JP2009097754A - Communication control device for air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication control device for an air conditioner capable of easily and effectively reducing a phenomenon of erroneous reception by another receiving element caused by potential difference generated on a communication circuit when one of transmitting elements of an outdoor unit and an indoor unit is switched off, with an inexpensive constitution. <P>SOLUTION: In this communication control device 1 of the air conditioner comprising the outdoor unit 2 and the indoor unit 3, performing signal transmission between the outdoor unit 2 and the indoor unit 3 by one AC power wire as a line in common use, and comprising transmitting/receiving circuits 21, 31 respectively connected between communication terminals of a communication line S and the line N in common use in series, the outdoor unit 2 comprises a switching mens 24 connected between the communication terminals of the communication line S and the line N in common use in parallel, the indoor unit 3 comprises a DC power source 34 for communication connected with the transmitting/receiving circuit 31 in series, and a switching means 35 connected between the communication terminals of the communication line S and the line N in common use in parallel, and the switching means 24, 35 are provided with switching circuits 24a, 35a operated on the basis of signals obtained by reversing output signals of the transmitting elements 21a, 31a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication control device for an air conditioner that performs data transmission between an outdoor unit and an indoor unit in a split type air conditioner.

  In a so-called split type (indoor / outdoor separation type) air conditioner in which an outdoor unit is installed outside the building and an indoor unit is installed inside the building, each operation is controlled between the outdoor unit and the indoor unit. Signal transmission is performed. In addition to the method of transmitting signals by connecting the outdoor unit and the indoor unit through a total of four lines of two AC power supply lines and two communication lines, the signal transmission method includes, for example, the following: A method disclosed in Patent Document 1 has also been proposed.

  That is, in Patent Document 1, an outdoor unit and an indoor unit are connected by two AC power supply lines (L, N) and one communication line (S), and are performed between the outdoor unit and the indoor unit. In the signal transmission, one of the AC power supply lines (in this example, the power supply line N) is used as a shared line. FIG. 4 is an explanatory diagram for explaining this configuration. In this explanatory drawing, the structure of the communication circuit in the air conditioner 100 is simply shown.

  The air conditioner 100 includes an outdoor unit 101 and an indoor unit 102, and the outdoor unit 101 and the indoor unit 102 are connected to each other with a crossover portion 103 interposed therebetween. The outdoor unit 101 is connected to an AC power source 104 and supplies power to the indoor unit 102 via two AC power lines L and N. The outdoor unit 101 and the indoor unit 102 each include a signal line for transmitting a signal between each other. The terminal of these signal lines is connected to the AC power line N and the communication line S among the AC power lines to constitute a communication circuit 105 that exchanges signals.

  The outdoor unit 101 and the indoor unit 102 include transmission / reception circuits 106 and 107, respectively. These transmission / reception circuits 106 and 107 are composed of, for example, transmission elements 106a and 107a made of photocouplers and reception elements 106b and 107b made of photocouplers. When transmitting, signals are received via the transmission elements 106a and 107a. This is done through the receiving circuits 106b and 107b. On the communication circuit 105, resistors 108 and 110 for limiting the current flowing through the communication circuit 105 and diodes 109 for preventing a reverse voltage from being applied to the respective sides of the outdoor unit 101 and the indoor unit 102. 111 is provided. Further, a DC power source 112 for communication (represented as “DC power source” in FIG. 4) is provided on the communication circuit 105 on the indoor unit 102 side.

  In this configuration, the signal “0” or “1” is transmitted and received depending on whether or not a current is passed through the communication circuit 105. For example, when a signal is transmitted from the indoor unit 102 to the outdoor unit 101, the transmission / reception circuit 106 on the outdoor unit 101 side is turned on, and the transmission element 107a of the indoor unit 102 turns on the current flowing on the communication circuit 105. Turn off. The ON / OFF signal is received by the receiving element 106b on the outdoor unit 101 side.

  However, when this configuration is adopted, an induced voltage between the two lines due to the line-to-line capacitance between the AC power supply line N and the communication line S used as a shared line is generated. When a signal is transmitted to the outdoor unit, a current flows through the communication circuit on the indoor unit side even though the transmission element of the outdoor unit is not turned on, and the receiving element on this communication circuit may receive the signal incorrectly. It was.

