阅读说明：本技术 车载电源装置 (Vehicle-mounted power supply device ) 是由 益井秀彰 于 2020-09-11 设计创作，主要内容包括：本发明包括一个或多个调节单元,被构造为在单元壳体中容纳影响电源部的输出的阻抗的一个或多个电子部件,在该单元壳体中至少连接部具有预定的形状和尺寸；以及单元支撑部,其设置在电源部的内部或电源部的输出与负载之间,并且可拆卸地支撑调节单元。当输出侧的线束和负载的阻抗根据车辆类型的不同而改变时,仅通过更换要安装的调节单元就可以实现充分的噪声降低,而无需改变电源部的主体的构造。由于不论车辆类型的差异如何都可以共同使用部件和部件编号,因此可以降低成本。(The present invention includes one or more adjusting units configured to accommodate one or more electronic components affecting impedance of an output of a power supply section in a unit case in which at least a connecting section has a predetermined shape and size; and a unit support part which is provided inside the power supply part or between an output of the power supply part and the load, and detachably supports the adjusting unit. When the impedances of the wire harness and the load on the output side are changed depending on the type of vehicle, sufficient noise reduction can be achieved only by replacing the adjusting unit to be mounted without changing the configuration of the main body of the power supply portion. Since the components and the component numbers can be commonly used regardless of the differences in the types of vehicles, the cost can be reduced.)

1. An onboard power supply apparatus includes: a power supply section including a noise generation source; and one or more output terminals capable of connecting a desired load to an output of the power supply section, the apparatus comprising:

one or more adjusting units configured to accommodate one or more electronic components affecting an impedance of an output of the power supply section in a unit case in which at least a connecting section has a predetermined shape and size; and

a unit support part disposed inside the power supply part or between an output of the power supply part and the load, and detachably supporting the adjusting unit.

2. The vehicular power supply apparatus according to claim 1, wherein

The power supply section includes:

a switching unit configured to periodically repeat switching of the power supply; and

a power distribution unit configured to distribute the output power of the switching unit to loads of a plurality of systems, and

the unit supporting part is formed at one side of the power distribution unit.

3. The vehicular power supply apparatus according to claim 2,

the adjusting unit includes a plurality of circuits independent from each other so as to adjust the impedance individually for each of the loads of the plurality of systems.

4. The vehicular power supply apparatus according to claim 2,

the power distribution unit includes a plurality of the unit supporting parts so as to accommodate the plurality of adjusting units individually corresponding to each of the loads of the plurality of systems.

5. The vehicular power supply apparatus according to any one of claims 1 to 4,

the adjusting unit includes at least one capacitor incorporated therein as the electronic component.

Technical Field

The present invention relates to a vehicle-mounted power supply device, and more particularly, to a technique for reducing noise generated by a power supply.

Background

For example, a power supply such as an in-vehicle battery capable of supplying a large amount of electric power is mounted on a vehicle such as an electric vehicle. Such power supplies include DC/DC converters so that power supplies having appropriate voltages can be supplied for various loads. Since such a DC/DC converter employs Pulse Width Modulation (PWM) control, switching of a large current is periodically repeated at a high speed, thereby generating relatively large noise in a frequency region such as a high frequency due to the switching thereof. Since noise generated by the power supply propagates to various portions of the vehicle via each wire of the wire harness and adversely affects the load on the vehicle, it is necessary to reduce the noise generated by the power supply.

Therefore, for example, the high-frequency noise filter for an in-vehicle apparatus in patent document 1 describes a technique that can obtain a sufficient noise reduction effect within a frequency band assumed at the time of design even in a case where a conductor to be grounded is not exposed in the vicinity of a load of a vehicle that radiates electromagnetic noise.

List of citations

Patent document

[ patent document 1] JP-A-2012- & 105081

When the above noise is reduced in a vehicle, for example, as described in patent document 1, a noise filter including a capacitor is generally connected between a power supply line and a ground line. Actually, as a countermeasure against noise, the following design is made: a noise filter is added to an internal circuit of the DC/DC converter, or the noise filter is inserted into an end portion and a middle portion of each wire of the wire harness.

