WO2020240607A1

WO2020240607A1 - Vehicle mounted charging device

Info

Publication number: WO2020240607A1
Application number: PCT/JP2019/020570
Authority: WO
Inventors: 雄一郎大林; 喬士平塚
Original assignee: 三菱電機株式会社
Priority date: 2019-05-24
Filing date: 2019-05-24
Publication date: 2020-12-03
Also published as: JPWO2020240607A1; JP6958764B2

Abstract

Provided is a vehicle mounted charging device which can prevent condensation on a relay contact and freezing of the relay due to the same.　A vehicle mounted charging device 10 comprising: an AC/DC converter 16; a condenser 20 which is provided between an output end of the AC/DC converter 16 and a battery 14 for traveling; a relay 30 which has a contact 42 switching an energizing path to the condenser 20, said contact 42 being covered by a case 43; a multilayer substrate 36 to which the relay 30 is provided, and which has a connecting pattern 46 connected to the contact 42; a temperature raising resistor 34 which is arranged on a wiring layer 52 in a position which overlaps with the connecting pattern 46 when viewed from a direction orthogonal to a main surface of the multilayer substrate 36, said wiring layer 52 being different from a wiring layer 50 where the connecting pattern 46 is positioned; and a control circuit 24 which energizes the temperature raising resistor 34 within a predetermined time period after the relay 30 switches from an on state to an off state.

Description

Car charger

The present disclosure relates to an in-vehicle charger for charging a traveling battery that supplies electric power to an electric motor for an electric vehicle.

In-vehicle chargers for charging running batteries that supply power to electric motors for electric vehicles such as EVs (electric vehicles) and PHEVs (plug-in hybrid electric vehicles) are AC for home use as an external power source. It is equipped with an AC / DC converter that converts the AC voltage from the AC power supply into a DC voltage so that the traveling battery can be charged using the power supply. This makes it possible to charge the traveling battery that is charged by the DC voltage. Further, in the power supply device of an electric vehicle, a capacitor for suppressing the pulsation of the DC voltage output from the AC / DC converter is connected between the output end of the AC / DC converter and the traveling battery.

However, because a capacitor is connected between the output end of the AC / DC converter and the running battery, an inrush current is generated when an AC power supply is connected to the in-vehicle charger. In order to mitigate the influence of this inrush current, when the power supply device of an electric vehicle is connected to an AC power supply, the capacitor is first charged via a resistor. After that, when the charging of the capacitor is completed, the energization path is switched and the charging of the traveling battery is started without going through the resistor. The switching of the energization path for charging the traveling battery is performed by switching the relay provided in the in-vehicle charger from the off state to the on state.

By the way, when charging the running battery, that is, when the relay is on, the contacts of the relay are warmed by the electric resistance. At the same time, the ambient temperature around the contacts covered by the case also rises. Then, when the charging of the traveling battery is completed and the relay is turned off, the connection pattern connected to the contact is colder than the contact, so that the temperature of the contact is higher than the temperature of the atmosphere around the contact due to heat conduction. It goes down fast. As a result, the temperature of the contact becomes lower than the ambient temperature around the contact, and the contact may condense. In such a situation, if the vehicle is stopped in an environment below the freezing point, the contacts may freeze and the traveling battery may not be charged. Here, in the power supply device described in Patent Document 1 (hereinafter, referred to as a conventional in-vehicle charger), in order to prevent freezing of the relay contacts, another on-state switching element is placed in a case covering the contacts. The heat is used to prevent the contacts from freezing.

Japanese Unexamined Patent Publication No. 2015-156254

However, even if the case covering the relay contacts is warmed, the temperature of the atmosphere around the relay contacts is only maintained high. Therefore, since the connection pattern connected to the contact is colder than that of the contact, the temperature of the contact becomes lower than the temperature of the atmosphere around the contact due to heat conduction, and dew condensation occurs on the contact. As a result, when the switching element is turned off and the temperature of the atmosphere around the relay contacts drops, there is a problem that the relay contacts freeze.

