DE2207255C3 - Circuit arrangement for the transmission of electrical energy in centrally fed telecommunication systems - Google Patents

Description

The invention relates to a circuit arrangement for transmitting electrical energy from one to one Central station arranged energy source to an energy consumer arranged in at least one outstation via a communication line connecting the central station to the relevant outstation in centrally fed telecommunication systems, in particular in telephone exchange systems.

The circuit arrangement has, in particular, a first monitoring device in the central station and Another monitoring device for receiving energy in the outstation.

Known measures for transmitting energy, e.g. B. for battery charging, cause deterioration the communication line properties and can only deliver very low charging currents. The impedance of the known charging circuits on the communication line wire pair is expressed as permanent low insulation between the a- and ö-wire and to earth, which leads to dial pulse distortion, a polarization of the line relay through which the charging current flows, and in connection with certain Line conditions can result in premature call triggering.

In order to at least partially overcome these disadvantages, is a circuit arrangement of the type mentioned according to the invention characterized by

net. that a first arranged in the central station Monitoring device at each end of the message transmission line becoming free switches to the energy source after a predetermined time interval and that one in the field

tion arranged further monitoring device when receiving energy to energy consumers for a further predetermined time interval is delayed to the other end aer communication line turns.

So that the circuit arrangement for a participant community operation is usable. the circuit arrangement is advantageously constructed in such a way that the first monitoring device is connected in series from a capacitor and a resistor

between one core of the communication line and the base of a transistor signaling a ringing state from the central station, whereby the monitoring device remains high resistance.

So that the connection of the further monitoring device to the communication line is independent on the line polarity, it is advantageous to connect the further monitoring device to the communication line to be connected via a bridge rectifier.

The predetermined first time interval is preferably not shorter than 40 s and also not greater than 55 s, while the predetermined second time interval is not shorter than 60 seconds and not longer than 80 seconds. The Time interval can be determined by the time constant of a capacitor circuit that charges or discharges and is so constructed that the capacitor current is the operating state of a voltage-sensitive Switch, e.g. B. a thyristor or a relay or another voltage-controlled semiconductor switching device secures.

The significance of the predetermined time intervals goes back to the line tests carried out by the Maintenance engineers. A maintenance engineer has been found to be mistaken Means about 30 s is needed to check a line zi, which is why when checking the line that is equipped according to the invention, the energy source and the energy consumer automatically for more than 30 must be switched off while the test is being carried out. So if the engineer first makes the line busy, operate the first 'monitoring device and the other monitoring chungseinrichtung their shutdown switch, so that the test engineer then the predetermined time interval voi z. B. 60 s (not less than 40 s), while the tests can be ended before the vo the test equipment detected the free state of the line, a restart of the other and the first Monitoring device causes. The difference i in the duration of the time intervals for the first and di further monitoring device is due to the fact that, if the further monitoring:

device would be switched before the first monitoring device. Current through the line relay would be drawn, which would be grasped at the first monitoring device as the busy state, so that the Relays in the first monitoring device could not work to match the transmission line To supply energy.

The invention also provides for an automatic shutdown the charging circuit impedance when the communication line wire pair is in the operating state normal message transmission is located. The circuit arrangement used according to the invention is designed so that the charging current does not flow through the line relay. That enables a higher one Value of the charging current and its dependence essentially on the internal resistance of the battery and the line resistance.

When used in a centrally powered telecommunications system, the invention enables one of the Telephone sets various electronic equipment located in the outstations, from the exchange or office battery directly or via rechargeable batteries in the front-door stations is supplied. The invention is particularly intended for use in a telecommunications system to Nickel-cadmium cells to supply a subscriber carrier system to load in the front-door station.

The invention enables the normal tip and ring wires of a telecommunications system to be used when they are not carrying communication traffic without any noticeable degradation of the communication line when it is used for normal communication.

