公开(公告)号：DE3472874D1

公开(公告)日：1988-08-25

申请号：DE3472874

申请日：1984-08-24

Applicant: IBM ,  IBM FRANCE

Inventor： GENESTE MICHEL ,  JACQUART CHRISTIAN

IPC: H04L1/24 ,  H04L25/02 ,  H04L69/40

Abstract: Outgoing terminals (1, 2) and incoming terminals (3, 4) are connected to an outgoing line (LX) and an incoming line (LR) respectively. A differential amplifier (T1-T2) has two load circuits and has its inputs connected to the incoming terminals. One of the load circuits is connected to the outgoing line. A switch (SW.T6) connects the incoming terminals wither to the incoming line or to the other load circuit. Control logic (a, b, T6, T7) allows the load circuit to be selected by connecting that circuit to the supply. The load circuits are diodes in series with resistors.

公开(公告)号：DE3473803D1

公开(公告)日：1988-10-06

申请号：DE3473803

申请日：1984-06-20

Applicant: IBM ,  IBM FRANCE

Inventor： BONNET YVES AIME JEAN ,  JACQUART CHRISTIAN

IPC: H04Q3/72 ,  H04M3/22

Abstract: A constant-voltage generator comprising a 100 kHz multivibrator (30), HF transformer (28) and full-wave rectifier (D1,D2) is connected to the terminals (A,B) of a resistance (r) of 10 ohms in series with the telephone line (LL). The prim. winding of the transformer (28) is centre-tapped to a 5V DC supply via a 511-ohm resistance (R). When current flows along the line (LL), its combination with the rectified HF current is detected at the centre tap (C) and pref. compared with the reference output of another DC-DC convertor, and amplified with addn. of an AC signal (Vref) corresp. to twice the amplitude of the line current signal.

公开(公告)号：FR2458950A1

公开(公告)日：1981-01-02

申请号：FR7915736

申请日：1979-06-12

Applicant: IBM FRANCE

Inventor： JACQUART CHRISTIAN

IPC: H03K17/04 ,  H01L27/07 ,  H02M3/337 ,  H03K17/567 ,  H02M7/537

Abstract: Signals to the base of a bipolar transistor and to the gate of a parallel - connected FET are timed to turn on the two transistors simultaneously and to turn off the bipolar transistor before the FET. The shorter switching time of the FET is combined with the low resistance of the bipolar transistor to provide a switch that is particularly useful in a switched-type power supply with increased switched frequency.