Power supply device

Abstract

To suppress common mode noise while suppressing increase in size and power loss.SOLUTION: A power supply device includes: a first input terminal and a second input terminal electrically connected to a control power supply; a first common mode choke coil having a first winding with one end electrically connected to the first input terminal and a second winding with one end electrically connected to the second input terminal; a main circuit having a switching element to output power to a load; a control circuit that receives power supply from the other end of the first winding and the other of the second winding of the first common mode choke coil and outputs a switching signal to the switching element; and a metallic body thermally connected to the switching element and electrically connected to the other end of the second winding of the first common mode choke coil.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power supply device. [Background technology]

[0002] Patent Document 1 describes a noise suppression technique for a switching power supply. In the technique described in Patent Document 1, a heat sink that dissipates heat from a switching element and the emitter of the switching element are electrically connected by a capacitor or a high resistor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-328710 Summary of the Invention [Problem to be solved by the invention]

[0004] A switching power supply includes a main circuit (power circuit) that supplies power to a load, and a control circuit that outputs a switching signal to a switching element of the main circuit. The low-potential side wiring of the control circuit is electrically connected to a reference potential (e.g., ground potential) wiring, but the low-potential side wiring of the main circuit is not electrically connected to the reference potential wiring.

[0005] Therefore, in the technology described in Patent Document 1, the heat sink is in an electrically floating state. Therefore, noise propagated from the switching element to the heat sink via parasitic capacitance flows as a noise current to the reference potential wiring via the parasitic capacitance between the heat sink and the reference potential wiring, generating common mode noise. This common mode noise flows out of the switching power supply and returns to the main circuit. Furthermore, if common mode noise flows out of the switching power supply, it can cause noise problems such as malfunctions of other devices.

[0006] To combat the common-mode noise, it is necessary to provide a high-inductance common-mode choke coil in the main circuit. High voltages and large currents often flow through the main circuit. Therefore, installing a high-inductance common-mode choke coil in the main circuit leads to disadvantages such as an increase in the size of the switching power supply and increased power loss.

[0007] The present invention has been made in view of the above, and has an object to suppress common mode noise while suppressing an increase in size and power loss. [Means for solving the problem]

[0008] A power supply device according to one aspect of the present invention includes: a first common mode choke coil having a first input terminal and a second input terminal electrically connected to a control power supply, a first winding having one end electrically connected to the first input terminal, and a second winding having one end electrically connected to the second input terminal; a main circuit having a switching element and outputting power to a load; a control circuit receiving a supply of power from the other end of the first winding and the other end of the second winding of the first common mode choke coil and outputting a switching signal to the switching element; and a metal body thermally coupled to the switching element and electrically connected to the other end of the second winding of the first common mode choke coil. [Effects of the Invention]

[0009] According to the present invention, it is possible to suppress common mode noise while suppressing an increase in size and power loss. This makes it possible to: [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an outline of a circuit configuration of a power supply device according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram of the power supply device according to the first embodiment. [Figure 3] FIG. 3 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the second embodiment. [Figure 4]FIG. 4 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the third embodiment. [Figure 5] FIG. 5 is a schematic diagram of a power supply device according to the third embodiment. [Figure 6] FIG. 6 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the fourth embodiment. [Figure 7] FIG. 7 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the fifth embodiment. [Figure 8] FIG. 8 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the sixth embodiment. [Figure 9] FIG. 9 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The following describes in detail embodiments of the power supply device of the present invention with reference to the drawings. However, the present invention is not limited to these embodiments. Each embodiment is merely an example, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible.

[0012] First Embodiment (composition) FIG. 1 is a diagram illustrating an outline of a circuit configuration of a power supply device according to a first embodiment.

[0013] The power supply device 1 operates by receiving power from a control power supply 2 and a main power supply 3, and supplies power to a load 4.

[0014] A high-potential terminal of the control power supply 2 is electrically connected to a first input terminal 1a of the power supply device 1. A low-potential terminal of the control power supply 2 is electrically connected to a second input terminal 1b of the power supply device 1. The control power supply 2 outputs a first voltage between the first input terminal 1a and the second input terminal 1b. The first voltage of the control power supply 2 is lower than the second voltage of the main power supply 3.

