Patent ID: 7239498

Claim:
Mining electromagnet for switching hydraulic pilot or main control valves used in underground mining, with a coil which is adapted to be connected to an intrinsically-safe power unit serving to supply current and voltage to the coil, with an armature which can be displaced by feeding current to the coil and with a control device, by means of which the current which is fed can be adjusted in the drawing-in phase of the armature to an excitation current and in the holding phase to a holding current which is lower than the excitation current, wherein said electromagnet further comprises a storage means adapted to be charged with the power unit voltage, and adapted to be switched on by the initiation of a switching procedure for the electromagnet so as to be placed in series with the power unit, and whereby discharge of the storage means has the effect for the drawing-in phase of increasing the voltage applied to the coil of the electromagnet which is to be switched in comparison with the supply voltage of the power unit.