An object of the present disclosure is to provide an in-vehicle charger capable of suppressing dew condensation on relay contacts and freezing of relay contacts due to this.

The in-vehicle charger according to the present disclosure includes an AC / DC converter that converts an AC voltage from an AC power supply into a DC voltage, a capacitor provided between the output end of the AC / DC converter and a traveling battery, and a capacitor. A relay having a contact for switching the energization path to the circuit, the contact being covered with a case, a multilayer substrate having a connection pattern in which the relay is provided on one main surface and connected to the contacts, and a main surface of the multilayer substrate. A heating resistor provided in a second wiring layer that overlaps the connection pattern when viewed from the orthogonal orthogonal directions and is different from the first wiring layer in which the connection pattern is located, and a traveling battery. It is provided with a control circuit that energizes the temperature rising resistor within a predetermined time after the energization is completed and the relay is switched from the on state to the off state.

According to the present disclosure, it is possible to suppress dew condensation on the relay contacts of the in-vehicle charger and freezing of the relay contacts due to this.

It is a figure which shows the circuit structure of the vehicle-mounted charger which concerns on Embodiment 1. FIG. It is a figure which shows the positional relationship of the component concerning the precharge circuit provided in the vehicle-mounted charger which concerns on Embodiment 1, and shows the cross section of the multilayer board included in the precharge circuit. It is a figure which looked at the multilayer substrate provided with the vehicle-mounted charger which concerns on Embodiment 1 from the direction orthogonal to the main surface. It is a flowchart about control of the temperature rise resistance in the vehicle-mounted charger which concerns on Embodiment 1. FIG. It is a figure which shows the relationship between the relay contact temperature of the vehicle-mounted charger which has no resistance for raising temperature, the temperature of the atmosphere around the relay contact, and time. It is a figure which shows the relationship between the relay contact temperature of the vehicle-mounted charger which concerns on Embodiment 1, the temperature of the atmosphere around a relay contact, and time. It is a figure which shows the positional relationship of the component which concerns on the precharge circuit included in the vehicle-mounted charger which concerns on Embodiment 2, and shows the cross section of the multilayer board included in the precharge circuit.

Below, the in-vehicle charger, which is one embodiment, will be described with reference to the attached drawings. The same reference numerals are given to the same configurations in each embodiment.

Embodiment 1.
FIG. 1 is a diagram showing a circuit configuration of the vehicle-mounted charger 10 according to the first embodiment. FIG. 2 is a diagram showing the positional relationship of parts related to the precharge circuit 22 included in the vehicle-mounted charger 10 according to the first embodiment, and showing a cross section of the multilayer board 36 included in the precharge circuit 22. FIG. 3 is a view of the multilayer substrate 36 included in the vehicle-mounted charger 10 according to the first embodiment as viewed from a direction orthogonal to the main surface thereof. In FIG. 3, the parts built in the multilayer board 36 and the parts hidden by the multilayer board 36 are shown by broken lines. As shown in FIG. 1, an AC power source 12 as an external power source is connected to the input side of the vehicle-mounted charger 10. Further, a traveling battery 14 as a load is connected to the output side of the vehicle-mounted charger 10. The traveling battery 14 supplies electric power to an electric motor for driving a vehicle.

As shown in FIG. 1, the vehicle-mounted charger 10 includes an AC / DC converter 16 and a DC / DC converter 18. Further, a capacitor 20 for smoothing the output from the AC / DC converter 16 is connected between the AC / DC converter 16 and the DC / DC converter 18 included in the vehicle-mounted charger 10. Further, a precharge circuit 22 is connected between the input terminal of the AC power supply 12 and the AC / DC converter 16 in the vehicle-mounted charger 10. In addition to this, the vehicle-mounted charger 10 includes a temperature rising resistor 34, a control circuit 24, and a charger internal temperature sensor 25 that detects the temperature inside the vehicle-mounted charger 10. Further, the in-vehicle charger 10 is used in the drive circuit 26 for driving the AC / DC converter 16, the drive circuit 27 for driving the DC / DC converter 18, and the precharge circuit 22 by the signal from the control circuit 24. A drive circuit 28 for driving the included relay 30 and a drive circuit 29 for driving the temperature rising resistor 34 are also provided.

