| 摘要 |
PURPOSE:To control and drive the magnetic force of an electromagnet safely and advantageously by full-wave rectifying and switching a three-phase alternating current. CONSTITUTION:Since a three-phase alternating current is full-wave rectified and outputted by a direct current output means 1, there is no timing when the output voltage becomes 0, and by duty controlling this by the use of a switching means 3 driven by a switching pulse control means 7, the magnetic force of an electromagnet is arbitrarily controlled. As the switching means, a gate turn-off thyristor (GTO) or a large-capacity FET can be used in addition to a high-power transistor, and as the switching pulse control means, a construction using a known PWM, PAM or the like can be thought of. With this, the magnetic force of an electromagnet can be variably controlled with safety, and the trouble due to the momentary loss of the magnetic force existing in the prior-art device using an alternating current as the power supply can completely be dissolved, thereby further improving the safety in use of an attracting device using an electromagnet.
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