[0015] The second input terminal 1b is electrically connected to a reference potential wiring 5. The reference potential of the reference potential wiring 5 is, for example, a ground potential. When the power supply device 1 is mounted on a vehicle, the reference potential of the reference potential wiring 5 is, for example, the potential of the vehicle body (chassis). However, the present disclosure is not limited to this.

[0016] A high-potential terminal of the main power supply 3 is electrically connected to the third input terminal 1c of the power supply device 1. A low-potential terminal of the main power supply 3 is electrically connected to the fourth input terminal 1d of the power supply device 1. The main power supply 3 outputs a second voltage between the third input terminal 1c and the fourth input terminal 1d.

[0017] One end of the load 4 is electrically connected to the first output terminal 1e of the power supply device 1. The other end of the load 4 is electrically connected to the second output terminal 1f of the power supply device 1.

[0018] The power supply device 1 includes a first common mode choke coil 10, a control circuit 20, a main circuit 30, and a metal body 40.

[0019] The control circuit 20 operates by receiving power from the control power supply 2, and outputs a switching signal to the switching element 30b in the main circuit 30. The main circuit 30 converts the power supplied from the main power supply 3 and outputs it to the load 4 as the switching element 30b performs a switching operation.

[0020] One end of the first winding 10a of the first common mode choke coil 10 is electrically connected to the first input terminal 1a. The other end of the first winding 10a is electrically connected to one end of a high-potential side wiring 23. The other end of the high-potential side wiring 23 is electrically connected to the control circuit 20.

[0021] One end of the second winding 10b of the first common mode choke coil 10 is electrically connected to the second input terminal 1b. The other end of the second winding 10b is electrically connected to one end of the low-potential side wiring 24. The other end of the low-potential side wiring 24 is electrically connected to the control circuit 20.

[0022] The control circuit 20 includes a power supply circuit 21 and a gate driver 22 .

[0023] The power supply circuit 21 includes an input capacitor 21a, a switching element 21b, and an output capacitor 21c. The power supply circuit 21 may be, for example, a converter, an inverter, a chopper, or the like, but the present disclosure is not limited to these. The switching element 21b may be one or more.

[0024] The input capacitor 21a smoothes the voltage input from the control power supply 2. The switching element 21b converts the power input from the control power supply 2. The output capacitor 21c smoothes the voltage output from the switching element 21b.

[0025] The power supply circuit 21 converts the power supplied from the control power supply 2 via the first common mode choke coil 10 and outputs the converted power to the gate driver 22.

[0026] The gate driver 22 operates using power supplied from the power supply circuit 21. The gate driver 22 outputs a switching signal to the gate of the switching element 30b in the main circuit 30.

[0027] The main circuit 30 is electrically connected to the third input terminal 1c via a high-potential side wiring 31. The main circuit 30 is electrically connected to the fourth input terminal 1d via a low-potential side wiring 32.

[0028] The main circuit 30 includes an input capacitor 30a, a switching element 30b, and an output capacitor 30c. The main circuit 30 may be exemplified by a converter, an inverter, a chopper, or the like, but the present disclosure is not limited to these. The switching element 30b may be one or more.

[0029] The main circuit 30 is electrically connected to the first output terminal 1e via a high-potential side wiring 33. The main circuit 30 is electrically connected to the second output terminal 1f via a low-potential side wiring 34.

[0030] The input capacitor 30a smoothes the voltage input from the main power supply 3. The switching element 30b converts the power input from the main power supply 3. The output capacitor 30c smoothes the voltage output from the switching element 30b.

[0031] The main circuit 30 converts the power supplied from the main power supply 3 and outputs it to the load 4 .

[0032] The metal body 40 is thermally coupled to the switching element 30b via a first thermally conductive sheet 50 (described later). Instead of the first thermally conductive sheet 50, thermally conductive grease or the like may be used.

