Invention Grant
US08154211B2 End-of-life protection circuit and method for high intensity discharge lamp ballast
有权
寿命终止保护电路和高强度放电灯镇流器的方法
- Patent Title: End-of-life protection circuit and method for high intensity discharge lamp ballast
- Patent Title (中): 寿命终止保护电路和高强度放电灯镇流器的方法
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Application No.: US12578093Application Date: 2009-10-13
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Publication No.: US08154211B2Publication Date: 2012-04-10
- Inventor: Nanu Brates , Bhavinkumar Shah , Yiyoung Tony Sun
- Applicant: Nanu Brates , Bhavinkumar Shah , Yiyoung Tony Sun
- Applicant Address: JP Osaka
- Assignee: Panasonic Corporation
- Current Assignee: Panasonic Corporation
- Current Assignee Address: JP Osaka
- Agency: Greenblum & Bernstein, P.L.C.
- Main IPC: H05B37/00
- IPC: H05B37/00 ; H05B41/00 ; H05B37/02 ; H05B39/02 ; H05B39/04 ; H05B41/36 ; H05B39/00 ; H01J11/04 ; H01J13/48 ; H01J17/36 ; H01J15/04

Abstract:
An apparatus and method thereof for igniting and operating a high intensity discharge (HID) lamp during an in service life, and powering down the lamp when an end-of-life (EOL) lamp condition is detected. The apparatus and method defines a series of thresholds of lamp voltage asymmetry, or rectification thresholds, and monitors the lamp rectification from ignition through normal operation. The detection scheme is masked off for a predetermined period of time when the lamp is initially started. Thereafter, the rectification threshold of the lamp voltage asymmetry is gradually reduced over time, until a defined minimum rectification threshold level is reached and maintained. The method continuously monitors the lamp voltage and records whenever the lamp voltage asymmetry is higher than the rectification threshold level at any lamp voltage cycle. An EOL lamp condition is determined to exist when a certain number of high asymmetrical cycles occurs in selected total number of lamp voltage cycles during a rolling measurement window.
Public/Granted literature
- US20110084613A1 END-OF-LIFE PROTECTION CIRCUIT AND METHOD FOR HIGH INTENSITY DISCHARGE LAMP BALLAST Public/Granted day:2011-04-14
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