JP2020144055A - Current detection circuit - Google Patents

Abstract

To suppress deterioration of a current detection circuit even when the circuit is exposed to a wide temperature change.SOLUTION: A current detection circuit 100 includes a first current detection unit 7 including shunt resistors 71 to 74, a second current detection unit 8 including shunt resistors 81 to 84 connected to the first current detection unit 7, a first circuit 10 connected to input electrodes 71a to 74a of the respective shunt resistors 71 to 74 of the first current detection unit 7, a second circuit 11 connected to output electrodes 81b to 84b of the respective shunt resistors 81 to 84 of the second current detection unit 8, a detection signal line 76 that is connected to the shunt resistor 74 of the first current detection unit and detects the current flowing in the shunt resistor 74, and a detection signal line 86 that is connected to the shunt resistor 81 of the second current detection unit 8 and detects the current flowing in the shunt resistor 81. The detection signal lines 76 and 86 are connected to the shunt resistors 74 and 81 in which the ratio of flowing current is the same on the basis of the structure of the first circuit 10 and the second circuit 11.SELECTED DRAWING: Figure 2

Description

The present invention relates to a current detection circuit.

Patent Document 1 discloses a current detection circuit that detects a current using a shunt resistor in an A / F sensor control device.

Japanese Unexamined Patent Publication No. 2016-90462

As shown in Patent Document 1, a current detection circuit using a shunt resistor is generally used as a current detection means in an electric circuit.

However, in this current detection circuit, when used in an environment exposed to a wide range of temperature changes from low temperature to high temperature, the solder fixing the shunt resistor to the substrate may deteriorate due to repeated expansion and contraction.

The present invention has been made in view of the above problems, and an object of the present invention is to suppress deterioration of the current detection circuit even when exposed to a wide range of temperature changes.

According to an aspect of the present invention, the current detection circuit is composed of a first resistor group composed of a plurality of resistors and a second resistor group composed of the plurality of resistors connected to the first resistor group. The first circuit connected to the input electrode of each of the resistors in the first resistance group, and the second circuit connected to the output electrode of each of the resistors in the second resistance group. The circuit, the first detection signal line connected to the resistor of one of the first resistance groups and for detecting the current flowing through the resistor, and the resistor of one of the second resistance groups. A second detection signal line that is connected and for detecting a current flowing through the resistor is provided, and the first detection signal line and the second detection signal line are configured as the first circuit and the second circuit. It is characterized in that it is connected to the resistor of the first resistance group and the resistor of the second resistance group having the same ratio of the current flowing through each of the resistors.

In this embodiment, by arranging a plurality of resistors to form a current detection circuit, the size of each resistor is reduced as compared with a current detection circuit using a single resistor. As the size of the resistor decreases, the amount of solder that joins the resistor to the substrate decreases. Therefore, the expansion / contraction range of the solder due to the temperature change becomes small, and the fatigue of the solder can be suppressed. Therefore, deterioration of the current detection circuit can be suppressed even when exposed to a wide range of temperature changes.

FIG. 1 is a block diagram of a heating device to which the current detection circuit according to the embodiment of the present invention is applied. FIG. 2 is a schematic diagram of a current detection circuit according to the first embodiment of the present invention. FIG. 3 is a schematic diagram of a current detection circuit according to a second embodiment of the present invention. FIG. 4 is a schematic diagram of a current detection circuit according to a third embodiment of the present invention.

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

(First Embodiment)
Hereinafter, the heating device 1 to which the current detection circuit 100 and the current detection circuit 100 according to the first embodiment of the present invention are applied will be described with reference to FIGS. 1 and 2.

First, the heating device 1 will be described with reference to FIG.

The heating device 1 includes a heater 4 driven by power supplied from a high-voltage battery 2, a first switching element connected to the heater 4, and an IGBT (Insulated Gate Bipolar Transistor) as a second switching element. ) 5a, 5b, and the like.

The heating device 1 is applied to a vehicle air-conditioning device (not shown) mounted on a vehicle such as an EV (Electric Vehicle: electric vehicle) or a HEV (Hybrid Electric Vehicle: hybrid vehicle). The vehicle air conditioner has a hot water tank (not shown) that heats the refrigerant by the heater 4 in order to perform the heating operation.

The high-voltage battery 2 is a high-voltage battery mounted on an EV or HEV. The output voltage of the high voltage battery 2 is a high voltage of 200 to 400 V. The high voltage battery 2 supplies electric power to the heater 4 through the supply line 3.