However, for example, since the length of the electric wire of the wire harness connected to the output side of the power supply and the type of the load connected thereto vary for each vehicle, the output impedance as viewed from the power supply side may vary for each vehicle. When the output impedance varies, the variation thereof affects the characteristics of the noise filter, and a sufficient noise reduction effect may not be obtained.

Therefore, as a countermeasure against noise in the vehicle, measures need to be taken individually for each vehicle, so that there is a problem that the working cost such as design change increases. When different types of noise filters may be mounted on the internal circuit of the DC/DC converter of each vehicle type or the noise filters mounted on the wire harness are changed, the number of components of the DC/DC converter and the wire harness varies according to each vehicle type, thereby hindering the versatility of the components and thus increasing the cost.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an in-vehicle power supply device in which sufficient countermeasures against noise can be performed, and generalization of the part number of a power supply component can be performed even if the type of vehicle in which the in-vehicle power supply device is mounted is different.

An onboard power supply apparatus, comprising: a power supply section including a noise generation source; and one or more output terminals capable of connecting a desired load to an output of the power supply section, the apparatus comprising:

one or more adjusting units configured to accommodate one or more electronic components affecting an impedance of an output of the power supply section in a unit case in which at least a connecting section has a predetermined shape and size; and

a unit support part disposed inside the power supply part or between an output of the power supply part and the load, and detachably supporting the adjusting unit.

The present invention has been described briefly above. The details of the present invention will be further clarified by reading the mode for carrying out the present invention (hereinafter, referred to as "embodiment") described below with reference to the drawings.

Drawings

Fig. 1 is a block diagram showing a first configuration example of an in-vehicle power supply device of an embodiment of the invention;

fig. 2 is a longitudinal sectional view showing a structural example of an adjustment unit mounted on a housing of the in-vehicle power supply device;

fig. 3 is a perspective view showing an outline of an external appearance in a first configuration example of the in-vehicle power supply device;

fig. 4 is a perspective view showing an outline of an external appearance in a second configuration example of the in-vehicle power supply device;

fig. 5 is a block diagram showing a circuit in a second configuration example of the in-vehicle power supply device;

fig. 6 is a perspective view showing a specific example of an external appearance in a second configuration example of the in-vehicle power supply device; and

fig. 7 is a longitudinal sectional view showing a mounted state of a plurality of adjusting units according to a modification.

Detailed Description

Hereinafter, specific embodiments according to the present invention will be described with reference to each drawing.

< first configuration example of in-vehicle Power supply apparatus >

Fig. 1 is a block diagram showing a first configuration example of an in-vehicle power supply device 10 according to an embodiment of the invention.

The vehicle-mounted power supply apparatus 10 shown in fig. 1 is mounted on a vehicle such as an electric vehicle and a hybrid vehicle, generates required power based on power supplied from a vehicle-mounted battery 21, and is used to supply the generated power to various loads 23, 24, and 25, respectively. The loads 23, 24, and 25 are, for example, various Electronic Control Units (ECUs), motors, lamps, and heaters.

In the example shown in fig. 1, the power input terminal 15 and the ground terminal 16 provided in the case 11 of the vehicle-mounted power supply device 10 are connected to the positive electrode of the vehicle-mounted battery 21 and the ground 22, respectively. The loads 23, 24, and 25 are connected to the plurality of output terminals 17, 18, and 19 provided in the housing 11 via wires 26, 27, and 28 of the wire harness WH, respectively.

The in-vehicle power supply device 10 includes a DC/DC converter 12 and a power distribution circuit section 13 incorporated therein. The DC/DC converter 12 has a function of converting a voltage (e.g., 200V) of the power supply power supplied from the vehicle-mounted battery 21 into a desired power supply voltage (e.g., 12V) required by the load. Specifically, PWM control is performed by periodically turning on and off a switching device, not shown, inside the DC/DC converter 12, so that a desired power supply voltage is generated with relatively small loss.

