DE2314291C3 - Circuit arrangement for the different supply of two consumers lying in a constant current circuit with constant DC voltages - Google Patents

Description

In telecommunication systems in which the news are transmitted to the subscriber stations using the carrier frequency and these with constant current ■) "> are fed, the problem occurs. that the load on the Fernspeisesiromes when transferring calls is so great is. that the sub-assemblies of the TF subscriber flour more can be supplied with a sufficiently large and constant voltage. However, it would be ineffectual borrowed, just because of this short-term exposure Design the power supply for a greater load.

Such telecommunication devices are for example on the subscriber lines one >, Telephone exchange used. Such Device dieni da / u, in addition to the existing one Low-frequency channel a further transmission channel operating according to the carrier frequency method to create the Ciegenssprechbetrieb Der / weck isi · " there, with a limited number of participants FINAL GUIDELINES Sufficient clearing paths for the For the speaking participant willing to agree

(3 for such a superimposed carrier frequency / channel the call transfer is made by the exchange " to the subscriber by keying the relevant carrier frequency in the rhythm of the call change for example at 25 Hz. In the receiver.

which is assigned to the subscriber connected to this carrier frequency channel, the sampled carrier frequency evaluated and fed to the control input of a pole reverser. This Umpoler is looped into the cable run that carries the direct current for the carrier frequency (TF) channel Telephone set delivers When receiving the keyed carrier frequency this is direct current polarity reversed by the polarity reverser in the rhythm of the alternating ringing voltage, whereupon the alarm clock of the telephone set sounds In DE-OS 21 30 083 such a pole reversal is described.

The pole reverser needs a relatively large one during the call reception and during the rest of the time Time a low performance. This large power consumption is particularly detrimental when the The subscriber station concerned does not get its electricity from a local power source but from a remote power supply received from the exchange In this case, the current supplied by the exchange battery must be the originally only used to feed the telephone set belonging to the low frequency channel, in addition still supply the TF device along with the associated telephone set.

It is therefore the object of the invention to provide such a circuit through which all of the control of the Rufumpolers not required power consumers are switched off so that the available Remote feed power as unrestricted as possible as call power for the subscriber station supplied with TF is only available when the called subscriber has picked up the switched off modules be reapplied to the supply voltage.

The features of the invention are evident from the claim.

An embodiment of the invention is shown in the drawing, on the basis of which the invention is to be explained in more detail. To explain how this circuit works, it should be noted that the output terminals of the polarity reverser L / μ lead to the telephone subscriber that is supplied with TF.

When the receiver is on-hook, the direct current path is interrupted. The entire current fed in then flows through the Zener diodes Di. D 2 and the diode D 3 and generates the supply voltage for the consumer E via the Zener diode D 2, which is fed to the latter via the diode D 4. The consumer therefore always flies on its supply voltage. At the same time, the transistor f is controlled through to saturation by the voltage drop across the diode D 3, so that the consumer S 'is short-circuited via the emitter-collector path of the transistor T.

If the telephone subscriber is called, the carrier oscillator oscillates in 25 Hz cycles, which are fed to the llmpoler LIp after amplification and rectification. The activated Umpoler polls the lines leading to the subscriber in a 25-Hz cycle and brings about its Weiker / um response. This happens through the short circuit across the emitter-collector-i-path of the transistor T.

The called 'lifts from the subscriber so the direct current circuit is closed, and z from the .efier * · diode ϋ I. Ü2 formed and the diode I) 3 Quef / vseig

becomes currentless. As a result, not only does the supply voltage for the consumer E disappear, but the control voltage for the transistor T disappears, which is blocked. The direct current now flows through the consumer S, and the parallel Zener diode D 6 stabilizes its supply voltage Applied via the diode D5 to the consumer E so that the TF device remains fully operational. The three capacitors C1, C2, C3 are used to block the NF,

The invention has the advantage that the peak power consumption is assigned to the subscriber TF-Endslelle is kept to a minimum. It is therefore a secure remote feed operation of this terminal is possible.

For this 1 sheet of drawings

Claims (1)

Claim: Circuit arrangement for the different supply of two consumers lying in a subscriber connection line fed with constant direct current ΐ with constant direct voltages, of which one consumer is only to be continuously supplied when the subscriber loop is closed and the other consumer, in telecommunications systems, in particular in telephone exchanges with carrier-frequency transmission to the subscriber station, characterized in that the one consumer (S) is firmly looped into the one wire (B) of the subscriber connection line and, when the subscriber loop is closed, is supplied with constant direct voltage from the flowing feed current through the direct voltage dropping across a parallel Zener diode (DS), as well as with open subscriber loop is short-circuited by the circuit section of a transistor (T) , which is parallel to it, which is caused by the partial voltage dropping at a diode (D 3) when the subscriber loop is open ng of a voltage divider (Di, D2, £> 3) is switched through, which is located between the wires (A, B) of the subscriber line and from the series connection of two further Zener diodes (Di. D2) and the forward-biased diode (Di) exists, and that the other consumer (E) with a closed subscriber loop: jrch the DC voltage dropping across the Zener diode (D 6) parallel to one consumer (S) via a further diode (D 5) and when the subscriber loop is open, the partial voltage of the voltage divider (D 1, D 2, D 3) dropping across the one further Zener diode (D 2) is supplied with constant DC voltage via a further diode (D4).