The heater 4 is a sheathed heater that generates heat when electric power is supplied. The heater 4 is housed in a hot water tank (not shown).

The IGBTs 5a and 5b are switched on and off in response to a command from the controller 6 to switch between supplying and shutting off the power from the high-voltage battery 2 to the heater 4. The IGBTs 5a and 5b are switched on and off by PWM (Pulse Width Modulation) control.

The controller 6 is, for example, an ECU (Electronic Control Unit: electronic control unit) that controls an air conditioner for a vehicle. The controller 6 includes a CPU (central processing unit) that executes control of the vehicle air conditioner, a ROM (read-only memory) that stores control programs and setting values required for the processing operation of the CPU, and various sensors. It includes a RAM (random access memory) that temporarily stores the detected information.

On the downstream side of the IGBT 5b, the first current detection unit 7 and the second current detection unit 8 of the current detection circuit 100 are connected in series. Details of the current detection circuit 100 will be described later.

Further, the heating device 1 is provided with a voltage detection circuit 9 having voltage detection units 9a and 9b for detecting the voltage applied to the supply line 3 connecting the high voltage battery 2 and the heater 4.

The voltage detection units 9a and 9b are connected to the upstream of the heater 4 and detect the voltage applied to the supply line 3. The voltage detection units 9a and 9b transmit an electric signal corresponding to the magnitude of the detected voltage to the controller 6. As described above, the heating device 1 is provided with two voltage detecting units 9a and 9b as voltage detecting means in the circuit, so that even if an abnormality occurs in one of the voltage detecting units 9a and the voltage cannot be detected, for example. The voltage can be detected by the other voltage detection unit 9b. That is, the heating device 1 can make the voltage detecting means redundant by providing the voltage detecting units 9a and 9b.

By the way, the environment in the heating device 1 becomes a high temperature environment due to the heat of the heater 4 for heating the refrigerant and the heat generated by the IGBTs 5a and 5b due to the operation. Further, the environment in which the heater 4 needs to be operated is an environment in which the outside air is cold. Therefore, the environment inside the heating device 1 is an environment exposed to a wide temperature change of, for example, −40 ° C. to 120 ° C. by the heater 4, the IGBTs 5a, 5b, the outside air, and the like.

Here, since the circuit of the heating device 1 is a circuit in which a high voltage is applied by the high voltage battery 2, a large resistor is generally adopted when incorporating a current detection circuit using a resistor. However, since the terminal wire of a large resistor becomes thicker with its size, the amount of solder for joining to the substrate also increases. When the resistor is exposed to the above-mentioned wide range of temperature changes, the solder that fixes the resistor to the substrate may deteriorate due to repeated expansion and contraction. Therefore, in the present embodiment, the current detection circuit 100 is configured as follows.

Next, the details of the current detection circuit 100 will be described with reference to FIG.

FIG. 2 is a schematic diagram of the current detection circuit 100. In the current detection circuit 100, the first circuit 10 to which the first current detection unit 7 as the first resistance group, the second current detection unit 8 as the second resistance group, and the first current detection unit 7 are connected. A second circuit 11 to which the second current detection unit 8 is connected, and a circuit pattern 12 for connecting the first current detection unit 7 and the second current detection unit 8 are provided.

In FIG. 2, arrows A to H indicate the current flowing through the current detection circuit 100. The width of the arrows A to H indicates that the ratio of the flowing current is large when the width is wide, and the ratio of the flowing current is small when the width is narrow.

The first circuit 10 is a circuit that connects the IGBT 5b and the first current detection unit 7, and has a circuit pattern 10b formed on the laminated printed circuit board 10a and a via 10c. Input electrodes 71a to 74a of shunt resistors 71 to 74, which will be described later, of the first current detection unit 7 are connected to the first circuit 10. The current flowing from the IGBT 5b into the first circuit 10 flows from the first circuit 10 to the shunt resistors 71 to 74 of the first current detection unit 7, as shown by arrows A to D in FIG.

The first current detection unit 7 has circuit patterns 75a to 75c connecting the shunt resistors 71 to 74 as resistors, the output electrodes 71b to 74b of the shunt resistors 71 to 74, and the first detection connected to the shunt resistor 74. It has a detection signal line 76 as a signal line.