[0033] Thermal coupling means that heat generated by the switching element 30b is dissipated from the metal body 40. As an example, heat is transferred directly from the switching element 30b to the metal body 40. Alternatively, heat generated by the switching element 30b may be transferred to a heat dissipation sheet or grease, and the heat transferred to the heat dissipation sheet or grease may be transferred to the metal body 40, and the heat transferred to the metal body 40 may be transferred (dissipated) into the air. The grease may be made of silicon, boron nitride, or the like. The heat dissipation sheet may be made of silicon, boron nitride, graphite, or the like.

[0034] In the first embodiment, the metal body 40 is a heat sink. The heat sink may be in the shape of a simple plate, or may have heat dissipation fins. The metal body 40 dissipates heat generated by the switching element 30b. The metal body 40 may be air-cooled or liquid-cooled. Alternatively, the metal body 40 may be cooled by a Peltier element or the like. A heat sink is considered to be a metal body 40 if the switching element 30b is thermally coupled to the metal body 40 that has a larger surface area than the switching element 30b.

[0035] A parasitic capacitance 42 occurs between the metal body 40 and the reference potential wiring 5 .

[0036] The metal body 40 is electrically connected to the wiring 24 via the wiring 41. In other words, the metal body 40 is electrically connected to the reference potential, and the potential of the metal body 40 is the reference potential.

[0037] Fig. 2 is a schematic diagram of the power supply device according to the first embodiment, as viewed from a direction parallel to the main surface of the substrate 60 on which the switching element 30b and the metal body 40 are mounted.

[0038] 2 does not show the first common mode choke coil 10 and the control circuit 20. The first common mode choke coil 10 and the control circuit 20 may be mounted on the substrate 60, or may be mounted on a second substrate (not shown) electrically connected to the substrate 60.

[0039] The wiring 24 is provided inside the substrate 60. The wiring 24 may be provided on the first main surface 60a or the second main surface 60b of the substrate 60.

[0040] The first thermally conductive sheet 50 has electrical insulation properties. If the thermal conductivity is higher than that of air, it is considered to be a thermally conductive sheet. Examples of materials for thermally conductive sheets include silicon, boron nitride, and graphite.

[0041] The first thermally conductive sheet 50 is thermally coupled to the switching element 30b. For example, the first thermally conductive sheet 50 may be attached to the switching element 30b.

[0042] The metal body 40 is thermally coupled to the first thermally conductive sheet 50. For example, the metal body 40 may be attached to the first thermally conductive sheet 50.

[0043] A parasitic capacitance 43 occurs between the switching element 30b and the metal body 40.

[0044] The metal body 40 is electrically connected to the wiring 24 through a wiring 41. The wiring 41 may be a via or the like.

[0045] (effect) 1, the metal body 40 is electrically connected to the wiring 24 via the wiring 41. That is, the potential of the metal body 40 is the reference potential. Therefore, noise current is less likely to flow from the metal body 40 to the reference potential wiring 5 via the parasitic capacitance 42. Therefore, the power supply device 1 can suppress the generation of common-mode noise.

[0046] Meanwhile, noise current flows from the metal body 40 into the control circuit 20 (wire 24) via the wire 41. The noise current that flows into the wire 24 also flows into the wire 23 via the input capacitor 21a. That is, a common mode current flows through the wires 23 and 24. If the common mode current reaches the control power supply 2, it will cause noise interference with other devices, which will be a problem. However, the power supply device 1 is provided with a high-inductance first common mode choke coil 10 between the wires 23 and 24 and the first input terminal 1a and second input terminal 1b. This allows the power supply device 1 to confine common mode noise within the power supply device 1 and to prevent the common mode current from leaking out of the power supply device 1.

[0047] The control circuit 20 operates at a low voltage and a small current. Therefore, even if the first common mode choke coil 10 has a high inductance, the size can be made small and power loss is small. Therefore, even if the power supply device 1 includes a first common mode choke coil 10 with a high inductance, the size can be kept small and power loss can be suppressed.

[0048] This allows the power supply device 1 to suppress common mode noise while suppressing an increase in size and power loss.

