JP2008253118A - Power distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power distribution system capable of supplying DC power to electric equipment of different actuating voltage with high utilizing efficiency of an electric power. <P>SOLUTION: A DC power is supplied to a DC equipment 20 from a DC power supply 10 through a power supplying line Lp. The power supplying line Lp has two wires, and the DC power supply 10 selects a voltage level applied across the power supplying line Lp in three stages, to apply each of the voltages to the line in circulation. The DC equipment 20 has a voltage detecting means 21 for detecting whether the voltage applied to the power supplying line Lp is suitable to the actuating voltage level of its own. The DC power supplied from the power supplying line Lp in an adjusted period of time when the voltage suitable to its own is applied is stored in a power supplying means 22, and supplied to an internal circuit 23 at a constant voltage level. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power distribution system that supplies DC power to a power supply line from a DC power source and drives a DC device connected to the power supply line with DC power.

  Conventionally, it is possible to distribute DC power indoors by providing only one AC / DC converter indoors instead of incorporating the AC / DC converter into an electrical device or connecting it to the electrical device as a power adapter. It has been proposed (see, for example, Patent Document 1).

By adopting such a power distribution system, it is no longer necessary to attach an AC / DC converter, which is conventionally required for each electric device, regardless of whether it is built-in or externally attached. It will be easier and will lead to improvements in efficiency and power factor.
JP 2004-112920 A

  However, the drive voltage is different between the information system or communication system electrical equipment represented by the microcomputer and the power system or drive system electrical equipment represented by the relay or motor, and the former is 3V or 5V. Is often used, and in the latter case, 12V or 24V is often used.

  In order to cope with such a difference in driving voltage, the voltage supplied from the AC / DC converter is set to the highest voltage among the driving voltages corresponding to the electrical equipment to be connected, and the electrical equipment may step down as necessary. It is conceivable that there is a problem that an electric device having the lowest drive voltage has a large difference between the supply voltage and the drive voltage, and thus a loss at the time of step-down increases, leading to a reduction in power utilization efficiency.

  The present invention has been made in view of the above-described reasons, and an object of the present invention is to provide a power distribution system that enables supply of DC power to electric devices having different driving voltages and high power use efficiency. .

  The invention of claim 1 has a DC power supply for supplying DC power and a DC device driven by DC power supplied from the DC power supply through a power supply line, and the DC power supply uses a plurality of types of DC voltages as power. The DC device is supplied to the supply line and operates by receiving DC power of a voltage corresponding to itself from the plurality of types of DC voltages. The DC device means an electric device that operates by receiving DC power.

  According to a second aspect of the present invention, in the first aspect of the invention, the power supply line is composed of two electric wires, and the DC power source is capable of varying the voltage applied between the power supply lines in a plurality of stages. The device detects whether the voltage applied between the lines corresponds to itself or not, and the voltage detection means detects that the voltage corresponding to itself is applied between the lines. Power supply means for receiving DC power from the power supply line during the adaptation period.

  According to a third aspect of the present invention, in the first aspect of the invention, the power supply line is composed of three or more electric wires, and the DC power supply has two or more types of voltages applied between two electric wires with different power supply lines. It is characterized by being set to.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the DC power source is different between a reference line and each of the other electric wires, with one electric wire constituting the power supply line as a reference line for a reference potential. A voltage is applied, and the DC device receives DC power from a reference line and another electric wire.

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the DC power source can vary the voltage applied between the electric wire serving as the reference line and at least one other electric wire in the power supply line in a plurality of stages. The DC detecting device for receiving DC power from the electric wire whose voltage with respect to the reference line is variable among the DC devices is a voltage detecting means for judging whether or not the voltage applied between the wires corresponds to itself. And a power supply means for receiving DC power from the power supply line during an adaptation period in which it is detected by the voltage detection means that a voltage corresponding to itself is applied between the lines.

  According to a sixth aspect of the present invention, in the second or fifth aspect of the present invention, the power supply means stores DC power during the adaptation period and uses it for an internal power supply.

  In the invention of claim 7, in the invention of claim 2, claim 5 or claim 6, the DC power supply changes the voltage applied between the power supply lines whose voltage is variable at regular intervals. Voltage selection means is provided.

