JP2009161104A - Load control circuit and battery exhaustion preventive method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a load control circuit capable of reducing cost by eliminating time and labor in manufacture, by reducing the number of part items. <P>SOLUTION: This load control circuit for a vehicle has a power supply line 102 connected in series with a fuse 14, a room lamp 10 and a transistor 12, a first line 103 connected in series with a courtesy lamp 20 and a switch 22, a microcomputer 13 for switching the transistor 12 in response to a state of the switch 22, and a first detecting line 110 connecting between the microcomputer 13, the courtesy lamp 20 and the switch 22, and is constituted such that the microcomputer 13 detects the state of the switch 22 by an electric current flowing in the first detecting line 110, by making the electric current flow from the first detecting line 110 in response to switching operation of the switch 22. The first line 103 is not connected to the room lamp 10 side from the fuse of at least a power supply passage 102. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle load control circuit that mainly controls lighting and extinguishing of a lamp mounted on a vehicle, and a method for preventing a battery from running out.

  Some lighting devices installed in a vehicle are turned on and off in conjunction with opening and closing operations of front doors and trunk room doors. FIG. 2 is a schematic diagram of a control circuit for turning on and off the lighting device. The control circuit performs lighting and extinguishing control of the lighting device installed in the vehicle, fuses 14, 15, and 16, diodes 21, 31, and 41, switches 22, 32 and 42, transistor 12, and microcomputer ( Hereinafter, it is configured to include an ECU (Electronic Control Unit) 11 having a microcomputer 13. Illumination devices include, for example, a room lamp 10 installed on the ceiling in the room, courtesy lamps 20 and 30 installed on the left and right front doors, and a trunk lamp 40 installed in the trunk room.

  One of the courtesy lamps 20 is connected in series in the order of the diode 21 and the switch 22, and the other of the switches 22 is grounded. The other of the courtesy lamps 20 is connected to the battery 100 via the fuses 14 and 15. The switch 22 is turned on / off in conjunction with the opening and closing of the door on which the courtesy lamp 20 is installed. For example, when the door is opened, the switch 22 is turned on. When the switch 22 is turned on, current flows from the battery 100 in the order of the fuses 14 and 15, the courtesy lamp 20, the diode 21, and the switch 22, and the courtesy lamp 20 is lit. In addition, when the door is closed, the switch 22 is turned off, power is not supplied from the battery 100, and the courtesy lamp 20 is turned off. The same applies to the courtesy lamp 30 and the trunk lamp 40.

  One of the room lamps 10 is connected to the ECU 11, specifically, the transistor 12 included in the ECU 11, and the other is connected to the battery 100 via the fuses 14 and 15. The transistor 12 is used as a switch, and is driven and controlled by a microcomputer 13 included in the ECU 11. That is, when the transistor 12 is driven by the microcomputer 13, power is supplied from the battery 100, and the room lamp 10 is turned on.

  The ECU 11 is connected to the battery 100 via the fuse 16, and driving power is supplied from the battery 100. The ECU 11 has detection terminals to which the detection lines 110, 111, and 112 that connect the diodes 21, 31, and 41 and the switches 22, 32, and 42 are connected. The on / off state of the switches 22, 32, 42 is monitored by monitoring the voltage level of the terminals. For example, when the door where the courtesy lamp 20 is installed opens, the switch 22 is turned on. At this time, a current flows from the ECU 11 through the switch 22. As a result, the potential of the detection terminal of the ECU 11 is lowered, and the voltage level becomes a low state. The microcomputer 13 detects that the switch 22 is turned on, that is, that the door is opened, by detecting the Low state. Further, when the door is closed, the switch 22 is turned off, and no current flows from the detection line 110 of the ECU 11. For this reason, the current stops flowing from the ECU 11, and the voltage level becomes a high state. The microcomputer 13 detects that the switch 22 is off, that is, the door is closed, by detecting the High state.

  The microcomputer 13 drives the transistor 12 when detecting that the door is opened, that is, when the detection terminal detects the low state. Thereby, the current from the battery 100 is supplied to the room lamp 10, and the room lamp 10 is turned on. In addition, when the microcomputer 13 detects that the door is closed, that is, when the detection terminal detects a high state, the microcomputer 13 stops the transistor 12. Thereby, the current from the battery 100 is not supplied to the room lamp 10, and the room lamp 10 is turned off. That is, the room lamp 10 is turned on and off in conjunction with opening and closing of the front door and the trunk door. In addition to the room lamp 10, downstream of the fuse 14, it is connected to devices such as a clock and a meter (not shown).

