CN2051807U

CN2051807U - Subscribers' telephone exchange capable of dialing into extension directly

Info

Publication number: CN2051807U
Application number: CN 89207643
Authority: CN
Inventors: 潘前鸿
Original assignee: POSTS AND TELECOMMUNICATIONS OFFICE FENGHUA CITY
Current assignee: POSTS AND TELECOMMUNICATIONS OFFICE FENGHUA CITY
Priority date: 1989-05-21
Filing date: 1989-05-21
Publication date: 1990-01-24

Abstract

The utility model relates to an automatic telephone exchange which can be used for community users, such as factories and mines, enterprises, organizations, schools, etc. A subscribers' telephone exchange capable of dialing into extension directly is connected to a subscriber line of a local exchange, as the utility model adopts a full automatic incoming relay which is composed of an answering circuit (7) of incoming call, a blocking capacitor (C) and a pulse repeater (8), and as a result, whatever incoming call or outgoing call has full-automatic connection; the utility model has the advantages that the subscribers' telephone exchange does not use an operator to watch and has low cost, etc.

Description

Subscribers' telephone exchange capable of dialing into extension directly

The utility model is a kind of automatic telephone switching equipment for the use of corporate users such as factories and miness, enterprise, office.

Private branch exchange all is connected on the subscribers feeder of local exchange usually.When the extension subscriber of private branch exchange is called out common local user, be automatically continue (needing to listen a secondary dial tone), but when the extension subscriber of local network customer call private branch exchange, then often will transfer by the operator.Therefore private branch exchange is provided with special console ， And will have the operator on duty all the time, and both wastes of manpower, financial resources are unfavorable for communication security again.Subscriber exchange will take a certain level number of local exchange if will realize full-automatic incoming call, and this will waste the number resource of public's local network.

The purpose of this utility model just is to provide on a kind of subscribers feeder that both had been connected on local exchange, can cancel console again, not need the full-automatic private branch exchange that the operator is on duty, can directly dial in extension subscriber.

This capable of direct inward dialing private branch exchange, form by marker, register(system), switching network, subscriber line circuit, outgoing trunk circuit and incoming trunk etc., the full-automatic incoming trunk that incoming trunk is made up of incoming call answering circuit, blocking capacitor and number transponder, blocking capacitor is serially connected between center line and the switching network, is connected across on the blocking capacitor after incoming call answering circuit and number transponder join.

Fig. 1 is a composition frame chart of the present utility model.(1) is marker, (2) be register(system), (3) be switching network, (4) be subscriber line circuit, (5) be outgoing trunk circuit, (6) are full-automatic incoming trunk, and (7) are the call answering circuit, (8) be the number transponder, (e) and (e ') be respectively to the going out of Local Exchange, incoming trunk line.

Fig. 2 is the embodiment electrical schematic diagram of full-automatic incoming trunk of the present utility model (6).The subscribers feeder of (a, b) termination local exchange, (a ', b ') termination switching network of the present utility model.Relay (J ₁) be connected across on a, the b line, by relay (J ₁) and contact group j _1-1, j _1-2, j _1-3And j _1-4Constitute the incoming call answering circuit.Dialled the general number of this subscriber exchange as the local network user after, local exchange is sent 60 volts of DC feedback, then relay J here ₁Electric and move, normally opened contact group j at this moment _1-1, j _1-2, j _1-3And j _1-4Closed.Because j _1-4Closure, started register(system) (2), register(system) (2) send dialing tone (at this moment the calling subscriber listens secondary dial tone) to the calling subscriber; j _1-1And j _1-2Closure, transmit number for number transponder (8) and get ready; j _1-3Closure, for BG2 has added power supply.By C ₃～C ₆, D ₁～D ₇, R ₁～R ₈, relay J ₂Roll up composition number transponders (8) such as L with chokes.After the calling subscriber hears secondary dial tone, dial desired extension number again.At this moment dial impulse is owing to passed through the cord circuit electric capacity of local exchange and the C of the full-automatic incoming trunk of this subscriber exchange (6) ₃, C ₄After be square wave no longer, but become spike.This spike can't be discerned by the register(system) of subscriber exchange.Extension in order to allow register(system) identification be dialled just must add transponder, gives register(system) (2) again after spike is become satisfactory number pulse.Represent the spike of dialed number, through R ₁, D ₁After the peak clipper of forming is whittled into unidirectional spike, again through D ₂, D ₃Rectification is added in C with signal ₅On.At this moment BG1 is transferred to by conducting by reverse bias to end, and BG1 is by making BG2 obtain positively biased, and BG2 is by by transferring conducting, relay J to ₂Electric and move, its back contact j at this moment _2-1Disconnect, a ' b ' DC loop is cut off; Changeover contact group j _2-2Conversion is C ₆And R ₅Be access in the base stage biasing circuit of BG2, make relay J ₂Has the characteristic that fast suction is put slowly.Therefore work as after the spike relay J ₂And does not discharge at once, and will treat just to discharge behind the certain hour, to guarantee certain opening time.By adjusting R ₆And R ₇Resistance, the break-make ratio of pulse is sent out in adjustable turn over.So relay (J ₂) suction moving identical with the number pulse number sent here on the number of times that discharges and the ab line, the break-make ratio in a ' b ' loop then depends on relay J ₂The release delay characteristic, thereby reach the purpose of transmitting pulse.

The utility model has been owing to adopted full-automatic incoming trunk, thereby brought following advantages:

1, the operator is not on duty. As long as dial earlier general number, wait to hear for the second time and dial again extension behind the dialing tone during External Call extension subscriber, just can automatically connect extension set. Calling between each extension set and outbound call, its continuation method is identical with private branch exchange commonly used.

2, cost is low.The utility model not only can be cancelled console, and the cost of its full-automatic incoming trunk is also low more than the incoming trunk of using always.

Claims

1, a kind of capable of direct inward dialing private branch exchange, form by marker, register(system), switching network, subscriber line circuit, outgoing trunk circuit and incoming trunk etc., it is characterized in that the full-automatic incoming trunk that incoming trunk (6) is made up of incoming call answering circuit (7), blocking capacitor (C) and number transponder (8), blocking capacitor (C) is serially connected between incoming trunk line (l ') and the switching network (3), is connected across on the blocking capacitor (C) after incoming call answering circuit (7) and number transponder (8) join.