Primary side lamp current sensing for minature cold cathode fluorescent lamp system
US5754012A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1996 |
| Grant date | May 19, 1998 |
| Priority date | — |
| Expiry date | Oct 7, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit for sensing a current in a fluorescent lamp. A control system comprises a buck regulator circuit for supplying a buck current, an inverter circuit for receiving the buck current and for generating a lamp voltage, a circuit for sensing a current in a fluorescent lamp, and a controller for controlling the buck regulator and the inverter. The inverter comprises a Royer-type inverter, a resonant tank, and a transformer. A current flows through a primary winding of the transformer to generate a voltage in a secondary winding of the transformer. The fluorescent lamp is coupled to the secondary winding of the transformer so that the fluorescent lamp is isolated from the remainder of the control system by the transformer. The circuit for sensing the current in the lamp senses a current in the Royer-type inverter which is representative of the current in the lamp. The circuit for sensing the current in the lamp is coupled to the controller for controlling the buck regulator and the inverter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.