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. 20, 2004
Filed:
Aug. 08, 2001
David D. Neranjan, Miami, FL (US);
Mark O. Gerwig, Pembrooke Pines, FL (US);
A-l Components, Corp., Hialeah, FL (US);
Abstract
A device for monitoring the state of relay contacts is especially useful for controlling motor windings in air conditioning systems. When a first relay switch, which is operative to supply power to a first motor winding does not open as desired, a switch monitoring module responsively controls the second relay switch energization to prevent the second relay switch from being closed. This prevents power that would be supplied to a second motor winding from being also supplied to the first motor winding and causing potential damage to the first motor winding. A disclosed example includes an opto isolator that is energized only when the first relay switch is open as desired. The opto isolator controls an output signal to a second relay control portion, which only operates the second relay if the first relay has opened as required.