DE72479C - Switching of telephone stations - Google Patents

Description

IMPERIAL

PATENTA ⁵ M

PATENT LETTERING

CLASS 21: Electrical apparatus.

Patented in the German Empire on January 14, 1893.

The present invention forms a circuit for telephone systems who switched the receiver of the calling station into the long-distance line during the call stay, so that an agreement from the called office is possible, while the wake-up button is still depressed, without any loss of wake-up current; Such a circuit also enables one to recognize the calling station can determine whether the alarm clock of the called station sounds, or whether there is a malfunction.

On the accompanying drawings are two embodiments of such a circuit shown.

In Fig. Ι the circuit is shown in the form that requires an existing system of the usual type. This system essentially consists of a microphone M, two remote listeners F ¹ F ^2, an alarm clock W, the inlet and shut off device A, the Inductionsspule /, the spindle lightning conductor S and the key T. The latter is in known manner with three Stromschlufsstücken S ¹ S ² S ³ equipped, of which the former is connected to terminal B of the wake-up battery through the line α . The Stromschlufsstück s ³ is through a line b 'and the spindle lightning arrester S with the long-distance line I in connection. If s ^{3 is} conductively connected to the circuit s ^l by the circuit spring f by the circuit spring f when the button h is pressed down, the current introduced into terminal B is transferred to the long-distance line / by adding the earth line c to the connected circuit The alarm clock is made to sound. Usually, however, the spring f rests on the power ^{connection piece s 2} , so that the long-distance line / is connected to a line d , which leads to the power connection piece ι of the circuit breaker A , by means of the spindle lightning arrester S and the line b. The latter comes - depending on whether the remote receiver F ² hangs on the hook ρ or not - with the power circuit piece 5 or that 3 in conductive connection; the Stromschlufsstück 5 mediates through a line e the connection of the alarm clock W, which on the other hand is led to earth by means of the lines gi. The Stromschlufsstück 3 but mediates the traffic over the line d and such k, in which the remote receiver F ¹ F ² as well as the induction coil / are inserted, and which is led to earth by means of the line c. The line m connected to the microphone M, the speech battery and the induction coil / emanates from the flow circuit pieces 2 and 4 of the switch A ; the circuit is closed as soon as the remote receiver F ^{2 is} removed from the switching lever, in that the latter acts on the leaf spring η , which conductively connects these current circuit pieces with one another. This device described so far is the usual one, but what is new is that the current connection pieces s' ² s ³ are also connected to one another continuously by a conductor w , the resistance of which, however, is considerably greater than that of the lines mentioned above, ¹ so that only one a very small part of that emanating from battery B of the calling station, caused by the current

Schlufsstück s ^ fs ³ to the long-distance line to be conveyed current through the line d and the switch A and from here - depending on the remote receiver F ² is hanging or removed - through the lines egi or kc to earth.

On the other hand, the current surges caused by the microphone on the called intercom can also be caused by the long-distance line /, the spindle lightning arrester S, the line b, the electrical connection piece s ^s , the conductor n>, the line d after the switch A and from here into the telephone line k arrive.

In the circuit of Fig. 2, the trunk line / respectively. The spindle lightning arrester is not connected to the power circuit s ^{3 of} the button T by a line b , but is routed to the power circuit 1 of the switch A , the power circuit s ^s on the other hand with the speech line k, and s ² through a line k ^l with the earth line c tied together. The current supplied by the long-distance line will, depending on whether the handset F ^{2 is} removed or is attached to the hook ρ , get into the handset line k or through the line e to the alarm clock W. In the former case, current goes through the key T, ie its current circuit s ^3,. Spring f, Stromschlufsstück s ² and the lines k ^l c to earth, or he gets there through the alarm clock W and the lines gi . As long as the key T is pressed, however, this current must reach earth through the line α and the battery B instead of the line k ^l. The current introduced via the terminal B will therefore not be able to get into the trunk line / without having flowed through the voice line k of the calling station, the remote receiver F ' ² being assumed to have been removed from the hook ρ. Current surges generated by the microphone on the called station, with a naturally higher potential than that of the battery, will be able to overcome the current emanating from it and set the records of the remote listeners of the calling station in motion according to the vibrations of the microphone plate at the called station.

With both circuits, the voice stream of the called station is enabled, to counteract the wake-up current of the calling battery by either dividing it learns, and the branched current is passed through the voice line of the calling station is, or - assuming an immediate long-distance line with the circuit breaker - in his full strength flows to the speech line. Also in the event that such a circuit If an inductor is inserted instead of the wake-up battery, the mode of operation remains exactly the same.

Claims (2)

Patent Claims: 1. A circuit for telephone systems, which serves to enable speaking from the called station while the alarm button of the calling station is still depressed, as well as to make the sounding of the alarm clock of the called station audible on the calling party, characterized in that dafs a part of the wake-up current is led through the speech line, for which purpose the current circuit pieces (s ³ s " ² ) of the wake-up button are connected to one another by a resistance conductor (w) , so that only a part of the wake-up current through line (d) and switch ( A) and from here it reaches earth through voice lines (k) and line (c) (Fig. 1), in such a way that the potential of the waking battery is wholly or partly overcome by the currents generated at the station called. 2. An embodiment of the below. 1. marked circuit for telephone systems, in which the wake-up current flows through the speech line in its full strength, for which purpose the long-distance line (I) through line (b) with the off switch (A) and the Stromschlufsstücke (s ³ s' ² ) of the wake-up button with the voice line; (k) resp. the earth line (k ¹ c) are connected so that the wake-up current cannot get into the long-distance line (I) without being closed by the voice line (k) (Fig. 2). 1 sheet of drawings.