| 摘要 |
PURPOSE:To decrease the number of the using relays and to prevent the rear-end collision of the next call after the end of talking by using the necessary and partial relay to the digit counting circuit. CONSTITUTION:When relay B has a reslease by the ring-off of the extension telephone, the velocity release is secured for relay group X excepting one of the digit counting circuits operating with the specified digit. And the delay release is given to one remaining relay Y in a longer time than the release time of relay B. Accordingly, the loop opening time to the main wire is delayed by the amount equivalent to the release time of relay B. However, the opening time is increased since the release time of relay C is delayed by the amount equivalent to the release time of relay Y. As a result, the rear-end collision can be avoided. Thus the number of the using relays can be decreased to attain a big economical effect for the release control of the central office trunk to prevent the rear-end collision when the connection is given to the next call after the ring-off between the extension and the main wire. |
