CH622653A5 - Equipment for a subscriber line in an automatic telephone exchange - Google Patents

Description

622653 2

PATENT CLAIMS characterized that two transformers (Tlx, Tly) and two

1. Equipment for a subscriber line in an automatic hall effect table, each connected to one of these transformers, characterized in that devices (HED1, HED2) are provided per sub-device, and that the subscriber or subscriber group has a transformer (T1) pre-DC power supply one of the There are subscriber line wires, the main windings of which are each connected between a 5 via a winding of one of the transformers and the other connecting terminal (JL, -) of a direct current source and one of the subscriber line wires via a winding of the other lead wires (A, B), so that the direct current - the transformers.

supply from the office is carried out via these main windings, that the transformer has two further, additional windings, the first additional winding applying the 10 call current to a lead wire that at least one Hall effect device (HED) is provided,

The present invention relates to equipment for a wire and that the magnetic circuit of the Hall subscriber line in an automatic telephone exchange. effect device is identical to that of the transformer. 15 In particular, equipment should be discussed

2. Equipment according to claim 1, characterized in that for applying the ringing tone to the desired line that a switching transistor (S 1) is provided, the collector are determined and on the on or off state emitter path between the first additional winding of the Address the transfor- mer cable loop. This response to the mators (T1) and a call current source is switched, and that the conditions mentioned is necessary when initiating a call, base the switching transistor with one of the outputs (ARI) 20 when the calling subscriber dials and opening pulses of a call flip-flop (AR ) is connected, one input of which sends out when the desired subscriber answers and one (RO) of the outputs of a signal encoder / decoder - when a subscriber hangs up his handset.

Unit (SCD) is connected in order to be able to

by switching on this one output (RO) which uses the electromechanical relay, which has too large a unit of the called subscriber, the switching transistor has small dimensions, is expensive and has to be maintained regularly and thus adjusts the application of the call current from and mechanically adjusted Need to become.

Ring current sources to the first auxiliary winding and consequently to the purpose of the present invention is to enable these drawbacks to lead wire (B). overcome by a device utilizing the Hall effect

3. Equipment according to claim 2, characterized in that the device is used. Of course, such applications are that a second (S2) and a third (S3) switching transistor are provided in equipment for automatic telephony, the collector-emitter paths of which are already known in the wires (A, B), see for Example, the CH patents no. Of the subscriber line are switched, and that the 583 491 or 600 721 are connected together. In the present invention, the switched bases of the transistors (S2, S3) are connected to the other, however, the Hall effect device in a very advantageous manner Outputs (ARO) of the call flip-flop are connected, the one used in the interface of a subscriber line, namely another input to another (RF) of the outputs of 35 for determining the loop state. In this way, signal encoder / decoder unit (SCD) can be connected, the electromechanical relay can be replaced by a device which does not move around the wires (A, B) of the called subscriber during parts.

the switching on of the call current to these wires by the barrier. The features of the equipment according to the invention can be found in the transistors (S2, S3) from the calling subscriber.

switch off line. 40 embodiments of the invention will now be based on the

4. Equipment according to claim 3, characterized in that the drawing is explained in more detail. Show it:

that the collector-emitter path of a fourth switching transistor Fig. 1 an inventive equipment for a single (S4) between the second additional winding of the transformer NEN, connected to the subscriber line, with (T1) and a test desk, and that Basis of the four-call and test access,

th switching transistor with one of the outputs (TAI) of a 45 Fig. 2 equipment for two on the subscriber line test flip-flops (TA) is connected, one input to connected subscribers, likewise with call and test access

a third (TA) of the outputs of the signal encoder / decoding gear and rer unit (SCD) is connected in order to apply equipment similar to that according to FIG. 1, but with a test signal to the unit (SCD ) the third output is designed to deliver counting pulses.

