Digital light ballast oscillator
US7187244B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 2004 |
| Grant date | Mar 6, 2007 |
| Priority date | — |
| Expiry date | May 30, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/3925
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An oscillator for a power converter control outputs a pulse train based on a charging time of a capacitor linked to a variable current source. A digital to analog converter (DAC) controls the variable current source in conjunction with a switch to determine the charging time of the capacitor. By varying the digital DAC input, the charging time of the capacitor is modified, thereby modifying the frequency of the pulse train. A comparator compares the capacitor voltage to a toggled threshold, which switches depending on whether the capacitor is charging or discharging. The comparator output supplies the pulse train that can be used in a half bridge switching arrangement for the power converter, which can also serve as an electronic ballast for a lamp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.