The AC / DC converter 16 is a converter for converting an AC voltage into a DC voltage, and is composed of a PFC coil, a diode, a semiconductor switch element (for example, MOSFET or IGBT) and the like. Examples of the power supply topology of the AC / DC converter 16 include a half-bridge system.

The DC / DC converter 18 boosts the DC voltage generated by the AC / DC converter 16 and applies the boosted DC voltage to the traveling battery 14 to supply power to the traveling battery 14. Further, the DC / DC converter 18 has an isolation transformer for insulating the AC power supply side and the traveling battery 14 side from the viewpoint of safety to prevent electric leakage or electric shock, and has a diode and a semiconductor switch element (for example,). , MOSFET and IGBT). Examples of the power supply topology of the DC / DC converter 18 include a circuit configuration such as a full bridge system.

The capacitor 20 is a component for suppressing the pulsation of the DC voltage output from the AC / DC converter 16, and is provided between the output end of the AC / DC converter 16 and the input end of the DC / DC converter 18. There is. Here, the output end of the DC / DC converter 18 is connected to the traveling battery 14. Therefore, the capacitor 20 is provided between the output end of the AC / DC converter 16 and the traveling battery 14.

The control circuit 24 shown in FIG. 1 is a so-called microcomputer, and switches the on / off state of the relay 30 included in the precharge circuit 22 via the drive circuit 28, and switches the AC / DC converter 16 via the drive circuit 26. , The DC / DC converter 18 is operated via the drive circuit 27. Further, the control circuit 24 is connected to a charger internal temperature sensor 25 that detects the internal temperature of the vehicle-mounted charger 10, and based on the value of this temperature sensor, the temperature rise is described later via the drive circuit 29. Controls the energization of the resistance 34.

The precharge circuit 22 is a circuit for charging the capacitor 20 prior to charging the traveling battery 14. The precharge circuit 22 is composed of a relay 30, a precharge resistor 32, and a multilayer board 36 (shown in FIG. 2) on which these are mounted.

As shown in FIG. 1, one end of the relay 30 is connected to an input terminal connected to the AC power supply 12, and the other end is connected to the AC / DC converter 16. Further, the relay 30 has a movable contact 40 and a fixed contact 42. Then, the relay 30 is switched on / off by bringing the movable contact 40 and the fixed contact 42 into contact or non-contact state. As a result, the energization path to the capacitor 20 is also switched. Further, as shown in FIGS. 2 and 3, the movable contact 40 and the fixed contact 42 of the relay 30 are surrounded by a resin case 43 on a rectangular parallelepiped. Here, the relay 30 is held in an on state, that is, in a state where the movable contact 40 and the fixed contact 42 are in contact with each other in a state where power is supplied from the AC power source 12 to the traveling battery 14. Therefore, in the on state, the relay 30 generates heat due to Joule heat due to the contact resistance of the movable contact 40 and the fixed contact 42. In the state where power is not supplied from the AC power supply 12 to the traveling battery 14, the movable contact 40 and the fixed contact 42 are held in a non-contact state, that is, the relay 30 is held in an off state.

As shown in FIG. 1, the precharge resistor 32 is connected in parallel with the relay 30. Here, when the capacitor 20 is charged by the precharge circuit 22, the relay 30 is held in the off state. Therefore, when charging the capacitor 20, the capacitor 20 is charged via the precharge resistor 32. This alleviates the influence of the inrush current generated when the in-vehicle charger 10 is connected to the AC power supply.

