DE580498C - Circuit arrangement for the optional individual call from call stations located on company lines - Google Patents

Description

The invention relates to a circuit arrangement for the optional individual call of telephone stations located at company management, where the choice can be made through advanced. Switching of dials by means of current surges using common power sources he follows.

Circuit arrangements are already known in which a central control station common power sources are provided, with direct current used as the control current is used, while alternating current is used to set the selection devices and to operate the Alarm clock is used. However, the previously known arrangements of this type have the disadvantage that both relatively complicated facilities at the subscriber stations as well as at the central control station special relays for intermittent connection of the alternating current are required and also the operation of such systems only using a Auxiliary line (earth) is possible.

These disadvantages are avoided in the subject of the application in that a per se for the signaling of a transmission point in telegraph systems known method for Current impulses of the subscriber stations in company lines for setting the at the common lead lying voter is applied. According to the invention is namely one of a common AC power source Continuous current sent into the line by intermittent short-circuiting of the line in current surges to switch the Dialing mechanisms dismantled.

When dialing · there is a line short-circuiting the line in the dialing subscriber station Bridge switched on, which opened and closed intermittently when the dial ran out will. This results in the continuous current sent out by the common current source to a number of over the line corresponding to the number dialed Disassembled selection currents. This will make all of the dials connected to the line Call stations adjusted in a known manner by the same number of steps. The call is only made in a known manner in the intercom, the code number of which corresponds to the number of current surges emitted by a contact device controlled by the dialing mechanism is only effective in this intercom will.

To reset the dials after dialing or after the call has ended and separation of the connection, according to the invention, the generation of the current surges for the switching of the dialing mechanisms is carried out intermittently short-circuiting the line in the main office itself. In doing so, preferably in the main station, a control switch is arranged, which together with the Dials in lockstep and when resetting the shutdown of the Dialing works as soon as it reaches its zero position contact devices for

O U '■■

5S0498

Switching off the power surges. For the control switch in a known manner can be provided with cam disks and contacts controlled by these, are expedient provided at certain intervals locking positions to also make a choice with multiple Allow pulling up the dial.

The drawing shows exemplary embodiments according to the invention. Fig. Ι shows the circuit diagram of a main station H in connection with a subscriber station T in the idle state, ie when no connection is established. FIG. 2 shows an embodiment of the control switch, by means of which the reset is determined and a selection in several selection stages is made possible. FIG. 3 shows a specific operating state of the circuit arrangement according to FIG. 1.

The station T contains a number switch Nu to which the contacts,% and n _{2 are} assigned. Contact%, to which a throttle D ₂ is connected in parallel, is only open when the number switch is in the rest position. If the number switch is actuated,% already _{short-circuits the throttle D 2} , which has a few thousand ohms of direct current resistance, while the number switch is being opened. The current surge contact n ₂ suspend and close the end of the berm number switch, the Strömschleife from after the main body as much times, indicating how the drawn number. The line relay assigned to the subscriber station is labeled LR. Tn the main unit is a control relay A to the contacts% and _"2 arranged, which is partly due to the central battery ZB and the other hand on the α-branch of the double cord. D ₁ is a choke coil that blocks the central battery and relay A against alternating current. ZJ and V are relays with the contacts% and V ₁ , V ₂ , v _s and have a strongly delayed dropout; K and F are relays with ■ their assigned contacts Ii ₁ , k ₂ , k ₃ and f _v f ₂ and have less delayed dropout. M is an electromagnet with the associated contacts W ₁ , W _{2 and W 3} , which turns a control switch referred to in the following, which is shown in more detail in Fig. 2, forwards in steps. The reset is already assigned at the beginning of each selection, goes along with the alternating current surges (relay C with contact c) and ensures the switching of the contacts W ₁ , W ₂ and W ₃ , through the mediation of two rotating disks P ₁ and P ₂ , which have gaps and projections at corresponding points on their circumference. The resetter remains in the call position; after the call has ended, ie after contact O _{1 has been closed} , it is triggered again and, with the help of relays Ji and jF, sends the alternating current surges required to reset the selector into the line.

The mode of operation of the device is as follows: When. If a subscriber calls the receiver picked up, the contact h is closed and a current flows through: ZB, relay A, «line, W ₂ , D ₂ , h, & line, D ₁ , ZB. Initially, only a weak current flows from the central battery via this direct current path, so that relay A does not yet respond. Now the dial is pulled up. When the dial is pulled up, the high-resistance inductor D _{2 is} short-circuited _{via contact%: M 2} still remains closed. The relay A in the control center responds as a result of the short-circuiting of the choke D ₂ and closes its contact a ₂ . The magnet M receives a current impulse from ZB over « ₂ and m _x . The reset takes one step and opens contact W ₁ and closes contacts w ₂ and W ₃ (see Fig. 2). Relay TJ is excited via w ₃ , which in turn switches on relay F via U _1. The relay V puts the AC clamp W via V ₁ and V ₂ on the line and via z / ₃ the relay A in a holding circuit for the time the dial is running. The line relays LR of the subscriber stations and the AC relay C on the main station cannot yet respond when the number switch is opened, since a bridge h, n _x and W _{2 is} laid parallel to the line relay LR at the calling subscriber station. Rather, the addressing takes place only when the number switch expires. When the number switch runs down, the bridge is first interrupted at n ₂ according to the number dialing that has been drawn. During the interruptions at n ₂ , alternating current flows from W through all line relays LR of the subscriber stations connected from and also through relay C in the main station. Let it be For example, assume that the number switch was pulled at number 5; then relay C switches the reset device through contact c via: ZB, a ₂ , c, M, ZB five steps further. After the first step, W _{3 was} interrupted again by P ₂ (Fig. 2), and the task of keeping the alternating current on the line now falls solely to the delay relays TJ and V , the delay of which is such that V ₁ and W _{2 are} only opened when the finger washer has safely returned to its rest position. Due to the five current impulses which act on all line relays £ -22 of the subscriber stations, all dialing mechanisms of the same are switched forward by five steps. However, the call only takes place at position 5 in the known manner. This would call telephone number 5. The conversation can now take place. Of the

