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. 23, 2001
Filed:
Jun. 09, 2000
Bay E. Estes, Palatine, IL (US);
Ranco Incorporated of Delaware, Wilmington, DE (US);
Abstract
A water temperature control circuit for a washing machine includes window detector and dual water valve drivers to modulate the hot and cold water valves to maintain the water temperature at a desired level. A temperature selector switch provides hot, regulated hot, warm, regulated warm, and cold temperature settings for the washing machine. During regulated temperature operation the window detector modulates one of the water valves to maintain the water temperature within a narrow temperature band. The window comparator includes two comparators that receive a common temperature input from a temperature sensing element. As such, no shunt resistor is required for one or the other comparators, thus improving accuracy. The control circuit operates open loop with respect to the hot and cold water valves that it controls, utilizing instead only the temperature input for controlling the proper water valve when enabled.