The shunt resistors 71 to 74 are resistors having the same predetermined resistance value, and are arranged in parallel with respect to the direction of the current flowing from the first circuit 10 (directions of arrows A to H shown in FIG. 2). The output electrodes 71b to 74b of the shunt resistors 71 to 74 are connected in parallel by the circuit patterns 75a to 75c, and the input electrodes of the shunt resistors 81 to 84 described later in the second current detection unit 8 are connected by the circuit patterns 12a to 12d. Each is connected in series to 81a to 84a. The current flowing from the first circuit 10 to the first current detection unit 7 includes shunt resistors 71 to 74, circuit patterns 75a to 75c, and circuit patterns 12 (12a to 12d) formed on a laminated printed substrate (not shown). The current flows to the second current detection unit 8.

At this time, the first current detection unit 7 transmits an electric signal corresponding to the magnitude of the voltage generated in the shunt resistor 74 due to the flow of the current to the controller 6 via the detection signal line 76. The controller 6 calculates the value of the current flowing through the shunt resistor 74 based on the transmitted electric signal and the resistance value of the shunt resistor 74.

The second current detection unit 8 has circuit patterns 85a to 85c for connecting the shunt resistors 81 to 84 as resistors, the input electrodes 81a to 84a of the shunt resistors 81 to 84, and the second detection connected to the shunt resistor 81. It has a detection signal line 86 as a signal line.

The shunt resistors 81 to 84 are resistors having the same predetermined resistance values as the shunt resistors 71 to 74 of the first current detection unit 7. The shunt resistors 81 to 84 are arranged in parallel with respect to the direction of the current flowing from the first circuit 10 (directions of arrows A to H shown in FIG. 2). The input electrodes 81a to 84a of the shunt resistors 81 to 84 are connected in parallel by the circuit patterns 85a to 85c, and the outputs of the shunt resistors 71 to 74 of the first current detection unit 7 are connected by the circuit patterns 12 (12a to 12d). They are connected in series to the electrodes 71b to 74b, respectively. The current flowing from the first current detection unit 7 to the second current detection unit 8 via the circuit pattern 12 flows to the second circuit 11 via the circuit patterns 85a to 85c and the shunt resistors 81 to 84 (FIG. 2). Arrows E to H).

At this time, the second current detection unit 8 transmits an electric signal corresponding to the magnitude of the voltage generated in the shunt resistor 81 due to the flow of the current to the controller 6 via the detection signal line 86. The controller 6 calculates the current value flowing through the shunt resistor 81 based on the transmitted electric signal and the resistance value of the shunt resistor 81.

The second circuit 11 is a circuit to which the output electrodes 81b to 84b of the shunt resistors 81 to 84 of the second current detection unit 8 are connected, and connects the circuit pattern 11b formed on the laminated printed circuit board 11a and the via 11c. Have. The current flowing from the second current detection unit 8 into the second circuit 11 (arrows E to H in FIG. 2) flows through the circuit pattern 11b and the via 11c to the high-voltage battery 2 via a circuit (not shown).

As described above, in the heating device 1, a plurality of shunt resistors 71 to 74, 81 to 84 are arranged to form the first current detection unit 7 and the second current detection unit 8. This reduces the size of the individual shunt resistors 71-74, 81-84 as compared to a current detection circuit using a single shunt resistor. As the size of the shunt resistors 71-74, 81-84 becomes smaller, the amount of solder that joins the shunt resistors 71-74, 81-84 and the first and second circuits 10 and 11 decreases. Therefore, the expansion / contraction range of the solder due to the temperature change becomes small, and the fatigue of the solder can be suppressed. Therefore, deterioration of the current detection circuit 100 can be suppressed even when exposed to a wide range of temperature changes.

When a plurality of resistors used in the first current detection unit 7 are used as described above, the ratio of the current flowing through each of the shunt resistors 71 to 74 is the circuit patterns 10b and 11b of the first circuit 10 and the second circuit 11. Variations may occur depending on the configurations of the vias 10c and 11c. Similarly, the ratio of the current flowing through each of the shunt resistors 81 to 84 of the second current detection unit 8 may also vary depending on the configurations of the first circuit 10 and the second circuit 11. Therefore, the calculated current value may fluctuate depending on which shunt resistors 71 to 74, 81 to 84 of the first current detection unit 7 and the second current detection unit 8 are connected to the detection signal lines 76 and 86. There is.

Therefore, in the present embodiment, the shunt resistors 71 to 74, respectively, are based on the resistances of the circuit patterns 10b and 11b, the vias 10c and 11c, and the solder constituting the first circuit 10 and the second circuit 11. The ratio of the current flowing through 81 to 84 is obtained, and the shunt resistance of the first current detection unit 7 (indicated by arrows A and E having the same width in FIG. 2) is the same. The detection signal lines 76 and 86 are connected to the shunt resistor 74) in FIG. 2 and the shunt resistor (shunt resistor 81 in FIG. 2) of the second current detection unit 8, respectively.