  The invention according to claim 8 is the invention according to claim 7, wherein the voltage selection means changes the voltage applied between the lines of the power supply line whose voltage is variable periodically and periodically. And

  According to a ninth aspect of the invention, in the second or sixth aspect of the invention, the DC power supply and the DC device can communicate with each other, and the DC device notifies the DC power supply of a voltage corresponding to the DC power supply. Comprises voltage selection means for selecting a voltage corresponding to the type of voltage notified from all the DC devices connected to the power supply line and applying the voltage between the lines of the power supply line.

  In the invention of claim 10, in the invention of claim 2, claim 5 or claim 6, the DC power supply and the DC device are communicable, and the DC power supply always supplies a voltage required for communication to the power. It is provided with voltage selection means for applying between the lines of the supply line and applying the voltage higher than the time required for the operation of the DC device for a predetermined time when the operation start of the DC device is notified by communication. And

  According to an eleventh aspect of the invention, in the invention of the second, fifth, or sixth aspect, the DC power supply and the DC device are communicable, and the DC power supply always supplies a voltage required for communication to the power. Voltage selection that is applied between the lines of the supply line, and when a DC device operation start is notified by communication, a voltage higher than the normal voltage required for the operation of the DC device is applied intermittently during the operation period of the DC device. Means are provided.

  In the invention of claim 12, in the invention of claim 2, claim 5 or claim 6, the DC power supply and the DC device can communicate, and information between the DC power supply and the DC device is In the power supply line, transmission is performed using a voltage change between two specific lines supplying DC power to a DC device.

  According to the configuration of the first aspect of the invention, a plurality of types of DC voltages are supplied from the DC power source to the power supply line, and the DC device operates by receiving DC power of a voltage corresponding to itself. The difference between the drive voltage and the supply voltage from the power supply line can be reduced or made zero. As a result, even when the supply voltage from the power supply line is stepped down to the drive voltage of the DC device, the difference between the supply voltage and the drive voltage is small, so the power loss due to the step-down is reduced, and the power utilization efficiency Becomes higher. In addition, since a plurality of types of DC voltages are supplied from the power supply line, it is possible to reduce power loss due to step-down in any DC device having a different driving voltage.

  According to the configuration of the invention of claim 2, when the voltage between the lines of the two electric wires is variable in a plurality of stages, and the DC device detects the voltage between the lines and is a voltage corresponding to itself, the DC power Therefore, it is possible to supply a plurality of types of voltages to the DC device by using only two electric wires. That is, while supplying a plurality of types of voltages, there are few wiring materials, wiring is easy, and wiring can be performed at low cost.

  According to the configuration of the invention of claim 3, since a plurality of types of voltages are supplied using three or more electric wires, the electric power supply line is pre-wired, and the electric wires that can obtain a required voltage in each DC device are provided. A drive voltage required for each DC device can be obtained simply by selecting.

  According to the configuration of the fourth aspect of the present invention, since one electric wire in the power supply line is used as a reference line for the reference potential and the voltage between the other electric wires is used in the DC device, the DC power is supplied. By setting the voltage applied to the wires other than the reference line to the same polarity with respect to the reference potential, even if a short circuit occurs in any DC device, abnormal overvoltage is prevented from being applied to other DC devices. Is done. In addition, if voltages having different polarities are applied to the other electric wires with respect to the reference potential, a voltage larger than the potential difference between the reference line and each electric wire can be applied to the DC device.

  According to the configuration of the fifth aspect of the invention, the voltage between at least one electric wire and the reference line is variable in a plurality of stages, and in the DC device, the voltage between the lines is detected by detecting the voltage between the lines. Since DC power is sometimes received, a plurality of types of voltages can be supplied to the DC equipment by using only two electric wires.

  For example, in information system and communication system integrated circuits such as microcomputers, driving voltages of 3.3V and 5V are mainstream, so two levels of voltage are used so that both driving voltages can be supported. If the voltage applied to the power supply line is selected and the voltage suitable for the DC device is selected, it becomes possible to deal with DC devices having different driving voltages with only two electric wires. In addition, if the voltage for driving the relay and motor is applied to the remaining wires, voltage fluctuations that occur during operation of the relay and motor will affect the operation of information and communication circuits such as microcomputers. And the reliability of the operation is increased. Furthermore, since the voltage stability required for relays and motors is lower than that for information and communication integrated circuits, the voltage supplied to information and communication integrated circuits is stabilized by the internal circuit of the DC device. Power can be supplied with a margin of 1 to 2 V (for example, 5 V and 7 V) so that the voltage supplied to the relay and motor can be used as it is. Is possible.

