JP5926837B2 - booster - Google Patents

Description

  The present invention relates to a booster.

  In recent years, with the progress of optical communication technology, optical transmission systems using optical cables have become widespread. According to this optical transmission system, since repeatless transmission of about several tens of kilometers is possible, the transmission system can be easily widened. This optical transmission system generally includes an optical transmitter that is arranged on the sender side and an optical receiver (optical terminal unit, ONU: Optical Network Unit) that is arranged on the receiver side. Connected via a long-distance transmission line. In the optical transmission system configured as described above, on the transmission side, an electric signal mixed with a TV signal and a notification broadcast signal is converted into an optical signal by an optical transmitter, and the optical signal is transmitted via an optical cable. On the other hand, on the receiving side, this optical signal is received via an optical receiver, converted into an RF signal or an FM signal, and these RF signals are output to a television receiver and an announcement broadcast receiver (see, for example, Patent Document 1). ).

JP 2008-236442 A

  By the way, in the conventional optical transmission system as described above, when a signal is branched from an optical receiver to a television receiver or an announcement broadcast receiver, an optical receiver and a branching device are connected to compensate for a branching loss in the branching device. It was necessary to connect a booster between them. FIG. 6 is a configuration diagram of an optical transmission system using a conventional booster. As illustrated in FIG. 6, conventionally, a signal output from the optical receiver 102 is amplified by the booster 103, and the signal amplified by the booster 103 is amplified by the branching device 104 by the television receiver 105 or the notification broadcast receiver. It was branched to 106.

  Here, as the optical receiver 102, a non-feed-type optical receiver has been put to practical use. This non-powered optical receiver is an optical receiver that can output a signal regardless of whether or not the receiver is powered. This is an optical receiver that can be operated by an electromotive force of a PD (Photo Diode). By using such a parasitic power receiver, a signal can be received from the optical receiver 102 even when there is no power. Can be output. However, in the optical transmission system 101 using the conventional booster 103 illustrated in FIG. 6, in order to perform the emergency notification broadcast from the notification broadcast receiver 106 even when no power is supplied, the optical receiver It is necessary to operate not only 102 but also the booster 103. For this reason, the backup power source 107 for the booster 103 has to be provided, which may increase the cost required for installation and maintenance of the equipment.

  The present invention has been made in view of the above, and an object of the present invention is to provide a booster capable of continuing signal output even when no power is supplied.

  In order to solve the above-described problems and achieve the object, a booster according to claim 1 is provided with an input terminal for receiving signal input, amplification means for amplifying a signal, and a signal amplified by the amplification means. Distributing means for distributing the power supply output system to the constant output system, a power supply output terminal for outputting the signal distributed to the power supply output system by the distributing means, a constant output terminal for outputting the signal, and the amplification When power is supplied to the device, the signal input to the input terminal is output from the power supply output terminal via the amplifier and the distributing device by connecting the input terminal to the amplifier. In addition, by connecting the constant output terminal to the distribution means, the signal distributed to the constant output system by the distribution means is output from the constant output terminal, and is connected to the amplification means. Switching means for causing the signal input to the input terminal to be output from the constant output terminal by connecting the input terminal to the constant output terminal when the power supply is not performed. Was set to be substantially the same as the distribution loss of the distribution means.

  Thus, according to the booster according to claim 1, since the gain of the amplification means is set to be substantially the same as the distribution loss of the distribution means, the level of the signal always output from the output terminal at the time of power feeding is set. The level can be suppressed to the same level as when no power is supplied, and the level of the signal input to the notification broadcast receiver can be kept constant regardless of whether power is supplied.

1 is a configuration diagram of an optical transmission system using a booster according to Embodiment 1. FIG. It is a circuit diagram in a booster. 6 is a configuration diagram of an optical transmission system using a booster according to Embodiment 2. FIG. 6 is a circuit diagram in a booster according to Embodiment 2. FIG. FIG. 6 is a circuit diagram showing a modification of the circuit configuration of the booster according to the second embodiment shown in FIG. 4. It is a block diagram of the optical transmission system using the conventional booster.

  Hereinafter, embodiments of a booster according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited by these embodiments.

[Embodiment 1]
First, the first embodiment will be described. The first embodiment relates to a booster that is configured most simply.