When the DC/DC converter 12 supplies a large current to the output side, relatively large electrical noise is generated particularly in a region having a high frequency according to the periodic current switching operation. Since the amount of heat generated by the DC/DC converter 12 increases due to internal loss, it is necessary to take a heat dissipation countermeasure to suppress a temperature rise.

The distribution circuit section 13 distributes the power supply power supplied from the output of the DC/DC converter 12 to a plurality of systems, and then supplies the distributed power supply power to the loads 23 to 25 through the output power lines 13a to 13c, the output terminals 17 to 19, and the electric lines 26 to 28, respectively.

< description of noise >

On the other hand, high-frequency electrical noise generated inside the DC/DC converter 12 may also be transmitted from the output of the DC/DC converter 12 to the loads 23 to 25 via the distribution circuit section 13, the power supply lines 13c to 13c, the output terminals 17 to 19, and the electric wires 26 to 28. Noise is emitted from the electric wires 26 to 28 as unnecessary radiation, thereby adversely affecting the reception of the vehicle-mounted radio, or noise transmitted to the loads 23 to 25 may cause various ECUs to produce undesirable functions.

In order to reduce the above noise, a noise filter is generally mounted on the internal circuit of the in-vehicle power supply device 10 and the wire harness WH as necessary. However, the length of each of the electric wires 26 to 28 of the wire harness WH and the type of each of the loads 23 to 25 vary depending on the type of vehicle of the vehicle in which the on-vehicle power supply device 10 is installed. That is, the impedance Z when the load side is viewed from the output of the in-vehicle power supply device 10 varies depending on the vehicle type. Therefore, when the impedance Z changes, the noise reduction characteristic of the noise filter mounted thereon also changes.

Therefore, in order to reduce the noise transmitted to the loads 23 to 25 via the wire harness WH and the noise radiated from the wire harness WH within an allowable range, at the time of design, different countermeasures for the noise need to be individually performed for each vehicle type, resulting in an increase in cost. For example, even when the types of the loads 23 to 25 are changed due to the user changing the option selection, the impedance Z is changed, so that the noise level is changed.

< noise countermeasure of example >

In the in-vehicle power supply apparatus 10 shown in fig. 1, one kind of the adjusting unit 14 selected from a plurality of kinds of adjusting units 14 prepared in advance may be mounted on the housing 11 as needed. The adjusting unit 14 is configured to be attachable to and detachable from the housing 11. Each of the plurality of adjusting units 14 includes one or more noise filters respectively having different characteristics. Each noise filter in the adjusting unit 14 mounted on the housing 11 is connected between each of the output power lines 13a to 13c and the ground line 22.

When the impedance Z changes depending on the type of vehicle of the vehicle in which the in-vehicle power supply device 10 is installed, the noise reduction characteristics in the adjusting unit 14 installed on the housing 11 change, so that the noise transmitted to the loads 23 to 25 via the wire harness WH and the noise radiated from the wire harness WH may exceed the allowable range. Therefore, the adjusting unit 14 is replaced with another adjusting unit having an appropriate specification, so that noise can be reduced within an allowable range by corresponding to the change in the impedance Z.

Here, in addition to the adjustment unit 14, since it is not necessary to change the circuit components with respect to the main body of the in-vehicle power supply device 10, the component number of the component and the unit number of the unit can be commonly used regardless of the type of the vehicle. Therefore, the component cost and the manufacturing cost of the device can be reduced by the generalization of the components. Since only the adjustment unit 14 is replaced, man-hours required for designing countermeasures against noise can be reduced.

< construction example of adjustment Unit >

Fig. 2 is a longitudinal sectional view showing a configuration example of the adjusting unit 14 mounted on the housing 11 of the in-vehicle power supply device 10.

At least the connection portion of the adjusting unit 14 is formed in a predetermined shape and size, and is configured in a rectangular parallelepiped shape or a card shape as a whole. A recess 11a having a shape and a size capable of accommodating the adjustment unit 14 is formed in the housing 11.

