DE158798C - - Google Patents

Description

PATENT OFFICE.

M 158798 CLASS 21 a.

When powering extensions from the central battery of the telephone exchange is the call to the office is not required in the case where an extension is with her Main unit or the branches of a main unit in direct speech communication with each other occur, since the office then does not establish a connection, but only the supply current has to deliver automatically. For this

ίο Power supply are the same lines available through which the electricity for the call to the office is to be conducted at other times. While now in the latter case the addressing of the call sign is required in the office, must be the same in the aforementioned The case of the automatic supply of the feed current can be avoided. According to the present Invention, the call of the office is achieved in that the two

ao branches of the subscriber line on the office via an electromagnetic winding of the call organ with a grounded battery respectively. are connected to grounded batteries in such a way that the branches of the line are different Have voltage to earth and the windings of the call organ are arranged and dimensioned so that they are connected in series the branches of the line on the main or branch are under the influence of those between the branches Support the voltage difference and cause the office to be called, but cancel each other out in the effect and make the call prevent if, as a result of earthing both branches on the extension, the same are flowed through in parallel by the feed current of the auxiliary units.

An embodiment of the circuit is illustrated on the accompanying drawing. The drawing illustrates the case that two extensions JV _1, JV ₂ of the main body H are together in the voice traffic and received on the twin conductor 1, 2 and ground the required microphone supply current from said central battery E of the office A, wherein d by inductors, the course of Speech streams are limited in the known manner to the local branch exchange connection · bb. - The devices required to establish the last-mentioned connection as well as those which mediate the traffic between main and branch offices on the one hand and the traffic between a branch and the office on the other hand have been omitted from the drawing for the sake of clarity and are carried out in the usual way think. For the same reason, the internal equipment of the stations, which does not differ from the traditional, is only illustrated in a simple design for the main station H. Since the well-known exchange facilities for call switching between two subscriber lines (with and without extensions) and for calling the subscribers (by means of alternating

Claims (1)

Strom) do not experience any change, the establishment of the office is also simplified Way shown, so that the circuit according to the invention emerges clearly from the same. This circuit consists in that the branch ι of the subscriber line has a j winding Wi _{1 of} the calling electromagnet and a small battery C ₁ with one pole is connected ίο the grounded at the other pole microphone battery e while branch 2 m above a second winding. ₂ of the call electromagnet also communicates with the first pole of the battery in connection e. The windings Wi ₁ and m ₂ are arranged on their common iron core so that they counteract each other when, as shown, both branches of the line in parallel circuit are flowed through by the microphone stream of the extensions. As a result, the anchor α remains at rest and the local circuit of the callsign 5 is open, so that a call from the office does not occur. The second circuit characteristic of the invention comes about when the main station switches itself or an extension for a call to the office in a bridge to the subscriber line by flipping the switch u of the main station - which schematically represents any such switching or connecting element. When the handset of the call station is removed, a current flows from the battery C ₁ via the loop line 1, 2, the call station and both windings of the calling electromagnet, through which current flow the windings are now excited in the same sense, so that the armature a is attracted and the call lamp 5 lights up. In order to ensure the described mode of operation of the windings! 7Z ₁ and m. ₂ , an appropriate dimensioning of the resistance and the number of turns is necessary. In the diagram, this is indicated for the same number of turns by the resistor ip inserted in front of the battery C ₁ , by means of which the excess voltage of the branch 1 for the supply circuit is compensated for in the required manner. The size of the battery e _{ is to be selected according to the line resistances and the required call current. The same can also be arranged with reversed poles in opposition to the battery e , whereby the measures mentioned to compensate for the excess voltage have to be changed accordingly. are to be attached to the other line branch ". Batteries e and e _: can be replaced by other equivalent arrangements. For example, each branch of the line can be connected to earth via its own battery, the two batteries being of unequal size to be chosen so that the voltage between earth and one branch (1) of the voltage between earth and the other branch (2) exceeds a certain amount (e _t ). This amount is only effective in the described call circuit of the branches as a result of the batteries interacting with one another, while in the case of the supply circuit, both batteries produce electricity in parallel with one another. Further embodiments result when the interaction of the windings Wz ₁ and m ₂ according to the invention is achieved in a structurally different, equivalent manner instead of by means of a common iron core and common armature. Ρλτεντ claims: Telephone circuit with central battery for calling the office and supplying power of extensions in which the branches of the subscriber line on the exchange with each one electromagnet winding of the call organ are connected, characterized in that, that the windings of the call organ BEZW with different strong grounded batteries. different Parts of the grounded office battery are connected in such a way that the branches have different voltage to earth and the windings of the call organ are arranged and dimensioned in such a way that that when the branches are connected in series on the main body, they are subject to the influences of the Branches of the prevailing voltage difference support and the call of the office cause, however, in the effect cancel and prevent the call if • as a result of earthing both branches on the extension the same flowed through by the feed current of the extension in parallel will. " 1 sheet of drawings.