  According to the configuration of the invention of claim 6, since the DC power received from the power supply line during the adaptation period is stored and used for the internal power source, the voltage applied to the power supply line changes with time However, power can be stably supplied to the internal circuit of the DC device. Further, if the electric power to be stored is increased, the function of the DC device can be maintained even if the electric power supplied from the electric power supply line is temporarily interrupted.

  According to the configuration of the seventh aspect of the present invention, the voltage applied between the lines of the power supply line where the voltage is variable is changed at regular intervals. Can receive power.

  According to the configuration of the eighth aspect of the invention, the voltage applied between the power supply lines whose voltage is variable is changed periodically and cyclically. DC power can be received evenly. In particular, when the DC power received during the adaptation period is stored and used as in the configuration of claim 6, the time interval between storage and discharge in each DC device is substantially constant. Becomes easier.

  According to the configuration of the ninth aspect of the invention, since the DC power source can know the drive voltage of the DC device connected to the power supply line when the DC device communicates with the DC power source, It is sufficient to apply only the necessary voltage to the power supply line, and it is not necessary to output an unnecessary voltage that is not used from the DC power supply, and the power utilization efficiency is increased. In particular, when a power converter such as an AC / DC converter is used as a direct current power source, useless operation of the power converter can be prevented and power use efficiency can be increased.

  According to the configuration of the invention of claim 10, the DC power supply always applies a voltage required for communication to the power supply line, and only when the DC device notifies the DC power supply of the start of operation by communication, Since a high voltage is applied between lines for a specified time, it is possible to prevent unnecessary power supply from the DC power supply by outputting a high voltage only when the DC device is in operation. The time for applying a higher voltage than the normal time may be a time for obtaining energy required for the operation of the DC device. For example, when the DC device includes a latching relay, the moving time required for reversing the contact of the latching relay. Longer than that.

  According to the configuration of the invention of claim 11, the DC power supply always applies a voltage required for communication to the power supply line, and is higher than the normal only when the DC device notifies the DC power supply of the start of operation by communication. Since the voltage is intermittently applied between the lines during the operation period of the DC device, it is possible to prevent unnecessary power supply from the DC power supply by supplying a high voltage only during the operation of the DC device. For example, by intermittently applying a voltage higher than usual between on and off of a switch provided in a DC device, a plurality of LEDs connected in series are used for lighting a liquid crystal display backlight. be able to.

  According to the configuration of the twelfth aspect of the present invention, since the information is transmitted using the voltage change of the DC power supplied to the DC device, the power supply line can be shared for the power supply and the information transmission. There is no need to add a separate track. Further, compared to the case where information is transmitted using a high-frequency carrier wave on a wired transmission line, radiation noise from the power supply line can be reduced. In order to transmit information using a voltage change, it is possible to use the order of the voltage to be changed and the length of time, and the order of the rising edge and the falling edge of the voltage regardless of the voltage value. Timing can be used.

(Embodiment 1)
As shown in FIG. 1A, the present embodiment basically includes a DC power source 10 housed in the switchboard 1 and a DC device 20 driven by DC power, and is connected to the DC power source 10. DC power is supplied to the DC device 20 through the power supply line Lp. The switchboard 1 also stores a trunk breaker and a branch breaker (not shown).

  In the present embodiment, the DC power source 10 includes an AC / DC converter 11 that converts AC power from an AC power source AC such as a commercial power source into DC power, and a DC / DC converter that converts voltage using a switching element. 12 is used in combination. The DC / DC converter 12 may use any configuration such as a chopper circuit, a forward type, and a flyback type. The output voltage of the DC / DC converter 12 is instructed by the voltage selection means 13. That is, the voltage selection means 13 has a microcomputer (hereinafter abbreviated as “microcomputer”) as a main component, and changes the output voltage of the DC / DC converter 12 by giving an instruction to change the on-duty of the switching element. .

  The DC power source 10 can be used in combination with a distributed power source (not shown) using a solar power generator, a wind power generator, a fuel cell, an engine-driven generator, or the like. However, in the following description, the distributed power source is not particularly described, and the DC power source 10 will be described as being constituted by an AC / DC converter 11 and a DC / DC converter 12.

  The power supply line Lp is made up of two electric wires, and is usually pre-wired indoors. The output voltage of the DC / DC converter 12 is applied between the two electric wires. The voltage selection means 13 switches the output voltage of the DC / DC converter 12 in a plurality of stages, and sequentially selects each voltage at regular intervals as shown in FIG. In the illustrated example, three stages of voltages of 5V, 7V, and 24V are cyclically selected, for example, every several tens of ms.

