JP2015053740A - Collective housing intercom system and system expansion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collective housing intercom system allowing simultaneous communication using main lines of plural systems while reducing a loss on main lines of the systems.SOLUTION: The collective housing intercom system having a communication channel includes: sub-main lines of plural systems in which one or plural dwelling unit terminals which are branched therefrom and connected thereto; and a main line in which the sub-main lines of the plural systems are branched therefrom and connected thereto via plural branching devices. Each of the plural branching devices includes: a pair of main line connection sections which are inserted in series along the main line; a sub-main line connection section to which the sub main lines to the system expansion device are connected; and a branching circuit for branching a signal flowing a pair of main line connections to the sub-main line connection.

Description

  The present invention relates to a collective housing intercom system and a system adder used in the collective housing intercom system.

  As a conventional example, an intercom system for collective housing described in Patent Document 1 is illustrated. This conventional example is connected to a lobby interphone via a common unit (lobby intercom) installed in a common entrance of a housing complex, a dwelling unit installed in each dwelling unit, and a common unit trunk line, and a plurality of dwelling main lines And a main line distribution device connected to the network. Further, in this conventional example, a number of branching units are connected to each dwelling unit trunk line, and a dwelling unit of each dwelling unit is connected to a dwelling unit line branched from the dwelling unit trunk line by each branching unit.

JP 2010-178073 A

  By the way, in a large-scale apartment building composed of a plurality of buildings, a plurality of systems of trunk lines (secondary trunk lines) may be branched from one trunk line (main trunk line) for each building. For example, the first-floor dwelling units in each building are connected by the main trunk line, and each sub-building is connected to the upper-floor dwelling unit by the sub-trunk line set up from the first-floor dwelling unit. In this case, in the first-floor dwelling units in each building, there is a problem that distribution loss of the secondary trunk line increases when the distributor distributes the main trunk line to the secondary trunk line. In addition, there is a conventional example in which a plurality of trunk lines are selectively switched and connected using a relay. However, in such a conventional example, it is not possible to simultaneously communicate with a plurality of trunk lines (main trunk line and sub trunk line). There was a problem that the use was limited.

  The present invention has been made in view of the above problems, and an object of the present invention is to reduce the loss of the trunk line of each system while enabling simultaneous communication with a plurality of trunk lines.

  An intercom system for an apartment house according to the present invention includes a shared terminal installed at a common entrance of an apartment house, a dwelling unit terminal installed at each dwelling unit of the apartment house, and a communication path between the shared unit terminal and the dwelling unit terminal. An intercom system for a housing complex comprising a trunk line control terminal that relays a communication signal via the communication line, wherein the communication path includes a main line that connects the shared section terminal and the trunk line control terminal, and the trunk line control terminal; A plurality of sub trunk lines branchingly connected to the main trunk line via a plurality of system adders between the dwelling unit terminals, and one to a plurality of dwelling unit terminals branching to the sub trunk line via a branching unit Each of the plurality of system expansion units is connected to a pair of main line connection portions inserted in series along the main line, and a sub trunk line to the system expansion unit Sub trunk line connection part and the pair of main trunk lines A branch circuit for branching a signal flowing between the connecting parts to the sub-main line connection part, and in the branch circuit, a communication signal input from one of the main line connection parts is sent from the other main line connection part The attenuation when output is smaller than the attenuation when a communication signal input from the pair of main trunk connection units is output from the sub trunk connection unit.

  The system expansion device according to the present invention includes a common unit terminal installed at a common entrance of a housing complex, a dwelling unit terminal installed in each dwelling unit of the housing complex, and a communication path between the common unit terminal and the dwelling unit terminal. A main line control terminal for relaying communication signals, and the communication path includes a main trunk line connecting the shared section terminal and the main line control terminal, and a plurality of lines between the main line control terminal and the dwelling unit terminal. For multiple dwelling houses having a plurality of sub trunk lines branch-connected to the main trunk line via a system expansion unit, and a dwelling unit line in which one or a plurality of dwelling unit terminals are branch-connected to the sub trunk line via a branching unit A system expansion device used in an interphone system, a pair of main trunk connection portions inserted in series along the main trunk line, a sub trunk connection portion to which a sub trunk line to the system expansion device is connected, and The signal flowing between a pair of main line connections A branch circuit for branching to the main line connection unit, in the branch circuit, the amount of attenuation when the communication signal input from one of the main line connection unit is output from the other main line connection unit, The communication signal input from the pair of main trunk line connection units is smaller than the attenuation when output from the sub trunk line connection unit.

  The intercom system for multi-dwelling houses and the system expansion device according to the present invention have an effect that the loss of the trunk line of each system can be reduced while enabling simultaneous communication with a plurality of systems of trunk lines.

