DE2607722A1 - EMERGENCY POWER SYSTEM WITH OVERVOLTAGE PROTECTION FOR RADIO FREQUENCY DISTRIBUTION NETWORKS - Google Patents

Description

Power system with surge protection for radio frequency

Distribution Networks The invention relates to electronic Circuits, specifically to an overvoltage protection and emergency or replacement power distribution circuit for radio frequency signal distribution amplifier that is automatically resettable, when the overvoltage condition has ended, the flow of energy during the period the overvoltage is maintained and during an interruption of an AC mains voltage a replacement DC voltage is supplied to one or more preselected amplifiers will.

With many interesting applications today, for example bein n-etri eb of radio frequency distribution systems, such as a television community antenna system, A protective mechanism is required to protect the sensitive electronic active elements against possible destruction in the event of overvoltages from the power supply For example, communal antenna systems have to be conventional opposite to Tension states be secured, which by uneven loads in a Energy distribution system of a connected community or settlement, electrical Storms or the like be evoked.

Because of such mains voltage surges, a so-called "crowbar" voltage protection circuit is necessary used in which an energy-conducting semiconductor, for example a silicon-controlled Rectifier, a TRIAC (a bidirectional thyristor diode), a power transistor or the like. Via a voltage sensing device connected to the control terminal of the Lei stungseleientes or circuit is switched on. When triggered or ignited as a result of an overload condition ignites the silicon-controlled rectifier, the TRIAC or the like. and closes one Energy flow channel short. This bridging the energy flow channel with low impedance completely prevents the supply of energy and thus protects those to be protected Devices, but at the same time puts them completely out of action. With those previously known Devices will supply energy after termination of the faulty voltage state turned back on, and this is done either manually or automatically by for example, the thermal switch switched off by igniting the "crowbar" circuit how you are switched on.

However, this "crowbar-like" operation induces high, unwanted Voltage jumps in the systems; it often leads to failure of fuses and Circuit breakers and often makes the inspection of very remote line amplifiers or the like.

necessary; uiid he sets, as already mentioned, those to be protected Devices completely out of operation for the entire duration of the overvoltage protection. In the context of communal television antenna systems, radio frequency activities interrupted as long as the state of the fault persists and until that which causes the short circuit "Crowbar" element is put back again.

The basic object of the present invention is that Creation of an improved device for overvoltage protection.

More specifically, the invention is based on the object To create an improved overvoltage protection circuit that is auto-volatile turns on again when an overvoltage condition has ended; such a protection circuit is not intended to operate in the "crowbar-like" mode described, i. do not create a short circuit on a power supply channel, and should during the Keeping the overvoltage condition ensures the continuous supply of energy.

The invention is also based on the object / a high-frequency amplifier to create a power supply circuit that is instead of an accumulator-fed Replacement AC power source fed directly from a backup DC voltage source is, so that the cost of the DC-AC converter otherwise required with its own shortcomings are avoided.

The invention also provides a circuit for feeding a radio frequency video distribution amplifier, which offers protection against overvoltage conditions in the network and which enables line amplifiers to be programmed to operate during periods of power interruption assume a switched-on or switched-off state through the AC network, so that the useful duration of the energy supply by a DC voltage source as a reserve energy source can be extended by, for example, during an interruption in the power supply Amplifier in branch or branch lines or the like. switches off, but at the same time the operability maintains in the main line.

According to the invention, this object is achieved and there are further advantages achieved in a specific, illustrative Overvoltage protection circuit, in which a power supply circuit, as for the distribution system of a television community antenna (for example, a relay amplifier) one with an AC power line coupled transformer includes. One controlled, conductive in two directions Device, such as a TRIAC, connects the primary winding of the transformer to a Wechseispaniiungsquelle, and the Sel.urldälswickung of the transformer feeds a Any conventional DC voltage supply device, for example a diode back circuit as a full-wave rectifier, an I + filter capacitor and / or dg1. When you put it on for the first time of energy a control capacitor is charged to a sufficient value, to control the TRIAC, so that the primary winding of the transformer with the AC source is connected and the system to be supplied is supplied with power.

