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. 11, 1988
Filed:
Oct. 09, 1984
Charles Crocket, Colleyville, TX (US);
Merle Bengston, La Crosse, WI (US);
Ranco Electronics Division, Irving, TX (US);
Abstract
A heater including a sensing device for sensing an ambient temperature, a temperature input device for providing a user selectable input temperature both connected to a first circuit to control the heater. The first control circuit includes positive feedback and negative feedback to electrically define a temperature range. The first circuit provides an on/off time duty cycle output wherein the on to off time of the duty cycle is relative to the relationship between the temperature range and the sensed ambient temperature. A second circuit is connected to receive the duty cycle output from the first circuit and is further connected to an alternating current power source to provide a second output signal during the zero crossing of the alternating current power source and when the duty cycle output is present. A driver circuit is connected to receive this second signal and activates the heater when the second signal is active by providing a third signal to a triac which regulates power to the heater.