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Patent Searching and Data


Title:
CONTROL METHOD OF BRUSHLESS MOTOR
Document Type and Number:
Japanese Patent JPH09261993
Kind Code:
A
Abstract:

To simplify the position detecting circuit of a rotor of a brushless motor, and enable transition to position detecting operation in a short time.

When a DC power source is applied to a brushless motor 4, its rotation is controlled by chopping and driving the switching of the upper and the lower arms of an inverter part 3. A position detecting circuit 10 combines terminal voltages through a resistance circuit 10a, and obtains a neutral point voltage. It is made to pass a capacitor 10 and its DC component is cut off. This voltage is based up with a resistance circuit 10c, and compared with a reference voltage generated by a reference voltage generating circuit 10d. The result is delivered to a control circuit 11, as a position detecting signal. When the motor is started, the control circuit 11 perfoms the changeover of the upper and the lower arms chopping, several times in each induced voltage section. A differential circuit constituted of a capacitor and a resistor is balanced, and the position of the rotor is detected by the inputted position detecting signal. Based on the detected result, current application is changed over, and position detecting operation and synchronous operation are used together.


Inventors:
OHARA YOSHIYUKI
Application Number:
JP9196496A
Publication Date:
October 03, 1997
Filing Date:
March 21, 1996
Export Citation:
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Assignee:
FUJITSU GENERAL LTD
International Classes:
H02P6/12; H02P6/06; H02P6/08; H02P6/18; H02P6/182; H02P6/21; (IPC1-7): H02P6/18; H02P6/12
Attorney, Agent or Firm:
Takuya Ohara