US Patent 7663275 Linear compressor controller

Patent 7663275 was granted and assigned to Fisher & Paykel on February, 2010 by the United States Patent and Trademark Office.

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Is a

Patent

Patent attributes

Current Assignee

Fisher & Paykel

Patent Jurisdiction

United States Patent and Trademark Office

Patent Number

76632750

Patent Inventor Names

Zhuang Tian0

Ian Campbell McGill0

Date of Patent

February 16, 2010

Patent Application Number

112266750

Date Filed

September 14, 2005

Patent Primary Examiner

‌

Quyen Leung

Patent abstract

A sensorless method and apparatus for detecting piston collisions in a free piston linear compressor motor. The waveform of the back EMF induced in the motor stator windings is analysed for slope discontinuities and other aberrations in a time window centred on the back EMF zero-crossings. Waveform slope artefacts are indicative of piston collisions and cause the motor power to be decremented in response.