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:
Nov. 13, 1990
Filed:
Dec. 11, 1989
Kenneth E Lutz, Hickory Corners, MI (US);
Ralph S Robertson, Delton, MI (US);
Keltech, Inc., Richland, MI (US);
Abstract
A closed loop, electronic temperature control system for a tankless water heater. The control system incorporates error range comparison circuitry for comparing the difference between a water temperature selected from a temperature selection device and an actual water temperature sensed by a temperature sensing device. An error range comparison circuit operates to select a high gain when the sensed water temperature is within about +/-3.degree. Fahrenheit of the selected temperature, and a low gain when the sensed water temperature is more than +/-3.degree. Fahrenheit of the selected water temperature. A slow start network is included for applying current gradually to the heating element of the water heater when power is initially applied to the system. A master power down circuit quickly interrupts current flow to the heating element after the system has been powered down.