JP2011089915A - Power measuring device and power measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power measuring device or the like suitable for measuring power consumption of an electric apparatus or the like. <P>SOLUTION: The power measuring device 1 includes a non-insulation power source supply circuit 3 for regarding one line of a power source line which is a measuring object as ground potential of the power measuring device 1 and supplying power to the power measuring device, a voltage measuring circuit 4 for dividing a voltage between the power source lines excluding the ground potential and a ground in a resistor, a communication driver 9 for outputting power measuring result, and a photocoupler 8 for insulating the communication driver 9 from a power line. The power measuring device supplies a power source of the communication driver 9 from a power source part 10 included in a display 2 connecting the communication driver 9. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power measurement device and a power measurement method suitable for measuring power consumption of an electrical device or the like.

  In order to insulate a power measuring device from an AC (Alternating Current) power source, an insulated power source using a power transformer is used as the operating power source of the device, and a voltage transformer is installed in a voltage measuring circuit that converts the power source voltage into a small voltage that is easy to measure. The power measuring device used is known. However, since the insulated power source and the voltage transformer are large and expensive, the power measuring device is generally large and expensive. Further, when the voltage measurement circuit is configured by a non-insulated circuit such as a resistance voltage dividing circuit, it is necessary to prepare a power source for the non-insulated circuit unit separately from the isolated power source of the power measuring device.

  Therefore, in Patent Document 1, as a technique for simplifying the multiphase power measurement, there is a technique for eliminating the voltage transformer used for the measurement and calculating the power based on the voltage value detected from the power supply circuit of the load device that measures the power. It is disclosed.

JP 2001-359297 A

  However, the configuration disclosed in Patent Document 1 has a problem that the measurement accuracy and circuit configuration of the power measurement device depend on the load device when measuring the voltage based on the voltage value detected from the power supply circuit. Therefore, a new method suitable for measuring the power consumption of electric devices and the like is required.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a power measurement device and a power measurement method suitable for measuring power consumption of an electrical device or the like.

In order to achieve the above object, the power measuring device of the present invention is
A non-insulated power supply circuit in which one of the power supply lines is set to the ground potential, the other lines except the one line are connected to the input terminal, and the power supply voltage is supplied from the power supply line;
A voltage measuring circuit for connecting the other line of the power line to the input terminal and measuring a voltage value of the power line;
A current measuring circuit for detecting a current of the other power line and measuring a current value of the power line;
A power supply voltage for operation is supplied from the non-insulated power supply circuit, an output terminal of the voltage measurement circuit and an output terminal of the current measurement circuit are connected to an input terminal, and the voltage value and / or the analog of the current value An A / D converter for converting the value into a digital value;
A power supply voltage for operation is supplied from the non-insulated power supply circuit, an output terminal of the A / D conversion unit is connected to an input terminal, and a calculation unit that calculates a measurement value based on the digital value;
The non-insulated power supply circuit is connected to a primary side, an external power source is connected to a secondary side, and an insulating circuit that insulates the output end of the arithmetic unit from the power supply line is provided. .

  According to the present invention, it is possible to measure the power consumption of an electrical device or the like. In addition, the power measuring device can be reduced in size and cost.

It is a figure which shows the structure of the electric power measurement apparatus which concerns on Embodiment 1. FIG. It is a flowchart for demonstrating operation | movement of an electric power measurement apparatus. It is a figure which shows the structure of the electric power measurement apparatus which concerns on Embodiment 2. FIG. It is a figure which shows the example in which the electric power measuring apparatus was integrated in the air conditioner. It is a figure which shows the example in which the electric power measurement apparatus was integrated in the IH cooking heater. It is a figure which shows the example in which the electric power measurement apparatus was integrated in the water heater. It is a figure which shows the example in which the electric power measurement apparatus was integrated in the refrigerator. It is a figure which shows the example in which the electric power measurement apparatus was integrated in the solar power generator.

  Embodiments of the present invention will be described below. The embodiments described below are for illustrative purposes and do not limit the scope of the present invention. Therefore, those skilled in the art can employ embodiments in which each or all of these elements are replaced with equivalent ones, and these embodiments are also included in the scope of the present invention.

