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:
Apr. 24, 1990
Filed:
May. 24, 1989
Alan D Gustafson, Eden Prairie, MN (US);
Lowell B Naley, Minnetonka, MN (US);
David A Christiansen, Bloomington, MN (US);
Stanley O Hoium, Eagan, MN (US);
Robert L Harrington, Eden Prairie, MN (US);
Dannis R Johnson, Savage, MN (US);
Gregory R Truckenbrod, Fridley, MN (US);
Thermo King Corporation, Minneapolis, MN (US);
Abstract
A method of controlling a refrigeration system by determining an average air temperature by sensing and averaging evaporator return and discharge air temperatures, and developing an average error by using the average air temperature and a selected set point temperature. The average air temperature is then used to calculate a proportional error and an integral error, and the discharge air temperature is used to calculate a floor error. The proportional error, integral error and floor error are weighted by predetermined gain factors and then summed to provide an error signal which is used to modulate the capacity of the refrigeration system, with the control mode depending upon the location of the error signal relative to set point.