In the example shown in fig. 2, the regulating unit 14 includes three capacitors 14b, 14c, and 14d incorporated therein. Since each of these capacitors 14b to 14d internally includes a residual inductance, in the high-frequency region, a circuit in which the capacitance component (C) of one capacitor and the residual inductance component (L) thereof are connected in series is equivalently formed, and each of these capacitors 14b to 14d functions as a self-resonant notch filter. That is, since the impedance of the circuit is lowered in the vicinity of the resonance frequency, noise can be reduced by connecting the noise filter between the power supply line and the ground line.

Here, in the actual in-vehicle power supply device 10, since a parallel circuit of the impedance Zf of each of the capacitors 14b to 14d and the impedance Z on the load side is configured, the degree of noise reduction varies according to the variation in the impedance Z. Therefore, the adjusting unit 14 having appropriate characteristics is selected from the plurality of adjusting units 14 prepared in advance and mounted in the recess 11a, so that the noise reduction effect in the actual vehicle can be improved, and the noise transmitted to the loads 23 to 25 and the noise radiated from the wire harness WH can be reduced to the allowable range.

Regarding the types of the plurality of adjusting units 14 prepared in advance, the number of types required is prepared in consideration of the difference in the length and thickness of the electric wires of the wire harness WH mounted on each vehicle, and the difference in the kinds of the loads 23 to 25 and their combinations at the time of design.

The adjusting unit 14 shown in fig. 2 is provided in a state where a plurality of electrodes 14e, 14f, 14g, and 14h are exposed on the surface of the unit case 14 a. Electrodes 11b, 11c, 11d, and 11e are provided on one side of the recess 11a of the housing 11 at positions opposed to the electrodes 14e, 14f, 14g, and 14h of the adjustment unit 14. That is, the pair of electrodes 14e and 11b, the electrodes 14f and 11c, the electrodes 14g and 11d, and the electrodes 14h and 11e are electrically connected to each other in a state where the regulating unit 14 is fitted into the recess 11 a.

The capacitor 14b in the adjusting unit 14 includes one end connected to the electrode 14e and the other end connected to the electrode 14 h. The capacitor 14c includes one end connected to the electrode 14f and the other end connected to the electrode 14 h. The capacitor 14d includes one end connected to the electrode 14g and the other end connected to the electrode 14 h.

The electrodes 11b, 11c, 11d, and 11e on the case 11 side of the in-vehicle power supply device 10 are connected to output power supply lines 13a, 13b, and 13c and a ground line 22, respectively.

Therefore, when the adjusting unit 14 having the configuration shown in fig. 2 is used, the capacitance of the capacitor 14b is designed so that appropriate noise reduction characteristics can be obtained for the impedance Z determined for the electric wire 26 connected to the output terminal 17 and the load 23. In the same manner, the capacitance of the capacitor 14c is designed so that appropriate noise reduction characteristics can be obtained for the impedance Z determined by the electric wire 27 and the load 24. The capacitance of the capacitor 14d is designed so that appropriate noise reduction characteristics can be obtained for the impedance Z determined by the electric wire 28 and the load 25.

That is, the capacitance of each of the capacitors 14b to 14d determined at the time of designing for each vehicle type of all vehicles having a possibility of mounting the in-vehicle power supply apparatus 10 is considered in the case of the impedance Z according to the combination of the wire harness WH and the loads 23 to 25, and the adjusting unit 14 is manufactured and prepared for each vehicle type.

< first example of appearance of vehicle-mounted Power supply apparatus >

Fig. 3 shows an outline of an appearance in a first configuration example of the in-vehicle power supply device 10.

In the example shown in fig. 3, the case 11 of the in-vehicle power supply device 10 is formed in a box shape, and the output terminals 17 to 19 are configured at the end portions of the case 11. A recess 11a is formed on the upper surface of the housing 11. The recess 11a is shaped and sized to be able to fit into the insertion portion of the adjustment unit 14.

