| 摘要 |
PURPOSE:To drastically decrease power consumption by forming a holding coil connected to a power source for holding as a part of a solenoid, and holding a plunger after attracted only with this holding coil. CONSTITUTION:When a main power source is turned on, a voltage is impressed to the power source 5 for holding and a power source 3 for operation, but since a switch 2 is in off-state, no current flows through a coil 1a for operation. Then, a signal from a control circuit (not shown in the figure) gives out a signal, and a potential to turn on the switch 2 is supplied to the switch 2 to make the power source for operation 3 and the coil 1a for operation conductive, and the solenoid 1 forms a magnetic field by the current flowing from the power source 3 to attract the plunger 4. After this attraction, the potential turning on the switch 2 is cut off also by means of the signal from the control circuit to separate the power source 3 and the coil 1b from each other. Thus the plunger 4 keeps being attracted by the magnetic field of the holding coil 1b, and as far as the main power source of a disc device is not cut off, the plunger 4 does not recede to its original position. As a result, the power consumption can be drastically reduced.
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