Another, normally non-conductive, controlled switch, for example an additional TRIAC is connected in parallel to the switch-on capacitor and by elements or a circuit for detecting overvoltages, for example controlled by conducting Zener diodes when the threshold is breached. When an overvoltage condition is determined, the additional TRIAC becomes conductive, thereby discharging the control capacitor and switches off the conductive power TRIAC (powertriac). That way will the primary winding of the transformer from one side of the AC line separated for the duration of the fault condition, so that during the voltage surge the following facilities are valued.

Further circuit parts occur in a further development of the inventive concept in action if the power TRIAC is non-conductive during a fault condition and ensure that an energy supply is maintained (albeit at a reduced Voltage) to the facilities to be supplied. This is how the protected ones work Facilities continuously. Furthermore, such additional circuit parts can affect the + Switching Local distribution amplifier during the disturbance in the AC voltage line either in or out of operation. For example, a trunk repeater be set up so that its operation during the operation of the DC auxiliary source continues, while stub or branch line amplifier or the like. put out of service so that excessive use of the auxiliary energy source is avoided and the system is kept operational to the maximum extent possible.

In the drawing, preferred embodiments of the invention are for example shown.

Fig. 1 is a schematic of the basic circuit of the overvoltage protection in accordance with the principles of the invention; iFig. 2 is a schematic of an overvoltage protection circuit of the same type as that according to Fir. 1, but with a first additional circuit to maintain the flow of energy during an overvoltage disturbance; 3A is a diagram illustrating an overvoltage protection circuit before: same type as that according to FIG. 1, but with a second additional circuit to maintain the flow of energy during a disturbance; Fig. 3B is a Scheme to illustrate the mode of operation of the circuit according to FIG. 3A during operation during a fault; 4A schematically illustrates an overvoltage protection circuit of the same type as that of FIG. 1, but with a third additional circuit to maintain the flow of energy when a fault occurs; Fig. Figure 4B is a diagram for illustrating the operation of the circuit of Figure 4A in operation during a fault; Utld Fig. 5 is an illustrative diagram the present power supply circuit when used for maintenance the operation of a selected trunk amplifier (trunc emplifier) of a radio frequency TV community antenna system from a substitute DC voltage source at times of the disruption of the energy supply from AC network.

Identical parts are all identified with the same reference numerals designated. In Fig. 1, for purposes of illustration, there is a special over-protection circuit for use in supplying power from an AC power source 10 to a load 36 (after conversion into a direct current potential), with simultaneous' protection of the Load 36 against an overvoltage supplied by source 10 is shown. The from the AC voltage supplied to the source 10 is to the primary coil 31 of a transformer 30 created. The voltage on the secondary winding 32 of the transformer is used for further use, for example by means of a bridge circuit equipped with diodes 33 converted into direct current as a full-wave rectifier and a filter capacitor 35. A voltage regulator or the like can of course be used between the capacitor 35 and the load 36. be arranged.

The main path from terminal 1 to terminal 2 of the energy TRIAC 29 connects the lower terminal of the primary winding 31 of the transformer to the one Side of the line from the AC power source (which is only for the sake of clarity is assumed to be grounded), and the other side is the transformer winding connected directly to the other AC line. The control electrode or the Control terminal of the power TRIAC 29 is set in the manner described below controlled by a resistor 28 and another TRIAC 24, whose The control electrode itself is excited by the low voltage of a capacitor 18 which is effective via a resistor 25 and a diode 27. The condenser 18 is activated during the negative half-cycles of the alternating conduction current by means of a Resistor 20 and a diode 19 charged.