Therefore, in the following Patent Document 2, the signal line (corresponding to the communication line (S)) of the outdoor unit and one commercial power line (corresponding to the AC power supply line N) are parallel to the transmission / reception circuit unit of the indoor unit. Discloses a configuration in which a circuit in which a switch unit and a resistor for limiting current are connected in series is provided. According to this configuration, even if a voltage is generated between the signal line and the commercial power line due to the capacitance between the wires, no current flows through the transmission / reception circuit unit of the indoor unit, and the reception detection unit of the indoor unit detects falsely. It is said that it can be prevented.
Japanese Patent Laid-Open No. 2-146456 Japanese Patent No. 3828035

  However, in the configuration disclosed in Patent Document 2 described above, a DC power supply for communication is provided on the outdoor unit side, and the indoor unit exchanges signals on the communication circuit based on this DC power supply. Therefore, in the case of a so-called multi-configuration in which a plurality of indoor units are connected to one outdoor unit, the capacity of the DC power source mounted on the outdoor unit is increased according to the number of connected indoor units. There is a need to.

  In addition, when the outdoor unit and the indoor unit are electrically connected, it is necessary to appropriately connect the two AC power supply lines L and N and the communication line S. For example, either the indoor unit or the outdoor unit is connected. On the other hand, when the AC power supply line L that is not the shared line N is connected to the communication line S, each element, circuit, etc. constituting the switch path for the induced voltage countermeasure is destroyed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to receive the other receiving element based on the potential difference generated on the communication circuit when one transmitting element of the outdoor unit or the indoor unit is turned off. Is to provide a communication control device for an air conditioner that can more effectively reduce the phenomenon of erroneous signal reception with a simple and inexpensive configuration.

  A feature according to an embodiment of the present invention is that an outdoor unit, an outdoor unit, and an indoor unit connected by two AC power supply lines and a single communication line are provided, and between the outdoor unit and the indoor unit. Signal transmission for operation control is performed using one AC power line as a shared line, and the outdoor unit and the indoor unit each include a transmission / reception circuit connected in series between the communication terminals of the communication line and the shared line. In the communication control device for an air conditioner, the outdoor unit includes switching means connected in parallel between the communication terminals of the communication line and the shared line, and the indoor unit includes a communication DC power source connected in series to the transmission / reception circuit, Switching means connected in parallel between the communication terminals of the communication line and the shared line, and the switching means provided in the outdoor unit and the indoor unit is a transmission element constituting a transmission / reception circuit provided in the outdoor unit and the indoor unit The output signal of Comprising a switching circuit that operates based on No..

  According to the present invention, the phenomenon in which a signal is erroneously received by the other receiving element based on a potential difference generated on the communication circuit when one transmitting element of the outdoor unit or the indoor unit is turned off can be achieved with a simple and inexpensive configuration. A communication control device for an air conditioner that can be effectively reduced can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is an explanatory diagram simply showing the configuration of a communication control device 1 in an air conditioner. As shown in FIG. 1, the air conditioner including the communication control device 1 according to the first embodiment of the present invention includes an outdoor unit 2 and an indoor unit 3, and the outdoor unit 2 and the indoor unit 3 are They are connected to each other with the crossover part 4 interposed therebetween.

  The outdoor unit 2 is connected to an AC power source 5 and supplies power to the indoor unit 3 via two AC power lines L and N. Moreover, the outdoor unit 2 and the indoor unit 3 are each provided with the signal wire | line for transmitting a signal between each other. These signal lines are connected at their terminals by an AC power line N (hereinafter referred to as “shared line N” as appropriate) of the AC power lines and a communication line S, so that the outdoor unit 2 and the indoor unit 3 A communication circuit 6 for exchanging signals between the two is configured.

  The outdoor unit 2 and the indoor unit 3 include transmission / reception circuits 21 and 31, respectively. These transmission / reception circuits 21 and 31 are composed of transmission elements 21a and 31a and reception elements 21b and 31b. When transmitting signals, the reception elements 21b and 31b are connected via the transmission elements 21a and 31a. Done through.

  That is, when both the transmitting elements 21a and 31a are turned on, a current flows through the communication circuit 6. On the other hand, the receiving elements 21b and 31b are turned on when a current flows through the communication circuit 6 to detect this. Therefore, the presence / absence of current flowing in the communication circuit 6 is controlled by controlling on / off of the transmitting elements 21a, 31a, and this is detected by the receiving elements 21b, 31b.