(Constitution)
FIG. 1 is a configuration diagram of an optical transmission system using a booster according to the first embodiment. As shown in FIG. 1, an optical transmission system 1 includes an optical receiver 2 and one notification broadcast receiver 6 connected via a booster 3, and the optical receiver 2 and a plurality of television receivers. 5 is connected via a booster 3 and a distributor 4. The distributor 4, the television receiver 5, and the notification broadcast receiver 6 can be configured in the same manner as in the prior art, and thus detailed description thereof is omitted. Also, the optical receiver 2 can be basically configured in the same manner as in the prior art, and therefore, only the configuration related to the present embodiment will be described below, and other detailed description will be omitted.

(Configuration-optical receiver)
The optical receiver 2 is a non-powered optical receiver and includes a PD, an amplifier, and an output terminal (all not shown). When the optical receiver 2 is supplied with power from an external power source, the optical receiver 2 uses the supplied electric power to convert an optical signal into an electrical signal (hereinafter referred to as RF signal). Signal), an FM signal is obtained from the RF signal, the RF signal and the FM signal are mixed and output to the outside through an output terminal. The optical receiver 2 generates an electromotive force by driving the PD in the no-bias mode when the power from the external power source is not supplied to the optical receiver 2, and uses this power. The RF signal is generated, and the FM signal acquired from the RF signal is output to the outside through the output terminal. Hereinafter, the RF signal, the FM signal, or the mixed signal output from the optical receiver 2 is simply referred to as “signal” when it is not necessary to distinguish them from each other. As a specific circuit configuration of such a non-feed type optical receiver 2, for example, configurations disclosed in Japanese Patent Application Laid-Open Nos. 2010-068195 and 2010-093778 can be applied. Note that the case where power is supplied from an external power source to the optical receiver 2 usually means that there is no power failure, and power is supplied from the external power source to the optical receiver 2. The case of no power usually means a power outage, but in the latter case, even when there is no power outage, the external power supply fails or the power line between the external power supply and the optical receiver 2 is disconnected. May be included. Hereinafter, a state in which power is supplied to the target device (including the optical receiver 2 and the booster 3) is referred to as “power supply”, and a state in which power is not supplied to the target device is the cause. Regardless, it is referred to as “no power supply”.

(Configuration-Booster)
The booster 3 outputs a signal input from the upstream side to the downstream side. FIG. 2 is a circuit diagram in the booster 3. As shown in FIG. 2, the booster 3 includes a booster input terminal 30, an amplifying element 31, a branching device 32, an attenuator 33, a power supply output terminal 34, a constant output terminal 35, a first switch 36a, a second switch 36b, DC cut capacitors 37a, 37b, and 37c are provided.

(Configuration-Booster-Booster input terminal)
The booster input terminal 30 is an input terminal that receives a signal input from the upstream side, and is connected to the output terminal of the optical receiver 2 via a coaxial cable (not shown).

(Configuration-Booster-Amplifier)
The amplifying element 31 is an amplifying means for amplifying a signal, and an input terminal (not shown) of the amplifying element 31 is connected to the booster input terminal 30 via the first switch 36a and the DC cut capacitor 37a. As the amplifying element 31, a known amplifying element such as a field effect transistor can be used.

(Configuration-Booster-Branch)
The branching device 32 includes a power supply output system that reaches the power supply output terminal 34 via the DC cut capacitor 37b, the attenuator 33, the second switch 36b, and the DC cut capacitor 37c. Distribution means that distributes to a constant output system that reaches the constant output terminal 35 via the input terminal (not shown) of the branching device 32 is connected to the output terminal (not shown) of the amplifying element 31. In the first embodiment, as shown in FIG. 2, in the power transmission system of the branching device 32, the power supply output system is a trunk line system, and the constant output system is a branch line system. As the branching device 32, a known branching device can be used. A distributor may be used instead of the branching device 32.

(Configuration-Booster-Attenuator)
The attenuator 33 is an attenuating means for attenuating a signal that is always branched to the output system by the branching device 32, and an input terminal (not shown) of the attenuator 33 is an output terminal (not shown) on the constant output system side of the branching device 32. Is omitted). The amount of attenuation by the attenuator 33 is set so that the gain of the amplifying element 31, the sum of the branch loss of the branching device 32 and the amount of attenuation by the attenuator 33 are substantially the same. As the attenuator 33, a known attenuator can be used.

