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. 30, 1990
Filed:
Jun. 23, 1989
Robert W Peitz, Jr, Fayetteville, NY (US);
Carrier Corporation, Syracuse, NY (US);
Abstract
An emergency heat circuit for a microprocessor-controlled furnace has a first emergency heat switch with one terminal in contact with a rectifier circuit that provides a DC voltage when the thermostat calls for heat, and another terminal connected to an emergency heat-active input of the microprocessor. A first opto-isolator has an optical actuator, such as an LED connected to the microprocessor failure output and a switched element unless such as a photo-transistor, with terminals connected in parallel to the first emergency heat switch. A second opto-isolator is also connected to the emergency heat switch and has an AC photo-actuated switch element, such as a photo-triac, connected, for example, to the W conductor and with an output connected to the rectifier circuit. The photo-triac latches on until the thermostat is satisfied.