DE596719C - Circuit arrangement for private branch exchanges, in which exchange and consultation calls are made over the same connection line - Google Patents

Description

The present invention relates to private branch exchanges in which exchange and inquiry calls are conducted over the same connection line and the switching of the voice line leading to the extension from the exchange line to an inquiry line and from this to the exchange line is effected by a switching means of the extension.
In known arrangements in which a

ίο excited by earthing the subscriber loop If the differential relay itself is used as an inquiry switch, it is necessary to connect to the Extension to keep the earth applied for the duration of the inquiry connection. These However, permanent earth connection always results in operational difficulties, for example: poorer speech communication, possibility of interference or unwanted switchovers etc. Furthermore, the permanent ground connection at the station either causes the Use of complicated lock keys, or the participant has to keep the key pressed keep; an operational complication for the participant that should not be underestimated.

Other known arrangements show special inquiry switching devices that by feed bridge relay depending on a special temporary switching measure can be controlled at the extension. These arrangements are only for certain systems applicable. In some cases they require buttons to enable reliable operation at the extension, which, in addition to the ground connection, also cause a loop interruption. . Furthermore, the subsequent installation of this inquiry device in existing systems even only with relatively extensive interventions in the existing system perform.

The present invention now aims to provide an arrangement which those discussed Avoids deficiencies, and achieves this by having one in the supply circuit of the extension horizontal differential relay triggered by temporary actuation of a switching device the extension given incentives to establish and clear inquiry calls transmits to the switching devices controlling the inquiry switching point, '

The switching means to be temporarily actuated at the auxiliary unit expediently works without Line interruption, so that therefore as a result of the omission of a special one in the voice line lying contact in the extension also in systems with an inquiry facility the sources of interference in the station are not greater than in systems without Inquiry facility.

The arrangement according to the invention can also be designed such that the Switchover only after termination of the

*) The patent seeker stated as the inventor:

Adolf Waschnack in Finkenkrug b. Berlin.

stimulus, i.e. after releasing the button. That has to be highlighted Advantage that an influence, in particular even without the provision of special aids, the connection devices that can be reached via the line connected by the switchover avoided by the earth at the station.

In the present drawings Fig. Ι ίο and 2 is an example of the mode of action said invention shown.

Incoming traffic

If the office calls in the secondary

»5 digits on (Fig. 2, right), the call relay A ² winding I is energized. The energization of this relay causes the call lamp AL to light up as follows: earth, battery, call lamp AL, normally open contact γ / α ^% , earth.

By closing contact 30 « ² , a holding circuit is closed for relay A ² : earth, normally closed contact 28 ^> ² , query switch off, normally closed contact 2o, £ ² , normally open contact 30« ² , II. Winding of relay A ² , night switch N, Relay AC, battery, earth. Closing contact 4iac closes a circuit for lamp ACL : earth, normally open contact 4i «c, lamp ACL, battery, earth. At the same time, the following circuit for the DC alarm clock is established in parallel with the ACL lamp: earth, contact / [iac, DC alarm clock W, relay SR, battery, earth. Then, the official of the PBX switches in the line, by putting the request switch from the working position. By opening the holding circuit for the second winding of the relay A ² , this relay drops out, so that the call lamp A ² goes out when the contact 37a ^{2 is opened} . RelayJ.Cab also drops out at the same time as relay A ^2. The dropping out of the relay AC causes the lamp ACL to go out and the alarm clock W to be switched off by opening the contact i ^ ac.
By pressing the query switch from , the officer switched on with her query device after the main exchange. At the same time, by closing the manual switch from, a circuit for the relay T- is closed: earth, manual switch from, I. and II.

Winding of relay Γ ² , battery, earth. When relay Γ ² responds, a circuit for the monitoring lamp UL is closed: earth, normally closed contact 33c, normally closed contact 34s, normally open contact 35i ² , normally closed contact 32c,

UL monitoring lamp, battery, earth. The relay C is short-circuited by the contact ijt * and this initiates a block for outgoing traffic. If the civil servant has now found out the desired extension participant from the public authority with the help of her query apparatus, | so she puts the plug Q into the jack Kl, whereby a test circuit is closed after the subscriber station as follows: earth, break contact 27c, II. and I. winding of the relay 6s P ² , e-wire of the cord system, c-arm of the preselector, I. and II. winding of the relay T ¹ , d-Arrh of the preselector, position O, battery, earth. When relay P ² responds, winding II of the relay is short-circuited and the connection is blocked. The test relay P ² switches the cord system to the exchange line with its contacts 25p ² and ^{26p 2.}

