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:
Mar. 04, 1986
Filed:
Feb. 04, 1985
American Standard Inc., New York, NY (US);
Abstract
A microcomputer based defrost control for a heat pump system that 'learns' from previous defrost cycles to achieve optimum defrost control at each of a plurality of outdoor temperature ranges, even if the heat pump system operating parameters change due to system aging. At the conclusion of each defrost cycle, the control determines the differential temperature between the outdoor ambient air and the outdoor heat exchanger and compares that value to a value stored in microcomputer memory representing a previous best such post-defrost differential temperature for the same ambient air temperature range. The control then calculates a defrost differential temperature initiate value, corrected to compensate for any loss of defrost performance indicated by the current post-defrost cycle differential temperature. After a period of time during which a number of defrost cycles have occurred, the minimum post defrost differential temperature value for each ambient temperature range becomes the best performance measure of the defrost cycle for the heat pump system. The stored minimum values are reset to zero when the control and heat pump system are deenergized. When the system is again turned on, new optimum defrost initiate values are again determined over a period of time. In addition, various default conditions cause the control to initiate an extended defrost cycle. The control is programmed to alert the operator by lighting a lamp on the thermostat should such a fault condition occur.