  On the communication circuit 6, resistors 22 and 32 for limiting the current flowing through the communication circuit 6 on the respective sides of the outdoor unit 2 and the indoor unit 3 and a diode 23 for preventing a reverse voltage from being applied. 33 is provided. On / off of the transmitting elements 21a and 31a is controlled by an outdoor control circuit and an indoor control circuit (not shown), respectively, and on and off signals received by the receiving elements 21b and 31b are respectively input to the outdoor control circuit and the indoor control circuit. The

  On the communication circuit 6 and on the indoor unit 3 side, a communication DC power supply 34 for communication is further provided. In this way, the indoor unit 3 is provided with a communication DC power supply (represented as “DC power supply” in FIGS. 1 to 3) 34, so that even if a multi-configuration is adopted, a plurality of indoor units 3 are provided. Even when connected to the outdoor unit 2, it is possible to distribute the load of the entire communication circuit with a communication DC power source provided in each indoor unit. On the other hand, when providing a communication DC power supply on the outdoor unit side, it is necessary to increase the power supply capacity as the number of indoor unit connections increases.

  Further, the outdoor unit 2 and the indoor unit 3 have switching means 24 and 35 connected in parallel between the communication terminals of the shared line N and the communication line S, respectively. In these switching means 24 and 35, switching circuits 24a and 35a that operate based on signals obtained by inverting the output signals of the transmitting elements 21a and 31a are provided. For example, the switching circuits 24a and 35a are turned off when the transmission elements 21a and 31a are turned on, and turned on when the transmission elements 21a and 31a are turned off. In the first embodiment of the present invention, the switching circuits 24a and 35a use photocouplers. Also, diodes 24b and 35b are provided to prevent application of reverse voltage.

  Further, in the switching means 24 in the outdoor unit 2, a DC power supply (represented as “DC power supply” in FIGS. 1 to 3) 24c is further provided. The DC power supply 24c has a positive side connected to the switching circuit 24a.

  Next, signal transmission performed between the outdoor unit 2 and the indoor unit 3 via the communication circuit 6 will be described.

  First, a signal is transmitted from the indoor unit 3 toward the outdoor unit 2. In the outdoor unit 2, the transmission element 21 a in the transmission / reception circuit 21 is turned on in order to receive a signal from the indoor unit 3. Since the transmission element 21a is connected in series on the communication circuit 6, the communication circuit 6 does not conduct when the transmission element 21a is turned off, and the reception element 21b does not receive a signal from the indoor unit 3. It is.

  In the transmission / reception circuit 31 of the indoor unit 3 on the transmission side, the current supplied from the communication DC power supply 34 via the communication circuit 6 is made conductive or non-conductive by turning the transmission element 31 ON and OFF. A signal is transmitted to the outdoor unit 2. The receiving element 21b of the outdoor unit 2 receives a signal transmitted from the transmitting element 31a of the indoor unit 3, transmits it to the control means of the outdoor unit 2 (not shown in FIG. 1), and performs an operation based on the signal.

  Generally, when the transmission element on the transmission side is turned from ON to OFF, an induced voltage due to the line capacitance between the shared line N and the communication line S is generated. This induced voltage causes a potential difference between the communication terminals of the shared line N and the communication line S, and the receiving element 21b of the outdoor unit 2 is induced by the induced voltage even though the transmitting element 31a of the indoor unit 3 is turned off. An erroneous reception occurs as if the signal from the transmitting element 31a was received.

  Therefore, in the configuration according to the embodiment of the present invention, in order to prevent this erroneous reception, when the transmission element 31a shifts from ON to OFF, the switching circuit 35a of the switching means 35 is shifted from OFF to ON. As a result, the current flowing on the communication circuit 6 is short-circuited in the communication DC power supply 34, the transmission / reception circuit 31, and the switching means 35, and the occurrence of a potential difference between the shared line N and the communication line S can be eliminated (substantially). Generation of an induced voltage can be prevented. Therefore, it is possible to prevent the reception element 21b on the outdoor unit 2 side from receiving a signal erroneously. Here, the reason why the voltage is set to approximately 0 V is that there is a slight impedance in the switching circuit 35a.

  Next, a signal is transmitted from the outdoor unit 2 toward the indoor unit 3. Also in this case, as described above, first, the transmitting element 31a of the indoor unit 3 on the receiving side is turned on. Then, a signal is transmitted from the outdoor unit 2 to the indoor unit 3 when the transmission element 21a of the outdoor unit 2 is turned on and off.

  The induced voltage between the shared line N and the communication line S is generated when the transmission element 21a shifts from ON to OFF, and thereby the reception element 31b of the indoor unit 3 performs erroneous reception.