As shown in FIG. 2, the relay 30 is arranged on one of the main surfaces of the multilayer board 36. Further, the relay 30 is connected to another circuit of the vehicle-mounted charger 10 via the multilayer board 36. For example, the relay 30 is connected to a drive circuit 28 that drives a coil included in the relay 30 via a multilayer board 36. Further, as shown in FIG. 2, the multilayer board 36 has a movable contact terminal connection pattern 44 connected to the terminal of the movable contact 40 and a fixed contact terminal connection pattern 46 connected to the terminal of the fixed contact 42. The movable contact terminal connection pattern 44 and the fixed contact terminal connection pattern 46 are located on the same wiring layer 50 in the multilayer board 36.

As shown in FIG. 2, the temperature rising resistor 34 is a rectangular parallelepiped resistor called a surface mount resistor or a chip resistor, and is provided along the other main surface of the multilayer substrate 36. Further, the other main surface of the multilayer board 36 provided with the temperature rising resistor 34 is the wiring layer 52. The wiring layer 52 is a wiring layer adjacent to the wiring layer 50. That is, the wiring layer 52 provided with the temperature rising resistor 34 and the wiring layer 50 provided with the movable contact terminal connection pattern 44 and the fixed contact terminal connection pattern 46 are different wiring layers. Therefore, even if the temperature rising resistor 34 is energized, the temperature rising resistor 34 does not directly touch the movable contact terminal connection pattern 44 and the fixed contact terminal connection pattern 46, so that the movable contact terminal connection pattern 44 and the fixed contact terminal connection are connected. The insulation against the pattern 46 is maintained. Further, as shown in FIG. 3, the temperature rising resistor 34 is provided at a position overlapping the fixed contact terminal connection pattern 46 when viewed from a direction orthogonal to the main surface of the multilayer substrate 36. In addition to this, the temperature rising resistor 34 is contained inside the fixed contact terminal connection pattern 46 when viewed from a direction orthogonal to the main surface of the multilayer substrate 36. The temperature rising resistor 34 is a resistor for warming each contact of the relay 30 when the charging of the traveling battery 14 is completed. The details of the operation of the temperature rising resistor 34 will be described later.

As shown in FIG. 3, the charger internal temperature sensor 25 is a thermistor located inside the housing of the vehicle-mounted charger 10 and measuring the temperature inside the vehicle-mounted charger 10.

Next, with reference to the flowchart of FIG. 4, the control for preventing dew condensation on the contacts of the relay 30 performed by the control circuit 24 will be described. FIG. 4 is a flowchart relating to the control of the temperature rising resistance in the vehicle-mounted charger according to the first embodiment. The control for preventing dew condensation on the contacts of the relay 30 is started when the running battery 14 is fully charged and the relay 30 is switched from the on state to the off state.

When the relay 30 is switched from the on state to the off state, in step ST1, the control circuit 24 determines whether or not to energize the temperature rising resistor 34. This determination is made based on the temperature inside the vehicle-mounted charger 10 detected by the charger internal temperature sensor 25. Specifically, when the temperature detected by the charger internal temperature sensor 25 is within the range of + 5 ° C. to −10 ° C., it is determined that the temperature rising resistor 34 is energized. On the other hand, when the temperature detected by the charger internal temperature sensor 25 is other than + 5 ° C. to −10 ° C., it is determined that the temperature rising resistor 34 is not energized. When it is determined to energize the temperature rising resistor 34, this control proceeds to step ST2, and when it is determined not to energize the temperature rising resistor 34, this control ends. If the temperature detected by the charger internal temperature sensor 25 is other than + 5 ° C. to −10 ° C., the temperature rising resistor 34 is not energized. This is because it is unlikely that the contacts of the relay 30 will freeze when the temperature detected by the charger internal temperature sensor 25 is higher than + 5 ° C, and dew condensation will occur when the temperature is lower than -10 ° C. This is because it is difficult.

Next, in step ST2, the control circuit 24 starts energizing the temperature rising resistor 34 via the drive circuit 29.