For the purposes of overvoltage protection, a TRLW 12 becomes a capacitor 18 connected in parallel. The control terminal of the TRIAC 52 is polarized opposite Zerierdioden 15 and 17 and a current limiting resistor 13 with t the AC line tied together. The voltage conducting threshold levels of the Zener diodes 15 and 17 correspond to those to be determined at the output of the threshold 10 overvoltage values.

If (“as this is normally the case) AC power from a Amplitude below the error value of the overvoltage to the circuit of Fig. 1 is applied, the capacitor 18 is during the negative half periods in the Line charged to a sufficient value to control the control electrode of the TRIAC 24 via the resistor 25 and the diode 27 to excite the negative potential at the upper end of the capacitor 18 remains on the line for both half-periods, so that the TRIAC 24 remains permanently switched in the conductive state.

The conductive TRIAC 24 in turn supplies sufficient energy the control terminals of the power TRIAC 29 to keep it conductive so that the lower end of the primary winding 31 of the transformer continuously with the grounded side of the output of AC power source 10 remains operationally connected. In this way thus essentially the full output energy of the source 10 is applied to the primary winding 31 created. The fully energized transformer and subsequent circuit generate then a DC voltage for feeding the load 36 in a conventional manner.

Under such conditions a normal input potential + the Load or as described, the maximum voltage excursion is sufficient during each half-cycle supplied by the AC voltage source 10 not ans, in order to züiiden the oppositely polarized Zener diode 15 or 17 (for that half period). The TRIAC 12 remains non-conductive and thus affects the one just described The circuit does not work.

Conversely, if on the line during any half cycle an overvoltage occurs, the oppositely directed diode 15 or 17 conductive, and, since the other of the cascaded diodes 15, 17 in the forward direction is operated, the control electrode of the TRIBCS 12 is supplied with energy. Accordingly the capacitor 18 is quickly via pn n conductive path of the TRAC 12 between the Terminals 1 and 2 are discharged, usually at the top in the drawing Terminal of the capacitor 18 existing negative potential is eliminated. To this In this way, the TRIACs 24 and 29 become non-conductive and separate the primary winding 31 of the transformer from the AC voltage source 10. Energy supply lines are accordingly and load is separated from the potential, and thus the load is protected so long an overvoltage condition persists. This protection is provided by means of a open circuit instead of a short circuit, as in the "crowbar" method and thus surge conditions become volatile when voii occur Changes in electrical quantities are reduced to the utmost.

After the overvoltage condition has subsided, the control electrode receives of the TRIAC 12 no more energy, and the TRIAC 12 hears about the next zero crossing to conduct the alternating current wave supplied by the source 10, since in this Point the potential at terminals 1 and 2 of the TRIAC is no longer sufficient to achieve the Maintain conductivity. This is achieved by adding a resistor 26 the introduction of the potential, which tends to zero and changes polarity supported for TRIAC 12. Subsequent to the termination of the overvoltage condition will so the capacitor 18 is charged again in its state discussed above, so that the flow of energy to the load is resumed normally.

The basic overvoltage protection circuit shown in FIG According to the description above, it completely protects the load, provides the load 35 however, no energy during the existence of the overvoltage condition. As in 2, the main power TRIAC 29 of the Basic arrangement according to Fi. 1 another transformerz primary effect 34 as well as a TRIAC 37 must be connected in parallel.

If an overvoltage condition occurs, the fRIAC 29 is in the travel non-leit eijd described above. Accordingly, is originally on the supplied potential of the AC voltage source to the TRIAC 37, and the TRIAC 37 ignites quickly under the supply of energy to the control electrode via a resistor 39. Way the TRI & C 37 is conductive, winding 34 is with winding 31 ii connected in series and supports this in its effect, so that the effective number of turns ratio of the transformer, which in the Rulie state is N32 N32, is now N31 N31 + N34 where N is the number of turns of the corresponding windings. 51S at the exit of the transformer 32 occurring potential is therefore during the T) outside of the disturbance considerably reduced by overvoltage.