Here, “same” means comparing the ratio of the current flowing through each of the shunt resistors 71 to 74 of the first current detection unit 7 and the ratio of the current flowing through each of the shunt resistors 81 to 84 of the second current detection unit 8. Sometimes it means that the values are the same or the values are closest.

By determining the connection points of the detection signal lines 76 and 86 as described above, the current value detected by the first current detection unit 7 and the current value detected by the second current detection unit 8 become the same value. Become. Therefore, it is possible to improve the consistency of current detection between the first current detection unit 7 and the second current detection unit 8 in the current detection circuit 100.

Further, since the current values detected by the first current detection unit 7 and the second current detection unit 8 are the same, there is no difference in the values between the current detection units. Therefore, it is not necessary to add a configuration for filling the difference to the current detection circuit 100 or to have the controller 6 perform control for adjusting the difference.

Further, the current detection circuit 100 includes two current detection means (first current detection unit 7 and second current detection unit 8), so that, for example, an abnormality occurs in the first current detection unit 7 and the current cannot be detected. Even so, the second current detection unit 8 can detect the current. That is, the current detection circuit 100 can make the current detection means redundant by including the first current detection unit 7 and the second current detection unit 8.

Further, the controller 6 compares the current value detected by the first current detection unit 7 with the current value detected by the second current detection unit 8, and if the values are the same, the first current detection unit 7 and the second current detection unit 7. The state of the current detection unit 8 may be determined to be normal, and if the values are different, the first current detection unit 7 or the second current detection unit 8 may be determined to be abnormal. With the above configuration, it is possible to monitor whether or not the operating states of the first current detection unit 7 and the second current detection unit 8 are normal.

According to the above first embodiment, the following effects are obtained.

In the current detection circuit 100, a plurality of shunt resistors 71 to 74, 81 to 84 are arranged to form the first current detection unit 7 and the second current detection unit 8. This reduces the size of the individual shunt resistors 71-74, 81-84 as compared to a current detection circuit using a single shunt resistor. As the size of the shunt resistors 71-74, 81-84 becomes smaller, the amount of solder that joins the shunt resistors 71-74, 81-84 to the first circuit 10 and the second circuit 11 becomes smaller. Therefore, the expansion / contraction range of the solder due to the temperature change becomes small, and the fatigue of the solder can be suppressed. Therefore, deterioration of the current detection circuit 100 can be suppressed even when exposed to a wide range of temperature changes.

Further, the current detection circuit 100 determines the ratio of the current flowing through each of the shunt resistors 71 to 74 and 81 to 84 based on the configurations of the first circuit 10 and the second circuit 11, and the current flowing ratio is the same. The detection signal lines 76 and 86 are connected to the shunt resistance of the first current detection unit 7 (shunt resistance 74 in FIG. 2) and the shunt resistance of the second current detection unit 8 (shunt resistance 81 in FIG. 2). As a result, the current value detected by the first current detection unit 7 and the current value detected by the second current detection unit 8 become the same value, so that the first current detection unit 7 and the second current in the current detection circuit 100 It is possible to improve the consistency of current detection with the detection unit 8.

Further, the current detection circuit 100 includes the first current detection unit 7 and the second current detection unit 8 as the current detection means, so that the current detection means can be made redundant.

Further, the controller 6 compares the current value detected by the first current detection unit 7 with the current value detected by the second current detection unit 8, and if the values are the same, the first current detection unit 7 and the first current detection unit 7 and the third. 2 The state of the current detection unit 8 may be determined to be normal, and if the values are different, the first current detection unit 7 or the second current detection unit 8 may be determined to be abnormal. With the above configuration, it is possible to monitor whether or not the operating states of the first current detection unit 7 and the second current detection unit 8 are normal.

(Second Embodiment)
Hereinafter, the current detection circuit 200 according to the second embodiment of the present invention will be described with reference to FIG. In each of the following embodiments, the points different from those of the first embodiment will be mainly described, and the same reference numerals will be given to the configurations having the same functions, and the description thereof will be omitted.

In the second embodiment, the output electrodes 71b to 74b of the shunt resistors 71 to 74 of the first current detection unit 7 and the input electrodes 81a to 84a of the shunt resistors 81 to 84 of the second current detection unit 8 are formed by a circuit pattern 21. It differs from the first embodiment in that it is selectively connected.

