Lamp driver circuit
US4987347A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 1989 |
| Grant date | Jan 22, 1991 |
| Priority date | — |
| Expiry date | Mar 8, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A lamp driver circuit is presented herein for driving a lamp circuit with an AC squarewave voltage at a relatively high frequency. The driver circuit includes a self-oscillating half-bridge circuit having a pair of input terminals connected across a DC voltage supply, which may be obtained from rectifying an AC voltage signal, and a pair of output terminals connected across a lamp circuit including a lamp, either a resistive lamp or a gaseous discharge lamp, to be energized. The circuit also includes a pair of capacitors connected together in series across the input terminals and having a junction therebetween connected to a first one of the output terminals. The bridge circuit also includes first and second switching transistors connected together in series across the input terminals. A transformer is provided having first and second windings thereon respectively connected to the first and second switching transistors for alternately applying forward biasing base drive current to the first and second transistors. A third winding on the transformer is connected in series from the junction of the two transistors to a second one of the output terminals for purposes of supplying a squ…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.