  5V and 7V are voltages selected to be supplied to the DC device 2 incorporating an information system or communication system circuit (usually an integrated circuit) such as a microcomputer. The main drive of this type of integrated circuit Since the voltages are 3.3 V and 5 V, these voltages are selected in consideration of the step-down by the DC device 2. 24V is selected as a voltage for operating the latching relay. The voltage value and the number of stages of the output voltage of the DC power supply 1 are not limited to the above example, and for example, 12V may be selected and may be set in four stages.

  Since the voltage between the power supply lines Lp changes with time as described above, the DC device 20 needs to receive a voltage corresponding to itself. That is, in this example, there are three types of DC devices 20 with drive voltages of 5V, 7V, and 24V. In each DC device 20, the period during which the line voltage of the power supply line Lp is its own drive voltage (hereinafter referred to as the drive voltage). This period is called “adaptation period”), and the other period is operated with the power received during the adaptation period.

  Accordingly, as shown in FIG. 1A, the DC device 20 includes a voltage detection unit 21 that determines whether or not the voltage applied between the power supply lines Lp corresponds to itself, And power supply means 22 for receiving DC power from the power supply line Lp. In the case of the DC device 20 that operates the latching relay, the latching relay can be operated if the adaptation period is longer than the moving time of the latching relay. Therefore, the internal circuit 23 only needs to operate during the adaptation period.

  For example, as shown in FIG. 1C, the voltage detection means 21 is connected to another switching element SW2 at the base of a switching element SW1 (transistor in the illustrated example) inserted in a power supply path from the power supply line Lp to the power supply means 22. And the upper and lower limits of the drive voltage for the voltage between the power supply lines Lp are detected by the zener diodes ZD1 and ZD2 (ZD1 defines the upper limit and ZD2 defines the lower limit), and within the range between the upper limit and the lower limit A configuration may be adopted in which the switching element SW1 is turned on when a voltage of 2 is applied.

  In the illustrated example, when the Zener voltage (upper limit) of the Zener diode ZD1 is exceeded, the switching element SW2 is turned on and the switching element SW1 is turned off. Further, when the voltage falls below the Zener voltage (lower limit) of the Zener diode ZD2, the switching element SW1 is turned off without being biased. Between the upper limit and the lower limit, the switching element SW2 is turned off and the switching element SW1 is turned on.

  In the voltage comparison by the comparator, power supply is required. However, in the above-described configuration, the switching element SW is turned on by the voltage comparison, so that it can be operated only by applying a voltage between the electrode supply lines Lp.

  On the other hand, when it is necessary to operate continuously in addition to the adaptation period, as in the case of the DC device 20 including an information system or communication system integrated circuit, the power received during the adaptation period is stored and the next adaptation period is stored. It is necessary to maintain the operation of the internal circuit 23. Further, since the voltage between the power supply lines Lp varies with time, the operation of the internal circuit 23 needs to be stabilized. Therefore, the voltage means 22 is provided with a capacitor C for storage (which may be a secondary battery) and a constant voltage circuit Rg such as a three-terminal regulator.

  In this DC device 20, when the voltage detection means 21 detects that a voltage of 5V or 7V is applied between the power supply lines Lp, the voltage is stored in the capacitor C during the adaptation period, and further the voltage is supplied by the constant voltage circuit Rg. It is stabilized and supplied to the internal circuit 23. If the relationship between the power consumption of the internal circuit 23, the adaptation period, and the capacity of the capacitor C is appropriately designed, power can be stably supplied to the internal circuit 23, and the charge stored in the capacitor C during the adaptation period can be used. Thus, the internal circuit 23 can be continuously operated until the next adaptation period. Further, if the capacity of the capacitor C is increased, the DC device 20 can be continuously operated with the charge of the capacitor C even when the DC power supplied from the power supply line Lp is temporarily interrupted. The function of the DC device 20 can be maintained even when the AC power supply AC is blacked out.

  In the present embodiment, the voltage applied between the power supply lines Lp is changed at regular intervals, so that the DC devices 20 having different drive voltages can receive DC power almost evenly. In addition, since the adaptation period is constant and the time for storing in the capacitor C and the time for discharging from the capacitor C are substantially constant, the power supply means 22 including the capacitor C can be easily designed.