As shown in fig. 3, for example, since a plurality of types of adjustment units 14 having the same shape and size are manufactured and prepared in advance, an operator who mounts the in-vehicle power supply apparatus 10 in a vehicle can select any one of the adjustment units 14 suitable for the type of the vehicle and mount the selected adjustment unit 14 on the recess 11a of the housing 11. Here, the type of the adjusting unit 14 selected by the operator has a filter characteristic optimized for noise reduction in consideration of the different wire harnesses WH and the impedances Z of the loads 23 to 25 according to the vehicle type. The main body of the in-vehicle power supply device 10 does not need to be replaced depending on the type of vehicle of the vehicle to which the in-vehicle power supply device 10 is mounted, and has a general structure as a whole.

< second example of appearance of vehicle-mounted Power supply apparatus >

Fig. 4 shows an outline of an appearance in a second configuration example of the in-vehicle power supply device 10.

In the in-vehicle power supply device 10B shown in fig. 4, the DC/DC converter 12 is housed in a case 31a of the converter unit 31. The power distribution circuit portion 13 is accommodated in a housing 32a of the power distribution unit. That is, the in-vehicle power supply apparatus 10B has a structure in which the converter unit 31 and the power distribution unit 32, which are configured by the housings 31A and 32A independent of each other, respectively, are combined and integrated.

In the example of fig. 4, in order to flow the cooling air, a minute space 34 having a substantially constant gap is formed between the converter unit 31 and the power distribution unit 32. The converter unit 31 and the power distribution unit 32 are configured as separate bodies, so that adverse effects on the converter unit 31 and the power distribution unit 32 due to heat generation can be reduced. That is, it is possible to prevent the ambient temperature of the distribution circuit unit 13 from increasing due to the influence of heat of the DC/DC converter 12 having a large amount of heat generation. In particular, by flowing the cooling air in the space 34, an insulating layer is formed in the space 34, and the temperature rise on the power distribution unit 32 side can be effectively prevented.

In the configuration of fig. 4, a recess 32b is formed on the upper surface of the housing 32a on the side of the power distribution unit 32. One adjusting unit 14 prepared in advance is fitted into the recess 32b so that the installed adjusting unit 14 can be connected to the circuit of the power distribution unit 32.

The operator can appropriately select the adjusting unit 14 to be mounted for each vehicle type, so that the noise reduction characteristics can be optimized according to the impedances Z of the loads 23 to 25 and the wire harnesses WH connected to the output terminals 17 to 19.

< second configuration example of in-vehicle Power supply apparatus >

Fig. 5 shows a circuit in a second configuration example of the in-vehicle power supply device 10.

In the example shown in fig. 5, the space 34 between the converter unit 31 and the power distribution unit 32 is kept constant by the spacer 33 provided therebetween. Air can flow in the space 34.

As shown in fig. 5, the DC/DC converter 12 is disposed in a case 31a of the converter unit 31, and the power distribution circuit section 13 is provided in a case 32a of the power distribution unit 32. In the structure of fig. 5, in the same manner as fig. 1, the power supply power to be supplied from the vehicle-mounted battery 21 is input to the DC/DC converter 12, and the DC/DC converter 12 generates the power supply power required on the load side.

The power supply power generated by the DC/DC converter 12 in the converter unit 31 is supplied to the input side of the distribution circuit section 13 in the distribution unit 32. The power distribution circuit section 13 appropriately distributes the power supply power supplied from the output of the DC/DC converter 12 to each load system, and outputs the distributed power supply power to the output power lines 13a to 13c as needed.

The adjusting unit 14 is mounted on the recess 32b of the power distribution unit 32 such that the respective capacitors 14b to 14d in the adjusting unit 14 are connected to the output power lines 13b to 13d and the ground line 22, respectively.

The influence of the electrical noise generated by the switching of the large current in the DC/DC converter 12 is transmitted through each path of the output power lines 13a to 13c, and radiated as unnecessary radiation from the electric lines 26 to 28 or input as noise to the loads 23 to 25. This noise is reduced by the regulating unit 14 mounted on the power distribution unit 32.