(TA) to turn on the fourth flip-flop in this way. In the equipment described, the line-to-transformer (S4) is made conductive, and consequently the test desk was detected by a Hall-effect device in one with the second additional winding of the transformer (T1 ) to ways that already connect in the aforementioned Swiss Patent No. 600 721 and to enable a test of the line. has been described. Such a device contains a Hall

5. Equipment according to claim 4, characterized in element in the form of a flat plate which, for example, from that on the subscriber line side of said transformer 55 a thin film or a corresponding semiconductor mother (T1) is formed a further, three-winding transistor was or is a single crystal structure. The format (T2, Fig. 3) is connected, whereby two of the winding Hall elements are attached in a magnetic circuit, in series with one of the subscriber line wires each and that the magnetic field with the level of the element makes a third winding over the Emitter-collector path includes a fifth right angle. Switching transistor (S5) flows via connecting lines to a counting pulse source connected 60 a control current between connections to two parallel Seis, and that the base of the fifth switching transistor over one of the element and there are output connections provided counting pulse flip-flop (MP) with the signal encoder / Decoder- on the other two element sides. Changes in the magneti-unit (SCD) are connected such that a counting pulse causes the field and / or control current to generate a potential called flip-flop in its "1" state and thereby causes the fifth transistor between the output terminals, its value and direction conducts to count a 65 depends on the field and the current. So the field or the counter must be fed into the subscriber set and operated. Current is constant and the current or field changes

6. Equipment according to claim 1 for two participants (X, Y, Fig. 2) connected to a participant, the output potential of the changing size corresponding to the line, thereby Chen. The ma-

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Magnetic circles and circuits are given in simplified form in the figures; the magnetic circuit of the Hall effect device is provided by the magnetic circuit of the line transformer T1. The transformer windings are primarily intended as battery supply impedances 5, but they enable test and call devices to be connected to the line. The arrangement with the line coupling capacitors C1 and C2 is basically a Stonebrücke. The control current of the Hall element is kept constant; consequently, the Hall effect device output signal changes in response to changes in the magnetic field and hence the line current.

When a subscriber whose line equipment is shown in Fig. 1 is to be called, the signal encoder / 15 decoder unit SCD is instructed by the office control equipment, not shown, to turn on his call-on output RO; the latter sets the call flip-flop AR in its “1” state, which in turn switches on a switching transistor S1 via ARI in order to apply a low-voltage call current 20 to a winding of the transformer T1 and consequently to the line, whereby the alarm clock of the subscriber is actuated. In addition, since the O output of AR is no longer on, switching transistors S2 and S3 turn wires A and B off the calling line. At the end of the ringtone burst, SCD sets the call flip-flop AR to 0 via its call cutoff output RF in order to switch off S1 and likewise switch on switches S2 and S3.

The call timing is applied by the control equipment so that with each call activation signal AR is set to 1 to turn on the switch S1, which calls continuously (10 volts, 25 Hz) to the transformer and consequently to the line creates and to switch off the switches S2 and S3.

This state remains unchanged until the called 35 subscriber answers; the output of the Hall effect device HED determines that the line loop is closed and passes this determination on to the unit SCD via its output signal amplified by an amplifier AMP. The device SCD then informs the control equipment 40 that the called subscriber has answered. Then the ringer is switched off by resetting AR and the conversation between the participants can begin.

When the subscriber hangs up, HED determines that the loop has been broken; SCD sends an unoccupied signal to the central processor. Detecting the presence of a loop when the subscriber initiates a call leads to the same response of the Hall Effect device as described above, with the result that SCD "notifies" the central equipment that a call was initiated . As already described, the interruption and the reclosure of the loop by the dial-opening impulses triggers the sending of corresponding information to the central equipment.

The test access is generally similar to creating the ringing tone, with the test access signal typically being of a much longer duration than the ringing tone burst to allow the test desk access to the line for testing purposes. When the test access signal is received in the SCD, it is discovered, the unit SCD switches on its test access 60, which sets the flip-flop TA to its “1” state, which in turn switches on the switching transistor S4; the switching transistor then connects the test panel to another winding of the transformer T1. This alternating current connection to the line wires enables the line impedance to be tested, an alternating current bridge being used.