Preferred embodiments of the invention are described in further detail. Other features and advantages of the present invention will be better understood with reference to the following detailed description and accompanying drawings.
FIG. 1A is a system configuration diagram showing Embodiment 1 of an intercom system for an apartment house according to the present invention, and FIG. 1B is a block diagram showing an embodiment of a system expansion device according to the present invention. It is a circuit diagram of the branching device same as the above. It is a block diagram which shows another structure of the system expansion device same as the above. It is a block diagram which shows another structure of the system expansion device same as the above. It is a system block diagram which shows Embodiment 2 of the intercom system for apartment houses which concerns on this invention. It is another system block diagram of the intercom system for apartment houses same as the above. It is a block diagram of the amplifier in Embodiment 3 of the intercom system for apartment houses which concerns on this invention. 8A and 8B are block diagrams of an amplifier in the fourth embodiment of the intercom system for an apartment house according to the present invention. It is a block diagram of the amplifier in Embodiment 5 of the intercom system for apartment houses which concerns on this invention. It is a block diagram which shows another embodiment of the system | strain expansion device which concerns on this invention.

  Hereinafter, embodiments of an intercom system for collective housing and a system expansion device according to the present invention will be described in detail.

(Embodiment 1)
As shown in FIG. 1A, the intercom system for an apartment house of the present embodiment includes a common terminal (lobby interphone) C installed at the common entrance (lobby) of the apartment house, and a dwelling unit installed in each unit of the apartment house. A terminal (communication terminal) A and a main line control terminal B are included. The plurality of dwelling unit terminals A and the lobby intercom C are connected via a trunk line control terminal B through a communication path. The communication path includes a shared trunk LC connecting the lobby intercom C and the trunk control terminal B, one end (first end) connected to the trunk control terminal B, and the other end (second end) terminated at the terminator E. Main line LA, a plurality of secondary trunk lines LB1, LB2,..., LBn and a plurality of (second) ) It consists of a plurality of dwelling unit lines LD branched from the secondary trunk line LBi (i = 1, 2,..., N) by the branching unit D. The communication path is composed of a balanced two-wire communication cable.

  The lobby intercom C is an imaging device configured to image a visitor, a microphone and a speaker, a numeric keypad or touch panel for a visitor to input the dwelling unit number of the visited residence, a packet of voice and video through a communication path A transmission unit configured to transmit data is included. In the lobby intercom C, when the ten key switch or the touch panel is operated and the operation input of the dwelling unit number of any dwelling unit is received, the packet storing the dwelling unit number in the data field and the visitor image (video) captured by the imaging device. The packet storing information) in the data field is transmitted (packet transmission) from the transmission unit to the address of the trunk control terminal B via the shared trunk LC.

  The main line control terminal B stores the correspondence between the address assigned to the dwelling unit terminal A of each dwelling unit and the dwelling unit number of the dwelling unit. Then, the trunk line control terminal B compares the dwelling unit number stored in the data field of the packet received from the lobby intercom C with the corresponding relationship, converts it to an address, stores the address in the destination address field, and stores the address in the lobby intercom A packet storing a call command for notifying a call from C in the data field and a packet storing the video information in the data field are sent to the main line LA.

  The dwelling unit A includes a control unit 1, a transmission processing unit 2, a call processing unit 3, a microphone 4, a speaker 5, an A / D converter 6, a D / A converter 7, a video processing unit 8, a display unit 9, and an operation input. The reception unit 10 is provided. The sound collected by the microphone 4 is converted into an electrical signal (voice signal), and the analog voice signal (speech voice signal) output from the microphone 4 is converted into a digital voice signal (speech) by the A / D converter 6. Voice data) and input to the call processing unit 3. Further, the digital voice signal (received voice data) output from the call processing unit 3 is converted into an analog voice signal (received voice signal) by the D / A converter 7. An analog received voice signal output from the D / A converter 7 is input to the speaker 5, and a voice (received voice) is generated from the speaker 5.

  The call processing unit 3 includes a voice switch, an echo canceller, and the like, and performs signal processing on the received voice signal input from the transmission processing unit 2 and the transmission voice signal input from the A / D converter 6 to perform howling and The echo is suppressed to realize a good hands-free call. The transmitted voice signal processed by the call processing unit 3 is output to the transmission processing unit 2.

  The display unit 9 includes a display device such as a liquid crystal display or an organic EL display, and a drive circuit that drives the display device to display an image (none is shown). The video processing unit 8 reconstructs the original video from the video signal (video data) output from the transmission processing unit 2 and causes the display unit 9 to display the reconstructed video.

