Circuit for driving a gas discharge lamp load
US5124619A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1991 |
| Grant date | Jun 23, 1992 |
| Priority date | — |
| Expiry date | May 28, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit (100) for driving a gas discharge lamp load (102, 104, 106) and including: an inverter (112) receiving a unidirectional voltage output and producing an alternating voltage, and having a control input (156, 166); a series-resonant oscillator (126) coupled to the inverter output (116) and having an inductance (128) and a capacitance (130) in series for producing an alternating current; an output transformer (134) coupling the lamp load to the oscillator in series with the inductance and in parallel with the capacitance; and a feedback transformer (146) having a primary winding (148) coupled in parallel with the output transformer and coupled in series with the capacitance and a secondary winding (150, 152) coupled to the control input of the inverter. Since the feedback transformer primary winding carries only capacitive current (I.sub.C), the frequency of the circuit is substantially independent of the load. This allows the feedback transformer to be of the non-saturating-core type while retaining control of the oscillator frequency. Also, the circuit automatically shuts down in the event of load short-circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.