When the fault has been rectified, the main power THIAC 29 ignites again in the manner described above and short-circuits the TRIAC 37 and the winding 34, so that the output potential of the secondary winding 32 of the transformer is normal Value again. The circuit according to FIG. 2 therefore not only protects against the Overvoltage condition but also ensures the in the case of the disturbance condition Continuation of energy supply (albeit at a reduced level).

Another embodiment of circuitry for maintaining the flow of energy during the duration of an overvoltage condition is shown in FIG. 3A shown. Here is a node of bridge 33 - instead of the grounded AC line - rilt of the connection between the winding 31 and the TRIAC 29 connected. While of normal operation are the lower terminals of the winding 31 and in the drawing the node of the full-wave rectifier bridge between rectifier diodes 40 and 40 1d 11.9 42 grounded and operate in the usual manner described above. Upon finding in an overvoltage condition, however, the TRIAC 29 becomes non-conductive, and the circuit FIG. 3A assumes the operating state illustrated in FIG. 3B. The primary winding 31 of transformer 30 operates essentially as a series inductance, and the energy supply capacitor 35 is made by the bridge diodes - the the effect as two diodes connected in a cascade in each of the two parallel current paths are connected - brought about half-wave rectification charged. The load 36 thus continues to receive energy with a direct current potential, which (in the absence of a regulation) is reduced compared to the previous normal value and a value slightly below that during the fault condition from the AC voltage source 10 accepts the currently delivered value. If again the fault condition ends is, the TRIAC 29 becomes conductive again and the composite circuit operates in the conventional way.

It should be noted that the direct connection between the bridge 33 and the node between transformer 31 and TRIAC 29 are normally only used should be when the transformer 30 is stepping up, i.e. the winding 32 a higher number of turns than the winding 31 iiat, so that that of the winding 32 output potential supplied exceeds that with which the winding 31 is operated will. If the arrangement of FIG. 3A. The aim is to have an isolating or shutdown transformer used during a fault condition of the Source 10 supplied overvoltage in the case of reflection parallel to the capacitor 35 are sufficient, to endanger the load 36.

Yet another embodiment of the invention for protecting a Load during conditions of excessive tension and for the continuous supply of energy to the load during such a condition is shown in Fig. 4A. The order is essentially the same as in Fig. 3A, only here is between those with the upper end of the transformer secondary winding 32 connected node of the rectifier bridge 33 and the connection between the primary winding 31 and the TRIAC 29 a device or a circuit 38 is connected. Here, too, the circuit works in the same way As described above, as long as no overvoltage occurs. That regarding Construction and operation of the network 38 described in more detail below with normal operation of the circuit simply at most one additional load in the secondary circuit of the transformer.

If an overvoltage condition occurs, the TRIAC 29 will be in the above described manner non-conductive, and the circuit of Fig. 4A takes with respect to their effect takes the form of the circuit according to FIG. 4B. As with the circuit according to Fig. 3A, 3B is the primary winding 31 of the transformer in terms of its effect to an inductance in series, and the capacitor 35 and a bridge diode 41 act as a half-wave rectifier and filter for supplying energy to the load 36 in the presence of the overvoltage condition. Element 38 is connected in series used to (assuming a frying or step-down transformer) the during of the overvoltage condition on the capacitor 35 to decrease Element 38 can be: a zener diode that simply lowers the potential; a capacitor which acts as a voltage divider with the capacitor 35, a voltage reducing resistor; a diode that e in the same 1 ' direction is polarized like the bridge diodes (for a step-up transformer where only a coupling, but not a frictional stress reduction, is required); or the like. By using the tension-reducing and / or coupling element or Network 38 may persist the load 36 during the persistence of the fault condition be supplied with energy.

As stated repeatedly above, the TRIAC 29 becomes conductive again and the circuit of FIG. 4A resumes its normal operation when the fault is cleared is.

Arrangements described above also protect a load as shown against overvoltage conditions and enable the maintenance of an energy flow while the overvoltage continues.