(Configuration-Booster-Power supply output terminal)
The power supply output terminal 34 outputs a signal branched to the power supply output system by the branching device 32, and is connected to the power supply output system side output terminal of the branching device 32 via the DC cut capacitor 37b. Yes.

(Configuration-Booster-Constant output terminal)
The constant output terminal 35 outputs a signal and is connected to the second switch 36b via a DC cut capacitor 37c.

(Configuration-Booster-1st switch, 2nd switch)
The first switch 36 a and the second switch 36 b are switching means for switching connection of circuits in the booster 3. Among these, the first switch 36a is connected to the booster input terminal 30 via the DC cut capacitor 37a, and the connection destination of the booster input terminal 30 is connected to the input terminal (not shown) of the amplifying element 31 and the second switch 36b. Switch between. The second switch 36b is connected to the constant output terminal 35 via a DC cut capacitor 37c. The constant output terminal 35 is connected to the output terminal (not shown) of the attenuator 33 and the first switch 36a. Switch between. As these 1st switch 36a and 2nd switch 36b, well-known switches, such as a mechanical switch, an electromechanical switch, a semiconductor switch, can be used, for example. Further, the switching of the first switch 36a and the second switch 36b may be performed manually by a user or a maintenance person at an arbitrary timing, or is automatically performed according to the power supply status to the booster 3. You may do it.

(Configuration-Booster-DC cut capacitor)
The DC cut capacitor 37a is a capacitor that cuts inflow of the DC component to the first switch 36a, and the DC cut capacitor 37b is a capacitor that cuts inflow of the DC component to the output terminal 34 at the time of power supply, and the DC cut capacitor Reference numeral 37 c denotes a capacitor that cuts inflow of a direct current component to the output terminal 35 at all times.

(Operation)
Next, the operation of the booster 3 configured as described above will be described. First, at the time of power feeding, the signal input to the booster input terminal 30 is amplified by switching the first switch 36a and the second switch 36b to the state of the dotted line in FIG. 2 and connecting the booster input terminal 30 to the amplification element 31. The power is output from the power supply output terminal 34 via the element 31 and the branching device 32, and the constant output terminal 35 is connected to the branching device 32 via the attenuator 33. Further, the signal attenuated by the attenuator 33 is always output from the output terminal 35. Since power is supplied to the amplifying element 31 during power feeding, the signal input to the booster input terminal 30 is input to the amplifying element 31 via the DC cut capacitor 37a and the first switch 36a, and the amplifying element 31 is connected. Is amplified by. The signal amplified by the amplifying element 31 is branched by a branching device 32 into a power supply output system and a constant output system. Among these, the signal branched to the power supply output system is output from the power supply output terminal 34 via the DC cut capacitor 37 b, distributed by the distributor 4, and input to each television receiver 5. On the other hand, the signal branched to the constant output system is attenuated by the attenuator 33 and output from the constant output terminal 35 via the DC cut capacitor 37c. The signal output from the constant output terminal 35 is input to the notification broadcast receiver 6. As a result, a television image received by the television receiver 5 and an announcement broadcast by the announcement broadcast receiver 6 can be performed.

  On the other hand, when no power is supplied, the first switch 36 a and the second switch 36 b are switched to the solid line state in FIG. 2, and the booster input terminal 30 is always connected to the output terminal 35, whereby the signal input to the booster input terminal 30. Is always output from the output terminal 35. In this case, the signal input to the booster input terminal 30 is always output from the output terminal 35 via the DC cut capacitor 37a, the first switch 36a, the second switch 36b, and the DC cut capacitor 37c. The signal output from the constant output terminal 35 is input to the notification broadcast receiver 6. As a result, notification broadcast by the notification broadcast receiver 6 is possible even when no power is supplied.