(Embodiment 1)
FIG. 1 is a diagram showing a configuration of a power measuring device according to an embodiment of the present invention. In this embodiment, as shown in the figure, the power measuring device 1 that performs power measurement and the display device 2 that displays the measured result are separated.

(Configuration of power measuring device)
The power measuring apparatus 1 includes a non-insulated power supply circuit 3, a voltage measurement circuit 4, a current measurement circuit 5, an A / D (Analog to Digital) conversion unit 6, a calculation unit 7, a photocoupler 8, a communication driver 9, and the like. The The display device 2 includes a power supply unit 10, a communication unit 11, a control unit 12, a display unit 13, and the like.

  The power measuring device 1 measures the power of the single-phase three-wire power source 14, for example. The ground of the power measuring device 1 is connected to the neutral wire 15 in the single-phase three-wire power source 14. One of the outer lines in the single-phase three-wire power source 14 is connected to a non-insulated power supply circuit 3 described later. Further, the two wires other than the neutral wire 15 of the single-phase three-wire power source 14 are connected to a voltage measuring circuit 4 described later. Further, the two wires except the neutral wire 15 of the single-phase three-wire power source 14 are electromagnetically coupled to a current measuring circuit 5 described later via a current transformer 16.

  The display device 2 is connected to the power measurement device 1, receives the result measured by the power measurement device 1, and displays the result. The display device 2 is connected to a neutral line 15 and one external line in the single-phase three-wire power source 14.

  The non-insulated power supply circuit 3 includes, for example, a converter and a switching control circuit, and generates a power supply voltage for operating the power measuring apparatus 1. The input of the non-insulated power supply circuit 3 is connected to one external line, and the output of the non-insulated power supply circuit 3 is connected to the primary side of the A / D converter 6, the arithmetic unit 7 and the photocoupler 8. . A power supply voltage created in the non-insulated power supply circuit 3 is supplied as a power supply voltage for operating the A / D converter 6, the arithmetic unit 7, and the photocoupler 8.

  The voltage measurement circuit 4 includes, for example, a resistance voltage dividing circuit, measures a voltage applied from the power supply line, and converts (divides) the voltage to a level suitable for an analog input. The voltage measurement circuit 4 is connected to two lines excluding the neutral line 15 of the single-phase three-wire power source 14. Each voltage between the ground of the power measuring device 1 connected to each power line and the neutral line 15 is divided by the voltage measurement circuit 4, and the divided voltage is analog of the A / D conversion unit 6. Input to input.

  It should be noted that a high input impedance element such as an operational amplifier may be inserted into the output of the voltage dividing circuit included in the voltage measuring circuit 4 in order to prevent a change in the voltage dividing ratio due to variations in impedance of the current measuring circuit 5 and fluctuations.

  The current measurement circuit 5 includes, for example, a load resistor, measures the current of the current transformer 16, and converts the current to a voltage suitable for analog input. The current measuring circuit 5 is electromagnetically coupled by a current transformer 16 to two wires excluding the neutral wire 15 of the single-phase three-wire power source 14. The two-wire current measurement values measured by the current transformer 16 are converted into a voltage proportional to the current by the current measurement circuit 5, and the voltage is input to the analog input of the A / D conversion unit 6. The current value scaled by the current measurement circuit 5 is input to the A / D converter 6 and converted into a digital value.

  In order to adjust the level, an amplification element such as an operational amplifier or a voltage dividing element may be inserted into the current measurement circuit 5.

  The A / D conversion unit 6 includes, for example, an integration circuit, converts an input analog value into a digital value, and outputs the digital value. Analog values output from the voltage measurement circuit 4 and the current measurement circuit 5 are converted into digital values by the A / D conversion unit 6, and the digital values are output to the calculation unit 7.

  The calculation unit 7 calculates phase voltage, phase current, phase power, total power, and the like using the current measurement result and the digital value of the voltage measurement result input from the A / D conversion unit 6. The calculated value output from the calculation unit 7 is input to the photocoupler 8.

  The photocoupler 8 includes, for example, a light emitting element and a light receiving element, converts an input electric signal into light, and transmits the signal by conducting the light receiving element with the light. Since the input end and the output end of the photocoupler 8 are electrically insulated, the output of the arithmetic unit 7 is insulated from the communication driver 9 described later. Since the secondary side voltage of the photocoupler 8 is supplied from a power supply unit 10 to be described later, it becomes the same DC (Direct Current) voltage as the display device 2.

