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. 27, 1999
Filed:
Apr. 01, 1997
Junichi Hamatani, Shiga, JP;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
A motor start-up circuit is incorporated in a motor-driving circuit provided with an auxiliary coil which operates during a start-up time of the motor and a main coil for a steady-state operation of the motor. The start-up circuit in one form has a start-up thermistor with positive temperature characteristic and a Triac switch connected in series with the auxiliary coil and a triac-controlling thermistor with positive temperature characteristic connected in parallel to the start-up thermistor, and one of the terminals of the triac-controlling thermistor is connected to the gate of the Triac switch. The start-up circuit in another form has a Triac switch connected in series with the auxiliary coil and a triac-controlling thermistor with positive temperature characteristic connected in parallel to the auxiliary coil and the Triac switch and one of the terminals of the triac-controlling thermistor is connected to the gate of the Triac switch. In both forms, the triac-controlling thermistor has resistance 300-3000 .OMEGA. at 25.degree. C. and volume of 30-60 mm.sup.3 and doubles its value of resistance at 25.degree. C. at 70-125.degree. C.