To explain the invention, the terms "occupied" and "free" are used to denote the two to indicate possible states of the message transmission. The line is called "busy" when one Communication connection is established, e.g. B. when dialing pulses are on the line when the message transmission or when a line review takes place. The line is called "free" when it is not as Message channel is required and when a message channel using this line is suspended has been.

The invention thus monitors the status of the message transmission and the Line switched to the energy source only when it is free. The line is also managed by the Power source switched off immediately when the monitoring device indicates that the line is busy shall be. This indicated occupation can take place in that the fr-wire by triggering a call from the central station or exchange is grounded from ("exchange-side call") that the line loop at a subscriber outstation through Triggering a call is closed by the subscriber (»subscriber-side call«) or by one of line testing or supervision generally performed by an engineer in the central office.

The invention will now be explained with reference to the drawings in its application in a telephone system, in its application when charging nickel-cadmium batteries, which are located in the subscriber front-door station and which form the power supply for a local cable carrier system. In detail indicates

Figure I is a block diagram of part of a telephone exchange or an office or a central station with the switch shown in detail image of the first monitoring device arranged in the central station in a first embodiment,

F i g. 2 shows the block diagram of part of a subscriber front-door station with the detailed circuit diagram of the arranged in the subscriber front-door station further monitoring device in a likewise first embodiment,

ίο Fig.3 the block diagram of part of a telephone exchange or an office or a central station with the circuit diagram shown in detail the first monitoring device arranged in the central station in a second embodiment,

F i g. 4 shows the block diagram of part of a subscriber front-door station with the detailed circuit diagram of the arranged in the participant outskirts further monitoring device in a likewise second embodiment.

The invention is applied in a

Message or telecommunications system described, which is known as a local line carrier system.

The one in Fig.1 and 3 in different structures

The first monitoring device 1 shown is via wires 2 and 3 with a trunk circle and via wires 4 and 5 and a filter 6 connected to a communication line 7,8, which is a pair of cables to one Participant educates. A suitable energy source (here a 50 V power source) is connected via connections 9 and 10 the monitoring device 1 connected. A branch circuit (not shown) is over a line II, 12 connected to a wire radio carrier unit 13 which sends a carrier signal to the communication line 7, 8 emits and in a manner not specified in detail with the energy required for their operation is supplied.

According to FIG. 2 and 4, the line 7, 8 is in the subscriber remote station via a filter 14 with a (nich shown) the subscriber's trunk circuit connected to wires 15 and 16. The line 7, Ϊ is also with a further monitoring device shown in Fig. 2 and 4 in the same: different structure 17 and a wire radio carrier unit 18 connected. The wire radio carrier unit 18 is Connected via wires 19 and 20 to a branch circuit (not shown) of a subscriber The monitoring device 17 supplies the wire radio carrier unit 18 via wires 21 and 22 with the zi energy required for their operation.

The following is a description of the mode of operation in front of two circuit arrangements:

This is done in the following order:

1. idle state,

2. Energy transfer,

3. Message transmission in the event of a call from the subscriber,

4. Message transmission in the event of a call from the operator, and

5. Switching back to energy transmission.

a) circuit arrangement according to FIG. 1 and 2

!. Idle state

The monitoring device 1 in the central station or switching part shown in FIG

contains the relay 25 with the (switching) contacts 23, 24. In the mechanical rest country of the circuit arrangement the relay 25 is de-energized, and the contacts 23, 24 are in the position shown.

The wires 2, 3 are thus connected through to the wires 4, 5, so that a (not shown) standard subscriber circuit is connected in the exchange to the line 2, 3 and that via the Message transmission line 7, 8 normal message transmission from the central station to Subscriber front-door station can take place.