  The non-insulated power supply circuit 3, the voltage measurement circuit 4, the A / D conversion unit 6, and the calculation unit 7 are all connected to the primary side ground.

  The communication driver 9 is connected to the display device 2 via an interface such as a connector and a communication line. Measurement data of the power measuring device 1 is transmitted to the display device 2 via the communication driver 9.

  The power supply unit 10 is a power supply circuit that creates a DC power supply for operating the display device 2 from 100 VAC. The power supply unit 10 is connected to the power measuring device 1 through an interface such as a connector and a power supply line, and supplies power to the secondary side of the photocoupler 8 and the communication driver 9. The power supply unit 10 supplies power to the communication unit 11, the control unit 12, and the display unit 13. The power supply unit 10 is connected to a neutral line 15 and one external line in the single-phase three-wire power supply 14.

  The communication unit 11 is connected to a communication driver 9 included in the power measurement device 1 via an interface such as a connector and a communication line. Measurement data measured by the power measuring device 1 is received via the communication unit 11, and the received data is passed to the control unit 12.

  The control unit 12 includes, for example, a CPU (Central Processing Unit), and outputs measurement data received from the power measurement device 1 via the communication unit 11 to the display unit 13.

  Note that the control unit 12 has a function of controlling an electric device connected to the single-phase three-wire power source 14 and also has a function of controlling the operation of the electric device based on the measurement data of the power measuring device 1. Good. In addition, the control unit 12 may have a function of setting and controlling the power measuring device 1.

  The display unit 13 includes a liquid crystal panel, for example, and displays measurement data of the power measurement device 1 under the control of the control unit 12.

(Operation of power measuring device)
Next, operation | movement of the electric power measurement apparatus 1 which concerns on this embodiment is demonstrated with reference to drawings. FIG. 2 is a flowchart showing the operation of the power measuring apparatus 1.

  Here, as shown in FIG. 1, the power measuring apparatus 1 sets one line of the AC power supply line to be measured as the ground potential of the power measuring apparatus 1. The power measuring device 1 also includes a photocoupler 8 that insulates the communication driver 9 that outputs the power measurement result from the AC power supply. The power of the communication driver 9 is externally supplied from the power supply unit 10 provided in the display device 2 to which the interface is connected.

  First, the voltage measuring circuit 4 is suitable for analog input of the A / D converter 6 by using a resistance voltage dividing circuit or the like for each voltage between the grounds of the power measuring device 1 connected to each power line and the neutral line 15. The level is converted (divided) to a certain level (step S101).

  It should be noted that a high input impedance element such as an operational amplifier may be inserted into the output of the voltage dividing circuit in order to prevent variation in the voltage dividing ratio due to variations in impedance of the current measuring circuit 5 and fluctuations.

  The current measurement circuit 5 measures the current of the two wires with the current transformer 16 (step S102). The measured current is converted into a voltage proportional to the current by the load resistance, and the voltage is input to the analog input of the A / D converter 6.

  In order to adjust the level, an amplifying element such as an operational amplifier or a voltage dividing element may be inserted.

  Next, the voltage value scaled by the voltage measurement circuit 4 and the current value scaled by the current measurement circuit 5 are input to the A / D conversion unit 6, and the A / D conversion unit 6 The current value is converted into a digital value (step S103).

  Next, the calculation unit 7 calculates and calculates phase voltage, phase current, phase power, total power, and the like using the digital values of the current measurement result and the voltage measurement result obtained from the A / D conversion unit 6. (Step S104). Measurement data such as electric power calculated by the calculation unit 7 is insulated by a digital signal via the photocoupler 8 and is output to the communication driver 9.

Here, the flow of signals will be described by taking as an example the case where the power output of the non-insulated power supply circuit 3 is 5V, the arithmetic unit 7 is a 5V logic circuit, and the power output of the power unit 10 is 5V.
The AC voltage 100 V of the single-phase three-wire power source 14 is divided into signals of 5 V or less so that the voltage measurement circuit 4 is within the analog signal input range of the A / D converter 6. The analog signal input to the A / D converter 6 is converted into a digital signal by the A / D converter 6 and input to the arithmetic unit 7 as a 5V digital signal. The result calculated by the calculation unit 7 is input to the primary side of the photocoupler 8 as a 5V digital signal. Since the secondary power supply of the photocoupler 8 is supplied with 5 V from the power supply unit 10 included in the display device 2, the output of the photocoupler 8 is input to the communication driver 9 as a 5 V digital signal.