The equipment shown does not offer a DC link

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Possibility to use the cable so that it is not possible to locate an insulation fault. If such a connection is required, it must be established by other means, for example by a connection to the main distribution frame.

The equipment in FIG. 2 is based on that according to FIG. 1, but is designed for two subscribers, one connected to each arm of the line. In this equipment, the identification of subscriber X depends on the battery call. Another possibility is in the case where the top contact of the call button X is grounded; here the central windings of transformers Tlx or Tly can be brought to the potentials +25 V or -25 V, which leads to a supply of 50 V to the line.

In order to be able to operate two subscribers, each of which is connected to one arm of the loop, the individual transformer T1 from FIG. 1 is replaced by two already mentioned transformers Tlx and Tly. Each transformer has its own Hall effect device HED1 or HED2, so that the calling subscriber can be identified. If a subscriber is to be called, a signal from the unit SCD, which indicates the subscriber X or Y, sets the XY flip-flop to its 1 or 0 state, depending on which of the subscribers is desired. When the call turn-on signal sets the flip-flop AR to 1, the ringing tone is applied to the X or Y arm of the loop depending on the state of X and Y, respectively. Provided the subscriber X is desired, the ringing tone is applied to the winding Tlx via the switching transistor Six, this switch being set by the gate connected to its base; the ringing tone reaches arm A and actuates subscriber X's alarm by connecting it to earth. When subscriber X lifts off, line current flows in winding Tlx and device HED1 responds to indicate that X has closed the line loop. A signal is generated via SCD, which "informs" the central equipment that a call has been disconnected. This central equipment then adjusts the flip-flop AR again via SCD in order to switch off the ring tone. The conversation can now take place.

If the called subscriber is Y, the flip-flop XY is set to its O state; as a result, the switching transistor SI y is actuated and connects the ring tone to the arm B via Tly, as a result of which the alarm clock of the subscriber Y is actuated. The following procedure corresponds to the procedure already described for subscriber X.

When the subscriber calls X, he or she is identified by the call button or call button that connects the on-site battery to arm A, thereby generating a signal in Hall effect device HED1 indicating that X is calling and not Y. When Y calls, arm B is connected to earth, which actuates device HED2. In both cases, the central equipment is informed which subscriber is calling. It has already been mentioned that subscriber X can make a call by connecting the line to earth if a +25 V, -25 V supply is used for the lines.

Test access is accomplished via two windings in series, one via Tlx and one via Tly, which are connected in such a way that access to the line via both transformers takes place in a balanced mode. Practically the same conditions arise as for an individual subscriber call. As before, access is brought about by setting TA to its "1" state, which closes S4 to connect the test console. AC tests can then be made.

FIG. 3 shows how a subscriber counter can be actuated via a phantom circuit in equipment similar to that shown in FIG. 1. In addition to the circuit

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1 there is a transformer T2 with a secondary winding in each of a lead wire and a counting pulse circuit which is controlled by a switching transistor S5 when the counting flip-flop MP is in its “1” state. MP is switched on by a counting pulse via SCD and switched off when this pulse ends. As a result, a counting pulse, for example 5 V, 50 Hz, is applied to the line in a phantom-like manner, which actuates the subscriber counter.

Equipment can also be provided for several subscribers connected to the same subscriber line. However, these are not shown because it is only an extension of the technology intended for two participants. Two groups of subscribers, each of whom create the ring tone above ground, are fed from a first or a second transformer, the first transformer being similar to the transformer Tlx from FIG. 2, but having n / 2 feed windings and any one connected to arm A. Number of participants dined.

5 The second, similarly designed transformer feeds the subscriber connected to arm B. In this case, the alarm clocks only respond to their own frequency. Also, the ringer timing can provide the characteristic call feature, in which case only two transformers, as in Fig. 2, are required. In these cases, no identification is provided, so that only a single Hall effect device is used to determine a closed line loop. As before, the switches corresponding to the switching transistors S2 and S3 must be switched off 15 when the ringing tone is applied.

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2 sheets of drawings