  The control unit 1 includes hardware such as a CPU and a memory, and various programs (software) executed by the CPU. The operation input accepting unit 10 has an input device such as a touch panel or a push button switch, accepts various operation inputs by operating the input device, and outputs an operation signal corresponding to each operation input to the control unit 1. To do. For example, a response button (not shown) is provided on the front of the housing of the dwelling unit terminal A. When this response button is pressed, an operation input is received by the operation input receiving unit 10 and a response operation signal is output. Is done. When an operation signal is input from the operation input receiving unit 10, the control unit 1 executes processing (described later) according to each operation signal.

  The transmission processing unit 2 performs packet transmission with the trunk line control terminal B and other dwelling unit terminals A via a communication path. The transmission processing unit 2 divides the control signal (control data) created by the control unit 1 to create a packet (control packet), and the transmission voice signal (transmission voice data) also created by the call processing unit 3. ) To create a packet (voice packet). Furthermore, the transmission processing unit 2 encodes the control packet and the voice packet, converts (modulates) the encoded bit string into an electric signal, and sends the electric signal to the dwelling unit LD. Further, the transmission processing unit 2 converts (demodulates) an electric signal flowing through the dwelling unit line LD into a bit string and decodes a packet (voice packet, control packet, video packet) from the demodulated bit string. The transmission processing unit 2 discards the packet if the address of the decrypted packet does not match its own address (address of the dwelling unit terminal A), and if the address matches, it is included in the data field of the packet. If the data is video data (video signal), it is output to the video processing unit 8, if it is control data (control signal), it is output to the control unit 1, and if it is audio data (voice signal), it is output to the call processing unit 3.

  As shown in FIG. 1B, the system expansion unit F includes a first main line connection part (first main connection part) 20 including first and second main line connection terminals 20A and 20B, and first and second main lines. A second main trunk connection portion (second main connection portion) 21 including connection terminals 21A and 21B and a sub main line connection portion (sub connection portion) 22 including first and second sub trunk connection terminals 22A and 22B are provided. . The first and second main line connection portions 20 and 21 are composed of two first lines connecting the first main line connection terminals 20A and 21A and two second lines connecting the second main line connection terminals 20B and 21B. It is inserted in series along the main line LA so as to constitute a part of the main line LA of the formula. The secondary trunk connection unit 22 is connected to the secondary trunk line LBi. That is, the main line connection portions 20, 21 are provided with a pair of main line connection terminals 20A, 20B, 21A, 21B, respectively, and the main line connection terminals (20A and 21A, 20B and 21B) are electrically connected to each other. It is connected to the. Further, the system expansion device F includes a branch circuit 23 for branching a signal flowing between the main line connection units 20 and 21 to the sub main line connection unit 22.

  The branch circuit 23 includes a transformer T, a resistor R1 and a capacitor C1 connected in series between one end (first end) of the primary winding of the transformer T and the main line connection terminals 20A and 21A (first line). The resistor R2 and the capacitor C2 connected in series between the other end (second end) of the primary winding of the transformer T and the main line connection terminals 20B and 21B (second line), and the secondary winding of the transformer T A capacitor C3 connected in series between one end (first end) of the wire and the secondary trunk connection terminal 22A, and between the other end (second end) of the secondary winding of the transformer T and the secondary trunk connection terminal 22B And a capacitor C4 connected in series. Here, in the branch circuit 23, an attenuation amount (for example, 0.5 dB) when a communication signal input from one main line connection unit 20 (or 21) is output from the other main line connection unit 21 (or 20). ) Is smaller than the attenuation (for example, 10 dB) when the communication signal input from the main trunk line connection units 20 and 21 is output from the sub trunk line connection unit 22. That is, the secondary trunk line connecting portion 22 has a high impedance when viewed from the main trunk line connecting portions 20 and 21.

  FIG. 2 is a circuit diagram of each branching device D of the present embodiment. The branching device D shown in FIG. That is, the branching device D includes a first main connection portion D1 including first and second connection terminals D11 and D12, a second main connection portion D2 including first and second connection terminals D21 and D22, A sub-connecting portion D3 including second sub-connecting terminals D31 and D32. Since the branch circuit D23 for branching the signal flowing between the main connection parts D1 and D2 to the sub connection part D3 is basically configured in the same manner as the branch circuit of the system expansion device F, it will not be described in detail here.

  Next, an intercom call performed between the dwelling unit terminal A and the lobby intercom C will be described. In the lobby intercom C, when a visitor receives an operation input of a dwelling unit number of any dwelling unit by operating a numeric keypad or a touch panel, the packet storing the dwelling unit number in the data field and the visitor imaged by the imaging device A packet storing video (video data) in the data field is transmitted (packet transmission) from the transmission unit to the address of the trunk control terminal B via the shared trunk line LC. The main line control terminal B sends a control packet storing a call command for notifying the call from the lobby intercom C in the data field and a video packet storing the video data in the data field to the main line LA.