  When the A / D conversion unit 6 is a positive / negative analog signal input, a signal can be directly input. However, when the A / D conversion unit 6 supports only a positive analog signal input, A bias of a voltage half the A / D analog signal input range is applied.

  The A / D conversion unit 6 and the calculation unit 7 operate using the non-insulated power supply circuit 3 as a power source. In the non-insulated power supply circuit 3, the input and the output are not insulated, but in the insulated power supply circuit, the input and the output are insulated. The technique for isolating the input from the output is typically performed by a transformer. Since an insulated power supply circuit using a transformer is large and expensive, a power measuring device including the insulated power supply circuit is large and expensive as a result.

  In the power measuring device 1 according to the present invention, the non-insulated power supply circuit 3 is connected to the primary side of the A / D converter 6, the arithmetic unit 7, and the photocoupler 8, and serves as a power source for the power measuring device 1. Function. The power supply unit 10 included in the display device 2 is connected to the secondary side of the photocoupler 8 and the communication driver 9 insulated by the photocoupler 8. Since the input end and the output end of the photocoupler 8 are electrically insulated, the communication driver 9 can be insulated. As a result, since the power measuring device 1 can be operated without using an insulated power supply circuit, the power measuring device 1 can be reduced in size and cost.

  Next, the communication driver 9 transmits the measurement data of the power measurement device 1 via the communication unit 11 included in the display device 2. The control part 12 with which the display apparatus 2 is provided outputs the received measurement data to the display part 13, and displays measurement data (step S105).

  Note that the control unit 12 may have a function of controlling an electrical device connected to the single-phase three-wire power source 14 and may have a function of controlling the operation of the electrical device based on measurement data of the power measurement device 1. In addition, the control unit 12 may have a function of setting and controlling the power measuring device 1.

  By repeating the above processing, measurement data such as a power value measured by the power measuring device 1 is displayed.

  As described above, since the power measuring device 1 can be operated without using an insulated power supply circuit, the power measuring device 1 can be reduced in size and cost.

  Moreover, in the voltage measurement circuit 4, by using a resistance voltage dividing circuit instead of the voltage transformer, the power measuring device 1 can be reduced in size and cost. By not using the voltage transformer, the phase error of the voltage measurement circuit 4 is reduced, and the voltage can be measured with high accuracy.

  Further, the power can be measured without depending on the load device measured by the power measuring device 1, and a configuration that can easily cope with load devices with different power distribution methods can be obtained.

(Embodiment 2)
In the first embodiment, the power measuring device 1 and the display device 2 are separated from each other, and the measurement data measured by the power measuring device 1 is displayed on the separated display device 2. This embodiment demonstrates the case where an electric power measuring device is integrated in a household appliance device in order to measure the electric power of a household appliance device.

(Configuration of power measuring device)
First, the structure of each part of the electric power measurement apparatus of this embodiment is demonstrated with reference to drawings. FIG. 3 is a diagram illustrating a configuration of the power measuring device 1a according to the present embodiment.

  As shown in the figure, the power measuring device 1a includes a non-insulated power supply circuit 3, a voltage measurement circuit 4, a current measurement circuit 5, an A / D conversion unit 6, a calculation unit 7, a photocoupler 8, and the like. Moreover, the household appliances 17 are comprised from the electric power measurement apparatus 1a, the power supply part 10, the control part 12, the display part 13, etc. Since the configuration other than the photocoupler 8 and the power supply unit 10 is the same as that of the power measurement device 1 according to the first embodiment, the description thereof is omitted.

  The power measuring device 1a is driven by a three-phase three-wire power source 18 and is incorporated in the home appliance device 17 in order to monitor power consumption. The ground of the power measuring device 1 a is connected to the S line 19 in the three-phase three-wire power source 18. The R line or T line in the three-phase three-wire power source 18 is connected to a non-insulated power supply circuit 3 that creates a power source for operating the power measuring device 1a.

