DE1090253B - Circuit arrangement for telephone subscriber stations with indirect control of the receiving magnet - Google Patents

Description

The invention relates to a circuit arrangement for telex subscriber stations with indirect control of the receiving magnet by a polarized telegraph relay, which is partly via the connection line, partly via the Can be excited via a pre-excitation winding and its armature is arranged in a local circuit Receiving magnet controls.

It is known in telex switching technology a polarized one for the evaluation of the single current characters transmitted from the exchange to the subscriber To use telegraph relay, the armature of which indirectly contacts the receiving magnet of the teletypewriter controls by the local circuit of the receiving magnet in the cycle of the teletype steps interrupts or closes. Such a known circuit is shown in FIG.

In Fig. 1, a subscriber Tu is shown on the left by the sending contact Sk and the receiving magnet EM . The receiving magnet EM is not in the subscriber loop α ljb 1, but in its own local circuit {-TB, EM, Wi3, he in the separating position T, + TB) and is indirectly controlled by a telegraph relay ER provided in the subscriber loop a ljbl. The subscriber Tn is connected to the exchange J ^r S via the connection line Ans . The exchange 1 ~ S is in a known manner with a converter circuit built up from the two telegraph relays A and B

The advantage of this known arrangement compared to the direct connection of the teletypewriter receiving magnet EM in the subscriber loop a IJb 1 is that the range of reception of the teletypewriter receiver is independent of the curve shape of the telegraph characters, i.e. independent of the bridged line length or line type. The prerequisite for this, however, is that both the line current effective in the relay winding ER I and the pre-excitation current effective in the relay winding ER II are kept constant. A change in the line current, for example a reduction due to a drop in the telegraphic voltage in the exchange, or a change in the pre-excitation current, for example as a result of a change in the local circuit voltage, which can be generated via a small power rectifier, results in telex character distortion and thus narrows the reception scope of the Teletypewriter receiver.

These causes of the teletype distortion can occur within the local circuit the use of a well stabilized rectifier device and in the exchange by a sufficient constant telegraph power supply prevents circuit arrangement

for telephone subscriber stations

with indirect control

of the receiving magnet

Applicant:
Siemens & Halske Aktiengesellschaft,

Berlin and Munich,
Munich 2, Witteisbacherplatz 2

Friedrich Kreuzer, Munich,
has been named as the inventor

but the effort involved in avoiding the distortion in this way is considerable.

In contrast, the object of the invention is to prevent this type of circuit from occurring to prevent telex character distortion without affecting the voltage stabilization of the telegraph voltage large in the exchange and the pre-excitation circuit at the subscriber To make demands. According to the invention, this object is achieved in that the partial and via the connection line to be carried out excitation of the telegraph relay serving relay winding is only partially fixed and the other part pulsed to the connection line and that the The pre-excitation winding compensates at most only the throughflow component that is allotted to the fixed coupling, so that the pulse-wise coupling resulting flooding causes the intended control of the relay.

Because with a pulse-wise coupling the current rise and the current fall in the telegraph relay winding are essentially symmetrical to each other and this symmetry also by a drop the pre-excitation is not influenced, it is achievable according to the invention, in this way the separation and to transmit character stream steps to the receiving magnet at the correct spacing.

Details of the invention can be found in the exemplary embodiments described with reference to the drawings emerged. In the drawing shows

Fig. 2 shows a recorded according to the invention for the indirect control of a telex receiving magnet

009 530/221

'»Ante circuit arrangement with a capacitive pulse-wise Coupling and

Fig. 3 such a circuit with an inductive

-. '<ίϋ'φ riS ^ gSffsfr' a subscriber circuit Tn is shown in which the relay winding £ 7? II for a pulsed coupling to the connection line α 1/6 1 with a capacitor Cn 1 in series and both are connected in parallel to a resistor i / 71 arranged in the connection line, while for a fixed coupling of the relay winding -Ei ?! to the an> ch! uß.le.jtm> g to the capacitor Cn 1 a resistor ' -.Wi 2 is connected in parallel.

