Dimmable instant start ballast
US8547029B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 2012 |
| Grant date | Oct 1, 2013 |
| Priority date | — |
| Expiry date | May 25, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/3927
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A ballast for dimming a lamp is provided. The ballast includes an inverter circuit for providing a lamp current for energizing the lamp and a dim interface for receiving an input indicative of a selected lighting level. A control circuit is connected to the dim interface for generating a pulse-width-modulated signal having a duty cycle corresponding to the selected lighting level. A switching network is connected to the control circuit for receiving the pulse-width-modulated signal. The switching network operates between a conductive state and a non-conductive state as a function of the pulse-width-modulated signal. An impedance device is connected across the switching network and is configured for connecting in series with the lamp so that the impedance device receives the lamp current when the switching network is operating in the non-conductive state and the lamp current bypasses the capacitor when the switching network is operating in the conductive state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.