DE1487453C3 - Circuit arrangement for subscriber stations in telecommunication systems, in particular telephone systems - Google Patents

Description

4. Circuit arrangement according to claim 2, is coupled there. The expense of this arrangement is characterized in that the electrical bi-considerable.

stable switching element a triode (z. B. a cold- In another known arrangement is the

cathode tube or a semiconductor current gate) is, switch, with which the call alarm clock in the idle state

whose control electrode is separated from the subscriber line with a further 40, a

also via the mentioned rectifier arrangement glow lamp, which only occurs when a call

voltage of the chargeable capacitor is connected, the signal ignites. It is considered a disadvantage of this arrangement

that their ignition voltage was felt with increasing awareness, that the call energy was only inadequate.

Charge of this additional capacitor increases and is used accordingly.

that the capacitor during each 45 Another known arrangement goes from the

Pauses in the call maintains its charge level. Realization that the polarization of the call

5. Circuit arrangement according to claim 4, da- weckers, d. H. its pre-excitation by a permeate marked that the further condensate magnet, one of the main causes of the sator via a contact of the hook switch generating the microphone voltage is and beats is discharged. 50 therefore propose to eliminate the pre-magnetization

6. Circuit arrangement according to claim 4, furthermore by means of a rectifier arrangement characterized in that the further con-rectified call alternating current to be generated, capacitor a high resistance parallel in addition to the weakening of the ringing caused by it is, through which he has so slowly developed alternating current - this measure still the that the discharge time constant has the disadvantage that it increases the microphone voltage as a result The order of magnitude of the mean conversation duration of the remanent magnetism does not completely eliminate has. can.

The invention has the object that

Disadvantages of these known arrangements to be eliminated

60 or reduce their effort.

It also goes from such participant locations

Some of the components of a subscriber station that are made up of where the alarm clock is ready to call

is in the idle state that is ready for a call, the state only takes effect when the

known as electroacoustic transducers, so that voltage to the subscriber line is effective-

with their help at the location of the subscriber station, the switch is connected in series and triggers

Discussions after appropriate reinforcement regardless of the fact that the striking mechanism of the

can be intercepted fugly. alarm clock with a non-polarized drive

The effect of the microphone voltages, which is equipped with a fixed rest position in the system, of which

3 4

Control coil in the discharge circuit of one of the call also via the mentioned rectifier arrangement

voltage chargeable capacitor is arranged that its chargeable capacitor is connected

and that this discharge circuit is caused by the ignition voltage as the charge increases

th with the alarm clock in series switching capacitor increases and that the capacitor

ter can be switched on periodically, this switch 5 being charged during the individual call pauses.

of the charge level occurring at the capacitor is maintained. So while the ignition voltage

voltage or is controlled by the ringing voltage. of the electrically bistable switching element first

This creates a circuit arrangement that is small, that is, the capacitor discharges extremely little effort and at the same time starts with a low voltage and the following Advantages: Because the drive system doesn’t take the impact force of the alarm clapper into place Permanent magnets are only very low when the volume is comparatively low, increases generates small microphone voltages. In addition, this volume increases as the charge of the said switch is open in the idle state and sets another capacitor and thus increasing ignition As a result, a very large resistance to the voltage of the electrically bistable switching element the microphone voltages 15 which arise nevertheless continue from call to call. The feature that the represents, in addition, of the capacitor further capacitor during its state of charge are short-circuited. Another advantage is that individual pauses in the call should not change, has undarin, that as ringing voltage, optionally optionally, the result that any alarm clock with wise either an alternating voltage or one of the same volume begins with that of the previous direct voltage can be used. 20 outgoing call has ended. This achieves

A further development of the invention is characterized in that a participant who is in the vicinity of his part thereby from the fact that the subscriber station with the call alarm clock is in series, not with the maximum loudness Switch is harassed in a manner known per se as strength, on the other hand it is ensured • electrically bistable switching element is designed so that the more distant subscriber also receives the call signal whose ignition voltage is greater than that in the idle state 25 can hear. According to a further development of the invention Charging voltage occurring at the capacitor is that in the control circuit of the controllable electrical however, is smaller than the voltage on which this bistable switching element is arranged further Kon capacitor is charged in the call state. In the capacitor via a contact of the hook switch In contrast to the known arrangements, with de- to unload again, so that after the termination NEN as a switch also an electrically bistable 30 of a call restores the idle state Switching element is used in the form of a glow lamp. According to another development of the invention is, it is marked by the invention, this further capacitor is a high resistance Neten arrangement also not possible, this switch resistor connected in parallel, through which it is so by applying an external voltage - e.g. B. one is slowly discharged that the discharge time constant High-frequency voltage, by which the alarm clock does not 35 the order of magnitude of an average conversation time is directly influenced - in its passage - has.

control state. Because since the function of the The invention can also be advantageous with so-called alarm clock circuit irrespective of the frequency of the named electronic two-way connections use ringing voltage such an auxiliary voltage would be det. Under electronic two-way connections also make the alarm clock sound and one understands those in which in the participants Participants were warned against such manipulations - lines rectifier for the respective participants. As a further advantage of the slave position according to the invention, characteristic polarity is inserted. Arrangement can be stated that the sound- These rectifiers are used for identification Strength of the alarm clock from those in the ringing circuit before and to ensure the secret traffic. she On the other hand, however, existing resistances, in particular the resistance, make the transmission of the Status of the subscriber line, independent of the ring voltage to the alarm clock of the subscriber station, is because the discharge current surge of the capacitor, which when this in the usual way by capacitors causes the clapper to strike, are only sealed off from the DC supply voltage by the ignition. the and the extinction voltage of the electrically bistable on-switching element formed according to the present invention depends. It is also possible to use it as a 50-call alarm clock without any change for it Call alarm clock a signal generator with a gong-like such an electronic two-way connection ver-sound character to use and the entire wah- can be turned.