FIG. 3 is a schematic view of the current detection circuit 200 according to the second embodiment.

In the present embodiment, the output electrodes 71b to 74b of the shunt resistors 71 to 74 of the first current detection unit 7 and the input electrodes 81a to 84a of the shunt resistors 81 to 84 of the second current detection unit 8 are selectively connected. Therefore, the ratio of the flowing current between the shunt resistor 74 of the first current detection unit 7 and the shunt resistor 84 of the second current detection unit 8 is intentionally made the same.

As shown in FIG. 3, the output electrode 72b of the shunt resistor 72 and the input electrode 82a of the shunt resistor 82 are connected by a circuit pattern 21b, and the output electrode 74b of the shunt resistor 74 and the input electrode 84a of the shunt resistor 84 are circuited. Connect by pattern 21d. Further, the output electrode 71b of the shunt resistance 71 and the input electrode 81a of the shunt resistance 81, and the output electrode 73b of the shunt resistance 73 and the input electrode 83a of the shunt resistance 83 are not connected.

As described above, by connecting the first current detection unit 7 and the second current detection unit 8, the ratio of the current flowing through the shunt resistors 71 to 74, 81 to 84 of the current detection circuit 200 changes. As a result, the shunt resistance 74 of the first current detection unit 7 and the shunt resistance 84 of the second current detection unit 8 have the same ratio of the flowing currents (in FIG. 3, arrows A and H having the same width). (Indicated by). That is, the ratio of the current flowing through the shunt resistor 74 and the shunt resistor 84 can be intentionally made the same.

According to the second embodiment described above, the same effect as that of the first embodiment is obtained, and the output electrodes 71b to 74b of the shunt resistors 71 to 74 of the first current detection unit 7 and the second current detection unit 8 By selectively connecting the input electrodes 81a to 84a of the shunt resistors 81 to 84, the shunt resistors 71 to 74, 81 to 84 having the same ratio of the flowing currents can be arbitrarily selected. Therefore, in the current detection circuit 200, the positions where the detection signal lines 76 and 86 are connected can be arbitrarily selected, and the design of the circuit board can be facilitated. Further, by facilitating the design of the circuit board, it becomes possible to select a small circuit board, and the manufacturing cost of the current detection circuit 200 can be reduced.

(Third Embodiment)
Hereinafter, the current detection circuit 300 according to the third embodiment of the present invention will be described with reference to FIG.

In the third embodiment, the circuit patterns 30b and 40b of the first circuit 30 and the second circuit 40 have the same ratio of the flowing currents in all the shunt resistors 71 to 74, 81 to 84 in the current detection circuit 300. Is set, which is different from the first and second embodiments.

FIG. 4 is a schematic diagram of the current detection circuit 300 according to the third embodiment.

In the present embodiment, the circuit patterns 12, 30b and 40b are formed so that the ratios of the currents flowing through the shunt resistors 71 to 74 and 81 to 84 are all the same.

As shown in FIG. 4, the circuit pattern 30b is formed in a comb-teeth shape composed of a plurality of conductive portions 30c to 30f having different widths. The circuit pattern 40b is also formed in a comb-teeth shape composed of a plurality of conductive portions 40c to 40f having different widths. In the present embodiment, the widths of the conductive portions 30c to 30f and 40c to 40f are formed so as to correspond with each other in the circuit pattern 30b and the circuit pattern 40b. Specifically, if the width of the conductive portion 30c is formed narrow, the width of the conductive portion 40c is formed wide, and if the width of the conductive portion 30f is formed wide, the width of the conductive portion 40f is formed narrow. Further, the circuit pattern 12 is formed so as to connect the output electrodes 71b to 74b of the shunt resistors 71 to 74 and the input electrodes 81a to 84a of the shunt resistors 81 to 84 in series.

The shapes of the circuit patterns 30b and 40b are the total resistance of the path from the conductive portion 30c to the conductive portion 40c via the circuit pattern 12a and the total resistance of the path from the conductive portion 30d to the conductive portion 40d via the circuit pattern 12b. The resistance, the total resistance of the path from the conductive portion 30e to the conductive portion 40e via the circuit pattern 12c, and the total resistance of the path from the conductive portion 30f to the conductive portion 40f via the circuit pattern 12d are all equal. Is set to. As a result, the ratio of the flowing current becomes the same in all the shunt resistors 71 to 74, 81 to 84 of the current detection circuit 300. The same current value can be detected regardless of which shunt resistors 71 to 74, 81 to 84 are connected to the detection signal lines 76 and 86.

