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:
Jan. 29, 2002
Filed:
Apr. 26, 2000
Prasad S. Khadkikar, Seville, OH (US);
James A. Tennant, Perrysville, OH (US);
Bernd D. Zimmerman, Ashland, OH (US);
David W. Reynolds, Galion, OH (US);
Thomas C. Anderson, Arlington Heights, IL (US);
Therm-O-Disc, Incorporated, Mansfield, OH (US);
Abstract
A temperature control circuit provides for optical isolation, dry start protection, dedicated load control, manual reset, and relay control in hot water heaters and related applications. The control circuit removes power from a load at a first temperature, and includes a first optical isolation device, a first diode temperature sensor, and a first switching mechanism. The first optical isolation device controls operation of a power source, where the power source is provided to the load, such as a hot water heater heating element. The first diode temperature sensor is biased to provide a switching signal at the first temperature. The first switching mechanism is disposed between the first diode temperature sensor and the first optical isolation device, where the first switching mechanism disengages operation of the first optical isolation device in response to the switching signal. The control circuit can further include a high limit cycling circuit for disengaging operation of the power source at the second temperature. A latching circuit can be used to maintain the temperature control circuit in a switched state until a manual reset occurs.