  Therefore, when transmitting from the outdoor unit 2 to the indoor unit 3, the switching circuit 24a in the switching means 24 is switched from OFF to ON as the transmission element 21a shifts from ON to OFF, and from the DC power source 24c. A voltage having the same potential as that of the communication DC power supply 34 on the indoor unit 3 side is applied. Thereby, the potential between the terminals of the shared line N and the communication line S is made substantially the same as the potential of the communication DC power supply 34, and the both-ends potential of the transmission / reception circuit 21 of the outdoor unit 2 is fixed to almost zero. As a result, no current flows on the indoor unit 3 side of the communication circuit 6, and it is possible to prevent the receiving element 31b from receiving a signal erroneously.

  Thus, the phenomenon that the other receiving element erroneously receives a signal based on the potential difference generated on the communication circuit by turning off one transmitting element of the outdoor unit or the indoor unit, for example, using a photocoupler, etc. It is possible to provide a communication control device for an air conditioner that can be effectively reduced by using switching means having a simple and inexpensive configuration.

  Moreover, since the DC power supply is provided on the communication circuit of the indoor unit, there is no need to change the capacity of the DC power supply because the DC power supply is provided for each indoor unit even if the air conditioner has a multi-configuration. The communication circuit configuration can be shared between single and multiple indoor units.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the following embodiments, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description of the same components is omitted because it is duplicated.

  In the second embodiment, a configuration in which a current limiting circuit is newly incorporated in the switching means in the first embodiment described above is adopted.

  That is, as shown in FIG. 2, the switching means 40 of the outdoor unit 2 includes a switching circuit 24a, a diode 24b, a DC power supply 24c, and a current limiting circuit 41. The switching means 50 of the indoor unit 3 includes a switching circuit 35a, a diode 35b, and a current limiting circuit 51.

  When the outdoor unit 2 and the indoor unit 3 are electrically connected, the two AC power lines L and N and the communication line S need to be appropriately connected. For example, the AC power line that is not the shared line N When L is connected to the communication line S, each element, circuit, etc. provided on the communication circuit 6 is destroyed. That is, since the communication circuit 6 is composed of a constant voltage DC circuit, the communication circuit 6 is destroyed when an AC power supply is applied due to incorrect wiring. In particular, in the present invention, the switching means is provided to eliminate erroneous reception of the receiving element due to the induced voltage generated between the shared line N and the communication line S. However, the switching means is also destroyed by the erroneous wiring. . Therefore, in order to prevent the switching means from being destroyed, current limiting circuits 41 and 51 are provided in the switching means 40 and 50, respectively.

  As shown in FIG. 2, the current limiting circuit 41 includes a first transistor 41a, a second transistor 41b, a bias power supply 41c, a current limiting resistor 41d provided between the DC power supply 24c and the diode 24b, and a switching circuit. The current limiting resistor 41e is provided between the circuit 24a and the second transistor 41b. The configuration of the current limiting circuit 51 provided in the switching means 50 of the indoor unit 3 is also the same.

  The first transistors 41a and 51a employ transistors having characteristics of higher withstand voltage and higher allowable collector loss than the second transistors 41b and 51b. Normally, the second transistors 41b and 51b are in an off state, a sufficient base current flows through the first transistors 41a and 51a, the on-voltage between the collector and the emitter is saturated, and the power loss is sufficiently small.

  However, if the current limit value of the switching means 40, 50 path is exceeded due to incorrect wiring, that is, the value of the voltage across the current limit resistor 41d (51d) when ON is greater than the VBE of the second transistor 41b (51b). The second transistor 41b (51b) is turned on, and the first transistor 41a (51a) is de-saturated due to the deprivation of the base current, thereby suppressing overcurrent due to erroneous wiring. In this state, the path current value of the switching means 40 and 50 is a resistance value obtained by dividing VBE of the second transistor 41b (51b) by the current limiting resistor 41d. At this time, the first transistor 41a (51a) is in an unsaturated state, and a high voltage is applied between the collector and the emitter to almost bear the power loss of the circuit. Therefore, an element having a high breakdown voltage and a high allowable collector loss is used. Required.

  In the current limiting circuits 41 and 51 in the second embodiment, all of the first transistors 41a and 51a and the second transistors 41b and 51b are NPN type. The bias power supply 41c is a bias power supply for the first transistor 41a and the second transistor 41b.

  Thus, the phenomenon that the other receiving element erroneously receives a signal based on the potential difference generated on the communication circuit by turning off one transmitting element of the outdoor unit or the indoor unit, for example, using a photocoupler, etc. It is possible to provide a communication control device for an air conditioner that can be effectively reduced by using switching means having a simple and inexpensive configuration.