  In this embodiment, the voltage applied to the power supply line Lp is cyclically changed every fixed time, but it is not essential to change the voltage cyclically every fixed time, and each drive of the DC device 20 is performed. Depending on the total power consumption for each voltage, the time for each voltage applied between the lines may be lengthened or the number of times each voltage is applied between the power supply lines Lp may be changed in unit time. .

  As described above, a plurality of stages of voltages are applied between the power supply lines Lp while shifting the time, and each DC device 20 receives power during a compatible period in which a voltage corresponding to itself is applied. The difference between the voltage and the drive voltage of the internal circuit 23 is small or zero, and the power loss associated with the voltage drop in the constant voltage circuit Rg is reduced and the power use efficiency is increased. In addition, since a plurality of stages of DC voltages are supplied from the power supply line, the loss due to step-down can be reduced in any of the DC devices 20 having different drive voltages. Since a plurality of stages of voltage are supplied to the DC device 20 having different drive voltages using only two wires, wiring materials are reduced while supplying a plurality of stages of voltage. As a result, wiring construction is easy and wiring can be performed at low cost.

  In addition, although the example which gives the instruction | indication which controls the on-duty of a switching element by the voltage selection means 13 using the DC / DC converter 12 provided with a switching element was shown as a structure of the direct-current power supply 10, multiple different output voltages are shown. A configuration may be adopted in which a constant voltage circuit is provided and a constant voltage circuit to be applied to the power supply line Lp is selected. Further, when the DC / DC converter 12 including the switching element is used, control may be performed so that the voltage is smoothly changed instead of being sharply changed at the voltage boundary of each stage. If this configuration is adopted, the generation of noise can be suppressed.

(Embodiment 2)
In the first embodiment, since the DC power supply 10 determines the voltage to be applied to the power supply line Lp, even if there is no DC device 20 that operates with the voltage applied to the power supply line Lp, the power supply line Lp has The voltage is applied. For example, although a DC device 20 with a drive voltage of 5V and 24V is connected to the power supply line Lp, a voltage of 7V is applied to the power supply line Lp even if the DC device 20 with a drive voltage of 7V is not connected. Since a period for applying the voltage is provided, useless loss of power occurs. If the drive voltage of the DC device 20 connected to the power supply line Lp is known, the setting of the DC power supply 10 may be changed so that unnecessary voltage is not applied among the output voltages of the DC power supply 10. If the device 20 is detachable from the power supply line Lp, it is difficult to cope with the configuration in which the setting of the DC power supply 10 is changed.

  Therefore, in the present embodiment, as shown in FIG. 2, the power source communication unit 14 is provided in the DC power source 10, the device communication unit 24 is provided in the DC device 20, and communication is performed between the DC power source 10 and the DC device 20. The DC device 20 notifies the DC power supply 10 of a voltage corresponding to itself by communication, and the voltage selection means 13 of the DC power supply 10 outputs only the voltage notified from the DC device 20. That is, the voltage selection unit 13 determines the voltage to be applied to the power supply line Lp according to the type of voltage notified from the DC device 20. By this operation, a voltage not used by the DC device 20 is not applied to the power supply line Lp, and wasteful loss of power can be prevented.

  However, since communication is performed between the DC power supply 10 and the DC device 20, it is necessary to secure power for communication in the DC device 20. Since it is necessary to operate a communication integrated circuit for communication, a voltage for ensuring the operation of the communication integrated circuit, for example, 5 V, is always applied to the power supply line Lp, and the drive voltage is When a DC device 20 having a drive voltage (for example, 24 V) higher than the voltage constantly applied to the power supply line Lp is connected and a voltage of 24 V is requested from the DC device 20 by communication, FIG. As shown in FIG. 4, 24V is applied intermittently and regularly at regular time intervals. Of course, if the DC device 20 having a drive voltage of 24V is not connected, a voltage of 24V is not applied to the power supply line Lp.

  This operation can be applied, for example, when the DC device 20 includes a plurality of light emitting diodes connected in series for the backlight of the liquid crystal display, and a voltage of 24 V is applied to the series circuit of the light emitting diodes. .

  As described above, since there are two types of drive voltages in the information system and communication system integrated circuits, as shown in FIG. 3 (b), there are always 5V and 7V between the power supply lines Lp. A configuration may be adopted in which voltages are applied alternately and periodically, and when connection of the DC device 20 having a drive voltage of 24 V is notified, 24 V is periodically applied.

