The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 20, 1992
Filed:
May. 24, 1991
Robert W Redlich, Athens, OH (US);
Sunpower, Inc., Athens, OH (US);
Abstract
The displacement of a Stirling cycle cryocooler is controlled as a function of temperature by controlling the amplitude of the fundamental component of an AC signal which is applied to the motor at its operating frequency. A pulse train is generated, having a frequency which is a harmonic of the operating frequency. The duty cycle of the pulse train is modulated between 50% and 100% as a function of the temperature. The modulated pulse train is applied to the motor during one-half of the load's operating period and the complement of the pulse train is applied to the load during the other half of its operating period. Modulating the duty cycle of the pulse train (and consequently simultaneously of its complement) as a function of temperature variably controls the amplitude of the fundamental component of the drive voltage and therefore variably controls the displacement of the motor and, as a consequence, of the cryocooler piston.