  The output of the photocoupler 8 is connected to the control unit 12 included in the home appliance device 17 through an interface such as a connector. Measurement data measured by the power measuring device 1 a is output from the photocoupler 8 and passed to the control unit 12. The output of the arithmetic unit 7 is insulated from the home appliance 17 by the photocoupler 8.

  The power supply unit 10 is connected to the S line 19, R line, and T line in the three-phase three-wire power supply 18. The power supply unit 10 supplies power to the control unit 12 and the display unit 13, and is connected to the power measuring device 1 a through an interface such as a connector and a power supply line, and supplies power to the secondary side of the photocoupler 8. To do.

  Note that the power measuring device 1 a may include the display unit 13, and a remote controller for operating the home appliance device 17 may include the display unit 13.

  The home appliance device 17 is an arbitrary device such as an air conditioner, an IH (Induction Heating) cooking heater, a water heater, a refrigerator, a solar power generator, or the like. The power measuring device 1a is incorporated in the home appliance device 17 and measures the power consumption of the home appliance device 17 and the like.

  4-8 is a figure which shows the example in which the electric power measurement apparatus 1a was integrated in the air conditioner 20, the IH cooking heater 21, the hot water heater 22, the refrigerator 23, and the solar power generator 24. FIG. As shown in the figure, the power measuring device 1a is incorporated in an arbitrary home appliance such as an air conditioner 20. The measurement data measured by the power measurement device 1a is transmitted to the control unit 12, the remote controller, the centralized controller, or the like included in the home appliance device 17, and the measurement result is displayed.

  The operation of the power measurement device 1a according to the present embodiment is the same as that of the power measurement device 1 according to the first embodiment, except that measurement data is transmitted without going through the communication driver 9 or the communication unit 11. Description is omitted.

  In the power measuring device 1a according to the present invention, the non-insulated power supply circuit 3 is connected to the primary side of the A / D conversion unit 6, the calculation unit 7, and the photocoupler 8 as a power source for the power measuring device 1a. Function. The power supply unit 10 included in the home appliance device 17 is connected to the secondary side of the photocoupler 8. Since the input end and the output end of the photocoupler 8 are electrically insulated from each other due to the structure, the power measuring device 1a and the home appliance device 17 can be insulated.

  As described above, since the power measuring device 1a can be operated without using the insulated power supply circuit, the power measuring device 1a can be reduced in size and cost.

  Moreover, it becomes possible to acquire information, such as the power consumption of the household appliances 17, by incorporating the electric power measuring device 1a in the household appliances 17. FIG. Thereby, since the household appliances 17 can be controlled based on power consumption information, the household appliances 17 can be highly functionalized.

  It is also possible to display power information on an interface mounted on the home appliance device 17 body or on a remote control interface for operating the home appliance device 17 to notify the user of an electricity bill in real time, Can be aroused.

  In addition, it is possible to detect an abnormality of the home appliance device 17 from the power information and perform control such as stopping the operation, or to notify the user of the abnormality of the home appliance device 17.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation and application are possible.

The power measuring device 1 measures the power of the single-phase three-wire power source 14, but the same effect can be obtained when measuring the power of the three-phase four-wire, three-phase three-wire, and single-phase two-wire power sources. Obtainable.
Moreover, although the power measuring device 1a is a device driven by the three-phase three-wire power source 18, the same effect can be obtained for devices driven by a three-phase four-wire type, a single-phase three-wire type, and a single-phase two-wire type power source. Can be obtained.

  In addition, by changing the resistance voltage dividing ratio of the voltage measurement circuit 4 and the calculation method in the calculation unit 7 in the power measuring devices 1 and 1a, it is possible to easily cope with power sources having different methods.

  Further, by appropriately selecting the resistance voltage dividing ratio and the calculation method, it is possible to easily configure a power measuring device that supports a plurality of power supply systems.

  In the power measuring devices 1 and 1a, the photocoupler 8 is used as the insulating means for the communication driver 9, the control unit 12, and the like, but the same effect can be obtained when the insulating means is a transformer or a capacitive element. However, it is desirable to use the photocoupler 8 because it is small and inexpensive.

