| 摘要 |
PURPOSE:To start holding the stopping state of a rotor and to maintain it without loss of a power source stability of a low voltage source by eliminating the influence of an electromagnetic induction at the time of supplying a holding current. CONSTITUTION:Since a transistor 19a is OFF when a driving current iA is switched to a holding current ia, the current ia flows to a limiting resistor 17a and a diode 18a. Since the current iA is switched to a current i1a, an electromagnetic induction based on the variation in this current occurs in a coil LLa. The resistance value of the control resistor 17a is suitably determined, thereby eliminating the excess of the set value of the current ia. When the influence of the induction is eliminated and the value of the current i1a is reduced, the transistor 19a is turned ON, a current i2a starts flowing to a branch resistor 20a, and is added to the current i1a which starts reducing. Then, a current obtained by adding the current i2a flowing to the resistor 20 to the current i1a flowing to the resistor 17a becomes the holding current ia. |
