发明授权
- 专利标题: Method and apparatus for RMS current approximation
- 专利标题(中): RMS电流近似的方法和装置
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申请号: US104747申请日: 1993-08-11
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公开(公告)号: US5450268A公开(公告)日: 1995-09-12
- 发明人: Timothy B. Phillips , Antoine D. Stentz
- 申请人: Timothy B. Phillips , Antoine D. Stentz
- 申请人地址: IL Palatine
- 专利权人: Square D Company
- 当前专利权人: Square D Company
- 当前专利权人地址: IL Palatine
- 主分类号: G01R19/02
- IPC分类号: G01R19/02 ; H02H3/093 ; H02H3/26
摘要:
A method and apparatus provides for a measurement technique which approximates the true rms value of a current waveform. The technique involves converting the current waveform to a voltage by rectification and determining the peak value and the average value of the resultant voltage. A summing circuit combines the two values at a predetermined ratio to create a DC voltage that is approximately equal to the rms value of the input currents. The DC voltage output is suitable for a wide range of applications. A combination of the approximation circuit with a time integrating circuit and a level detecting circuit produces a low cost solid state overload relay in a preferred embodiment of the invention. Other uses include metering and use as a current feedback control signal for controlling PWM inverters and the like.
公开/授权文献
- USD425613S Sheet stainless steel formed burner 公开/授权日:2000-05-23