  By the way, for the communication between the DC power supply 10 and the DC device 20, a configuration in which an information line independent from the power supply line Lp may be adopted, but the power supply line is used for construction with two electric wires. It is desirable to use Lp also as a communication path for information transmission. In order to use the power supply line Lp as a communication path, a high-frequency carrier wave used for the power supply line Lp is superimposed on the DC voltage.

  In addition, when information is transmitted from the DC power supply 10 to the DC device 20, the information transmission may be performed using a change in voltage applied to the power supply line Lp. For example, the order of voltage to be changed and the length of time can be assigned to bit values. However, since the voltage value applied to the power supply line Lp varies, it is desirable to transmit information using the direction of voltage change and the length of the period during which each voltage is applied. In other words, it is desirable to use the order and timing of the rising edge and falling edge of the voltage regardless of the voltage value.

  When information transmission is performed using the voltage applied to the power supply line Lp as described above, radiation noise from the power supply line Lp can be reduced as compared with the case of using a high-frequency carrier wave. Other configurations and operations are the same as those of the first embodiment.

(Embodiment 3)
In the second embodiment, after collecting information related to the drive voltage of the DC device 20 connected to the power supply line Lp, a voltage corresponding to the drive voltage of the DC device 20 is applied to the power supply line Lp. However, when it does not operate, a driving voltage for operation is unnecessary. The present embodiment shows an example in which the power loss is further reduced by applying a necessary voltage to the power supply line Lp only when requested by the DC device 20.

  By the way, a DC device 20 that requires a higher driving voltage (for example, 24V) than usual may be supplied with electric power to operate like the DC device 20 including a latching relay as a load, and a light emitting diode. Some of them require continuous power supply, such as a DC device 20 having a motor as a load.

  Now, it is assumed that the DC device 20 having a switch and the DC device 20 having a load such as a latching relay or a light emitting diode are connected to the power supply line Lp and the load is operated by operating the switch. When the power is supplied as in the former case, as shown in FIG. 4A, the DC power supply 10 requires the DC power supply 10 to apply a voltage of 24 V in a single operation in response to the switch operation. To do. In response to this request, when a voltage of 24V is applied to the power supply line Lp as shown in FIG. 4B, the driving DC power is supplied to the DC device 20 having a load. The latching relay or the like can be driven as shown in FIG. In this case, the time for applying the voltage of 24V may be longer than the moving time of the latching relay.

  On the other hand, when the power is continuously supplied as in the latter case, the DC power supply 10 is configured so that the DC device 20 continuously applies a voltage of 24 V in response to the switch ON operation as shown in FIG. To request. In response to this request, the DC power source 10 intermittently and periodically applies a voltage of 24 V to the power supply line Lp as shown in FIG. This state continues until the switch is turned off. Therefore, in the period from the on operation to the off operation of the switch, a voltage of 24 V can be continuously and intermittently supplied to the DC device 20 including the load, and the operation of the load can be continued. For example, when a load in which a plurality of light emitting diodes are connected in series is used as the load, the lighting state can be continued by this operation.

  In the above-described operation, 5 V, for example, is constantly applied between the power supply lines Lp for information system and communication integrated circuits, but 5 V and 7 V are alternately applied between the power supply lines Lp. May be applied periodically. That is, the operation of the third embodiment is the operation shown in FIG. 3B, and a voltage of 24 V is applied between the power supply lines Lp either once or intermittently in response to a request from the DC device 20. . Other configurations and operations are the same as those of the above-described embodiment.

(Embodiment 4)
In each of the above-described embodiments, the power supply line Lp is composed of two electric wires, and the operation of applying a plurality of stages of voltages between the power supply lines Lp in a time-sharing manner with a time shift has been described. 6 shows a configuration example in which the power supply line Lp is composed of three or more electric wires La, Lb, and Lc, as shown in FIG. In the DC power supply 10, two or more types of voltages to be applied between two electric wires La, Lb, and Lc on different power supply lines Lp are set. In the illustrated example, one electric wire Lc is used as a reference line for a reference potential (ground potential), and different voltages are applied to the other two electric wires La and Lb between the reference line Lc. Therefore, the DC power supply 10 is provided with two DC / DC converters 12a and 12b having different output voltages, and the ground side of both the DC / DC converters 12a and 12b is commonly connected to take out the output as three lines. ing. Although it is desirable in terms of construction that the three electric wires La, Lb, and Lc are housed in a sheath to form a cable, the three electric wires La, Lb, and Lc may be independent.

