Title:
CORD TENSION CONTROL APPARATUS
Document Type and Number:
WIPO Patent Application WO/2003/056695
Kind Code:
A1
Abstract:
A cord tension control apparatus includes a brushless motor (M) generating counter electromotive force, a rectifier circuit (2) connected to a winding of the brushless motor (M), and a constant current circuit (3) connected to the rectifier circuit (2). A voltage circuit (4) giving forward direction bias voltage is inserted between the constant current circuit (3) and the rectifier circuit (2). Even when the rotation speed of the motor (M) is lowered and the output voltage is lowered, at least the forward direction bias voltage generated by the voltage circuit (4) is applied to the constant current circuit (3). Accordingly, there is no non-operation state of the constant current circuit (3) when the rotation speed of the motor (M) is lowered. A constant current can be assured and the tension of cords can be controlled to be always constant (Fig. 1).
Inventors:
WANG GUO-HUA
KURITA YASUSHI
KURITA YASUSHI
Application Number:
PCT/JP2002/013204
Publication Date:
July 10, 2003
Filing Date:
December 18, 2002
Export Citation:
Assignee:
NITTA CORP (JP)
International Classes:
B65H59/10; B65H59/38; B65H59/40; H02P5/74; H02P9/10; (IPC1-7): H02P6/08; B65H59/10
Foreign References:
| JPH11325203A | 1999-11-26 | |||
| JPH11301927A | 1999-11-02 |
Attorney, Agent or Firm:
Inaoka, Kosaku c/o Ai Association of Patent and Trademark Attorneys (12F Jyutakukinyukoko-Sumitomoseimei Bldg.
5-20, Minamihommachi 4-chome, Chuo-k, Osaka-shi Osaka, JP)
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