[0049] The first common mode choke coil 10 can also suppress noise caused by the power supply circuit 21. That is, the power supply device 1 can also suppress noise caused by the power supply circuit 21.

[0050] <Second embodiment> Of the components of the second embodiment, the same components as those of the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0051] (composition) FIG. 3 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the second embodiment.

[0052] Compared to the power supply device 1 (see FIG. 1), the power supply device 1A further includes a second common mode choke coil .

[0053] One end of the first winding 70a of the second common mode choke coil 70 is electrically connected to the third input terminal 1c. The other end of the first winding 70a is electrically connected to the high-potential side wiring 31. One end of the second winding 70b of the second common mode choke coil 70 is electrically connected to the fourth input terminal 1d. The other end of the second winding 70b is electrically connected to the low-potential side wiring 32.

[0054] The second common mode choke coil 70 preferably has a lower inductance than the first common mode choke coil 10.

[0055] Alternatively, it is preferable that the self-resonant frequency of the second common mode choke coil 70 is lower than the self-resonant frequency of the first common mode choke coil 10. For example, the self-resonant frequency of the second common mode choke coil 70 is exemplified as being less than 10 MHz (megahertz), and the self-resonant frequency of the first common mode choke coil 10 is exemplified as being 10 MHz or higher.

[0056] (effect) As described in the first embodiment, the main propagation path of common mode noise is the first path that passes through the wiring 41 and the control circuit 20. However, there may also be a second path that does not pass through the wiring 41 and the control circuit 20. For example, the second path may be a path that returns from the switching element 30b to the switching element 30b via the parasitic capacitance 43 (see FIG. 2), the metal body 40, the parasitic capacitance 42 (see FIG. 3), and the reference potential wiring 5. Common mode noise, although weak, may flow through this second path.

[0057] Therefore, the power supply device 1A includes a low-inductance second common-mode choke coil 70 between the wiring 31 and 32 and the third input terminal 1c and the fourth input terminal 1d. This allows the power supply device 1A to suppress common-mode noise flowing through the second path. Therefore, the power supply device 1A can further suppress common-mode noise compared to the power supply device 1.

[0058] Furthermore, the common mode noise flowing through the second path is weak. Therefore, the second common mode choke coil 70 requires a lower inductance than the first common mode choke coil 10. That is, the second common mode choke coil 70 requires a smaller size and has a smaller power loss. Therefore, even if the power supply device 1A includes the second common mode choke coil 70, the disadvantages of size and power loss are small.

[0059] <Third embodiment> Of the components of the third embodiment, the same components as those of the other embodiments are denoted by the same reference numerals and description thereof will be omitted.

[0060] (composition) FIG. 4 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the third embodiment.

[0061] Compared to power supply device 1 (see FIG. 1), power supply device 1B further includes a housing 80.

[0062] The housing 80 accommodates the first common mode choke coil 10, the control circuit 20, and the main circuit 30.

[0063] The housing 80 is electrically conductive, and is exemplified by a metal. The housing 80 is electrically connected to the reference potential wiring 5 via a conductor 81. In other words, the housing 80 is electrically connected to the reference potential.

[0064] When the power supply device 1B is mounted on a vehicle, a metal screw is exemplified as the conductor 81. The housing 80 is electrically connected to the chassis of the vehicle, that is, to the reference potential, by the screw.

[0065] The housing 80 is thermally coupled to the metal body 40 via a second thermally conductive sheet 90 (described later). Instead of the second thermally conductive sheet 90, thermally conductive grease or the like may be used.

[0066] The housing 80 dissipates heat from the switching element 30b. The housing 80 may be air-cooled or liquid-cooled. Alternatively, the housing 80 may be cooled by a Peltier element or the like.

[0067] Fig. 5 is a schematic diagram of a power supply device according to the third embodiment, as viewed from a direction parallel to the main surface of a substrate 60 on which a switching element 30b and a metal body 40 are mounted.

[0068] Compared to the power supply device 1 (see FIG. 2), the power supply device 1B further includes a housing 80 and a second thermally conductive sheet 90.