By closing of the contact 51p ² is a bridge between the A- and E-cores of the connecting line VL is applied and thereby prevents release of the selector on the central office switch via a choke coil. By closing the contact I2 ^> ² a holding circuit is created for the relay T ² : earth, normally closed contact 13 ", working contact I2 ^> ² , I. and II. Winding of the relay T ^% , battery, earth.

The officer now presses the call button R. This creates an excitation circuit for the relay PL : earth, relay PL, call button R, resistor Wi ⁶ , battery, earth. The pole changer is switched to the cord system by the contacts ^{45p 1} and 46 ^ ¹ via the two working contacts of the call button R and the working contacts of the interrogation switch «δ. From the fact that the PrL lamp does not light up, the officer recognizes that the call goes through to the subscriber correctly.

If the subscriber N answers, he can communicate with the officer of the private branch exchange, who has connected her interrogation apparatus to the subscriber station by flipping the switch. By turning the switch RiI, a feed bridge is placed at the same time via the choke coil Dr at the subscriber station. After the official is convinced that the participants spoke up, she puts the query switches off again to its rest position. In this way, she connects the subscriber to the exchange line via the cord system. By switching the query switch from to its rest position, the feed bridge S is connected to the subscriber station: earth, winding-I of relay S, δ-wire, normally closed contact 43Ä, winding II of differential relay D, working contact 26p-, query switch from, δΖ-line of the cord system subscriber station, «Z-conductor of the cord system interrogation switch off, normally open contact 2Sp ² , winding I of relay D, normally closed contact 42Ä, winding II of relay 5, battery, earth. When relay S responds, contact 34s is opened and the monitoring lamp UL goes out. By closing the contact 22s an excitation circuit for the relay V ^{1 is} closed: Earth, normally open contact 22s, Re-

lais F ¹ , battery, earth, parallel to the relay F ¹ an excitation circuit for the second winding of the relay U is produced so that this relay responds and by opening the contact 13 "a holding circuit for the relays U and T ² via earth , Winding I of relay U, contact I2 ^> ² , winding I and II of relay Γ ² , battery, earth. With its contacts 53M and 54 «, the relay U switches off the interrogation apparatus of the officer from the exchange line, and by opening its contact 52« it interrupts the bridge between the «- and δ wires of the connecting line. When the relay T ¹ was energized, the contact 3t ^{1 was switched over} and the rotary magnet of the preselector was switched off so that it could not respond. This means that the preselector is blocked. With its contacts it ¹ and 2t ¹ , the re-

ao lais T ¹ the two windings of the relay R from the subscriber station. When relay F ¹ is triggered, contacts 47z; ¹ and 48 v ^1, the exchange line is switched through, while the short circuit for relay C is lifted by opening the contact τ ^ ν ¹ , but the relay C can not respond via the resistor Wi ¹ .

The conversation between the main unit and the subscriber of the extension can now be started take place.

If the subscriber of the private branch exchange now wishes to hold an inquiry with another subscriber of the same private branch exchange without the exchange connection collapsing, he presses his button RT and thus places earth on the δ line. As a result of this earthing of the δ-line, the II. Winding of the differential relay D is short-circuited, to which this relay responds: Earth, inquiry button RT, «-line of the cord system, I. winding of relay D, II. Winding of relay S, battery, earth . With its contact 24 "" the relay D connects the relay Z to the δ wire.

If the subscriber releases the query button RT again, the earthing of the δ wire is canceled. The relay D remains energized, however, because the current intensity in its two windings is no longer the same as a result of the branching via relay Z that has now been established. As a result, the contact 24 ^ remains closed and the relay Z responds: Earth, relay Z, normally closed contact 202, normally closed contact 23 « ² , normally open contact 240", normally open contact 26p ² ·, line system of the private branch exchange, subscriber station, ^{normally open contact 25 ^> 2} , I. winding of relay D, II. Winding of relay S, battery, earth. Relay Z switches its contact 202 to the working position, creating a circuit for relays H and F ² : earth, relay Z, working contact 20z, Relay H, relay F ² , battery, earth. ^{When relay F 2} responds, the choke coil of the bridge is switched into the «wires of the connecting line, when contact 44A closes relay S is held and the a and δ wires of the Connection line short-circuited via contacts 50s and 49W ² , whereby a retaining bridge is produced for the connection line, which prevents the exchange connection from collapsing. By switching contacts 42A and 43A, the subscriber becomes the extension le switched to the inquiry line RL , which leads to a preselector, and via this to the line selectors of the private branch exchange.

