Dimmable ballast with resistive input and low electromagnetic interference
- Summary
- An AC to AC power conversion apparatus with constant power feeding characteristics to fluorescent lamp or HID lamp is described. The constant power characteristic is achieved by discontinuous mode operation of capacitor coupled in series with the load. Packets of energy are pumped out to the load in each switching cycle, regardless of the resonant characteristics. The dependence of the input power on the square of the supply voltage make the input resistive and produces good power factor automatically. The lamp load is dimmable by external phase control dimmer like resistive incandescent lamps. Multiple lamp loads with different power rating can be integrated by adding more sets of said capacitors and associated components.
- Supplementary Information
- Patent Number: US7122972B2
Application Number: US2004796108A
Inventor: Poon, Franki Ngai Kit | Pong, Man Hay | Liu, Joe Chiu Pong
Priority Date: 10 Nov 2003
Priority Number: US7122972B2
Application Date: 10 Mar 2004
Publication Date: 17 Oct 2006
IPC Current: H05B003702 | H05B004128 | H05B0041282 | H05B0041392
US Class: 315209R | 315276 | 315244
Assignee Applicant: The University of Hong Kong
Title: Dimmable ballast with resistive input and low electromagnetic interference
Usefulness: Dimmable ballast with resistive input and low electromagnetic interference
Summary: Alternating current to alternating current conversion apparatus for ballast or gas discharge lamp, cold cathode fluorescent lamp, high intensity discharge (HID) lamp.
Novelty: Alternating current-alternating current power conversion apparatus for e.g. fluorescent lamp, has terminal which is connected through primary winding to voltage source that charges or discharges capacitor within pulsating cycle
- Industry
- Optics
- Sub Category
- Lighting
- Application No.
- US2004796108A
- Country/Region
- Hong Kong
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