[0069] The second thermally conductive sheet 90 has insulating properties. The second thermally conductive sheet 90 is thermally coupled to the metal body 40. For example, the second thermally conductive sheet 90 may be attached to the metal body 40.

[0070] The housing 80 is thermally coupled to the second thermally conductive sheet 90. For example, the housing 80 may be attached to the second thermally conductive sheet 90.

[0071] The housing 80 dissipates the heat generated by the switching element 30b.

[0072] A parasitic capacitance 82 occurs between the metal body 40 and the housing 80 .

[0073] (effect) 4, metal body 40 is electrically connected to wiring 24 via wiring 41. That is, the potential of metal body 40 becomes the reference potential. Therefore, noise current is less likely to flow from metal body 40 to housing 80 (chassis) via parasitic capacitance 82 (see FIG. 5). Therefore, power supply device 1B can suppress the generation of common mode noise.

[0074] On the other hand, common mode noise flows from the metal body 40 to the control circuit 20 via the wiring 41. However, the power supply device 1B includes a high-inductance first common mode choke coil 10 between the wirings 23 and 24 and the first input terminal 1a and second input terminal 1b. This allows the power supply device 1B to confine the common mode noise within the power supply device 1 and to prevent common mode current from flowing out of the power supply device 1B.

[0075] The control circuit 20 operates at a low voltage and a small current. Therefore, even if the first common mode choke coil 10 has a high inductance, the size can be made small and power loss is small. Therefore, even if the power supply device 1B includes a first common mode choke coil 10 with a high inductance, the size can be kept small and power loss can be suppressed.

[0076] This allows the power supply device 1B to suppress common mode noise while suppressing an increase in size and power loss.

[0077] The first common mode choke coil 10 can also suppress noise caused by the power supply circuit 21. That is, the power supply device 1B can also suppress noise caused by the power supply circuit 21.

[0078] <Fourth embodiment> Among the components of the fourth embodiment, the same components as those of the other embodiments are denoted by the same reference numerals and the description thereof will be omitted.

[0079] (composition) FIG. 6 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the fourth embodiment.

[0080] Compared to the power supply device 1B (see FIG. 4), the power supply device 1C further includes a second common mode choke coil .

[0081] (effect) As described in the first embodiment, the main propagation path of common mode noise is the first path that passes through the wiring 41 and the control circuit 20. However, there may also be a third path that does not pass through the wiring 41 and the control circuit 20. For example, the third path may be a path that returns from the switching element 30b to the switching element 30b via the parasitic capacitance 43 (see FIG. 5), the metal body 40, the parasitic capacitance 82 (see FIG. 5), the housing 80, the conductor 81 (see FIG. 6), the chassis (not shown), and the reference potential wiring 5. Common mode noise, although weak, may flow through this third path.

[0082] Therefore, the power supply device 1C includes a low-inductance second common-mode choke coil 70 between the wiring 31 and 32 and the third and fourth input terminals 1c and 1d. This allows the power supply device 1C to suppress common-mode noise flowing through the third path. Therefore, the power supply device 1C can further suppress common-mode noise compared to the power supply device 1B.

[0083] Furthermore, the common mode noise flowing through the third path is weak. Therefore, the second common mode choke coil 70 requires a lower inductance than the first common mode choke coil 10. That is, the second common mode choke coil 70 requires a smaller size and requires less power loss. Therefore, even if the power supply device 1C includes the second common mode choke coil 70, the disadvantages of size and power loss are small.

[0084] <Fifth embodiment> Of the components of the fifth embodiment, the same components as those of the other embodiments are denoted by the same reference numerals and the description thereof will be omitted.

[0085] (composition) FIG. 7 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the fifth embodiment.

[0086] In comparison with the power supply device 1C (see FIG. 6), the power supply device 1D has a metal body 40 connected to the wiring 23 via a wiring 41.

