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:
Feb. 04, 2003
Filed:
Feb. 14, 2001
Alex Horng, Kaohsiung, TW;
Nan Long Tsai, Kaohsiung, TW;
Sunonwealth Electric Machine Industry Co., Ltd., Kaohsiung, TW;
Abstract
A fan motor with variable frequency/constant speed control comprises a frequency comparator, a differential integrating circuit, and a differential amplifier. The frequency comparator calculates a frequency difference between a frequency of an external pulse signal input and a frequency of a speed signal detected from the fan. The differential integrating circuit converts the frequency difference into a voltage signal which is inputted to a negative terminal of the differential amplifier. A predetermined voltage is connected to a positive terminal of the differential amplifier. A voltage value at the negative terminal of the differential amplifier is compared with a voltage value at the positive terminal of the differential amplifier to thereby change a voltage outputted to an input end of the fan.