In step ST3, the control circuit 24 starts measuring the elapsed time by the timer built in the control circuit 24.

In the following step ST4, the control circuit 24 confirms whether or not the elapsed time of the timer has reached a predetermined time as the time for energizing the temperature rising resistor 34. Then, this step is repeated until the elapsed time of the timer reaches a predetermined time. The predetermined time is, for example, a value obtained by an experiment in advance. Specifically, if the time for energizing the temperature rising resistor 34 is too short, the temperature of the contact of the relay 30 will be changed to the temperature of the contact of the relay 30 after the energization of the temperature rising resistor 34 is completed, due to the heat conduction of the connection pattern connected to the relay. The temperature drops faster than the temperature around the contacts of the relay 30, and the contacts of the relay 30 condense. In order to prevent this, the predetermined time is such that the temperature of the contacts of the relay 30 does not fall below the temperature of the atmosphere around the contacts of the relay 30 even after the energization of the temperature rising resistor 34 is completed. It is time to continue energizing the heating resistor 34.

When the elapsed time of the timer reaches a predetermined time as the time for energizing the temperature rising resistor 34, this control proceeds to step ST5. In step ST5, the control circuit 24 ends energization of the temperature rising resistor 34 via the drive circuit 29. As a result, this control ends.

In the vehicle-mounted charger 10 configured as described above, it is possible to suppress dew condensation on the relay contacts and freezing of the relay contacts due to this. Specifically, it will be described with reference to FIGS. 5 and 6. FIG. 5 is a diagram showing the relationship between the relay contact temperature of the vehicle-mounted charger and the temperature and time of the atmosphere around the relay contact according to the comparative example having no resistance for raising temperature. FIG. 6 is a diagram showing the relationship between the relay contact temperature of the vehicle-mounted charger according to the first embodiment, the temperature of the atmosphere around the relay contact, and the time.

As shown in FIG. 5, in the vehicle-mounted charger according to the comparative example which does not have the temperature rising resistor 34, the relay 30 travels from the charging start time Ti1 when the relay 30 is switched to the on state to the charging end time Ti2 when the relay 30 is turned off. While charging the battery 14, the contact temperature Te1 of the relay 30 rises, and accordingly, the temperature Te2 of the atmosphere around the contacts of the relay 30 also rises. Then, after the charging end time Ti2, the contact temperature Te1 of the relay 30 and the temperature Te2 of the atmosphere around the contact of the relay 30 both decrease. At this time, since the connection pattern connected to the relay contacts is colder than that of the relay contacts, the temperature of the relay contacts drops faster than the temperature of the atmosphere around the contacts covered with the case due to heat conduction. As a result, the contact temperature Te1 of the relay 30 temporarily falls below the temperature Te2 of the atmosphere around the contacts of the relay 30. As a result, the contacts of the relay 30 will condense.

As shown in FIG. 6, in the vehicle-mounted charger 10 having the temperature rising resistor 34, the running battery 14 is charged up to the charging end time Ti2 after the charging start time Ti1 when the relay 30 is switched to the on state. During this, the contact temperature Te1 of the relay 30 rises, and the temperature Te2 around the contacts of the relay 30 also rises accordingly. Then, after the charging end time Ti2, the contact temperature Te1 of the relay 30 and the temperature Te2 of the atmosphere around the contact of the relay 30 both decrease. At this time, the control circuit 24 energizes the temperature rising resistor 34 after the charging end time Ti2, that is, within a predetermined time after the relay is switched from the on state to the off state. As a result, the heat of the temperature rising resistor 34 is transferred to the fixed contact 42 of the relay 30 via the fixed contact terminal connection pattern 46. As a result, the temperature of the fixed contact 42 drops more slowly than the temperature of the atmosphere around the contact of the relay 30. The temperature of the movable contact 40, which is located close to the fixed contact 42 of the relay 30, also drops more slowly than the temperature of the atmosphere around the contact of the relay 30 due to the heat from the fixed contact 42. As a result, the contact temperature Te1 of the relay 30 does not fall below the temperature Te2 of the atmosphere around the contacts of the relay 30, and the contact temperature Te1 of the relay 30 and the temperature Te2 of the atmosphere around the contacts of the relay 30 are the temperatures around the relay 30. That is, the temperature gradually decreases toward the internal temperature of the vehicle-mounted charger 10. As a result, in the vehicle-mounted charger 10, dew condensation on the contacts of the relay 30 can be prevented.