  In this configuration, for example, a voltage of 24V for driving a load such as a light emitting diode is applied between the electric wire La and the reference line Lc, and an information system or a communication system is integrated between the electric wire Lb and the reference line Lc. A voltage of 5V for the circuit is applied. The DC device 20 receives power from two wires of the electric wire La and the reference line Lc or two wires of the electric wire Lb and the reference line Lc in accordance with its own driving voltage. In addition, in a DC device having both an information system and a communication system circuit and a load such as a light emitting diode, power is received from the three wires La, Lb, and Lc, and the reference wire Lc and the other two electric wires La and Lb are connected. The voltage between them is used in the internal circuit 23.

  In the configuration of the present embodiment, since the voltage applied to the power supply line Lp does not change with time, the DC device 20 receives a voltage suitable for itself by simply selecting which of the electric wires La, Lb, and Lc is connected. If the output voltage is stabilized in the DC / DC converters 12a and 12b, the DC device 20 does not need to stabilize the voltage. As a result, it is possible to omit the voltage detection means 21 and the power supply means 22 that are necessary in the first embodiment.

  In the above configuration example, it is possible to obtain a voltage of 7V by using the line voltage of the electric wires La and Lb. However, due to a failure of the DC / DC converters 12a and 12b, the electric wires La and Lb If any of the above and the reference line Lc are short-circuited, there is a possibility that a high voltage is applied to the DC device 20 whose drive voltage is a low voltage. Therefore, it is necessary to consider this type of accident in the protection circuit of the DC power supply 10 (not shown but protects against overload). On the other hand, in the present embodiment, the reference line Lc is shared, and the polarity of the voltage applied to the other electric wires La and Lb is the same with respect to the reference potential of the reference line Lc. There is no problem, and the configuration of the protection circuit is simplified. Other configurations and operations are the same as those of the first embodiment.

(Embodiment 5)
In the fourth embodiment, the voltage applied between three or more (three is illustrated) wires La, Lb, and Lc is not changed over time, but in this embodiment, the reference line Lc and at least one other wire are used. The voltage between the electric wires La and Lb is changed over time as in the first embodiment. For example, when there are two types of drive voltages 3.3V and 5V for the internal circuit 23 of the information system and communication system used for the DC device 20, there are 5V and 7V between the electric wire Lb and the reference line Lc. The voltage is alternately applied periodically, and the DC device 20 is provided with the voltage detection means 21 and the power supply means 22 as in the first embodiment, and a voltage corresponding to its own drive voltage is applied between the lines. Power is received and stored in the power supply means 22 to supply DC power to the internal circuit 23. With this configuration, it is possible to supply DC power with two lines even when there are a plurality of types of driving voltages for information and communication circuits.

  Further, a voltage is set between the other electric wire La and the reference line Lc so as to drive the DC device 20 including a relay, a light emitting diode, a motor, or the like as a load. Although depending on the type of load provided in the DC device 20, this voltage does not necessarily have to change with time and may be fixed. FIG. 7 shows the voltage relationship when this voltage is fixed.

  In this configuration, the required voltage stability, such as relays, light-emitting diodes, and motors, is lower than that of information and communication circuits, and the power supply path is separated from the information and communication circuits. Therefore, voltage fluctuation due to the operation of the load does not affect the operation of the information system such as the microcomputer and the circuit of the communication system, and the operation reliability is increased. In addition, the voltage for driving the information system or communication circuit is fed with a margin of 1 to 2 V so that it can be stabilized by the internal circuit of the DC device 20 (for example, 5 V and 7 V), The voltage supplied to the relay and the motor can be properly used so that the voltage supplied from the DC power supply 10 is used as it is.

  Further, as shown in the second and third embodiments, the electric wire Lb that changes the voltage between lines with respect to the reference potential of the reference line Lc is communicated between the connected DC device 20 and the DC power source 10. It is also possible to adopt a configuration in which the voltage applied by the DC power supply 10 is determined according to the drive voltage of the DC device 20. For example, if the voltage between the reference line Lc and the electric wire Lb is selectable from two stages (5 V and 7 V) as described above, and the drive voltage of the connected DC device 20 is only 5 V, then 5 V May be applied. Further, normally, no voltage is applied between the electric wire La and the reference line Lc, and only when there is a request from the DC device 20 by communication, a corresponding voltage is generated between the electric wire La and the reference line Lc. It is also possible to adopt a configuration that applies intermittently, continuously or continuously. Other configurations and operations are the same as those of the above-described embodiments.