The adjusting unit 14 serves to sufficiently reduce noise so that a noise filter does not need to be added to the wire harness WH. However, when the type of the wire harness WH and the types of the loads 23 to 25 change according to the difference in the vehicle types, the impedance Z on the output side of the power distribution unit 32 changes, and thus the noise reduction characteristics also change. Therefore, it is important to select and install the adjusting unit 14 having appropriate characteristics according to the vehicle type of the vehicle on which the in-vehicle power supply apparatus 10B is installed.

< specific examples of appearance >

Fig. 6 shows a specific example of the appearance in the second configuration example of the in-vehicle power supply device 10.

In the vehicle-mounted power supply device 10B shown in fig. 6, the power distribution unit 32 and the converter unit 31 arranged above and below are fixed and integrated by a plurality of bolts 43. In order to effectively prevent the temperature from rising, the in-vehicle power supply device 10B is disposed above the blower unit 40, and the radiator 42 is disposed below the converter unit 31.

The blowing unit 40 can blow air in a direction opposite to the arrow of the Z axis shown in the drawing by a blower, not shown, arranged in the blowing section 41 on the rear side. The air flow generated by the blast air is guided to flow through each space between the fins of the lower side radiator 42 and the space 34 between the converter unit 31 and the power distribution unit 32, respectively, thereby achieving effective forced air cooling.

< description of modification >

Fig. 7 is a longitudinal sectional view showing a mounted state of a plurality of adjusting units according to a modification.

In the modification shown in fig. 7, a plurality of recesses 32c, 32d, and 32e independent of each other are formed in the housing 32a of the power distribution unit 32. Each of the plurality of adjusting units 14A, 14B, and 14C shown in fig. 7 includes only one noise filter (capacitor) system incorporated therein.

That is, since the plurality of concave portions 32C, 32d, and 32e are formed in the housing 32a, the plurality of adjustment units 14A, 14B, and 14C can be simultaneously attached to these members as shown in fig. 7.

Each of the adjustment units 14A, 14B, and 14C includes two electrodes 14i and 14j, respectively. One end of the noise filter (capacitor) in the adjusting units 14A, 14B, and 14C is connected to the electrode 14i, and the other end is connected to the electrode 14 j.

Two electrodes 32f are formed in the recess 32c at positions opposing the electrodes 14i and 14 j. Two electrodes 32g are formed in the recess 32d at positions opposing the electrodes 14i and 14 j. Two electrodes 32h are formed in the recess 32e at positions opposed to the electrodes 14i and 14 j.

Therefore, the electrodes 14i and 14j of the adjusting unit 14A shown in fig. 7 are connected to the output power supply line 13a and the ground line 22 of one system via the electrode 32f, respectively. The electrodes 14i and 14j of the adjusting unit 14B are connected to the output power supply line 13B and the ground line 22 of one system via the electrode 32g, respectively. The electrodes 14i and 14j of the adjusting unit 14C are connected to the output power supply line 13C and the ground line 22 of one system via the electrode 32h, respectively.

In the case of the modification shown in fig. 7, with respect to the variation of the impedance Z of the wire harness WH and the loads 23 to 25, the noise characteristics can be adjusted by using the individual adjusting units 14A to 14C for each system of the output terminals 17 to 19. Therefore, although it is necessary to simultaneously mount a plurality of regulating units 14A to 14C on the power distribution unit 32, the total number of types of regulating units 14A to 14C prepared in advance according to the types of vehicles can be reduced.

[1] In-vehicle power supply device (10) comprising: a power supply section (DC/DC converter 12) including a noise generation source; and one or more output terminals (17 to 19) capable of connecting a desired load to an output of the power supply section, the apparatus comprising:

one or more adjusting units (14) configured to accommodate one or more electronic components (capacitors 14b to 14d) that affect the impedance of the output of the power supply section in a unit case (14a) in which at least one connecting section has a predetermined shape and size; and

a unit support portion (concave portion 11a) which is provided inside the power supply portion or between the output of the power supply portion and the load, and detachably supports the adjustment unit.