  In the dwelling unit terminal A installed in the dwelling unit with the dwelling unit number, when the transmission processing unit 2 receives the control packet and the video packet through the main trunk line LA, the sub trunk line LBi, and the dwelling unit line LD, it is stored in the data field of the control packet. The paging command (control signal) being output is output to the control unit 1, and the video data stored in the data field of the video packet is output to the video processing unit 8. When receiving the call command, the control unit 1 causes the speaker 5 to ring. The video processing unit 8 processes the video signal received from the transmission processing unit 2 and causes the display unit 9 to display the video of the visitor. Then, when the resident who has heard the ringing tone confirms the video of the visitor displayed on the display unit 9 of the dwelling unit A and operates the response button, the operation input accepting unit 10 responds to the operation input of the response button. An operation signal is output. The control unit 1 that has received the operation signal activates the call processing unit 3, and a voice signal (sending voice signal) output from the microphone 4 is packet-transmitted from the transmission processing unit 2. As a result, a resident of the dwelling unit and a visitor can make an interphone call using the dwelling unit terminal A and the lobby intercom C.

  Then, when the response button of the dwelling unit terminal A is pressed during the interphone call and an operation signal is output from the operation input receiving unit 10 to the control unit 1, the control unit 1 transmits the call processing unit 3, the video processing unit 8, and the transmission. The processing unit 2 is stopped and the intercom call ends. However, even when the response button is not pressed, the control unit 1 switches the call processing unit 3, the video processing unit 8, and the transmission processing unit 2 when a predetermined time (for example, several minutes) has elapsed since the start of the call. Stop and end the intercom call. In the present embodiment, intercom calls can be performed between the dwelling unit terminals A of different dwelling units via the trunk line control terminal B, but basically the same procedure as that for the intercom call with the lobby intercom C is performed. Therefore, the description is omitted.

  As described above, in the present embodiment, the secondary trunk line LB is branched from the main trunk line LA by the system expansion unit F including the branch circuit 23. Therefore, each sub trunk line LB is compared with the case of distributing using the distributor. Loss can be reduced. In addition, the secondary trunk line LB is always connected to the main trunk line LA via the system expansion unit F. For example, a communication signal that is multicast or broadcast from the trunk control terminal B flows to all the secondary trunk lines LBi and can communicate simultaneously. Become. Furthermore, since communication can be performed simultaneously (in parallel) between the main line control terminal B and the plurality of dwelling unit terminals A, for example, intercom calls between the dwelling unit terminals A of different dwelling units via the main line control terminal B Can be done. In the present embodiment, since the impedance matching terminator E is connected to the ends of the main trunk line LA and the sub trunk line LBi, signal reflection at the ends of the main trunk line LA and the sub trunk line LBi can be suppressed.

  By the way, compared with the line length of the communication path (common use trunk line LC) connecting the lobby intercom C and the main line control terminal B, the communication paths (main trunk line LA, secondary trunk line connecting the main line control terminal B and each dwelling unit terminal A). The line length of LBi, Sumitomo Line LD) is much longer, and communication quality is likely to deteriorate due to increased transmission loss and noise. Therefore, in the present embodiment, in the packet transmission between the transmission processing unit 2 of the dwelling unit A and the trunk line control device C, the modulation scheme (multi-level modulation degree in digital modulation) is based on the result of measuring the noise level for each subcarrier. ), A multi-carrier adaptive modulation scheme that selects and sets a communication mode such as an error correction coding rate and a carrier to be used is employed. By adopting the multicarrier adaptive modulation method in this way, even when the transmission loss deviation within the communication band is large or when the S / N ratio varies greatly depending on the frequency, such as when narrow band noise is mixed, A decrease in communication quality can be suppressed.

  Here, it is preferable to form the branch circuit 23 so that the sum of the branch losses of all the system expansion devices F connected in series to the main line LA is equally distributed to all the system expansion devices F. For example, when the upper limit of the number of connection of the system expansion devices F is n, the branch loss in the branch circuit 23 of each system expansion device F satisfies the relational expression of 10log10 [1 / (n−i + 1)]. Thus, the circuit constants of the resistors R1 and R2 and the capacitors C1 to C4 are set (where i is the number of the secondary trunk line LBi, i = 1, 2,..., N). Therefore, if the upper limit of the number of connections is 15, the branch loss in the branch circuit 23 of the system extension F closest to the main line control terminal B becomes 10 log10 (1/15) decibels, and the system extension F closest to the second The branch loss in the branch circuit 23 is 10 log10 (1/14) decibels, and the branch loss in the branch circuit 23 of the farthest system adder F is 10 log10 (1/1) decibels. In this way, if the sum of the branch losses of all the system expansion devices F connected in series to the main line LA is equally distributed to all the system expansion devices F, the signal level of the communication signal branched to each sub-main line LBi. Are substantially the same.