  In particular, the amount of attenuation by the attenuator 33 is set so that the gain of the amplifying element 31, the sum of the branch loss of the branching device 32 and the amount of attenuation by the attenuator 33 are substantially the same. Therefore, during power feeding, a signal that is always output from the output terminal 35 via the DC cut capacitor 37a, the first switch 36a, the amplifying element 31, the branching device 32, the attenuator 33, the second switch 36b, and the DC cut capacitor 37c. At the time of the output level and without power supply, the amplifying element 31, the branching device 32, and the attenuator 33 are bypassed, and are always passed through the DC cut capacitor 37a, the first switch 36a, the second switch 36b, and the DC cut capacitor 37c. The output level of the signal output from the output terminal 35 is kept at a constant level. Thereby, the level of the signal input to the notification broadcast receiver 6 can be kept constant regardless of whether or not power is supplied.

  When the first switch 36a and the second switch 36b are configured to be manually switched by the user or the maintenance person, the user forgets to manually switch the first switch 36a and the second switch 36b during power feeding and when power is not fed. In order to prevent such a situation, an alert to the user may be output from the notification broadcast receiver 6 by voice or display in accordance with the power supply state from the external power supply to the notification broadcast receiver 6. . For example, a control unit (not shown) of the notification broadcast receiver 6 monitors the supply state of power from an external power source to the notification broadcast receiver 6, and the power source is shut off for a predetermined time and When a signal of a predetermined level or higher is not input to the self from the upstream side, a power failure or the like has occurred, but the user forgets to manually switch the first switch 36a or the second switch 36b, so that the signal of If there is a high possibility that there is no input, a voice message such as “Please switch the first switch 36a and the second switch 36b to the non-powered side” is output, or a similar character message is displayed on a liquid crystal panel (not shown). The user may be alerted by turning on or blinking a predetermined indicator light such as a switch confirmation request light (not shown). After that, when the power is continuously supplied for a predetermined time or longer, in order to prevent the user from forgetting to manually switch the first switch 36a or the second switch 36b, “the first switch 36a and the second switch 36 "Please switch 36b to the power supply side", display a similar text message on a liquid crystal panel, or turn on or blink a predetermined indicator such as a switch confirmation request light Thus, the user may be alerted.

(effect)
As described above, according to the first embodiment, by switching the first switch 36a and the second switch 36b, the booster input terminal 30 is connected to the amplifying element 31 at the time of power feeding, so that the booster input terminal 30 is input. The signal is output from the power supply output terminal 34 via the amplifying element 31 and the branching device 32, and the constant output terminal 35 is connected to the branching device 32. Output from the output terminal 35. When no power is supplied, the booster input terminal 30 is connected to the constant output terminal 35 by switching the first switch 36a and the second switch 36b, so that the signal input to the booster input terminal 30 can be transmitted from the constant output terminal 35. Output. Therefore, the signal input to the booster 3 can always be output from the output terminal 35 regardless of whether power is supplied or not, and the notification broadcast by the notification broadcast receiver 6 can be performed even when there is no power supply.

  Further, by switching the first switch 36a and the second switch 36b, the signal always attenuated by the attenuator 33 is output from the output terminal 35 by connecting the output terminal 35 to the attenuator 33 at the time of power feeding. The level of the signal always output from the output terminal 35 at the time of power feeding can be suppressed to the same level as that at the time of no power feeding, and the level of the signal input to the notification broadcast receiver 6 can be set regardless of whether or not power feeding is performed. Can be kept constant.

  In particular, since the gain of the amplifying element 31, the total value of the branching loss of the branching device 32, and the amount of attenuation by the attenuator 33 are substantially the same, the level of the signal that is always output from the output terminal 35 during power feeding The signal level always output from the output terminal 35 when no power is supplied can be reliably maintained at a constant level, and the level of the signal input to the notification broadcast receiver 6 can be set regardless of whether power is supplied. It can be surely kept constant.

[Embodiment 2]
Next, a second embodiment will be described. In the second embodiment, a plurality of power supply output terminals are provided. The configuration of the second embodiment is substantially the same as the configuration of the first embodiment, unless otherwise specified. The same configuration as that of the first embodiment is used in the first embodiment. The same reference numerals and / or names as those used are attached as necessary, and description thereof is omitted.

