Dimmer having a power supply monitoring circuit
USRE42425E1 · kind E1 · reissue
Assignee
Inventors
Key dates
| Filing date | Jun 9, 2009 |
| Grant date | Jun 7, 2011 |
| Priority date | — |
| Expiry date | Jun 9, 2029 |
Classification
- Technology area (CPC —)General
Abstract
A two-wire dimmer for control of a lighting load from an alternating-current (AC) power source includes a semiconductor switch, a power supply, and a control circuit. The power supply includes an energy storage input capacitor that is able to charge only when the semiconductor switch is non-conductive. The control circuit continuously monitors the voltage on the input capacitor and automatically decreases the maximum allowable conduction time of the semiconductor switch when the voltage falls to a level that will not guarantee proper operation of the power supply. The dimmer of the present invention is able to provide the maximum possible conduction time of the semiconductor switch at high end (i.e., maximum light intensity) while simultaneously ensuring sufficient charging time for proper operation of the power supply, and hence, the dimmer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.