DEVICE FOR INCREASING THE PARALLEL INDUCTANCE OF A TRANSFORMER

    公开(公告)号:CA1141454A

    公开(公告)日:1983-02-15

    申请号:CA352841

    申请日:1980-05-27

    Applicant: IBM

    Abstract: DEVICE FOR INCREASING THE PARALLEL INDUCTANCE OF A TRANSFORMER A device for increasing the parallel inductance of a transformer, consisting of a negative inductance element, connected across a winding of the transformer. In a particular application of the invention to telephone line transformers, the negative inductance elements are connected in the vicinity of the middle junctors of the switching net work. Thus, each element enables the parallel inductance of the line transformers to be increased when these line transformers are connected to the junctor through switches of the switching network. The number of negative inductance elements required is much lower than the number of transformers. FR9-79-017

    12.
    发明专利
    未知

    公开(公告)号:FR2462006A1

    公开(公告)日:1981-02-06

    申请号:FR7919131

    申请日:1979-07-20

    Applicant: IBM FRANCE

    Abstract: A switching network includes electronic crosspoint switches for providing electronic connection or disconnection between two voice stations. Each station is connected to the network through a line transformer. When two stations are connected to each other, the voice path in the network includes the secondary winding of the 1st station transformer, a series of crosspoint switches, a middle junctor, a series of crosspoint switches, and the secondary winding of the 2nd station transformer. Each middle junctor includes a negative resistance circuit which introduces a negative resistance in series with the voice path, thus compensating for the series losses in the network, and two negative inductance circuits connected on both sides of the junctor in parallel with the voice path, to compensate for the parallel losses, especially those introduced by the line transformers.

    13.
    发明专利
    未知

    公开(公告)号:DE3784490T2

    公开(公告)日:1993-09-16

    申请号:DE3784490

    申请日:1987-04-22

    Applicant: IBM

    Abstract: Echo cancelling device for providing an echo-free incoming data signal with a phase-roll tracking device comprising phase rotating means (58) for rotating the phase of the generated echo signal by a value X which is the estimated phase-roll value, thereby providing a complex phase-roll corrected echo signal a multiplier (124) for multiplying the error signal between the incoming signal and the real component (112) of the phase-roll corrected echo signal by the imaginary component (120) of the same signal, thereby providing a value Y function of the variation of the phase-roll; a phase-roll variation estimator (128) providing an estimation Z of the phase-roll variation X in half duplex mode or in full duplex mode, in response to value Y; and a phase filter (126) providing the estimated phase-roll value X in response to the estimation Z.

    14.
    发明专利
    未知

    公开(公告)号:IT1151017B

    公开(公告)日:1986-12-17

    申请号:IT2302080

    申请日:1980-06-26

    Applicant: IBM

    Abstract: A switching network includes electronic crosspoint switches for providing electronic connection or disconnection between two voice stations. Each station is connected to the network through a line transformer. When two stations are connected to each other, the voice path in the network includes the secondary winding of the 1st station transformer, a series of crosspoint switches, a middle junctor, a series of crosspoint switches, and the secondary winding of the 2nd station transformer. Each middle junctor includes a negative resistance circuit which introduces a negative resistance in series with the voice path, thus compensating for the series losses in the network, and two negative inductance circuits connected on both sides of the junctor in parallel with the voice path, to compensate for the parallel losses, especially those introduced by the line transformers.

    DEVICE FOR INCREASING THE PARALLEL INDUCTANCE OF TELEPHONE LINE TRANSFORMERS

    公开(公告)号:DE3069214D1

    公开(公告)日:1984-10-25

    申请号:DE3069214

    申请日:1980-06-24

    Applicant: IBM

    Abstract: A switching network includes electronic crosspoint switches for providing electronic connection or disconnection between two voice stations. Each station is connected to the network through a line transformer. When two stations are connected to each other, the voice path in the network includes the secondary winding of the 1st station transformer, a series of crosspoint switches, a middle junctor, a series of crosspoint switches, and the secondary winding of the 2nd station transformer. Each middle junctor includes a negative resistance circuit which introduces a negative resistance in series with the voice path, thus compensating for the series losses in the network, and two negative inductance circuits connected on both sides of the junctor in parallel with the voice path, to compensate for the parallel losses, especially those introduced by the line transformers.

    17.
    发明专利
    未知

    公开(公告)号:DE2221368A1

    公开(公告)日:1972-12-14

    申请号:DE2221368

    申请日:1972-05-02

    Applicant: IBM

    Inventor: MORLEC EMILE

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