  By the way, it turns out that the optimum value of the branch loss in the branch circuit 23 of the system expansion device F increases so as to be almost directly proportional to the number of the sub-main lines LBi branched from the main trunk line LA (the number of the system expansion devices F). Yes. Therefore, if the resistance values of the resistors R1 and R2 constituting the branch circuit 23 of the system expansion device F are fixed, the branch loss is also fixed. Therefore, it is possible to give each system amplifier F the optimum branch loss. It becomes difficult.

  Therefore, as shown in FIG. 3, a plurality of resistors R1j and capacitors C1j (illustrated example) are provided between one end (first end) of the primary winding of the transformer T and the main line connection terminals 20A and 21A (first line). 3) and a switch SW1 are connected, and a resistor R2j and a capacitor C2j are connected between the other end (second end) of the primary winding and the main line connection terminals 20B and 21B (second line). It is preferable that a plurality of (three in the illustrated example) series circuit and the selector switch SW2 are connected (j = 1, 2, 3). That is, by switching the two changeover switches SW1 and SW2, the resistance values of the resistors R1j and R2j inserted between the primary winding of the transformer T and the main line connection terminals 20A, 21A and 20B, 21B are different. Thus, the branch loss in the branch circuit 23 can be adjusted. As a result, the optimum branch loss for the system can be easily set. 3 has a plurality of branch circuits with different branch losses by a plurality of series circuits (R1j and C1j) and a plurality of series circuits (R1j and C1j). The changeover switches SW1 and SW2 are A switching unit for selectively switching and connecting any one of the plurality of branch circuits to the sub trunk line connection unit 22 is configured. The change-over switches SW1 and SW2 may be switched manually or may be switched by an electric signal like a relay. Further, the number of series circuits of the resistors R1j and R2j and the capacitors C1j and C2j is not limited to three, and may be two or four or more.

  By the way, the dwelling unit terminal A, the trunk line control terminal B, and the lobby intercom C are provided with a power supply circuit that converts AC power supplied from a commercial power source into DC power. However, depending on the system configuration of the communication system, the communication terminal may be installed in a place where it is difficult to supply power from a commercial power source. In this case, it is preferable to superimpose a DC current for power supply on the communication path and supply the communication terminal with the DC current. Then, in order to prevent the direct current superimposed on the communication path from being consumed by the resistors R1j and R2j in the branch circuit 23 of the system extension F, and to allow the DC to pass through the secondary trunk connection terminal, the system extension shown in FIG. F is an inductor L1 connected between the sub-line connection terminal 22A and the first line (in parallel with the series circuit of the resistor R1 and capacitors C1, C3, etc.), and the sub-line connection terminal 22B and the second line. It further includes a bypass circuit including an inductor L2 connected in parallel (in parallel with a series circuit such as a resistor R2 and capacitors C2, C4). Since these inductors L1 and L2 have a sufficiently high impedance with respect to the carrier frequency (subcarrier frequency) of the communication signal, they hardly affect the communication signal.

(Embodiment 2)
The intercom system for apartment houses of this embodiment has the repeater G comprised so that a communication signal may be relayed, as shown in FIG. However, since the system configuration other than the repeater G is the same as that of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and the illustration and description are omitted as appropriate.

  The repeater G includes a first connection terminal 30, a second connection terminal 31, a modem unit 32, a relay processing unit 33, (first and second) receiving units 34 and 37, (first and second) transmitting unit 35, 36 and so on. One (first) connection terminal 30 is connected to the main trunk line LA on the main line control terminal B side (hereinafter referred to as upstream side), and the other (second) connection terminal 31 is connected to the terminator E side (hereinafter referred to as “end terminal E”). , Called the downstream side)). That is, each of the connection terminals 30 and 31 includes a first terminal and a second terminal to which the two-wire main trunk line LA is connected. The relay processing unit 33 rewrites the source address of the communication signal received from the upstream main line LA with its own address, and transmits (relays) it to the downstream main line LA, and receives from the downstream main line LA. The transmission source address of the communication signal is rewritten from its own address to the address of the trunk line control terminal B or the upstream dwelling unit terminal A and transmitted (relayed) to the upstream trunk line LA. The modem 32 digitally demodulates the communication signal received at the receiving end Rx and outputs the demodulated signal to the relay processing unit 33, and transmits the communication signal obtained by digitally modulating the packet output from the relay processing unit 33 from the transmitting end Tx. The receiving units 34 and 37 are each composed of an amplifier inserted between the connection terminals 30 and 31 and the receiving end Rx of the modulation / demodulation unit 32. The transmission units 35 and 36 are respectively connected to the connection terminals 30 and 31 and the modulation / demodulation unit 32. It consists of an amplifier inserted between the transmitting end Tx. That is, the communication signal flowing in from the upstream connection terminal 30 is received (amplified) by the reception unit 34 connected to the first and second terminals of the connection terminal 30 and relayed by the modem unit 32 and the relay processing unit 33. Then, the signal is transmitted (amplified) by the transmission unit 36 connected to the first and second terminals of the connection terminal 31 and sent out from the connection terminal 31 on the downstream side. Similarly, a communication signal flowing in from the downstream connection terminal 31 is received (amplified) by the receiving unit 37, relayed by the modem unit 32 and the relay processing unit 33, and then transmitted (amplified) by the transmitting unit 35. It is sent from the connection terminal 30 on the upstream side.

