| 摘要 |
<p>PURPOSE:To prevent deterioration in unbalance attenuation by constituting a device in which a DC superposed current of an interface line flows only in the forward direction of diodes and connecting between an input and output of the diodes by capacitors. CONSTITUTION:An intra-office circuit terminal unit 1 and a subscriber's circuit terminal unit 2 are connected by a balancing cable 3, and the unit 2 and subscriber's devices 4 and 5 are connected by balancing cables 6 and 7. Capacitors 40-1-41-2 are provided on both ends of diodes 25-1-26-2 in the unit 2 to prevent deterioration in unbalance attenuation. As shown in the equivalent diagram, for instance, even when a diode 25-2 is cut off due to AC voltage Eac, and the impedance becomes Z2approx.=infinity , and on the other hand, the diode 25-1 is conductive and the impedance becomes Z1approx.=0, as a capacitor 40-2 is connected to both ends of the diode 25-2, large impedance deviation does not occur between the both ends due to the action of the impedance Z6.</p> |