If the subscriber of the extension now wants to reestablish the connection with the subscriber of the main exchange, he presses the inquiry button RT again. The differential relay D, which had previously been made to drop out again by switching over the contact 20z, now responds again and short-circuits the relay Z via the contacts 180 "and 19A, so that it is made to drop out. The relay Z can now not Find connection more "to the δ-wire, since the delay relay F ² with its contact 23W ² interrupts this connection. If the subscriber releases the query button RT again, the balance for the differential relay is restored, the contacts i8d and 24 «" drop out and the excitation circuit for H and F ² is interrupted. As a result, these two relays drop out and the subscriber opens of the holding bridges at the contacts 44Ä and 49.Ü ^{2 are switched} on again to the connection line.

Outgoing traffic

Outgoing connection lines from the extension are established with the help of dialers. If the subscriber N lifts his receiver, the excitation circuit for the relay R closes: earth, II. Winding of the relay R, break contact 2t ¹ , subscriber loop, break contact Xt ¹ , I. winding of the relay R, battery , Earth. By closing the contact 5r an excitation circuit for the rotary magnet of the preselector VW is closed: earth, self- breaker UR, rotary magnet D ¹ , normally closed contact 3 ^, normally open contact ^ r, battery, earth. The selection turns on and adjusts itself to a free line selector. In this case, the following test circuit is established: earth, head contact 8k, winding I of relay F, c-arm of the preselector, I. and II. Winding of relay T ¹ , normally open contact ψ, battery, earth. The response of the relay Γ ¹ causes the relocation of the contact 3t ¹ and thus once iao the shutdown of the rotary magnet D ¹ and by short-circuiting the winding II of the Re-

lais Γ ¹ Blocking of the line selector in use on the other hand. With its contacts τί ¹ and 2t ¹ relay T ¹ turns off the phone line through the selection of and the relay R. The response of relay V via winding I causes contacts 6v and gv to close. Contact gv prepares a holding current for relay V , while the test circuit after the first lifting step and thus ίο opening of head contact 8k via make contact 6v and the resistor Wi ^{1 runs} after the relay T ¹ .

The switching through of the voice line with the help of contacts ii ¹ and zt ¹ sets the feeder bridge ^{1 of} the line selector to the subscriber, relay A ^x is energized and thus the holding circuit for relay V via winding II is completed by switching contact 60 « ^1. The line selector LW adjusts itself in a known manner. The test circuit required for setting the line selector closes in the following way: Earth, test relay P ¹ , c-arm of the line selector, c-wire, night switch N, break contact 14 « ² , relay C, break contact xyt ^z , resistor Wi ³ , battery , Earth. The response of the relay P ¹ requires the interconnection of the voice line via the line selector with the help of the contacts top ¹ and tip ¹ , which at the same time disconnect the feed bridge A ^x from the connection line. Relay A ¹ drops out and puts the contact 60a ^{1 back} into the rest position, so that relay V is short-circuited and drops out. The test circuit via the selection VW now runs over the parallel to the contact 6v Laid contact γρ. ¹ When relay C responds, contact 16c is turned over and thereby the test circuit is ^{deflected via normally open contact 16c, 2nd winding of relay Γ 2} , battery, earth. By energizing the relay T ² , the contact xyt ^{2 is switched} to its working position and the relay C is short-circuited, but this does not drop out, since after the relay S has responded and thus the relay V ^{1 is} energized, the short circuit at the contact ^{τζυ 1 is} canceled and the relay C via earth, battery, resistor Wi ¹¹ , contact iyf \ relay C, contact 14 « ² , switch N, c-wire, via c-arm of the line selector LW (Fig. 1), relay P ¹ , earth held will.