End of a ringing current emission in the capacitor I _{n of} the drawing are two exemplary embodiments

Storable electrical energy shown in a single of the invention. The in F i g. 2 shown

To implement the clapper stop. In an expedient 55 circuit contains compared to the simple circuit

Further development of the invention can be the con after FIG. 1 as a development of the invention

capacitor already from the automatic volume control described in the call-ready idle zu-. the

was the voltage applied to the subscriber line- Mode of operation of the circuit according to FIG. 1 is extra-

voltage are charged, so that the actual call is neatly simple: The one connected to the two wires α and b

voltage only as a control signal for the ringing voltage applied to the 60 subscriber line

loading circuit-switching-on electrically bistable _n ung passes through the reputation capacitor CA to the

Switching elements is used. Rectifier arrangement G and charges the capacitor

Another development of the invention allows gate C to open. As soon as its charging voltage exceeds the ignition an automatic volume control of the call voltage of the four-layer diode V , the alarm clock switches. It is characterized in that the 65 this in a known manner a discharge current, electrically bistable switching element a triode (e.g. a circle in which the drive magnet AM of the call, a cold cathode tube or a semiconductor current gate) is excited. The capacitor C is there, the control electrode of which is connected to a further one up to the extinction voltage of the four-layer diode V.

unload. When the four-layer diode V has gone out and is thus again in its high-resistance state, the capacitor C is recharged with the alternating ringing voltage and a new discharge process can begin, etc. Tension on. This has the consequence that the rectifier arrangement is de-energized and thus the insertion loss of the alarm circuit is increased.

The in F i g. The circuit shown in FIG. 2 is suitable for so-called electronic two-way connections. The rectifiers G11 and G 21 inserted into the wires a 1 and a 2 , which are polarized in opposite directions with respect to the wires α and b , enable, in a known manner, the identification and the secret traffic of two subscriber stations connected to the same subscriber line. In the case of an incoming call for one of the two subscriber stations, the alternating ring voltage is superimposed on the voltage of the exchange battery, the polarity of which is characteristic of the respective called subscriber station. If the call is intended, for example, for the subscriber station connected to the speech wires a I and oil, the capacitor C is charged via the rectifier GIl. At the same time, the capacitor Ch is slowly charged via the cathode-grid section of the semiconductor current gate St, the rectifier G 13 and the resistor R. The charging current, which is at the same time the control current of the current gate St , influences its ignition voltage, and this increases as the charging of this capacitor increases, since the capacitor charging current is always

ίο gets smaller. This has the consequence that the discharge currents of the capacitor C flowing periodically through the alarm clock coil AM initially only have a small amplitude and the acoustic signal generated by the alarm clock is correspondingly low.

Since the capacitor Ch cannot discharge again in the individual pauses in the call because of the rectifier G 13 inserted in its charging circuit, each new call begins with the same volume as the previous one ended with, ie

zo the volume increases from call to call. When the handset is picked up at the subscriber station, the working side of the fork switchover contact u closes a discharge circuit for the 'capacitor Ch.

1 sheet of drawings

Claims (3)

1 2 Claims · Components arranged in a speaking circuit, such as microphone, receiver and transmitter, can easily be 1. Circuit arrangement for subscriber stations to be sided that this speech circuit is in rest Telecommunication systems, especially telephone systems, were briefly linked to contacts of the hook switch those with an electromagnetically resolved 5 and disconnected from the subscriber line activatable striking mechanism equipped call alarm clock. for the elimination of microphone voltages in the case of the call alarm clock, however, this is not possible to make a call ready idle state with a borrowed only because it must be reachable in the ready to call idle state for the application of ringing voltage to the subscriber ringing voltage. Known sound connection line effective switch -in.io young is connected in series to suppress the microphone voltage, thereby marked- of call alarm clocks suggest in the ₍ indicates that the striking mechanism of the call alarm clock circuit, non-linear switching elements a-'alarm clock with a non-polarized drive - add that the very low amplitudes of the system is equipped with a fixed rest position, microphone voltages oppose a large resistance to the control coil in the discharge circuit of a 15, while they are permeable to the ringing change from the ringing voltage to the chargeable capacitor voltage. These arrangements are arranged and that this discharge circuit However, there is the disadvantage that the non-linear switch can be periodically switched on by means of the switch connected to the call alarm clock in resistors by applying a voltage in series to the part, this switch being different from the switch at the terminal merleitung in their low-resistance state of the capacitor charging voltage or can be controlled without the call alarm clock being controlled by the ringing voltage. takes effect. In other known arrangements 2. Circuit arrangement according to claim 1, there is therefore the call alarm clock in the idle state of the · characterized in that the disconnected with the call subscriber line and is only by means of alarm clock in series switches in a relay that can be excited by the ringing current to the It is known that it is connected as an electrically bistable switching line. As such a relay its element is formed, whose ignition voltage can be a source of microphone voltages greater than that at rest on the condenser, suggests another known arrangement, Sator occurring charging voltage, but smaller that it can be used as a thermal relay, d. H. as a component without than the voltage to which this capacitor 30 inductance is formed. is charging when idle. Another known arrangement wants the back 3. Circuit arrangement according to claim 1 effect of the call alarm from the subscriber or 2, characterized in that the direct line disconnects or short-circuits it judge arrangement an ohmic resistance in front of the relay on the subscriber line thereby avoid is switched. 35 that this relay is photoelectrically connected to the ringing circuit