The relay winding £ 7? Because of the fixed connection to the connection line, a current flows through I at all times (A1, SK, ERl, WiT., 61). This line direct current component causes the relay ERl to be excited on the isolating side, at least half of which is compensated for by the pre-excitation of the winding ERiI on the sign side.

If, through the individual steps of the telex characters, a direct current flows through the connecting line β 1/61 in pulses, then the capacitor Oil is charged at the voltage drop with each current increase via ER1. which occurs at the resistor if71 due to the rise in current. The charging current causes the isolation side excitation of the winding £ 7? I. In any current drop, the capacitor discharges through the winding ER I and the resistance / Γ / 1 and now energizes the winding sign side-The separation and Zeiclienstromimpulse are of the same amplitude, so that the poled telegraph relay ER, the single current pulses equidistant to receipt of magnets EM transmits.

As when receiving single stream characters The AC control pulses are about eight times larger than those due to the fixed coupling caused direct current flow, changes in the pre-excitation due to fluctuations in the battery voltage or changes in the line Stromes cause only very minor distortions, which are practically negligible.

In the Fig. 3 shows a further subscriber line circuit is shown, in which the relay coil ERI for a partly solid, partly pulsed coupling to the Anschlulik-itung a 1 is connected '61 having a resistance ΓΓ73 in series and both arranged in parallel to a in the connecting line Throttle Dr are turned on. The inductance of this choke is a multiple of the inductance of the winding ERl. The resistor i / 73 is dimensioned so that about a fifth of the line current flows through the line winding ERl . In this example, the pre- excitation winding ERIl also receives a flow rate of approximately half the flow rate caused in the winding ERI for the line current. In this example, the direction of the pre-excitation is also on the drawing side. while the excitation caused by the line current in the winding ER I is on the triangle side.

When single-current characters are received, the alternating current edges are used as separating or character pulses forced by the winding 7: 7? I flow. Since this, as already stated, to are several times greater than those caused by the line current or by the pre-excitation Floods are fluctuations in the line current or the pre-excitation for the occurrence of distortions also negligibly small.

Claims (5)

Claims 1. Circuit arrangement for telegraph subscriber stations with indirect control of the receiving magnet by a polarized telegraph relay, which can be excited partly via the connecting line, partly via a pre-excitation winding and whose armature controls a receiving magnet arranged in a local circuit, characterized in that the partial and to be carried out via the connecting line The relay winding (ERl) serving the excitation of the telegraph relay can only be partially fixed and the other part pulsed to the Αη-circuit and that the pre-excitation winding (£ 7? II) only compensates for the flow rate due to the fixed coupling, so that the the pulsed coupling causes the intended control of the relay. 2. Circuit arrangement according to claim 1, characterized in that the line-side relay winding (ERl) for the pulsed coupling to the connecting line with a capacitor (O; 1) is connected in series and both connected in parallel to a resistor (WH) arranged in the connecting line and that a resistor (Wi-2) is connected in parallel to the capacitor (Ch-I) for the fixed coupling of the relay winding (ERl) to the connecting line. 3. Circuit arrangement according to claim 1, characterized in that the line-side relay winding (ERT) for a partly fixed, partly pulsed coupling to the connecting line connected in parallel to a throttle (Dr) arranged in the connecting line and a resistor (WiZ) for setting the coupling components is provided. 4. Circuit arrangement according to claim 3, characterized in that the throttle (Dr) is provided with an air gap and its inductance is greater than that of the relay winding (ERT) . 5. Circuit arrangement according to claim 1 and 2, characterized in that the flow rate of the relay winding (ERT) determined by the fixed coupling is only half compensated by the flow rate of the pre-excitation winding (£ 7? II). 1 sheet of drawings 009 530/221 6.60