The energy source or central battery (not shown), the terminal 9 of which is grounded and the terminal 10 of which negative potential (-50V) is in the idle state disconnected from the line. As a result, normal line current flows through a transmission bridge or line relay in the exchange and causes a voltage drop so that the ö wire 3 is positive with respect to terminal 10. The transistor 41, which is opposed by diodes 43 and 44 Is protected against overvoltages, receives the potential of the fc wire via resistor 45 and conducts (the Resistor 45 represents an input resistance of more than 2.5 ΜΩ under all circumstances). Through this The capacitor 37 charges (its discharge is prevented by the diode 34) and the transistors 32 and 28, whose base currents are limited by resistors 36 and 33, also conduct. The transistors 26 and 28 including resistors 27, 29, 30 and 31 form a Schmitt trigger. So if transistor 28 conducts, it is ensured that transistor 26 is locked and the relay 25 is de-energized.

2. Energy transfer

When the message transfer stops d. H. when the transmission line 7, 8 is free and the If the participant loop is opened, the 6-core becomes 3, the is connected to the coil of the call relay in the exchange, placed on -50 V. So if the vein 3 is not positive with respect to terminal 10, i.e. H. if it is at the same potential as terminal 10, the transistor 41 blocks, the capacitor 37 discharges, and the transistors 32 and 28 also block, whereby the potential at the base of the transistor 26 rises and makes it conductive, so that an excitation current flows through the coil of the relay 25. If that Relay 25 picks up, the contacts 23 and 24 switch to the other position, and energy can be drawn from the Energy source 9, 10 are transmitted to the subscriber front-door station.

The monitoring device 17 in the in Fig.2 subscriber outstation shown contains the bridge rectifier 51, the thyristor 47 and a Energy consumer, which is represented here by the battery 48 to be charged

When the energy source 9,10 in the central station the communication line 7, 8 is connected, the bridge rectifier generates independently of the polarity of the connected energy source such a voltage that that leading to the thyristor 47 Connection 54 is always positive and connection 55 leading to Zener diode 57 is always negative the gate potential of the thyristor 66 rises via a voltage divider from the resistors 68 and 69 increases rapidly, and the anode potential of the thyristor 66 increases more slowly and with a time constant a men. which is given by the resistor 62 and the capacitor 65. When the thyristor 6f ignites, the thyristor 47 also turns on, dcsser Ignition voltage from resistor 67 is supplied.

The energy transfer now takes place with the help of a charging current supplied by the central station Subscriber front-door station via the following circuit «flows: from connection 9 of the energy source via the Contact 23 in the working position, the wire 4, the filter 6, the wire 7, the resistor 52. the one branch dci Bridge rectifier 51, the connection 54. the thyristor 47, the connection point 59, the resistor 56, the battery 48, the zener diode 57. the connection 55, the second branch of the bridge rectifier 51, the Resistance 53. the wire 8. the filter 6. the wire 5. the Contact 24 in the working position and the resistance 3? to connection 10 of the energy source. To charge the Battery 48, the thyristor 47 and the Zener diode 57 are conductive, and the diode 57 remains conductive as long as the Zener voltage is exceeded.

A direct current series regulator (not shown) can be connected to the connection point 59 being. The capacitor is also located between the connection point 59 and the negative pole of the battery 48 58.

3. Message transmission by the subscriber

phone call

When a participant in the outdoor station "picks up" is reduced by the loop closure of the veins 15 and 16 in Fig.2 the voltage between the wires 7 and 8. This voltage reduction is in the Exchange displayed or monitored, since the line 4.5 in FIG. 1 galvanically with the line 7.8 in F i g. 2 is connected. Because of the drop in voltage, an increased current is generated through resistor 39 drawn. The capacitor 37 is charged so that the transistor 32 and thus the transistor 28 conduct: the Transistor 26 is blocked, whereby the relay 25 is de-energized and the energy transmission from the exchange as before in the order of switching the transistors is finished after the transistor 41 has become conductive.

