Brushless dc motor

Abstract

Abstract PURPOSE:To improve the power efficiency at the small current time and alleviate the saturation degree of a drive transistor at the large current time by switching and controlling a DC voltage by the operation voltage detecting output of the transistor to control the energization of a drive coil. CONSTITUTION:The first feedback loop is composed of a current controller 51, a selector 52, drive transistors 6-8, and a current detector 53, and a current Ia supplied to coils 3-5 becomes a value corresponding to a command signal 20. The second feedback loop is composed of an operation detector 12, a voltage converter 13 and the coils 3-5 to control the output voltage VM of the voltage converter 13 so that the detecting operation voltage V4 of the transistors 6-8 becomes equal to the prescribed value in the active range. When the voltage V4 becomes smaller than a reference voltage V3 due to the rise of the rotating speed, the output i2 of a correcting unit 16 becomes small by the output current i10 of the detector 12, the output V1 of a filter 17 becomes small, and the current Ia is corrected to small value by the operation of the first feed back loop.

Inventors

• 👤 Makoto Goto
• 👤 誠 後藤
• 👤 Takafumi Akeda
• 👤 明田　隆文
• 👤 Yoshiteru Hosokawa
• 👤 細川　芳輝

Bibliographic Details