(Constitution)
FIG. 3 is a configuration diagram of the optical transmission system 1 using the booster 3 according to the second embodiment. As shown in FIG. 3, an optical transmission system 1 connects an optical receiver 2 and one notification broadcast receiver 6 via a booster 3, and also includes an optical receiver 2 and a plurality of television receivers. 5 are connected to each other via a booster 3.

(Configuration-Booster)
FIG. 4 is a circuit diagram in the booster 3 according to the second embodiment. As shown in FIG. 4, the booster 3 includes a distributor 38 instead of the branching device 32 in the first embodiment, and also includes a plurality of power supply output terminals 34a, 34b, 34c, and 34d.

(Configuration-Booster-Distributor)
The distributor 38 is distribution means for distributing the signal amplified by the amplification element 31 to the power supply output system and the constant output system, and the input terminal (not shown) of the distributor 38 is the output terminal of the amplification element 31. (Not shown). In the second embodiment, as shown in FIG. 4, the distributor 38 is a five distributor that distributes the output to five systems, and the DC cut capacitors 37 b, 37 d, 37 e, and 37 f are supplied from the amplifier element 31. The four power supply output terminals 34a, 34b, 34c, and 34d are connected to the power supply output system through the amplifying element 31, the attenuator 33, the second switch 36b, and the DC cut capacitor 37c. The system leading to is always an output system. As this distributor 38, a well-known distributor can be used.

(Configuration-Booster-Attenuator)
The attenuator 33 is an attenuating means for attenuating the signal distributed to the output system by the distributor 38. An input terminal (not shown) of the attenuator 33 is connected to an output terminal of the constant output system of the distributor 38. ing. The attenuation amount by the attenuator 33 is set so that the gain of the amplifying element 31, the total value of the distribution loss of the distributor 38 and the attenuation amount by the attenuator 33 are substantially the same. As the attenuator 33, a known attenuator can be used.

(Configuration-Booster-Power supply output terminal)
The power supply output terminals 34a, 34b, 34c, and 34d output signals distributed to the power supply output system by the distributor 38, and are connected to the distributor 38 via the DC cut capacitors 37b, 37d, 37e, and 37f. It is connected to the output terminal of the power supply output system. In the second embodiment, four power supply output terminals 34a, 34b, 34c, and 34d are provided.

(Operation)
Next, the operation of the booster 3 configured as described above will be described. First, at the time of power feeding, the signal input to the booster input terminal 30 is amplified by switching the first switch 36a and the second switch 36b to the state of the dotted line in FIG. 4 and connecting the booster input terminal 30 to the amplification element 31. The power supply output terminals 34a, 34b, 34c, and 34d are output from the power supply terminals 34a, 34b, 34c, and 34d through the element 31 and the distributor 38, and the distributor 38 is connected to the distributor 38 through the attenuator 33. A signal distributed to the constant output system and further attenuated by the attenuator 33 is output from the constant output terminal 35. Since power is supplied to the amplifying element 31 during power feeding, the signal input to the booster input terminal 30 is input to the amplifying element 31 via the DC cut capacitor 37a and the first switch 36a, and the amplifying element 31 is connected. Is amplified by. The signal amplified by the amplifying element 31 is distributed by the distributor 38 to the power supply output system and the constant output system. Among these, the signal distributed to the power supply output system is output from the power supply output terminals 34a, 34b, 34c, 34d via the DC cut capacitors 37b, 37d, 37e, 37f, and directly to each television receiver 5. Entered. On the other hand, the signal distributed to the constant output system is attenuated by the attenuator 33 and is output from the constant output terminal 35 via the DC cut capacitor 37c. The signal output from the constant output terminal 35 is input to the notification broadcast receiver 6. As a result, a television image received by the television receiver 5 and an announcement broadcast by the announcement broadcast receiver 6 can be performed.

  On the other hand, the signal input to the booster input terminal 30 by switching the first switch 36a and the second switch 36b to the solid line state in FIG. 4 and connecting the booster input terminal 30 to the constant output terminal 35 when no power is supplied. Is always output from the output terminal 35. In this case, the signal input to the booster input terminal 30 is always output from the output terminal 35 via the DC cut capacitor 37a, the first switch 36a, the second switch 36b, and the DC cut capacitor 37c. The signal output from the constant output terminal 35 is input to the notification broadcast receiver 6. As a result, notification broadcast by the notification broadcast receiver 6 is possible even when no power is supplied.

