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:
Apr. 15, 2003
Filed:
Jul. 12, 2001
Hung D. Vu, Pembroke, MA (US);
Ralph W. Horber, Marshfield, MA (US);
Seiberco Incorporated, Braintree, MA (US);
Abstract
An electronic circuit and software control methodology tracks motor position in a motor drive system. High power consumption position transducers, such as inductive sensors or optical encoders, can be controlled in a variable active duty cycle mode to reduce power and yet maintain motor position information while the main power is off. A lower power battery backup circuit is implemented as a secondary power source, and is automatically brought in operation when the main power supply is disabled. A dedicated control circuit operates during AC power outages, and the circuit average power can be controlled to a minimal rate, based on the rate of change of motor position. The motor can be externally driven, up to a defined limit speed, without losing its actual position information.