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    Method and means for suppressing an a.c. component of a given frequency in a pulsed d.c. current
    1.
    发明授权
    Method and means for suppressing an a.c. component of a given frequency in a pulsed d.c. current 失效
    用于抑制脉冲直流电流中的频率分量的方法和手段

    公开(公告)号：US3555437A

    公开(公告)日：1971-01-12

    申请号：US3555437D

    申请日：1968-12-26

    Applicant: ASEA AB

    Inventor： PERSSON ERIK ,  GOLIATH KARL GUNNAR

    IPC: G05F1/46 ,  H02M1/14 ,  H02M3/135 ,  H02P7/29 ,  H03B1/04

    CPC classification number: H02M1/14 ,  H02P7/29

    Abstract: FOR SUPPLYING TO A MOTOR D.C. PULSES WITH A VARIABLE FREQUENCY WHILE SUPPRESSING AN A.C. COMPONENT OF A GIVEN FREQUENCY (F), A SWITCHING DEVICE IS CONNECTED BE TWEEN A SOURCE OF D.C. AND THE MOTOR, WHICH IS RENDERED ALTERNATELY CONDUCTING AND NONCONDUCTING SO AS TO SUPPLY THE MOTOR WITH PULSES IN GROUPS OF N PULSES PER GROUP. THE TIME INTERVAL BETWEEN THE GROUPS CAN BE VARIED, WHILE THE TIME INTERVAL $T BETWEEN SUCCESSIVE PULSES IN EACH GROUP IS KEPT CONSTANT AND EQUAL TO

    1

    F.N

    AS LONG AS THE AVERAGE VALUE OF THE PULSE FREQUENCY IS BELOW THE VALUE AT WHICH THE TIME INTERVAL BETWEEN SUCCESSIVE GROUPS IS LESS THAN $T. AT HIGHER AVERAGE VALUES OF THE PULSE FREQUENCY, UP TO A CERTAIN PRESELECTED VALUE, THE PULSE LENGTH IS KEPT SUBSTANTIALLY CONSTANT, WHILE, IF THE LOAD VOLTAGE IS TO BE INCREASED ABOVE THAT CORRESPONDING TO SUCH PRESELECTED VALUE, THE PULSE LENGTH IS INCREASED WHILE THE PULSE FREQUENCY IS KEPT SUBSTANTIALLY CONSTANT.

    Rail signal disturbance avoidance means
    3.
    发明授权
    Rail signal disturbance avoidance means 失效
    铁路信号干扰避免手段

    公开(公告)号：US3555270A

    公开(公告)日：1971-01-12

    申请号：US3555270D

    申请日：1968-04-22

    Applicant: ASEA AB

    Inventor： PERSSON ERIK

    IPC: B61L3/00 ,  B61L3/22

    CPC classification number: B61L3/221

    Abstract: In electrically operated rail vehicles in which signals are inductively transmitted from rails to vehicle through coils applied in the vehicle, disturbances are avoided by pivoting said coil (preferably series-connected) to such an angle in relation to the plane of the rails that the resultant voltage from an asymmetrical current conductor is very low or zero. The same effect could also be accomplished by placing said coils horizontally and supplementing them by transverse coils.

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