| 摘要 |
PURPOSE:To make a separator compact and light, by promoting a rise of exciting current by applying an excessive exciting-voltage to an exciting coil at the time of starting the exciting, in the separtor which excites by detecting an inclusion of a magnetic piece. CONSTITUTION:When a magnetic piece, mixed in raw materials on a moving conveyor 19, passes through a detecting means 24, a detecting signal is inputted to a controlling device 30 to close changeover-means MC1-1-3, thereby an excessive exciting-voltage VH is supplied to an electromagnet of an electromagnetic separator 12. An exciting current flows in the electromagnet as shown by the dotted line to rapidly increase toward an excessive stationary-current IH corresponding to the voltage VH, and shows a rapid rise so as to attain a lower limit value IL of exciting current capable of attracting the magnetic piece, in an extremely short time t1. When the exciting current exceeds a current vaue IS corresponding to an ordinary exciting-voltage VS, an ordinrily closed contact and an opened contact at the MC-2 opens and closes respectively to change over the voltage supplied to the electromagnet to the ordinary exciting-voltage VS. |