  Thus, since the communication signal flowing through the main line LA is relayed by the repeater G, transmission loss and the like are improved. Therefore, the wiring length of the main line LA is increased as compared with the case where the repeater G is not used. Or the number of system expansion devices F that can be connected to the main line LA can be increased. Further, the repeater G in the present embodiment is miniaturized by sharing the modulation / demodulation unit 32 on the upstream side and the downstream side, and can be easily installed in a narrow place.

  Incidentally, as shown in FIG. 6, the repeater G may be connected to the end of each secondary trunk line LBi instead of the terminator E. However, the repeater G only needs to have one connection terminal 30, one reception unit 34, and one transmission unit 35. Also in the configuration shown in FIG. 6, the communication signal flowing through the secondary trunk line LBi is relayed by the repeater G, so that transmission loss and the like are improved. Therefore, compared with the case where the repeater G is not used, The length of the wiring can be extended, or the number of system expansion devices F that can be connected to the main line LA can be increased. In addition, since only one connection terminal 30, one receiving unit 34, and one transmitting unit 35 are provided in the repeater G, the size can be further reduced.

(Embodiment 3)
The intercom system for apartment houses of this embodiment is characterized in that it has an amplifier H that amplifies a communication signal flowing in the communication path, and the other system configuration is the same as that of the first embodiment. The amplifier H is replaced with the repeater G of FIG. Constituent elements common to the first embodiment are denoted by the same reference numerals, and illustration and description thereof are omitted.

  As shown in FIG. 7, the amplifier H includes first and second amplifiers 40 and 41 and first and second power source separation units 42 and 43. The first amplifier 40 amplifies the downstream communication signal (communication signal flowing in the right direction in FIG. 7; the same applies hereinafter), and the second amplifier 41 is the upstream communication signal (the communication signal flowing in the left direction in FIG. 7). The same shall apply hereinafter). The input of the first amplifier 40 is connected to the output terminal of the second amplifier 41, and the output terminal of the first amplifier 40 is connected to the input terminal of the second amplifier 41.

  The first power source separation unit 42 separates the DC component superimposed on the communication path by the communication terminal (the trunk line control terminal B or the dwelling unit terminal A) that transmits the downstream communication signal, and the first amplifier 40 is separated by the DC component. Make it work. Similarly, the second power supply separation unit 43 separates the DC component superimposed on the communication path by the communication terminal (the trunk line control terminal B or the dwelling unit terminal A) that transmits the uplink communication signal, and uses the DC component to generate the second amplifier 41. To work. That is, if the communication terminal (the trunk control terminal B or the dwelling unit terminal A) that is the transmission source of the communication signal transmits the downlink communication signal and simultaneously superimposes the direct current on the communication path, the first power source separation unit 42 is the first The downstream communication signal is amplified by the amplifier H in order to operate the amplifier 40. At this time, since no direct current is superimposed on the output side of the first amplifier 40, the second power source separation unit 43 does not operate the second amplifier 41, and the communication signal flows backward in the upward direction. Never do. On the other hand, if the communication terminal (the trunk control terminal B or the dwelling unit terminal A) that is the transmission source of the communication signal transmits the uplink communication signal and simultaneously superimposes the direct current on the communication path, the second power supply separation unit 43 The upstream communication signal is amplified by the amplifier H in order to operate the second amplifier 41. At this time, since no direct current is superimposed on the output side of the second amplifier 41, the first power source separation unit 42 does not operate the first amplifier 40, and the communication signal flows backward in the downstream direction. Never do.

  As described above, in this embodiment, since the communication signal attenuated while flowing through the communication path is amplified by the amplifier H, the system extension F that can extend the wiring length of the main line LA or can be connected to the main line LA. The number of can be increased. In addition, since the on / off of the first and second amplifiers 40 and 41 is switched depending on the presence or absence of a DC current superimposed on the communication path, the configuration can be simplified as compared with the case where a control signal is used. The amplifier H may be inserted into either the main trunk line LA or the sub trunk line LBi.