Contact " ₃ " is open, but via ZB, A, "-line, W ₂ , D ₂ , h, δ-line, D ₁ , ZB a direct current flows, which is strong enough to switch relay A. hold, but on the other hand not enough to keep relay A. to respond to the fallen armature (rest position). When the call is ended, it is reset to zero. If both participants hang up their phones, so

ίο the contact h is opened and the holding current for the relay A is interrupted. A drops out, A ₁ closes the circuit for the reset relay and the reset magnet M; ZB, a _v F, K, M ₂ , M, ZB, M and K do not yet respond because F has a high resistance. F is excited and switches its own winding _{briefly via f t} . The current via K and M is now sufficient to excite these magnets. The relay K applies alternating current to the line via A ₁ and A ₂ , and M switches the reset device one step further. Meanwhile f _x has opened again, so that M lets go of his anchor again. As a result of its delayed fall, relay K _{keeps A 1} and A _{2 closed} until the next energization. From the mode of operation of the circuit of F, K and M it can be seen that the contact f _z takes over the task of W ₁ during resetting as during the selection. A relay does not respond to it because it is short-circuited through A ₃ during recovery. The reset currents via M and the line relay LR only occur until the reset is turned to its initial position, ie until contact m ₂ (see also Fig. 2) interrupts the reset circuit. The number of reset current surges is such that all line relays LR can safely bring the associated dials into their rest position.

When resetting, the interrupter relay F takes on the same task that the number switch had to perform when dialing, and the relay K the role of U and V. M comes into action both when dialing and when resetting, while relay C responds to the reset alternating current surges, but has no further effect, since the current path via contact c cannot be closed.

• As can be seen from Fig. 1, F and K must drop again after the end of the reset, since m _{2 is} interrupted; "As a result, all A and F contacts open. The line is free of AC power and ready for a new call.

With a suitable design of the control switch according to Fig. 2, the choice of call stations also made in several levels by pulling up the dial several times which significantly increases the number of intercom stations connected is made possible. The. the switching operations taking place in the process are listed below the figures, in particular Fig. 3, explained.

For example, the subscriber station with the code number 15 should be dialed and called; since the number switch only allows 10 pulses of electricity, the number becomes divided, and by first dialing the number ο, a series of 10 selection currents and then sending a series of 5 dialing surges over the line by dialing the number 5.

First, when dialing the number 0, the line relay LR in the call stations and the impulse relay C in the main station are energized ten times, so that both the dials in the call stations and the control switch in the main station (Fig. 2) are switched 10 steps forward. As soon as the number switch has reached its zero position, the circuit is in the operating state shown in FIG. The direct current circuit for the relay A is closed because the hook switch h is in its working position and the number _{disc contact w 2 is also} closed. As a result, contact% is open and a _{2 is} closed. The control switch according to FIG. 2 has reached a so-called latching position, in which a projection of the control disk P ₂ becomes effective and the contact m _{3 is} closed, while the control disk P ₁ is in a position in which the contact m ₂ is closed and m _{x is} open. The relay U is kept energized over m _s , so that the relay V is switched on via its contact U _1. Since the contacts W ₁ and V _{2 are also} closed, the alternating current source W is connected to the line until the next digit is dialed.

If the calling subscriber pulls the dial for the second time to dial the number 5, m ₃ opens with the first current surge of the series of current pulses that now follows. As a result of the delayed release of the relays U and V , however, the contacts V ₁ and V ₂ remain closed in the manner described above until the number switch has reached its rest position again. In the meantime, the call has been switched on on the selected call station 15 or 05, so that the desired conversation can take place.

With a suitable design of the control switch according to FIG. 2, any multi-digit call numbers can be used be chosen, e.g. B. the subscriber 27 can by dialing the number ο twice and then dialing the number 7 can be achieved. Each time after dialing the number ο, the circuit is located the main station in the operating state indicated by FIG. 3. In the event of a different

formation of the dial and the control switch are also other impulse combinations possible.

Claims (5)

Patent claims: 1. Circuit arrangement for the optional individual call from call stations located on company lines, where the choice by switching dials by means of power surges using common power sources takes place, characterized in that a. from. one Common alternating current source -in the line sent continuous current by intermittent Short-circuiting the line is broken down into power surges for switching the dials. 2. Circuit arrangement according to claim 1, characterized in that during the Dialing the intermittent short-circuiting of the line in the calling station takes place. 3. Circuit arrangement according to claim 1, characterized in that the intermittent short-circuiting of the line in the common to reset the electoral works Main office takes place. 4. Circuit arrangement according to claim 1 or 3, characterized in that for Reset a well-known circulating in step with the dials Control switch is provided, which together when an established connection is canceled is moved with the dialing mechanisms arranged in the microphone units into the zero position and in this by relocating of contacts causes the system to shut down. 5. Circuit arrangement according to claim 4, characterized in that for enabling a multi-stage choice of the control switch has latching positions in which of the control disks of the control switch dependent switching devices are influenced in such a way that the control switch remains unchanged until the next dialing level and at the same time the connection the common power source is effected in preparation for the following elective stage. For this t sheet of drawings