| 摘要 |
PROBLEM TO BE SOLVED: To provide a tension control device for a cord capable of constantly controlling tension even when a rotational speed of a motor is lowered, and capable of applying forwardly biasing voltage to a constant current circuit 3 which is generated at a voltage circuit 4 at least even when the rotational speed of the motor M is lowered and the output voltage is lowered, and thereby non-action of the constant current circuit 3 at lowering of the rotational speed of the motor M is prevented, and the tension of the cord is always controlled constantly. SOLUTION: This tension control device for the cord is provided with the brushless motor M generating counter electromotive voltage in accordance with the rotational speed, a rectifier circuit 2 connected to a winding wire of the brushless motor M, and the constant current circuit 3 connected to the rectifier circuit 2. The voltage circuit 4 for applying the forwarding biasing voltage is inserted between the constant current circuit 3 and the rectifier circuit 2. COPYRIGHT: (C)2003,JPO
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