| 摘要 |
PURPOSE:To save power consumption by simultaneously exciting a start coil and a holding coil, moving a movable body, generating an induced electromotive force on the holding coil and deexciting the start coil through detection of such induced electromotive force. CONSTITUTION:When a switch 24 is turned conductive, the main control circuit 25 applies a voltage to the lines 29, 30 through the lines 26, 27. Thereby, the start coil 2 is excited and an output voltage of power supply 23 is lowered by DELTAv1 from the voltage at the time of deexcitation due to the internal resistance of power supply 23. The main control circuit 25 applies a voltage to the holding coil 3 and the pulses p1, p2 are superposed to the lines 31, 32. A level discrimination circuit 33 discriminates the level of pulse p2 with the discrimination level Vl and applies an inactivation signal having the predetermined pulse width to the main control circuit 25 and auxiliary control circuit 28 from the line 34. Thereby, the auxiliary control circuit 28 cuts off the excitation power of the lines 29, 30. Only the holding coil 3 is excited and the start coil 2 is kept deexcited and therefore power consumption of electromagnet apparatus 1 can be saved.
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