Control system for an electromagnet
AssigneeLucifer S.A.
InventorHarald Stampfli
Life of this patent
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Abstract
Control system for an electromagnet having a movable core, wherein a power winding is provided for moving the core to active position and a holding winding requiring less power maintains the core in active position. A transistor controls the power supply circuit and, when made conductive, energizes a transistor in series with each winding, thus energizing both windings. After a time delay provided by a resistor-condenser circuit, another transistor is energized which causes the transistor in the power winding to become non-conductive, thus de-energizing the power winding. De-energizing the control transistor causes the transistor in the maintenance winding to become non-conductive so that the maintenance winding is de-energized and its energy is dissipated through a Zener diode and a resistor, both in series therewith.
Claims3
Control system for an electromagnet for furnishing a high initial current upon energizing, followed by a smaller maintenance current, containing a first semiconductor (T.sub.1), whose conductivity is controllable, connected in a first circuit adapted to control the initial current, and a second semiconductor (T.sub.2), whose conductivity is controllable, connected in a second circuit adapted to control the maintenance current, a control circuit (M, R.sub.1, D.sub.5, D.sub.6, T.sub.3, T.sub.4) common to the two semiconductors, switching means (T.sub.6) for applying to the control circuit a control voltage that will simultaneously render the two semiconductors (T.sub.1, T.sub.2) conductive, a power line for supplying current to the electromagnet adapted to be connected through said switching means to said control circuit, and a delay device (R.sub.2, C, D.sub.7, T.sub.5) acting on the first semiconductor so as to eliminate its control voltage at a predetermined time after its application, said delay device including a resistor (R.sub.2) directly connected to said switching means and to a condenser (C) connected to said resistor, a Zender diode (D.sub.7) connected to a point between said resistor and said condenser, a transistor (T.sub.5) connected to said control circuit for controlling said first semi-conductor (T.sub.1), and a connection from said Zener diode to said last named transistor.
Dependencies are inferred from the claim text.