By the way, in the conventional in-vehicle charger, the case covering the relay is heated by a switching element to keep the temperature of the atmosphere around the relay contacts high and prevent the relay contacts from freezing. In this case, since the connection pattern connected to the relay contacts is colder than that of the relay contacts, the temperature of the relay contacts drops faster than the temperature of the atmosphere around the contacts due to heat conduction. As a result, the temperature of the contact of the relay becomes lower than the ambient temperature around the contact, and dew condensation occurs on the contact. Therefore, when the switching element is turned off, the contacts of the relay may freeze. On the other hand, in the in-vehicle charger 10, immediately after the relay 30 is switched from the on state to the off state, the contact temperature Te1 of the relay 30 is temporarily lowered to the temperature Te2 of the atmosphere around the contacts of the relay 30 for raising the temperature. The heat from the resistor 34 prevents dew condensation on each contact of the relay 30. In this case, even if the energization of the temperature rising resistor 34 is terminated, the contacts of the relay 30 do not freeze because the dew condensation that causes freezing does not occur at the contacts of the relay 30. From the above, in the vehicle-mounted charger 10, dew condensation on the relay contacts and freezing of the relay contacts due to this can be suppressed.

Further, in the vehicle-mounted charger 10, the wiring layer 52 provided with the temperature rising resistor 34 is a wiring layer adjacent to the wiring layer 50 provided with the fixed contact terminal connection pattern 46. Therefore, in the vehicle-mounted charger 10, heat from the temperature rising resistor 34 is more likely to be transferred to the fixed contact terminal connection pattern 46 as compared with the case where a plurality of wiring layers are included between the wiring layer 52 and the wiring layer 50. .. As a result, the vehicle-mounted charger 10 can efficiently heat the contacts of the relay 30 as compared with the case where a plurality of wiring layers are included between the wiring layer 52 and the wiring layer 50.

The temperature rising resistor 34 is provided at a position overlapping the fixed contact terminal connection pattern 46 when viewed from a direction orthogonal to the main surface of the multilayer board 36. Further, the temperature rising resistor 34 is contained inside the fixed contact terminal connection pattern 46 when viewed from a direction orthogonal to the main surface of the multilayer substrate 36. By arranging the temperature rising resistor 34 in this way, for example, when viewed from a direction orthogonal to the multilayer board 36, the temperature rising resistor 34 protrudes from the fixed contact terminal connection pattern 46 as compared with the case where the temperature rising resistor 34 protrudes from the fixed contact terminal connection pattern 46. Then, in the vehicle-mounted charger 10, the heat of the temperature rising resistor 34 can be efficiently transferred to the fixed contact terminal connection pattern 46. As a result, in the vehicle-mounted charger 10, the contacts of the relay 30 can be efficiently heated as compared with the case where the temperature rising resistor 34 protrudes from the fixed contact terminal connection pattern 46.

Embodiment 2.
FIG. 7 is a diagram showing the positional relationship of parts related to the precharge circuit included in the vehicle-mounted charger according to the second embodiment, and showing a cross section of a multilayer substrate included in the precharge circuit. The difference between the vehicle-mounted charger 10A according to the second embodiment and the vehicle-mounted charger 10 according to the first embodiment is the position of the temperature rising resistor 34. This will be described in detail below.