(Embodiment 4)
The amplifier H of the third embodiment performs on / off control of the first and second amplifiers 40 and 41 by a direct current superimposed on the communication path (main trunk line LA or sub trunk line LBi). There is a possibility that the first and second amplifiers 40 and 41 may malfunction due to the superimposed noise components.

  Therefore, in the amplifier H of this embodiment, the operation is switched on / off by a control signal transmitted from the communication terminal that is the transmission source of the communication signal. Specifically, as shown in FIG. 8A, a control signal transmitted via a communication path (main trunk line LA or sub trunk line LBi), or a control signal transmitted via a dedicated communication line LS as shown in FIG. 8B. First and second control signal receivers 44 and 45 for receiving signals are provided. However, since the system configuration other than the amplifier H and the basic configuration of the amplifier H are the same as those in the third embodiment, the components common to the third embodiment are denoted by the same reference numerals and the illustration and description thereof are omitted.

  The first and second control signal receivers 44 and 45 turn on (activate) or off (inactivate) the first and second amplifiers 40 and 41 in accordance with a control command included in the received control signal. It is. The control signal includes a code indicating which of the first amplifier 40 and the second amplifier 41 is a control command. That is, even when the control signal is transmitted through the communication path, the second amplifier 41 malfunctions with the control command for the first amplifier 40, or the first command with the control command for the second amplifier 41. There is no possibility that the amplifier 40 malfunctions.

  As described above, in the present embodiment as well as the third embodiment, the communication signal attenuated while flowing through the communication path is amplified by the amplifier H, so that the length of the main line LA is increased or the main line LA is connected. The number of connectable system expansion devices F can be increased. Moreover, since the on / off of the first and second amplifiers 40 and 41 is switched according to the control signal transmitted via the communication path or the dedicated communication line LS, the switching is performed depending on whether or not the DC current is superimposed. There is an advantage that noise resistance is improved. The amplifier H may be inserted into either the main trunk line LA or the sub trunk line LBi.

(Embodiment 5)
As shown in FIG. 9, the amplifier H of the present embodiment includes a first hybrid circuit 46 that distributes upstream communication signals, a second hybrid circuit 47 that distributes downstream communication signals, and a first hybrid circuit 46. And a bi-directional amplifier circuit for amplifying the communication signal distributed by the second hybrid circuit 47.

  The first hybrid circuit 46 includes transformers T2 to T5 and resistors R3 and R4. The terminals (first and second terminals) of the first input / output terminal section 46A are connected in parallel to transformers T2 and T3. Is connected. One terminal (first terminal) of the second input / output terminal portion 46B is connected to one end (first end) of the transformer T4 and the resistor R3, and the other terminal (second terminal) of the second input / output terminal portion 46B. Terminal) is connected to one end (first end) of the transformer T5 and the resistor R4. One terminal (first terminal) of the third input / output terminal portion 46C is connected to the other end (second end) of the transformer T4 and the resistor R3, and the other terminal (first terminal) of the third input / output terminal portion 46C. 2 terminal) is connected to the other end (second end) of the transformer T5 and the resistor R4.

  Similarly, the second hybrid circuit 47 includes transformers T6 to T9 and resistors R5 and R6. The terminals (first and second terminals) of the first input / output terminal portion 47A are connected to the transformers T8, T8, Connected with T9. One terminal (first terminal) of the second input / output terminal portion 47B is connected to one end (first end) of the transformer T6 and the resistor R5, and the other terminal (second terminal) of the second input / output terminal portion 47B. ) Is connected to one end (first end) of the transformer T7 and the resistor R6. One terminal (first terminal) of the third input / output terminal section 47C is connected to the other end (second end) of the transformer T7 and the resistor R6, and the other terminal (second terminal) of the third input / output terminal section 47C. Terminal) is connected to the other end (second end) of the transformer T6 and the resistor R5.

  The bidirectional amplifier circuit includes a first amplifier 48 inserted between the second input / output terminal portions 46B and 47B of the first and second hybrid circuits 46 and 47, the first and second hybrid circuits 46, The second amplifier 49 is inserted between 47 third input / output terminal portions 46C and 47C.

  Here, the resistors R3 to R6 are resistors for determining the output impedance of the second amplifier 49, and absorb unbalanced power. The transformers T4 to T7 serve to distribute the signal into two or to mix the two signals into one. Transformers T2 and T3 are for impedance matching of the first input / output terminal portion 46A of the first hybrid circuit 46. Similarly, the transformers T8 and T9 are for impedance matching of the first input / output terminal portion 47A of the second hybrid circuit 47.

  Thus, the communication signal input from the first input / output terminal section 46A of the first hybrid circuit 46 is equally distributed to the two signal components, and the second input / output terminal section 46B and the third input / output section are distributed. Output to the terminal section 46C.

  The signal component output to the third input / output terminal portion 46C is amplified by the amplifier 49 connected in the forward direction and input to the third input / output terminal portion 47C of the second hybrid circuit 47.