  In particular, the attenuation by the attenuator 33 is set so that the gain of the amplifying element 31, the total value of the distribution loss of the distributor 38 and the attenuation by the attenuator 33 are substantially the same. Therefore, during power feeding, a signal that is always output from the output terminal 35 via the DC cut capacitor 37a, the first switch 36a, the amplifying element 31, the distributor 38, the attenuator 33, the second switch 36b, and the DC cut capacitor 37c. At the time of the output level and when no power is supplied, the amplifying element 31, the distributor 38, and the attenuator 33 are bypassed and are always passed through the DC cut capacitor 37a, the first switch 36a, the second switch 36b, and the DC cut capacitor 37c. The output level of the signal output from the output terminal 35 is kept at a constant level. Thereby, the level of the signal input to the notification broadcast receiver 6 can be kept constant regardless of whether or not power is supplied.

(effect)
Thus, according to the second embodiment, in addition to the same effects as those of the first embodiment, signals can be directly input from the booster 3 to the plurality of television receivers 5. Thereby, the configuration of the optical transmission system 1 can be further simplified.

[Modifications to Embodiments]
Although the embodiments of the present invention have been described above, the specific configuration and means of the present invention may be arbitrarily modified and improved within the scope of the technical idea of each invention described in the claims. Can do. Hereinafter, such a modification will be described.

(About problems to be solved and effects of the invention)
First, the problems to be solved by the invention and the effects of the invention are not limited to the above-described contents, and the present invention solves the problems not described above or has the effects not described above. There are also cases where only some of the described problems are solved or only some of the described effects are achieved.

(Specific circuit configuration)
As a specific circuit configuration of the booster 3, a known circuit configuration can be applied in addition to the circuit configurations illustrated in the embodiments as long as the functions described above can be realized. For example, FIG. 5 is a circuit diagram showing a modification of the circuit configuration of the booster 3 of the second embodiment shown in FIG. As shown in FIG. 5, in the booster 3 of the second embodiment, a branching device 32 may be further provided between the amplifying element 31 and the distributor 38. In this case, the branching device 32 reaches the power supply output terminals 34a, 34b, 34c, 34d via the distributor 38 and the DC cut capacitors 37b, 37d, 37e, 37f. Branching into an output system at the time of feeding and a constant output system that reaches the constant output terminal 35 via the attenuator 33, the second switch 36b, and the DC cut capacitor 37c. Even when the circuit of the booster 3 is configured in this way, the same function as the booster 3 of the second embodiment can be realized.

  In each of the above-described embodiments, the case where the booster 3 includes the attenuator 33 has been described. However, the attenuator 33 may be omitted. Also in this case, for example, by setting the gain of the amplifying element 31 to be substantially the same as the branching loss of the branching device 32 or the distributing loss of the distributor 38, the gain is always output from the output terminal 35 during power feeding. Therefore, the level of the signal input to the notification broadcast receiver 6 can be kept constant regardless of whether or not power is supplied.

[First note]
The booster of the first supplementary note 1 includes an input terminal for receiving a signal input, an amplifying means for amplifying the signal, and a distributing means for distributing the signal amplified by the amplifying means to the power supply output system and the constant output system. A power supply output terminal for outputting a signal distributed to the power supply output system by the distribution means, a constant output terminal for outputting a signal, and when the power is supplied to the amplifying means, the input By connecting a terminal to the amplifying means, a signal input to the input terminal is output from the power supply output terminal via the amplifying means and the distributing means, and the constant output terminal is connected to the distributing means. Thus, the signal distributed to the constant output system by the distribution means is output from the constant output terminal, and when the power is not supplied to the amplification means, the input terminal Wherein to output the signal inputted to the input terminal by connecting to the continuous output terminal from the continuous output terminal, comprising a switching means.

  Further, the booster of the first supplementary note 2 is the booster of the first supplementary note 1, further comprising an attenuating means for attenuating the signal distributed to the constant output system by the distributing means, and the switching means includes the amplification unit When power is supplied to the means, the constant output terminal is connected to the attenuation means, and the signal attenuated by the attenuation means is output from the constant output terminal.