For the sake of completeness, it should be noted that the charging diode 19 for the capacitor 18 is polarized in such a way that <laf? they are on the same phase of the AC voltage source 10 (in this case the negative) responds like the polarity of the on the capacitor 35 developed potential (negative) (i.e. active when bridge 33 conducts). From Fi. 3B and 4B it can be seen that the AC line is running the negative Half periods on the conductor by the condenser 35 and the load 36 are relative is heavily burdened. The correspondingly relatively high current in the Weehselstromleitun gene during such period causes a reduction in the line voltage during these times. This in turn has a reduction in the amount of time applied to the charging resistor 20 applied voltage, which is a maximum during such periods, there Part of the overvoltage supplied by the source 10 from the capacitor 18 is recorded, which is substantially completely discharged during the overvoltage is. Reduce AC line losses during the negative half cycle So the requirements for the resistor 20 to + Fig.

visible of the energy consumption.

Fig. 3 now shows a scheme to illustrate a radio frequency signal distribution network, as for example for the distribution of television programs over a coaxial cable 60, 60 'of a community antenna system is used. The distribution cable 60 receives power from an AC line source 62 via the normal at rest closed contacts 66-a (of a relay 66) for distribution to a cascade switched series of main line amplifiers (@ruhe line emplifiers) 70, stub line amplifiers (net work line extending emplifiers) or the like. As in the technology of community television reception typically, trunk line amplifiers 70 are spaced apart along the coaxial cable 60, 60 'of the main line, representing the spectrum of either or both Directions of the cable network periodically amplify propagating signals or regenerate. In addition, the video or other signals are selected (or at all) installation sites of main line amplifiers 70 of signal taps or secondary lines or stub lines 89 added and (total added or) to local areas, for example a group of individual participants along a Street, in a settlement, in a block of flats or the like. forwarded. This distribution or stubs 89 can in turn be quite long and provide signal amplification need. It is therefore fairly common to use radio frequency amplifiers in such lines to be provided, which is typically referred to as a stub line amplifier (line extender) will.

The main line amplifier 70 (and possibly line extenders) have Active devices that require energy for their operation.

Accordingly, an equivalent DC voltage source 68 can be used are automatically activated by the normally open relay contacts 66-b of the relay 66 can be switched into an operating state when a tiechselspannungsschwellungsschwelldetektor, connected to the cable 60 64 the failure of alternating voltage energy i'l. the cable and the relay coil 66 is energized in a corresponding manner. The one from the DC voltage source 68 then flows via cable 60 to the various system amplifiers.

When setting up large-scale distribution networks for community antennas it is usually desirable to use only a certain part of the system amplifier to keep the substitute DC energy in operation to avoid excessive stress to prevent the replacement energy source 68 and in this way the possible operating time of the community antenna network during periods of interruption in the AC power supply to extend if possible. For example, it may be desirable to reduce the energy supply to maintain all trunk amplifiers 70 when the DC power source 68 is switched on while all stub line amplifiers (extenders) are de-energized stay. 7.12 must be taken into account, then a main line at several points its expansion is connected to the AC network and supplied with energy is so that the main lines, as far as the power supply is concerned, operational are divided. So if only one of these AC sources fails and backup energy used to (exclusively) the main line amplifiers of this section the main line in operation to -inlten, the plague of the system works (except the section of the main line affected by the AC power failure connected stub lines) in the normal way.

The iil Sig. 5 illustrated trunk amplifier 70, which is known as the Illustrative embodiment also for the other main line amplifiers used applies, has a radio frequency main amplifier 78, which is connected via capacitors 72 and 87 between the amplifier input (left in the drawing) and the amplifier output is coupled. The capacitors 72 and 37 act as high-pass filters and filters Direct current and mains-frequency currents ((; o or 50 Hz) from (where billed that energy will be in either direction through the cable 60, 60 'can flow). When a composite amplifier 70 is used, to operate one or more branch lines 89, these are by means of a Bridge amplifier 80 and a signal splitter or splitter 83 operated.