At the subscriber front-door station, the drop in voltage on the line due to the "lifted" Participant that the thyristor 47 flowing through the current drops below the holding current, so that the Thyristor 47 turns off and the connection to battery 48 is interrupted. The capacitor 65 is on the Thyristor 60 and the series-connected resistor 61 completely discharged, so that the thyristor 66 and thus the thyristor 47 cannot be accidentally ignited.

The capacitor 70 is provided in order to delay the fall of the gate voltage at the thyristor 66, see above that the thyristor 60 is switched on before the thyristor 66) when the input voltage on the line 54 The ratio of the impedances of the decreases Resistors 63 and 64 are chosen so that when the capacitor 65 charges in the high state Impedance of the subscriber unit of the thyristor 66 before the thyristor 60 is switched on.

4. Transmission of messages through switching view

phone call

In the event of a call from the operator side, a Call voltage to earth applied to the Ö wire 3.

also a ground connection via resistor 46 to the a-wire 4, and similar processes run as on the subscriber's call from:

This ringing signal makes the transistor 41 in the Monitoring device 1 is conductive, and the voltage drop across resistor 42 turns the capacitor 37 quickly charged through resistor 40 and diode 35.

After the transistors 32 and 28 have been switched on and the transistor 26 has been blocked, the relay 25 becomes de-energized, so that the contacts 23, 24 switch back to the position shown, the wires 2,3 with the Connect wires 4, 5 and thus forward the ringing current to the monitoring device 17.

The interruption of the ringing signal is bridged by the capacitor 37, since its discharge over the Resistors 38, 40 and 42 take more than 30 s. Similarly, the thyristor 47 is through the to the Terminals 7, 8 disconnected ringing voltage, similar to that for the loop current has been described.

Because of the large time constants and because of the thyristor 60, which is shown in FIG acts, the circuit arrangement is not affected by dialing pulses.

5. Switching back to energy transmission

When the subscriber "hangs up" again, the voltage on the line 7, 8 in Fig. 2 returns, whereby the »hang-up state at the exchange end of the line 4, 5 is displayed in FIG. If the return of the line voltage is detected, the relay in the monitoring device 1 25 energized after a predetermined time interval by the discharge of the capacitor 37, so that the transistors 32 and 28 block and transistor 26 turns on.

b) circuit arrangement according to FIG. 3 and 4
1. Idle state

The monitoring device 1 in the FIG. 3 again contains the central station shown Relay 25 with the (changeover) contacts 23, 24. In the mechanical rest state of the sound arrangement the relay 25 is de-energized, and the contacts 23, 24 are in the position shown.

The wires 2,3 are also here with the wires 4,5 through-connected, so that a (not shown) standard subscriber circuit in the exchange to the Line 2, 3 is connected and that via the communication line 7, 8 a normal Messages can be transmitted from the central station to the subscriber front-door station.

The (not shown) energy source or central battery, the connection 9 of which is grounded and the connection 10 of which has a negative potential (-50V), is disconnected from the line in the idle state. As a result, a normal line current flows through a transfer bridge or line relay in the exchange and causes a voltage drop so that the ring wire 3 is positive with respect to the terminal 10

The transistor 41, which is protected against overvoltages by diodes 76 and 77, receives the high resistance Resistor 84 (in the special embodiment 2.7 Ω) the potential of the ö-wire and conducts.

This charges the capacitor 37 and the transistors 32 and 28 also conduct, with de Base sirom of transistor 28 through resistor 33 is limited. The transistors 26 and 28 including resistors 27, 29, 30, 31 and 74 form one Schmitt trigger. So if the transistor 28 conducts, it is ensured that the transistor 26 is blocked and the relay 25 is deenergized.