[0087] (effect) The metal body 40 is electrically connected to the wiring 24 via the wiring 41, the wiring 23, and the input capacitor 21a in terms of AC. Because the wiring 24 is at DC potential, noise current is less likely to flow from the metal body 40 to the reference potential wiring 5 via the parasitic capacitance 82 (see FIG. 5). Instead, the noise current flows through the wiring 23 and also flows to the wiring 24 via the input capacitor 21a, becoming a common mode current flowing through the wiring 23 and the wiring 24. However, this common mode current is blocked by the first common mode choke coil 10 and does not flow outside the power supply device 1D. Therefore, the power supply device 1D can suppress the generation of common mode noise.

[0088] Sixth Embodiment Of the components of the sixth embodiment, the same components as those of the other embodiments are denoted by the same reference numerals and description thereof will be omitted.

[0089] (composition) FIG. 8 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the sixth embodiment.

[0090] In comparison with power supply device 1C (see FIG. 6), power supply device 1E has metal body 40 connected to wiring 31 via wiring 41.

[0091] (effect) Common mode noise flows back from the metal body 40 to the main circuit 30 via the wiring 41. The power supply device 1E can confine a large proportion of the common mode noise inside the main circuit 30, and can suppress the common mode current from flowing out of the power supply device 1E.

[0092] Seventh Embodiment Of the components of the seventh embodiment, the same components as those of the other embodiments are denoted by the same reference numerals and the description thereof will be omitted.

[0093] (composition) FIG. 9 is a diagram illustrating an outline of a circuit configuration of a power supply device according to the seventh embodiment.

[0094] In comparison with the power supply device 1E (see FIG. 8), the power supply device 1F has a metal body 40 connected to the wiring 32 via a wiring 41.

[0095] (effect) The same effects as those of the sixth embodiment can be obtained.

[0096] <Configuration Example of the Present Disclosure> The present disclosure may also have the following configurations.

[0097] (1) a first input terminal and a second input terminal electrically connected to a control power supply; a first common mode choke coil having a first winding electrically connected to the first input terminal and a second winding electrically connected to the second input terminal; a main circuit having a switching element and outputting power to a load; a control circuit that receives power from the other end of the first winding and the other end of the second winding of the first common mode choke coil and outputs a switching signal to the switching element; a metal body thermally coupled to the switching element and electrically connected to the other end of the second winding of the first common mode choke coil; Including, power supply.

[0098] (2) The power supply device according to (1) above, The metal body is a heat sink. power supply.

[0099] (3) The power supply device according to (1) or (2) above, a first thermally conductive sheet provided between the switching element and the metal body; Further comprising: power supply.

[0100] (4) The power supply device according to any one of (1) to (3) above, a third input terminal and a fourth input terminal electrically connected to the main power supply; a second common mode choke coil having a lower inductance than the first common mode choke coil, the second common mode choke coil including: a first winding having one end electrically connected to the third input terminal and the other end electrically connected to the main circuit; and a second winding having one end electrically connected to the fourth input terminal and the other end electrically connected to the main circuit; Further comprising: power supply.

[0101] (5) The power supply device according to (1) above, a housing thermally coupled to the metal body and electrically connected to a reference potential; Further comprising: power supply.

[0102] (6) The power supply device according to (5) above, a second thermally conductive sheet provided between the metal body and the housing; Further comprising: power supply.

[0103] (7) The power supply device according to (5) or (6) above, a third input terminal and a fourth input terminal electrically connected to the main power supply; a second common mode choke coil having a lower inductance than the first common mode choke coil, the second common mode choke coil including: a first winding having one end electrically connected to the third input terminal and the other end electrically connected to the main circuit; and a second winding having one end electrically connected to the fourth input terminal and the other end electrically connected to the main circuit; Further comprising: power supply.

[0104] (8) The power supply device according to any one of (1) to (7) above, The metal body and the other end of the first winding of the first common mode choke coil are electrically connected. power supply.

[0105] (9) The power supply device according to (4) or (7) above, The metal body and the other end of the first winding of the second common mode choke coil are electrically connected. power supply.

[0106] (10) The power supply device according to (4) or (7) above, The metal body and the other end of the second winding of the second common mode choke coil are electrically connected. power supply.

[0107] The power supply device according to (4) or (7) above, The voltage of the control power supply is lower than the voltage of the main power supply. power supply.