  Moreover, since the DC power supply is provided on the communication circuit of the indoor unit, there is no need to change the capacity of the DC power supply because the DC power supply is provided for each indoor unit even if the air conditioner has a multi-configuration. The communication circuit configuration can be shared between single and multiple indoor units.

  Furthermore, by providing a current limiting circuit in the switching means due to erroneous wiring, it is possible to prevent the switching means from being destroyed.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In the following embodiments, the same components as those described in the first or second embodiment are denoted by the same reference numerals, and the description of the same components is omitted because it is duplicated. .

  In the third embodiment, the bias power sources 41c and 51c provided in the current limiting circuits 41 and 51 in the second embodiment described above are shared with the DC power sources 24c and 34 provided in advance. There are features.

  That is, as shown in FIG. 3, the switching means 60 of the outdoor unit 2 includes a switching circuit 24a, a diode 24b, a DC power supply 24c, and a current limiting circuit 61. The switching unit 70 of the indoor unit 3 includes a switching circuit 35a, a diode 35b, and a current limiting circuit 71.

  As shown in FIG. 3, the current limiting circuit 61 includes a first transistor 61a, a second transistor 61b, a current limiting resistor 61d provided between the DC power supply 24c and the diode 24b, a switching circuit 24a, A current limiting resistor 61e provided between the second transistor 61b and the second transistor 61b. The configuration of the current limiting circuit 71 provided in the switching means 70 of the indoor unit 3 is also the same.

  The first transistor 61a and the second transistor 61b incorporated in the current limiting circuit 61 in the third embodiment are both PNP type transistors. On the other hand, in the current limiting circuit 71 on the indoor unit 3 side, both the first transistor 71a and the second transistor 71b are NPN type.

  Thus, the phenomenon that the other receiving element erroneously receives a signal based on the potential difference generated on the communication circuit by turning off one transmitting element of the outdoor unit or the indoor unit, for example, using a photocoupler, etc. It is possible to provide a communication control device for an air conditioner that can be effectively reduced by using switching means having a simple and inexpensive configuration.

  Moreover, since the DC power supply is provided on the communication circuit of the indoor unit, there is no need to change the capacity of the DC power supply because the DC power supply is provided for each indoor unit even if the air conditioner has a multi-configuration. The communication circuit configuration can be shared between single and multiple indoor units.

  Furthermore, it is not necessary to newly provide a bias power supply by sharing the bias power supplies 41c and 51c provided in the current limiting circuits 41 and 51 in the second embodiment with the DC power supplies 24c and 34, respectively. And the circuit configuration can be simplified.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine the component covering different embodiment suitably.

It is explanatory drawing which shows simply the structure of the communication control apparatus in the air conditioner which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows simply the structure of the communication control apparatus in the air conditioner which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows simply the structure of the communication control apparatus in the air conditioner which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows simply the structure of the communication control apparatus in the conventional air conditioner.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Communication control device, 2 ... Outdoor unit, 3 ... Indoor unit, 4 ... Transition part, 5 ... AC power supply, 6 ... Communication circuit, 21 ... Transmission / reception circuit of the outdoor unit side, 21a ... Transmission element, 21b ... Reception element, 22 ... Current limiting resistor, 23 ... Diode, 24 ... Switching means, 24a ... Switching circuit, 24b ... Diode, 24c ... DC power supply, 31 ... Transmitting / receiving circuit on the indoor unit side, 31a ... Transmitting element, 31b ... Receiving element, 32 ... Current limiting resistor 33 ... Diode 34 ... DC power source 35 ... Switching circuit 35a ... Switching circuit 35b ... Diode

Claims (2)

A signal for operation control performed between the outdoor unit and the indoor unit, comprising an outdoor unit, an indoor unit connected to the outdoor unit with two AC power supply lines and one communication line The air conditioner includes a transmission / reception circuit that is connected in series between the communication line and the communication terminal of the shared line, while using one of the AC power supply lines as a shared line. In the communication control device of
The outdoor unit includes switching means connected in parallel between communication terminals of the communication line and the shared line,
The indoor unit includes a communication DC power supply connected in series to the transmission / reception circuit, and switching means connected in parallel between the communication terminals of the communication line and the shared line,
The switching means provided in the outdoor unit and the indoor unit includes a switching circuit that operates based on a signal obtained by inverting an output signal of a transmission element that constitutes the transmission / reception circuit provided in the outdoor unit and the indoor unit. A communication control device for an air conditioner.   The air conditioner communication control apparatus according to claim 1, wherein the switching circuit provided in the outdoor unit has the switching circuit connected in series with a DC power source.

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