current flow through the PTC resistor (KL); upon heating of the PTC resistor, this d-c current decreases and the voltage across the electrodes of the lamp will rise. When the lamp fires, it will drop below the supply voltage of the operating circuit for the lamp, thus causing the removal of the PTC resistor from the current carrying circuit, thereby eliminating energy loss through that resistor, and heating of the operating circuit assembly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.