2. Energy transfer

When the message transmission is terminated, i. H. when the transmission line 7, 8 is free and the If the subscriber loop is opened, wire 3, which is connected to the coil of the call relay in the exchange connected. placed on - 50 V. So if the wire 3 is not positive with respect to the connection 10. d. H. when it is at the same potential as the terminal 10, the transistor 41 blocks, the capacitor 37 discharges and the transistors 32 and 28 also block, whereby the potential at the base of the The transistor 26 rises and makes it conductive, so that an excitation current flows through the coil of the relay 25. When the relay 25 picks up, the contacts 23 and 24 switch to the other position, and it can power off the energy source 9, 10 are transmitted to the subscriber front-door station.

The monitoring device 17 in the subscriber outstation shown in FIG. Contains the Bridge rectifier 51. the thyristor 47 and an energy consumer, which is to be charged here by the Battery 48 is shown. whose voltage is limited by the Zener diode91.

When the energy source 9,10 in the central station the communication line 7, 8 is connected, the bridge rectifier generates independently of the polarity of the connected energy source such a voltage that that leading to the thyristor 47 Connection 54 is always positive and connection 55 leading to Zener diode 57 is always negative increases the gate potential of the thyristor 66, the gate-anode voltage through the Zener diode 86 be is bordered, via a voltage divider from the resistors 68, 89, 90 and via the diode 87 and the resistor 92 on quickly and the anode potential of the thyristor 66 rises more slowly and in contrast with a time constant given by resistor 93 and capacitor 65. If de Thyristor 66 ignites, thyristor 47 also switches through, the ignition voltage of which is determined by resistor 6 ' is delivered.

The energy transfer now takes place with the help of a charging current from the central station Participant outdoor station flows through the following circuit: From connection 9 of the energy source via the Contact 23 in the working position, the wire 4, the filter 6, the wire 7, the resistor 52, one branch of the Bridge rectifier 51, the connection 54, the thyristor 47, the connection point 59. the resistor 56, the battery 48, the zener diode 57, the connection 55. the second branch of the bridge rectifier 51, the Resistor 53, wire 8, filter 6, wire 5, contact 24 in the working position and resistor 3i to connection 10 of the energy source. The thyristor 47 and the zener diode 5 are used to charge the battery 48 conductive, and the diode 57 remains conductive as long as the Zener voltage is exceeded

A not shown can be attached to the connection point 59

609 614/18 (

Traction current series regulator must be connected. Between The connection point 59 and the negative pole of the battery 48 also have the capacitor 58.

3. Message transmission by the subscriber

phone call

When a participant in the front-door station "picks up", the loop closure of the wires 15 reduces and 16 in Fig.4 the voltage between the wires 7 and 8. This voltage reduction is in the Exchange displayed or monitored, since the line 4.5 in FIG. 3 galvanically with the line 7.8 in Fig.4 is connected. Because of the voltage drop, an increased current is passed through the resistor 39 drawn. The transistor 41 is conductive via the diode 80 and the resistors 81 and 82 in the base circuit, and the Capacitor 37 is charged, so that the transistor 32 and thus the transistor 28 conduct, during the Transistor 26 is blocked, a positive voltage jump across the capacitor 83 and the Resistor 82 is transferred to the base of transistor 41 so that it remains conductive and the capacitor 37 is fully charged; the relay 25 is de-energized, and the energy transmission from the exchange is terminated as before in the order of switching the transistors.

At the subscriber front-door station, the drop in voltage on the line due to the "lifted" Participant that the thyristor 47 flowing through the current drops below the holding current, so that the Thyristor 47 turns off and the connection to battery 48 is interrupted. The capacitor 65 is on the Resistor 94 and the thyristor 60 completely discharged, so that the thyristor 66 and thus also the Thyristor 47 cannot be accidentally ignited.

The capacitor 70 is provided to delay the drop in the gate voltage on the thyristor 60, see above that the thyristor 60 is switched on before the thyristor 66 when the input voltage on the line 54 going back. The ratio of the impedances of the resistors 68,89 and 90 is chosen so that when the Capacitor 70 is charged, the thyristor 66 turns on before the thyristor 60.

