发明名称 |
Zero crossing detection of line voltage/current of variable amplitude |
摘要 |
A method and apparatus for detecting a zero crossing or desired phase angle of a power line signal having a variable amplitude uses a ratio between a peak amplitude of the power line signal and the amplitude of the power line signal at a desired phase angle for a known amplitude version of the power line signal to detect when a variable amplitude version of the power line signal is at the desired phase angle or zero crossing. The detection of the phase angle is used to determine if a notch is present in the power line signal. A substantially constant width pulse is generated if a notch is detected regardless of the amplitude of the power line voltage or current. The invention is particularly useful in a lighting system for generating and detecting pulses used to communicate information from a power line communication controller to a series of electronic ballasts over a power line used to power the ballasts. The information can be used to control a dimming function of the ballasts.
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申请公布号 |
US7394204(B1) |
申请公布日期 |
2008.07.01 |
申请号 |
US20060332853 |
申请日期 |
2006.01.13 |
申请人 |
UNIVERSAL LIGHTING TECHNOLOGIES, INC. |
发明人 |
SHET DEEPAK;LI CHANGSHENG;DERNOVSEK JOHN JAY |
分类号 |
H05B37/02 |
主分类号 |
H05B37/02 |
代理机构 |
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地址 |
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