According to the third embodiment described above, the same effect as that of the first and second embodiments is obtained, and the ratio of the flowing current is different in all the shunt resistors 71 to 74, 81 to 84 of the current detection circuit 300. Since it is the same, the accuracy of the current value detected by the current detection circuit 300 can be improved.

Here, the shapes of the circuit patterns 12, 30b, and 40b are not limited to the shapes shown in FIG. 4, and if the ratios of the currents flowing in all the shunt resistors 71 to 74, 81 to 84 of the current detection circuit 300 are the same, whichever It may have such a shape.

Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiments. Absent.

In the present embodiment, four shunt resistors 71 to 74 (81 to 84) are used as the first current detection unit 7 (second current detection unit 8), but a plurality of shunt resistors may be used.

Further, if the ratio of the current flowing through the shunt resistor of one of the first current detection units 7 and the shunt resistance of one of the second current detection units 8 is the same, the first current detection unit 7 and the second current detection unit 7 and the second The number of shunt resistors used by the current detection unit 8 does not have to be the same.

Further, although the first circuits 10, 30 and the second circuits 11, 40 and the circuit pattern 12 have been described as being formed on separate substrates, they may be formed on a single substrate.

100 Current detection circuit 200 Current detection circuit 300 Current detection circuit 7 First current detection unit (first resistance group)
8 Second current detector (second resistance group)
10 1st circuit 10b Circuit pattern 10c Via 11 2nd circuit 11b Circuit pattern 11c Via 30 1st circuit 30b Circuit pattern 40 2nd circuit 40b Circuit pattern 71-74 Shunt resistor (resistor)
71a to 74a Input electrodes 71b to 74b Output electrodes 76 Detection signal line (first detection signal line)
81-84 Shunt resistor (resistor)
81a to 84a Input electrodes 81b to 84b Output electrodes 86 Detection signal line (second detection signal line)

Claims (5)

It is a current detection circuit
The first resistor group consisting of multiple resistors and
A second resistance group composed of a plurality of the resistors connected to the first resistance group,
A first circuit connected to the input electrode of each of the resistors in the first resistor group,
A second circuit connected to the output electrode of each of the resistors in the second resistor group,
A first detection signal line connected to the resistor, which is one of the first resistor groups, and for detecting a current flowing through the resistor.
A second detection signal line connected to the resistor, which is one of the second resistor groups, and for detecting a current flowing through the resistor.
With
The first detection signal line and the second detection signal line are the said of the first resistance group in which the ratio of the current flowing through each of the resistors is the same based on the configurations of the first circuit and the second circuit. Connected to the resistor and the resistor in the second group of resistors,
A current detection circuit characterized by that. The current detection circuit according to claim 1.
A plurality of the resistors of the first resistance group are connected in parallel, and the resistors are connected in parallel.
A plurality of the resistors of the second resistance group are connected in parallel, and the resistors are connected in parallel.
The output electrodes of the plurality of resistors in the first resistance group are connected in series with the input electrodes of the plurality of resistors in the second resistance group, respectively.
A current detection circuit characterized by that. The current detection circuit according to claim 1.
A plurality of the resistors of the first resistance group are arranged in parallel.
A plurality of the resistors of the second resistance group are arranged in parallel.
The output electrodes of the plurality of resistors in the first resistance group and the input electrodes of the plurality of resistors in the second resistance group are selectively connected.
A current detection circuit characterized by that. It is a current detection circuit
A first resistor group in which a plurality of resistors are arranged in parallel with respect to the current flow direction,
A second resistor group in which a plurality of the resistors connected in series with the output electrodes of the plurality of resistors in the first resistor group are arranged in parallel with respect to the current flow direction.
A first circuit connected to the input electrode of each of the resistors in the first resistor group,
A second circuit connected to the output electrode of each of the resistors in the second resistor group,
A first detection signal line connected to the resistor, which is one of the first resistor groups, and for detecting a current flowing through the resistor.
A second detection signal line connected to the resistor, which is one of the second resistor groups, and for detecting a current flowing through the resistor.
With
The shape of the circuit pattern formed in the first circuit and the second circuit is such that the ratio of the flowing current is the same in all the resistors of the first resistance group and the second resistance group. Set,
A current detection circuit characterized by that. The current detection circuit according to any one of claims 1 to 4.
The proportion of current flowing through the resistor is determined based on the circuit patterns, vias, and solder resistances that make up the first and second circuits.
A current detection circuit characterized by that.

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