The trunk line amplifier 70 has a power supply circuit 73 for the supply of DC power for the operation of the amplifiers 78 and 80 on. The power supply 73 is for the most part the same as repeated above described - for example in Fig. 4A and the associated description - and that Connection element @@ consists, for example, of a diode 38 '. During normal operation the alternating voltage energy present in the line flows through a low-pass filter coil 74 and will correspond to the conventional power supply company described above at the output of the secondary winding 32 of the transformer and as a full-wave rectifier serving diode bridge 33 into a (for the assumed case negative) DC voltage converted, which is applied to the filter capacitor. In a similar way the power supply system 75 acts during the periods in which on the AC power line an overvoltage prevails, in the one discussed above, for example with reference to FIG. 4A Way that the diode 38 'is turned on for every negative half cycle on the line so that the power supply system 75 continues to activate the amplifiers 78 and 30, while the overvoltage condition persists.

If an energy disturbance occurs in the AC voltage source 62 the DC voltage source 68 is switched to operation and supplies the required negative potential to power supply line 92 via coil 74. With main line amplifiers 70 which kept operating for the duration of an AC power failure are to be, no normally open relay contacts 90-a according to Fig. 5 are used (or are those short-circuited as indicated by a broken line ). For such main line amplifier 70 is the equivalent DC voltage over the Primary winding 31 of the transformer and the diodes connected in groove with it 3 'and 41 to the capacitor 35 and from there that claiming the energy supply Amplifiers 78 and 8C supplied. These amplifiers therefore remain in operation.

It can be seen that the diodes 19 and 27 according to FIG. 5 in comparison are polarized opposite to Fig. 4A. This has the effect of being controlled Switch 29 is non-conductive for the duration of the equivalent direct voltage energy, as necessary to the lower end of the winding 31 at this time of to separate the earth.

Consider now the case of an EX trunk amplifier 70 or, more likely a branch line amplifier or other iii a distribution line 89 built-in amplifier that was not kept in operation should be when the backup energy supply is in operation (main line and branch lines are connected to one another by mains energy coupling coils 82 and 84) 4 ,. for such an amplifier or similar effective arrangement employs a relay 90. The winding 90 becomes AC mains under normal and overvoltage conditions through a line polarity selection diode 93 and a filter capacitor 91 (i.e., through a line polarity opposite to the equivalent DC voltage potential is activated by a positive half cycle on the AC line. the Combined power supply circuit 75 is thus in the manner discussed above fully active during AC operation with normal voltage and overvoltage. The closed relay contacts 90a couple the diodes 38 'and 41 during an overvoltage condition of the alternating voltage with the negative half-waves of the Line, and closed contacts 90-b feed branch lines 89 everywhere where there is alternating voltage energy.

+ so will In the event of disturbances in the energy supply on the AC line blocks diode 93 that supplied by negative source 68 Equivalent voltage. The relay coil 90 is then not energized, and the contacts 90-a, -b are open wid therefore set the station or. Branch lines out of order.

It has thus been shown that the arrangement according to FIG. 5 states more normal and excessive voltage of the AC line power supply carries and an all-fit device for maintaining operation selected, important or crucial enhancer of the system during periods of time able to keep in operation, in which replacement energy is used. Also will by means of the energy supply system 75, substitute direct voltage energy is used directly, thus the high costs that are difficult to avoid with DC-AC converters uiid inadequate efficiency can be avoided.

The arrangements described above are for illustrative purposes only of the principles of the present invention. Manifold variations are for the Recognizable by a person skilled in the art, possible without deviating from the inventive concept.