  Further, although the current measuring means of the power measuring devices 1 and 1a is the current transformer 16, the same effect can be obtained even if an element such as a shunt resistor or a magnetic field sensor is used for the current measuring means.

  The present invention can be used for measuring the power consumption of an electric device or the like.

DESCRIPTION OF SYMBOLS 1, 1a Power measuring device 2 Display device 3 Non-insulated power supply circuit 4 Voltage measurement circuit 5 Current measurement circuit 6 A / D conversion unit 7 Calculation unit 8 Photocoupler 9 Communication driver 10 Power supply unit 11 Communication unit 12 Control unit 13 Display unit 14 Single-phase three-wire power source 15 Neutral wire 16 Current transformer 17 Home appliance 18 Three-phase three-wire power source 19 S wire 20 Air conditioner 21 IH cooking heater 22 Water heater 23 Refrigerator 24 Solar power generator

Claims (7)

A non-insulated power supply circuit in which one of the power supply lines is set to the ground potential, the other lines except the one line are connected to the input terminal, and the power supply voltage is supplied from the power supply line;
A voltage measuring circuit for connecting the other line of the power line to the input terminal and measuring a voltage value of the power line;
A current measuring circuit for detecting a current of the other power line and measuring a current value of the power line;
A power supply voltage for operation is supplied from the non-insulated power supply circuit, an output terminal of the voltage measurement circuit and an output terminal of the current measurement circuit are connected to an input terminal, and the voltage value and / or the analog of the current value An A / D converter for converting the value into a digital value;
A power supply voltage for operation is supplied from the non-insulated power supply circuit, an output terminal of the A / D conversion unit is connected to an input terminal, and a calculation unit that calculates a measurement value based on the digital value;
The non-insulated power supply circuit is connected to the primary side, an external power source is connected to the secondary side, and an insulating circuit that insulates the output end of the arithmetic unit from the power supply line,
A power measuring device characterized by that. The voltage measurement circuit divides the measured voltage value and outputs the divided voltage value to the A / D converter.
The power measuring device according to claim 1. The insulating circuit includes a photocoupler, a capacitive element, and / or a transformer.
The power measuring device according to claim 1 or 2, wherein The current measurement circuit includes a current transformer, a shunt resistor, and / or a magnetic field sensor.
The power measuring device according to claim 1, wherein the power measuring device is a power measuring device. The power line consists of a single-phase three-wire system, a three-phase four-wire system, a three-phase three-wire system, or a single-phase two-wire system.
The power measuring device according to claim 1, wherein the power measuring device is a power measuring device. A power supply voltage for operation is supplied from the external power supply, an output end of the insulation circuit is connected to an input end, and a communication unit that transmits the calculated measurement value;
A power supply voltage for operation is supplied from the external power supply, and the display unit receives the transmitted measurement value and displays the measurement value.
The communication unit is insulated from the power line by the insulation circuit.
The power measurement device according to claim 1, wherein the power measurement device is a power measurement device. A power measurement method executed by a power measurement device including a non-insulated power supply circuit, a voltage measurement circuit, a current measurement circuit, an A / D conversion unit, a calculation unit, and an insulation circuit,
The non-insulated power supply circuit includes a non-insulated power supply step in which one of the power lines is set to a ground potential, the other lines except the one line are connected to an input terminal, and a power supply voltage is supplied from the power line;
The voltage measuring circuit, the other line of the power supply line is connected to the input terminal, the voltage measurement step of measuring the voltage value of the power supply line;
The current measurement circuit detects a current of the other line of the power supply line and measures a current value of the power supply line; and
The A / D converter is supplied with an operating power supply voltage from the non-insulated power supply circuit, an output terminal of the voltage measurement circuit and an output terminal of the current measurement circuit are connected to an input terminal, and the voltage value And / or an A / D conversion step of converting an analog value of the current value into a digital value;
An arithmetic step in which the arithmetic unit is supplied with an operating power supply voltage from the non-insulated power supply circuit, an output terminal of the A / D converter is connected to an input terminal, and calculates a measurement value based on the digital value When,
The insulating circuit includes an insulating step in which the non-insulated power supply circuit is connected to a primary side, an external power source is connected to a secondary side, and an output end of the arithmetic unit is insulated from the power line.
A power measurement method characterized by that.

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