According to the in-vehicle power supply apparatus having the above configuration [1], the noise level output from the power supply section is reduced according to the unique characteristics of the adjusting unit mounted on the unit support section. Therefore, when the noise characteristics deteriorate due to the impedance variation according to the specification difference such as the type of the electric wire and the type of the load of the wire harness connected to the downstream side of the output terminal, the deterioration of the noise characteristics can be solved only by changing the adjustment unit actually installed. For example, when a plurality of types of adjustment units having different impedance characteristics from each other are prepared in advance, a desired impedance characteristic can be obtained only by replacing the type of adjustment unit to be mounted, and the noise level can be improved. Therefore, even when the in-vehicle power supply apparatus is mounted on various types of vehicles, the components of the main body of the in-vehicle power supply apparatus can be shared, and thus the cost can be reduced.

[2] In the vehicle-mounted power supply device, the power supply section may include: a switching unit (converter unit 31) configured to periodically repeat switching of the power supply; and a power distribution unit (power distribution unit 32) configured to distribute the output power of the switching unit to loads of a plurality of systems, and a unit support part is formed at one side of the power distribution unit.

According to the in-vehicle power supply apparatus having the above configuration [2], even if the impedance characteristics of the loads of the plurality of systems are different from each other, it is possible to adjust the impedance characteristics of each system separately and improve the noise level of each system separately by using the adjusting unit. Since the switching unit and the power distribution unit can be physically separated from each other, it is easy to prevent the temperature of the power distribution unit from increasing due to heat generation of the switching unit.

[3] In the vehicle-mounted power supply apparatus, the adjustment unit may include a plurality of circuits (capacitors 14b to 14d) independent of each other so as to individually adjust the impedance for each load of the plurality of systems.

According to the in-vehicle power supply apparatus having the above configuration [3], the impedance can be adjusted individually for each load of the plurality of systems by the internal configuration of the adjusting unit to be installed. Therefore, it becomes easy to optimize the noise characteristics for each system.

[4] In the vehicle-mounted power supply device, the power distribution unit may include a plurality of unit support portions (concave portions 32c to 32e) so as to accommodate a plurality of adjustment units individually corresponding to each load in a plurality of systems.

According to the in-vehicle power supply apparatus having the above configuration [4], a plurality of regulating units can be accommodated in the power distribution unit at the same time. Therefore, when a plurality of loads having different types and impedances are connected to the output of the power distribution unit, it is possible to individually improve the noise characteristics for each system by selecting and installing a regulating unit having individually suitable characteristics for each load. Since it is not necessary to include a plurality of circuits in each adjusting unit, the type of adjusting unit prepared in advance can be reduced.

[5] In the vehicle-mounted power supply device, the adjusting unit may include at least one capacitor (14b to 14d) incorporated therein as the electronic component.

According to the in-vehicle power supply apparatus having the above configuration [5], since the capacitor incorporated in the adjusting unit functions as a filter, high-frequency noise can be reduced. Since the capacitor used for such a purpose has a residual inductance inside, a circuit in which a capacitance component (C) of one capacitor and a residual inductance component (L) thereof are connected in series is equivalently formed in a high-frequency region. That is, since the impedance decreases in the vicinity of the resonance frequency of the series circuit, only the high-frequency noise component in the vicinity of the resonance frequency is filtered by connecting the series circuit between the power supply line and the ground line.

According to the in-vehicle power supply device of the present invention, it is possible to perform a sufficient noise prevention measure, and it is possible to generalize the part number of the power supply component even when the types of vehicles on which the in-vehicle power supply device is mounted are different. That is, even if the specification of the impedance in the wire harness connected to the output and the load of each system are changed according to the type of vehicle, the noise level can be sufficiently reduced only by installing the adjusting unit having appropriate characteristics. Since it is not necessary to change the structure and specifications of the main body of the in-vehicle power supply apparatus, the same power supply components can be commonly used for all vehicle types, so that the cost can be reduced.