As shown in FIG. 7, in the vehicle-mounted charger 10A, similarly to the vehicle-mounted charger 10, the temperature rising resistor 34 is provided on the other main surface side of the multilayer substrate 36, and the multilayer substrate 36 When viewed from a direction orthogonal to the main surface, it fits inside the movable contact terminal connection pattern 44. In addition to this, in the vehicle-mounted charger 10A, the temperature rising resistor 34 is arranged at a position overlapping the relay 30 when viewed from a direction orthogonal to the main surface of the multilayer substrate 36. By arranging the temperature rising resistor 34 in this way, for example, it is not necessary to extend the movable contact terminal connection pattern 44 or the fixed contact terminal connection pattern 46 to the position where the temperature rising resistor 34 is located. As a result, it contributes to space saving of the vehicle-mounted charger 10A in the direction parallel to the main surface of the multilayer substrate 36.

Other configurations of the vehicle-mounted charger 10A are the same as those of the vehicle-mounted charger 10. Therefore, other configurations in the vehicle-mounted charger 10A are as described in the vehicle-mounted charger 10.

Other embodiments.
It is also included in the scope of the present disclosure that each embodiment is appropriately combined, modified or omitted. For example, a plurality of temperature rising resistors 34 may be provided on the multilayer substrate 36. Further, in the above embodiment, after the traveling battery 14 is fully charged, the temperature rise resistor 34 is determined to be energized, but the charger is charged before the battery is charged, that is, before the relay 30 is turned on. From the temperature detected by the internal temperature sensor 25, it may be determined to energize the temperature rising resistor 34. At this time, in the control performed by the control circuit 24 to prevent dew condensation on the contacts of the relay 30, the temperature rising resistor 34 may be energized immediately before the relay 30 is turned from the on state to the off state. However, even in this case, the control circuit 24 energizes the temperature rising resistor 34 within a predetermined time after the relay 30 is switched from the on state to the off state. Further, the temperature rising resistor 34 may be located at a position overlapping the movable contact terminal connection pattern 44 or the fixed contact terminal connection pattern 46 when viewed from a direction orthogonal to the main surface of the multilayer board 36, and the multilayer board 36 When viewed from a direction orthogonal to the main surface, the temperature rising resistor 34 may protrude from the movable contact terminal connection pattern 44 or the fixed contact terminal connection pattern 46.

10, 10A in-vehicle charger, 12 AC power supply, 14 running battery, 16 AC / DC converter, 20 capacitors, 24 control circuits, 30 relays, 34 heating resistance, 36 multilayer boards, 40 movable contacts (contacts), 42 fixed contact (contact), 43 case, 44 movable contact terminal connection pattern (connection pattern), 46 fixed contact terminal connection pattern (connection pattern), 50 wiring layer (first wiring layer), 52 wiring layer (second) Wiring layer)

Claims

An AC / DC converter that converts AC voltage from an AC power supply to DC voltage,
A capacitor provided between the output end of the AC / DC converter and the traveling battery,
A relay that has a contact that switches the energization path to the capacitor, and the contact is covered with a case.
A multilayer board in which the relay is provided on one main surface and has a connection pattern connected to the contact.
A temperature rise provided in a second wiring layer that overlaps the connection pattern when viewed from an orthogonal direction orthogonal to the main surface of the multilayer substrate and is different from the first wiring layer in which the connection pattern is located. Resistance and
An in-vehicle charger including a control circuit that energizes the temperature rising resistor within a predetermined time after the energization of the traveling battery is completed and the relay is switched from the on state to the off state.
The vehicle-mounted charger according to claim 1, wherein the second wiring layer is a wiring layer adjacent to the first wiring layer.
The vehicle-mounted charger according to claim 1 or 2, wherein the heating resistance is contained inside the connection pattern when viewed from the orthogonal direction.
Any one of claims 1 to 3 is provided on the other main surface of the multilayer substrate and is provided at a position overlapping the relay when viewed from the orthogonal direction. The in-vehicle charger described in the section.