DE585882C - Circuit arrangement for telephone systems in which alternating current of a certain frequency is used within the voice frequency range for signaling - Google Patents

Description

GERMAN EMPIRE

ISSUED ON OCTOBER 13, 1933

'. GERMAN PATENT OFFICE

PATENT LETTERING

CLASS 21 ai GROUP 25oi

Siemens & Halske Akt.-Ges. in Berlin-Siemensstadt *)

⁵ Patented in the German Empire on September 25, 1930

The invention relates to a circuit arrangement for telephone systems in which the transmission of signals via -the Speech lines Alternating currents of a frequency lying in the range of the speech frequencies be used, with devices must be provided to influence the of the signaling devices through the speech streams.

There are now devices known at which influence the signal receiving device prevented by currents of other frequencies than the signal frequency is that z. B. can be used as a signal receiver relay based on the signal frequency are precisely matched, so that the excitation by · currents of other frequencies from the outset is turned off. Furthermore, one has blocking means in the signal receiving device arranged, which block the device when other than signal frequencies arrive. Signal receivers of the latter type exist z. B. from an arrangement of sieve circles and rectifier tubes, e.g. B. two cathode tubes, one of which responds to the arrival of signal frequencies and causes the signal to be transmitted while the other comes to response when other than signal frequencies arrive and the first makes it ineffective, so that a transmission of signals is prevented.

The present invention now provides an arrangement of the latter type, however Instead of two hot cathode tubes, there is only one, namely a double grid tube used by taking advantage of the characteristic properties of these tubes, in such a way that a double grating tube in the signal receiving device is provided, the two grids of which are each coupled to an oscillation circuit, wherein the latter so designed and with each other and with the control grid and space charge grid circle the tube are connected so that incoming signal frequencies enter the tube and the signal receiving relay located in its anode circuit to respond, while with incoming other frequencies the response is prevented.

This arrangement is not only characterized in from a technical point of view through substantial simplification and thus greater operational reliability compared to the known arrangements, but it also means one

'*) _ The patent seeker stated as the inventor:

'' Dipl.-Ing. Karl Faber in Berlin-Charlottenburg ..

significant advantage in economic terms due to cheaper prices, in particular by eliminating special power sources, since the voltage of the existing central battery as anode voltage is sufficient or used.

The principle mode of operation of the arrangement is approximately as follows: The one of the Upstream signal receiving device »o Transmitter incoming signal currents a resonant circuit tuned to the signal frequency and the primary winding of another transformer, both of which are connected to the Secondary winding of the first transformer are in series, supplied. The resonance circuit is with the control grid and the second transformer with the space charge grid of the double grid tube coupled, with a current flowing in the space charge grid circuit in the idle state, the magnitude of which is determined by the amount provided therein Battery is determinedi while the control grid has a certain negative bias receives.

If the incoming signal currents a5 are pure signal frequencies, since there is resonance at the resonance circuit in this case, the control grid of the tube is influenced, in which case the space charge grid current becomes smaller and the tube works as a normal rectifier tube. The relay located in the anode circuit of the double grid tube, which controls the transmission of the signal z. B. ₍ caused by closing a local circuit will respond.

However, meet other frequencies at the first transmitter, e.g. B. Speech frequencies, a, so if this current, other than signal frequency, have an effect on the second transformer or are superimposed on the space charge grid quiescent current, whereby this strengthens and thereby the flow of the anode current and consequently the response of the relay is prevented.

The invention is shown in the drawing using an exemplary embodiment and Their mode of operation is described below on the basis of this.

The signal receiver is connected to a line, assumed to be a telephone line F, via a transmitter Ue ¹ . In row

with the secondary winding! This transformer Ue ¹ has an oscillating circuit, the resonant circuit S tuned to the signal frequency, and the primary winding of a transformer Ue ² :. The resonance circuit S is on the one hand with the. Control grid Gst, on the other hand connected to the cathode of the double grid tube Gl , while the secondary winding of the transformer Ue is connected on the one hand to the space charge grid Gr, on the other hand to the cathode of the tube. The grid battery Bg ¹ is located in the control grid circle, the battery ^{Bg 2} in the space charge grid circle . In the idle state, a current of a magnitude determined by the battery Bg ² flows in the space charge grid circuit, while the control grid Gst receives a negative bias voltage from the grid battery Bg ^{1 S5.} In the anode circuit of the tube Gl , a relay R is in series with the battery AB.

If pure signal currents now arrive from the line F via the transformer ^{Ue x} , resonance prevails at the oscillating circuit S, which is tuned to the signal frequency, while the transformer Ue ² remains unaffected. As a result, the tube G ¹ is excited via the control grid Gst , the space charge grid current becoming smaller. The tube works as a normal rectifier tube, and the relay R comes to response and closes z. B. after responding via a contact 3 ^r a local circuit through which the transmission of the signal takes place.

If, on the other hand, alternating currents other than the signal frequency, e.g. speech currents, arrive from the line F via the transformer Ue ¹ , the resonance circuit 6 "remains unaffected. These currents now affect the transformer Ue ² and are superimposed by the secondary winding of the transformer Ue ² The relay R does not respond and no signal is transmitted. The signal receiver is blocked.

Claims (3)

Patent claims: i. Circuit arrangement for telephone systems in which alternating current is used for signaling a certain frequency within the speech frequency range is used is, characterized in that a double grille tube in the signal receiving device is provided, the two grids of which are connected with oscillation circles and by incoming currents be influenced in such a way that when signal frequencies arrive via the one Grid energizes the tube and the relay lying in the anode circuit to Emission of signals is actuated, while upon arrival of others, z. B. Speech frequencies, through the other grid, the tube is so influenced that no Anode current is flowing or the tube is blocked. 2. Circuit arrangement according to claim i, characterized in that the Control grid of the tube with a resonance tuned to the signal frequency circle is connected, while the space charge grid of the tube is coupled with a circle, is responsive to all frequencies. 3. Circuit arrangement according to Claim.2, characterized in that in a transformer is used in the circuit that responds to all frequencies, whose secondary winding is connected to the space charge grid, while its primary winding is connected to the resonance circuit in Row lies. For this purpose τ sheet drawings BERLIN. PRINTED IS THE EMPIRE PRINTING COMPANY