| 摘要 |
1,182,106. Energizing and de-energizing electromagnets. W. BINDER [trading as BINDER MAGNETE K.G.] 19 June, 1967 .[18 June, 1966], No. 28232/67. Addition to 1,097,209. Heading H2H. Apparatus for the rapid energization of an electromagnet as described and claimed in Specification 1,097,209, is modified in that the control means for the electronic switches which control the current flow in the electromagnet winding comprise a transistorized switching circuit. Closure of switch 290 causes thyristors 233, 234 to conduct and also, by way of a circuit including capacitor 414 and transistors 241, 242, thyristors 231, 232. Thus an electromagnet 270 is energized simultaneously from a high voltage source 213 and a normal voltage source 214. When the capacitor 414 has discharged, the gate potential of thyristors 231, 232 is removed and the electromagnet 270 remains energized only from the normal voltage source 214. When the switch 290 is opened to de-energize the magnet 270, the de-energization is accelerated by momentarily rendering the thyristors 231, 232 once more conductive so as to apply to the electromagnet 270 a high voltage in opposition to the self-induced voltage of the electromagnet. The means for rendering the thyristors 231, 232 conductive when the switch 290 is opened comprises a transistor 261 which is under the control of transistors 251, 252 and capacitor 514 together with a phase shifting circuit 280, 283. By means of this latter circuit the deenergization of the electromagnet is always initiated at a given point in a half wave of the supply, for example, at 135 degrees
|