[0108] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit and scope of the present invention, and equivalents thereof are also included in the present invention. [Explanation of symbols]

[0109] 1, 1A, 1B, 1C, 1D, 1E, 1F power supply 2 Control power supply 3 Main power 4. Load 5 Reference potential wiring 10 First common mode choke coil 20 Control circuit 21 Power circuit 21a, 30a input capacitor 21b, 30b Switching elements 21c, 30c output capacitor 22 Gate Driver 30 Main circuit 40 Metal body 42, 43, 82 Parasitic capacitance 50 First thermal conductive sheet 70 Second common mode choke coil 80 cabinets 81 Conductor 90 Second thermal conductive sheet

Claims

1. A main circuit having a switching element and outputting power to a load; a first input terminal and a second input terminal electrically connected to a control power supply; a first common mode choke coil having a first winding electrically connected to the first input terminal and a second winding electrically connected to the second input terminal, the first common mode choke coil being provided to reduce common mode noise caused by switching elements of the main circuit; a control circuit that receives power from the other end of the first winding and the other end of the second winding of the first common mode choke coil and outputs a switching signal to the switching element; a metal body thermally coupled to the switching element and electrically connected to the other end of the second winding of the first common mode choke coil; Including, power supply.

2. 2. The power supply device according to claim 1, The metal body is a heat sink. power supply.

3. 3. The power supply device according to claim 1 or 2, a first thermally conductive sheet provided between the switching element and the metal body; Further comprising: power supply.

4. 2. The power supply device according to claim 1, a third input terminal and a fourth input terminal electrically connected to the main power supply; a second common mode choke coil having a lower inductance than the first common mode choke coil, the second common mode choke coil including: a first winding having one end electrically connected to the third input terminal and the other end electrically connected to the main circuit; and a second winding having one end electrically connected to the fourth input terminal and the other end electrically connected to the main circuit; Further comprising: power supply.

5. 2. The power supply device according to claim 1, a housing thermally coupled to the metal body and electrically connected to a reference potential; Further comprising: power supply.

6. 6. The power supply device according to claim 5, a second thermally conductive sheet provided between the metal body and the housing; Further comprising: power supply.

7. 7. The power supply device according to claim 5 or 6, a third input terminal and a fourth input terminal electrically connected to a main power supply; a second common mode choke coil having a lower inductance than the first common mode choke coil, the second common mode choke coil including: a first winding having one end electrically connected to the third input terminal and the other end electrically connected to the main circuit; and a second winding having one end electrically connected to the fourth input terminal and the other end electrically connected to the main circuit; Further comprising: power supply.

8. A main circuit having a switching element and outputting power to a load; a first input terminal and a second input terminal electrically connected to a control power supply; a first common mode choke coil having a first winding electrically connected to the first input terminal and a second winding electrically connected to the second input terminal, the first common mode choke coil being provided to reduce common mode noise caused by switching elements of the main circuit; a control circuit that receives power from the other end of the first winding and the other end of the second winding of the first common mode choke coil and outputs a switching signal to the switching element; a metal body thermally coupled to the switching element and electrically connected to the other end of the first winding of the first common mode choke coil; Including, power supply.

9. 9. The power supply device according to claim 8, a third input terminal and a fourth input terminal electrically connected to the main power supply; a second common mode choke coil having a lower inductance than the first common mode choke coil, the second common mode choke coil including: a first winding having one end electrically connected to the third input terminal and the other end electrically connected to the main circuit; and a second winding having one end electrically connected to the fourth input terminal and the other end electrically connected to the main circuit; Further comprising: power supply.

10. 10. The power supply device according to claim 9, the metal body and the other end of the first winding of the first common mode choke coil are electrically disconnected, and the metal body and the other end of the first winding of the second common mode choke coil are electrically connected; power supply.

11. 10. The power supply device according to claim 9, the metal body and the other end of the first winding of the first common mode choke coil are electrically disconnected, and the metal body and the other end of the second winding of the second common mode choke coil are electrically connected; power supply.

12. 5. The power supply device according to claim 4, The voltage of the control power supply is lower than the voltage of the main power supply. power supply.

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