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:
Jun. 12, 1990
Filed:
Feb. 15, 1989
John E Zabinski, Naperville, IL (US);
Harper-Wyman Company, Lisle, IL (US);
Abstract
A temperature controller utilizes a square wave signal whose pulse width is incrementally stepped in variable increments by a variable count in a register to determine the temperature being read by a sensor. The square wave signal is integrated to provide an analog signal that is compared to an analog signal provided by the sensor. When the amplitude of the integrated analog signal approaches the amplitude of the signal from the sensor, the count in the register is noted and the temperature is determined from the count by a piecewise linear equation. The temperature thus obtained is compared to a user selected temperature to control the temperature in the sensed area. The controller also includes a monitoring system that monitors the status of switching devices that are controlled by the controller to assure that the status of the switching devices corresponds to the status selected by the controller.