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:
Jul. 21, 1998
Filed:
Jun. 03, 1997
James B Farr, Ann Arbor, MI (US);
Tecumseh Products Company, Tecumseh, MI (US);
Abstract
The present invention involves control and protection circuit for a compressor motor which includes an inductively activated contactor for controlling the flow of current to the compressor motor. The circuitry of the present invention includes a plurality of current detectors associated with each phase winding of the compressor motor for sensing the current in each phase winding. The sensed currents are combined in a predetermined manner and used to provide protection against an overcurrent condition, single phase operation and light loading condition. Additional detector circuits are also connected to the present control and protection circuit to provide protection against high temperature in the compressor motor windings, high temperature in various component of the compressor motor, and undervoltage in the power supply. A temperature detector disposed inside the cooling chamber also provides for cycling of the compressor motor to maintain the temperature in the cooling chamber at within a predetermined temperature range. The inductive coupling is activated by a protection timer and an oscillator. The protection timer deactivates the oscillator when a trip signal is received from the detector circuits. A predetermined time delay is provided by the protection timer to prevent spurious trips of the compressor motor.