  On the other hand, since the amplifier 48 is connected in the reverse direction to the second input / output terminal portion 46B, the signal component output from the second input / output terminal portion 46B is the second component of the second hybrid circuit 47. Does not flow to the input / output terminal portion 47B.

  The communication signal input to the third input / output terminal portion 47C of the second hybrid circuit 47 is transmitted again from the first input / output terminal portion 47A of the second hybrid circuit 47 via the second hybrid circuit 47. Is output.

  At this time, since there is a reverse coupling attenuation amount between the third input / output terminal portion 47C and the second input / output terminal portion 47B of the second hybrid circuit 47, the third input / output terminal portion 47C. The amount of the signal component input to is leaked to the second input / output terminal portion 47B is extremely small. However, in order to prevent signal oscillation, when the reverse coupling attenuation amount per hybrid circuit is −A [dB], the total gain of the amplifier 49 and the amplifier 48 must not exceed 2 A [dB].

  Similarly, the communication signal input from the first input / output terminal section 47A of the second hybrid circuit 47 is distributed by the second hybrid circuit 47, and the signal component output from the second input / output terminal section 47B is After being amplified by the amplifier 48, it is output from the first input / output terminal portion 46A of the first hybrid circuit 46.

  As described above, in the present embodiment as well as the third and fourth embodiments, the communication signal attenuated while flowing through the communication path is amplified by the amplifier H, so that the wiring length of the main line LA can be extended, The number of system expansion devices F that can be connected to the main line LA can be increased. In addition, in this embodiment, there is no need to perform on / off control of the amplifiers 40 and 41 included in the amplifier H as in the third and fourth embodiments, so that there is an advantage that the system configuration can be simplified and malfunctions can be suppressed. is there.

  By the way, the system expansion device F includes a housing 24 that houses a pair of main trunk line connecting portions 20 and 21, a sub trunk line connecting portion 22, and a branch circuit 23. The housing 24 is made of, for example, a box-shaped synthetic resin molded body. And the repeater G and the amplifier H mentioned above may be accommodated in the housing 24 of the system expansion device F (refer FIG. 10).

  While the invention has been described in terms of several preferred embodiments, various modifications and variations can be made by those skilled in the art without departing from the true spirit and scope of the invention, ie, the claims.

A Unit B B Main line control terminal C Lobby intercom (common use terminal)
D branching device F system expansion device
20,21 Main line connection
22 Secondary trunk connection
23 Branch circuit
LA trunk line (communication channel)
LB1, LB2, ... Secondary trunk (communication path)

Claims (2)

Main line control that relays communication signals via a communication path between the common unit terminal and the dwelling unit terminal, and the common unit terminal installed at the common entrance of the apartment, the dwelling unit terminal installed in each dwelling unit of the apartment An intercom system for collective housing comprising a terminal,
The communication path is
A main trunk line connecting the shared terminal and the trunk line control terminal;
Between the trunk line control terminal and the dwelling unit terminal, a plurality of secondary trunk lines branch connected to the main trunk line via a plurality of system adders,
One to a plurality of the dwelling unit terminals have a dwelling unit line branched and connected to the sub trunk line via a branching unit,
Each of the plurality of system expansion units includes a pair of main line connection units inserted in series along the main line, a sub-line connection unit to which a sub-system line to the system expansion unit is connected, and the pair of A branch circuit for branching the signal flowing between the main trunk connection parts to the sub trunk connection part,
In the branch circuit, the amount of attenuation when the communication signal input from one of the main line connection units is output from the other main line connection unit is the attenuation amount of the communication signal input from a pair of main line connection units. An intercom system for collective housing, characterized in that it is smaller than the amount of attenuation when it is output from the sub trunk line connection. Main line control that relays communication signals via a communication path between the common unit terminal and the dwelling unit terminal, and the common unit terminal installed at the common entrance of the apartment, the dwelling unit terminal installed in each dwelling unit of the apartment And the communication path is connected between the main line connecting the shared unit terminal and the main line control terminal, and between the main line control terminal and the dwelling unit terminal via a plurality of system adders. A system adder used in an intercom system for a collective housing having a plurality of sub-main lines branch-connected to a main line and one or a plurality of dwelling unit terminals connected to the sub-main line via a branching device. Because
A pair of main line connection parts inserted in series along the main line, a sub main line connection part to which a sub main line to the system adder is connected, and a signal flowing between the pair of main line connection parts A branch circuit for branching to the secondary trunk connection part,
In the branch circuit, the amount of attenuation when the communication signal input from one of the main line connection units is output from the other main line connection unit is the attenuation amount of the communication signal input from a pair of main line connection units. A system expansion device characterized by being smaller than the attenuation when output from the sub trunk line connection.

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