Claims (17)

P a t e n t a n s p r ü c h e Electronic energy supply system with a first and a second connection for receiving electrical energy, a transformer with primary and secondary winding and a rectifier device and a filter device connected to the secondary winding of the transformer are identified by one in series with the primary winding of the transformer Switched, controlled, switching device that is conductive in both directions for connection the primary winding of the transformer between the first and the second energy consumption connection, a device connected between the first and the second connection for reversing the double-sided conductive switching device in its conductive state, if an alternating voltage energy is applied to it within permitted limits, and one to the connection between the primary winding of the transformer and the controlled one Switching device connected device for maintaining the energy supply for the supply of electrical present at the first and the second terminal Power to the rectifier device. 2. Arrangement according to claim 1, characterized in that the device to maintain the supply of energy from a unidirectional device consists of the primary winding of the transformer and the rectifier device connects with each other. 3. Arrangement according to claim 1 or 2, characterized in that the Device for switching on the controlled switching device that conducts in two directions into the conductive state from a capacitor and a diode connected in series between the first and the second terminal, means for connecting the Capacitor to the control electrode connection of the controlled switch one overvoltage-controlled switching device connected in parallel to the capacitor and one with the control electrode connection of the overvoltage-dependent switching device and voltage-dependent threshold trigger means connected to the first or second terminal consists. 4. Arrangement according to 4nspruch 3, characterized by one between the Control electrode connection of the controlled switching device, which is conductive and capable in two directions the capacitor switched power buffer controlled switching device. 5. An arrangement according to claim!, Characterized in that the in Two-way conductive controlled switches and the overvoltage and buffer controlled switches Switching device each consists of a TRIAC (a bidirectional thyristor diode). 6. Arrangement according to claim 5, characterized by an between connected to the second terminal of the primary winding of the transformer and the capacitor Resistance. 7. Arrangement according to one of claims @ to 5, characterized in that that the voltage-dependent threshold trip device consists of two. opposite polarized zener diodes. 8. Arrangement according to claim 2, characterized in that the in one Direction conductive device consisting of a diode and a resistor in cascade connection consists. 9. Arrangement according to one of claims 1 to 8, characterized by an additional primary winding of the transformer connected to the bidirectional conductive, controlled switch is connected in parallel. 7-10. Arrangement according to claim 9, characterized in that the Two-way conductive controlled switch is a TRIAC, and that too additional primary winding of the transformer, an additional TRIAC is connected in series is. 11. Arrangement according to one of claims 1 to 10, characterized in that that the means for maintaining the power supply is a terminal of the primary winding of the transformer connects to a terminal of the secondary winding of the transformer. 12. The arrangement according to claim 11, characterized in that the connection between the primary and secondary winding of the transformer a voltage-reducing Has facility. 13. Arrangement according to claim 12, characterized in that the connection contains a diode between the primary and secondary winding. 14. Arrangement according to one of claims 1 to 13, characterized by an alternating voltage and, as a replacement, a direct voltage energy source, a first Switching device that normally connects the DC voltage source to the first and second terminal connects, and one responsive to failure of the AC voltage source Device for connecting the DC voltage source serving as a substitute source with the first and the second circuit connection. 15. The arrangement according to claim 14, characterized in that -en the Device for switching the switch, which is conductive in two directions, into the conductive switch State includes a device responsive to an occurring on the first and second terminals DC voltage potential or an AC voltage potential outside of a approved area and -the in two Rioltimgen conductive + facilities Switching device makes non-conductive. 16. Arrangement according to claim 14 or 15, characterized by several including such energy sources in a radio frequency signal distribution system a distribution cable network and a plurality of amplifiers contained therein, wherein the AC voltage sources and the substitute DC voltage sources the cable network pricing, each of the amplifiers one or more power delivery systems and wherein at least one of the power supply systems for the amplifiers Means for putting the devices out of operation for maintaining the Energy supply when applying the direct voltage potential to the energy-absorbing Includes connectors. 17. The arrangement according to claim 16, characterized in that subgroups of the power supply systems of the amplifiers have devices that the devices make conductive or non-conductive to maintain the energy supply, if a DC voltage potential is applied to the energy-absorbing connections.