  Further, the booster of the first supplementary note 3 is the booster of the first supplementary note 2, wherein the gain of the amplification means, the total value of the distribution loss of the distribution means and the attenuation amount by the attenuation means are approximately set. Made the same.

  According to the booster described in the first supplementary note 1, the switching means amplifies the signal input to the input terminal by connecting the input terminal to the amplification means when power is supplied to the amplification means. Output from the power supply output terminal via the means and the distribution means, and by connecting the constant output terminal to the distribution means, the signal distributed to the constant output system by the distribution means is always output from the output terminal, to the amplification means When power is not being supplied, the signal input to the input terminal is always output from the output terminal by connecting the input terminal to the output terminal. The signal can always be output from the output terminal at all times, and notification broadcast by the notification broadcast receiver can be performed even when no power is supplied.

  Further, according to the booster described in the first supplementary note 2, when the power is supplied to the amplifying means, the switching means always connects the output terminal to the attenuating means and the signal attenuated by the attenuating means. Is always output from the output terminal, so that the level of the signal output from the constant output terminal during power feeding can be suppressed to the same level as during no power feeding, and the level of the signal input to the notification broadcast receiver is It can be kept constant with or without power feeding.

  Further, according to the booster described in the first supplementary note 3, since the gain of the amplifying means and the total value of the distribution loss of the distributing means and the attenuation amount by the attenuating means are made substantially the same, it is always output during power feeding. The level of the signal that is output from the terminal and the level of the signal that is always output from the output terminal when no power is supplied can be reliably maintained at a constant level, and the level of the signal that is input to the notification broadcast receiver is Regardless of whether power is supplied or not, it can be kept constant.

[Second supplementary note]
The booster of the second supplementary note 1 includes an input terminal for receiving a signal input, an amplifying means for amplifying the signal, and a distributing means for distributing the signal amplified by the amplifying means to the power supply output system and the constant output system. A power supply output terminal for outputting a signal distributed to the power supply output system by the distribution means, a constant output terminal for outputting a signal, and when the power is supplied to the amplifying means, the input By connecting a terminal to the amplifying means, a signal input to the input terminal is output from the power supply output terminal via the amplifying means and the distributing means, and the constant output terminal is connected to the distributing means. Thus, the signal distributed to the constant output system by the distribution means is output from the constant output terminal, and when the power is not supplied to the amplification means, the input terminal Switching means for connecting to the constant output terminal to output the signal input to the input terminal from the constant output terminal, and setting the gain of the amplification means to be substantially the same as the distribution loss of the distribution means did.

  Thus, according to the booster described in the second supplementary note 1, since the gain of the amplifying means is set to be substantially the same as the distribution loss of the distributing means, the signal always output from the output terminal during power feeding The level can be suppressed to the same level as when no power is supplied, and the level of the signal input to the notification broadcast receiver can be kept constant regardless of whether power is supplied.

DESCRIPTION OF SYMBOLS 1,101 Optical transmission system 2,102 Optical receiver 3,103 Booster 4,38 Divider 5,105 Television receiver 6,106 Notification broadcast receiver 30 Booster input terminal 31 Amplifying element 32, 104 Branch device 33 Attenuator 34 , 34a, 34b, 34c, 34d Power supply output terminal 35 Constant output terminal 36a First switch 36b Second switch 37a, 37b, 37c, 37d, 37e, 37f DC cut capacitor 107 Backup power supply

Claims (1)

An input terminal for receiving signals;
Amplifying means for amplifying the signal;
Distributing means for distributing the signal amplified by the amplifying means to a power supply output system and a constant output system;
A power supply output terminal for outputting a signal distributed to the power supply output system by the distribution means;
A constant output terminal for outputting signals,
When power is supplied to the amplifying means, the input terminal is connected to the amplifying means so that the signal input to the input terminal can be connected to the output terminal during the power supply via the amplifying means and the distributing means. And the signal distributed to the constant output system by the distribution means is output from the constant output terminal by connecting the constant output terminal to the distribution means, and power is not supplied to the amplification means. In this case, the input terminal is connected to the constant output terminal, and the signal input to the input terminal is output from the constant output terminal.
The gain of the amplification means is set to be substantially the same as the distribution loss of the distribution means.
booster.

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