45

4. Message transmission through the exchange

phone call

In the case of a call from the operator side, FIG. 3 a Ringing voltage to earth is applied to the 6-wire 3, furthermore an earth connection via the resistor 85 to the a-wire 2, and processes similar to those of the subscriber-side call take place:

This ringing signal makes the transistor 41 in the monitoring device 1 conductive, and by the If the voltage drop across the resistor 78, the capacitor 37 is charged quickly via the resistor 79.

After the transistors 32 and 28 have been switched on and the transistor 26 has been blocked, the relay 25 becomes de-energized, so that the contacts 23, 24 switch back to the position shown, the wires 2,3 with the Connect wires 4, 5 and thus forward the ringing current to the further monitoring device 17.

The interruption of the ringing signal is bridged by the capacitor 37, since its discharge over the Resistors 79 and 78 take more than 30 s.

Similarly, the thyristor 47 by the the ringing voltage occurring at terminals 7, 8 is switched off, similar to that for the loop current has been described.

Because of the large time constants and because of the thyristor 60, which is shown in FIG acts, the circuit arrangement is not influenced by dialing pulses.

In the case of joint subscriber operation, the states for call on the exchange side can either be the a-wire 2 or the 6-wire 3. the Resistor 71 and capacitor 72 generate this Special condition at the base of transistor 41.

5. Switching back to energy transmission

When the participant "hangs up" again, the voltage on the line 7, 8 in Fig. 4 returns, whereby the "hang up" status at the exchange end of the line 4, 5 is indicated in FIG. If the return of the line voltage is detected, the relay in the monitoring device 1 25 energized after a predetermined time interval by the discharge of the capacitor 37, so that the transistors 32 and 28 block and transistor 26 turns on.

In addition to the differences mentioned, further differences between the two described shah arrangements are that the arrangement according to FIG. 3 compared to that according to FIG. 1 has a better defined time interval because of the feedback caused by the capacitor 83 and the resistor 82, furthermore better high-voltage protection and greater insensitivity to overcoupling disturbances on the transmission line; In addition, the transistors 41, 32, 28 can work here with a lower voltage. The arrangement according to FIG. 4 comes in comparison with the arrangement according to FIG. 2 with lower resistance values in the time interval circuit, the same impedance being maintained at the connections 7 and 8 in the idle state.

This has the advantage that this arrangement is less dependent on the electrical parameters of the thyristors 60 and 66.

For this purpose 2 sheets of drawings

Claims (5)

Patent claims: 1. Circuit arrangement for the transmission of electrical energy from one in a central station arranged energy source to an energy consumer arranged in at least one outstation via a communication line connecting the central station to the relevant outstation in centrally fed telecommunication systems, especially in telephone exchanges, characterized in that a first located in the central station Monitoring device (1) each time the message transmission line (7, 8) becomes free one end (4,5) delayed by a predetermined time interval (discharge time of 37) to the energy source (9,10) switches over (by means of 23, 24) and that a further monitoring device arranged in the outstation (17) when receiving energy, the energy consumer (48) by a further predetermined one Time interval (recharge time of 65) delayed to the other end of the communication line (7,8) switches on (using 47). 2. Circuit arrangement according to claim 1, characterized in that the first monitoring device (1) a series connection of a capacitor (72) and a resistor (71) between the one wire (2) of the communication line (2, 3) and the base of a signaling a call status from the central station Transistor (41) contains (Fig. 3). 3. Circuit arrangement according to one of claims 1 and 2, characterized in that the further Monitoring device (17) with the message transmission line (7, 8) via a bridge rectifier (51) is connected (fig. 2 and 4). 4. Circuit arrangement according to one of claims I to 3, characterized in that in the first monitoring device (1) the delay by the predetermined time interval (discharge time of 37) is between 40 and 55 s. 5. Circuit arrangement according to claim 1, characterized characterized in that in the further monitoring device (17) the delay by the further predetermined time interval (charging time of 65) between 60 and 80 s.