When relay C was energized when an outgoing connection was set up, contact 33c was switched over and contact 32c was interrupted. This closed a circuit for the monitoring lamp UL : earth, normally open contact 33c, monitoring lamp UL, battery, earth. At the same time, the contact 27c opens the test circuit for the cord system and thus prevents the relay Γ ¹ from responding due to the officer being rarely occupied. When relay T ' ¹ is triggered, contact 20, i ^{2 is} opened, which prevents relay AC from responding and thus closing of the alarm clock circuit if relay A ^{2 is} triggered at the same time (call from the exchange).

The connection of the voice line through the contacts ^{xop 1} and u ^ ¹ via the a and δ arms of the line selector requires the feed bridge S to be applied to the subscriber station N. When relay S responded, contacts 34s and 38s were opened, causing them to light up the call lamp AL and an activation of the alarm clock W prevented. By closing the contact 22s, the excitation circuit for the relays V ¹ and U ' ^{2 is closed} , as described above. The excitation of the relay V ¹ 'causes the connecting line from the subscriber to the exchange to be switched through with the help of contacts 4Jv ^{x and 48t) 1.} At the same time, by closing contact 50s, the bridge was placed across the choke coil Dr between the a and δ wires of the connecting line. When relay U is triggered, the officer's interrogation device is switched off from the exchange line using contacts 53 "and 54".

If the subscriber sends out further series of current impulses in order to set the voters in the office, the relay S is made to drop out according to the interruptions at the subscriber station. At the first interruption of the contact 22s relay V "is by opening. Earth contact 22s, relay V ^1, battery, earth energized, which is kept energized, even during the rush current range due to its delay, since now the contact 40," ² is brought into the working position, the current surges are transmitted to the exchange through contact 56s.

After setting the voters in the office, the voice connection is from the extension participant established with the subscriber.

If the extension subscriber now wishes to speak to another subscriber in the private branch exchange for the purpose of consultation without triggering the established connection, he presses the consultation button RT in the same way as described above. As a result, the relays D, Z, H and F ² respond in the same way as described above. Switching over the contacts 42A 43A causes the subscriber to be switched to the consultation line RL, via whose preselector he is able to reach the second subscriber of the private branch exchange in the manner described above. By switching over the contacts 42A and 43A, the feed bridge S is switched off by the extension subscriber, while relay S is held in the same way as described above via 44/2 · and the choke coil Dr is connected to the « ^{conductor via contact 49W 2}

switched and over. Contact 50s the same bridging of the a and δ lines, as described above, is achieved.

After completing the inquiry, the subscriber N presses the inquiry key a second time, whereupon the process described for incoming traffic, switching off the inquiry line, takes place and. the extension subscriber is reconnected via the connection lines to the exchange and thus to the subscriber previously called.

The connections for incoming and outgoing traffic are triggered themselves in a known way.

Claims (7)

Patent claims: i. Circuit arrangement for private branch exchanges in which exchange and inquiry calls are made via the same connection line and the switching of the voice line leading to the extension from the exchange line to an inquiry line and from this to the exchange line is effected by a switching means of the extension, characterized in that an im Difference relay (D) located in the supply circuit of the extension, which transmits the incentives given by the temporary actuation of a switching means (RT) of the extension to establish and cancel inquiry connections to the switching devices (RU) controlling the inquiry switching point. 2. Circuit arrangement according to claim 1, characterized in that the switching means (RT) temporarily actuated at the extension acts without a line interruption. 3. Circuit arrangement according to claim 1, characterized in that the switching devices (RU) bring about the switchings when the incentives are terminated. 4. Circuit arrangement according to claim 3, characterized in that the switching of the voice line to the extension is initiated when the differential relay (D) is excited and is carried out by the switching device (RU) when the differential relay drops. 5. Circuit arrangement according to claim 1, characterized in that a control relay (F ² ) brought into effect when the consultation connection is established opens the stimulus circuit for initiating consultation connections (at contact 23W ² ). 6. Circuit arrangement according to claim 5, characterized in that the control relay (F ² ) is kept in its state of excitation assumed during the establishment of the inquiry connection until the termination of the stimulus initiating the cancellation of the inquiry connection. 7. Circuit arrangement according to claim 5 for systems with selector operation, characterized in that a control relay (F ² ) which comes into effect during the current impulse also controls the switching device for making inquiry connections. 1 sheet of drawings