(A) is a block diagram which shows Embodiment 1, (b) is operation | movement explanatory drawing which shows a voltage change same as the above. (A) is a block diagram showing a second embodiment. It is operation | movement explanatory drawing which shows the example of a voltage change same as the above. FIG. 10 is an operation explanatory diagram of one operation example of Embodiment 3. It is operation | movement explanatory drawing of the other operation example same as the above. FIG. 6 is a configuration diagram illustrating a fourth embodiment. FIG. 10 is an operation explanatory diagram illustrating an example of a voltage change in the fifth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 DC power supply 11 AC / DC converter 12 DC / DC converter 12a, 12b DC / DC converter 13 Voltage selection means 14 Power supply communication means 20 DC equipment 21 Voltage detection means 22 Power supply means 23 Internal circuit 24 Equipment communication means La, Lb, Lc Electric wire Lc Reference line Lp Power supply line

Claims (12)

  A DC power source that supplies DC power and a DC device that is driven by DC power supplied from the DC power source through the power supply line. The DC power source supplies a plurality of types of DC voltages to the power supply line, and The equipment operates by receiving DC power of a voltage corresponding to itself from the plurality of types of DC voltages.   The power supply line is composed of two electric wires, the DC power supply is capable of changing the voltage applied between the lines of the power supply line in a plurality of stages, and the DC device is capable of self-applying the voltage applied between the lines. Voltage detecting means for judging whether or not it is compatible, and power supply means for receiving DC power from the power supply line during an adaptation period in which it is detected that a voltage corresponding to itself is applied between the lines by the voltage detecting means The power distribution system according to claim 1, further comprising:   2. The power supply line is composed of three or more electric wires, and the DC power supply is set to two or more kinds of voltages to be applied between two electric wires having different power supply lines. Power distribution system.   The DC power supply applies a different voltage between the reference line and each of the other electric wires using one electric wire constituting the power supply line as a reference line of a reference potential, and the DC device is connected to the reference line and other electric wires. 4. The power distribution system according to claim 3, wherein DC power is received from a single electric wire.   The DC power supply can vary the voltage applied between the electric wire serving as the reference line in the power supply line and at least one other electric wire in a plurality of stages, and the voltage with respect to the reference line among the DC devices can be varied. A DC device that receives DC power from a wire is a voltage detection means that determines whether or not the voltage applied between the lines corresponds to itself, and a voltage corresponding to itself by the voltage detection means The power distribution system according to claim 4, further comprising power supply means for receiving DC power from the power supply line during an adaptation period in which it is detected that the power is applied to the power supply line.   6. The power distribution system according to claim 2, wherein the power supply means stores DC power during the adaptation period and uses it for an internal power supply.   The said DC power supply is provided with the voltage selection means which changes the voltage applied between the lines of the said electric power supply line whose voltage is variable for every fixed time, The claim 5 or Claim 6 characterized by the above-mentioned. The described power distribution system.   The power distribution system according to claim 7, wherein the voltage selection unit cyclically changes a voltage applied between the lines of the power supply line whose voltage is variable at regular intervals.   The DC power supply and the DC device are communicable, and the DC device notifies the DC power supply of a voltage corresponding to itself, and the DC power supply is notified from all the DC devices connected to the power supply line. The power distribution system according to claim 2, further comprising a voltage selection unit that selects a voltage according to a voltage type and applies the voltage between the power supply lines.   The DC power source and the DC device are communicable, and the DC power source applies a voltage required for communication between the power supply lines at all times, and directs the operation when the DC device starts operating by communication. The power distribution system according to claim 2, further comprising a voltage selection unit that applies a voltage higher than a normal time necessary for the operation of the device between the lines for a specified time.   The DC power supply and the DC device are communicable, and the DC power supply applies a voltage required for communication between the lines of the power supply line at all times. 7. The voltage selection means for applying a voltage higher than usual necessary for the operation of the device intermittently between the lines during the operation period of the DC device is provided. Power distribution system.   The DC power source and the DC device are communicable, and information between the DC power source and the DC device is between specific two lines supplying DC power to the DC device among the power supply lines. The power distribution system according to claim 2, wherein the voltage distribution is transmitted using a voltage change of the power distribution.

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