  By the way, when the vehicle is transported, the power of the battery 100 may be consumed when the door is opened due to standby power of each device or for some reason and the room lamp 10 and the courtesy lamp 20 are turned on. For this reason, in order to eliminate wasteful power consumption of the battery 100, it is common to transport the vehicle with the fuse 14 removed in the control circuit of FIG. Thereby, for example, even if the switch 22 is turned on, the courtesy lamp 20 is not supplied with power from the battery 100, and the courtesy lamp 20 is not lit. In addition, even when transportation is performed for a long period of time, power is not supplied to devices such as a clock and a meter, and battery consumption can be prevented.

  In this case, the diodes 21, 31, and 41 are essential components in the control circuit of FIG. 2 in order to prevent the following malfunction. The ECU 11 not only controls lighting devices such as courtesy lamps, but also controls vehicle door locks, security systems, and the like, so that electric power is supplied from the battery 100 even when the vehicle is transported, and the ECU 11 can be driven. ing. For this reason, for example, when the door is opened and the switch 22 is turned on, the courtesy lamp 20 is not lit, but the ECU 11 is supplied with power from the battery 100, and the detection line 110 has a resistance 200 (see FIG. 1) in the ECU 11. ) Through the switch 22 that is turned on from the ECU 11. At this time, since the detection terminal of the ECU 11 is connected to the ground potential via the switch 22, the potential is lowered and the voltage level is in a low state.

As described above, the microcomputer 13 of the ECU 11 drives the transistor 12 by detecting the Low state. In this case, since the fuse 14 is removed, no power is supplied to the room lamp 10, and therefore the room lamp 10 is not lit. However, at this time, assuming that the diode 21 is not present, even if the door is closed and the switch 22 is turned off, the current passes through the courtesy lamp 20 and the room lamp 10 from the ECU 11 to the transistor 12 as indicated by the arrows in the figure. Flows. As a result, even when the switch 22 is turned off, the microcomputer 13 detects that the voltage level of the detection terminal of the ECU 11 is in the low state and continues to drive the transistor 12, so that the current continues to flow as indicated by the arrow in the figure. When such a state continues for a long time, such as when the vehicle is transported, there arises a problem that the battery runs out. In order to prevent such a current, a diode 21 is provided between the courtesy lamp 20 and the switch 22. The same applies to the other diodes 31 and 41.
Toyota Camry Wiring Diagrams ACV # series H0602 (2006-1) 3-118-123

  The control circuit and other electric circuits shown in FIG. 2 are wired by a wire harness. The wire harness is formed by combining various types of electric wires such as a spliced electric wire, a non-spliced single wire, a shielded electric wire, and a twisted pair electric wire. For example, electronic components such as the diodes 21, 31, 41 are mounted on connectors connected to the wire harness. FIG. 3 is a schematic diagram illustrating a state in which the diode is assembled to the wire harness. Generally, the diode 21 is fitted to a connector 23A connected to an electric wire 23B of a wire harness branch line branched from the wire harness main line 25, and is fixed by fixing the connector 23A or the electric wire 23B to the wire harness with an adhesive tape or the like. ing.

  For this reason, additional steps are required in the manufacturing process to connect a connector for mounting an electronic component such as a diode, and it takes time and labor. It is desired to reduce the score.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a first path provided in the order of protection means, a first load and a first switch from the battery side, a second load from the battery side, and A second path provided in the order of the second switch, a controller that switches the first switch according to the state of the second switch, a controller, a second load, and a second switch are connected to each other. In the vehicle load control circuit configured to detect the state of the second switch based on the potential detected through the detection line. By adopting a configuration in which the first load side is disconnected from the first path protection means, the number of parts can be reduced, so that time and labor during manufacture can be saved. To provide a load control circuit which can be achieved Sutodaun.

  Another object of the present invention is to provide a load control circuit capable of preventing complication of wiring by connecting the battery side from the second load of the second path to the battery side from the protection means of the first path. Is to provide.

  Another object of the present invention is to provide a load control circuit capable of omitting troublesome switch operation by adopting a configuration in which the second switch can be switched according to an opening / closing operation of an opening / closing member provided to be openable / closable in the vehicle. It is in.

  Another object of the present invention is to control lighting / extinguishing of the lamp in the vehicle compartment according to the opening / closing operation of the vehicle opening / closing member by using the first load as a room lamp and the second load as a courtesy lamp and / or a trunk lamp. An object of the present invention is to provide a load control circuit capable of

  Another object of the present invention is to provide a protection means for interrupting and protecting an overcurrent in the first path as a fuse that interrupts the current when a current exceeding a predetermined current value flows, thereby providing an overcurrent in the first path. An object of the present invention is to provide a load control circuit that can easily cut off and protect a current.

  Another object of the present invention is to provide a load control circuit that can be easily routed by forming the first path, the detection line, and the second path with a wire harness.

  Another object of the present invention is to make the protection means detachable so that when it is mounted on a vehicle, the current flowing to the controller during parking or transportation for a long time can be cut off, and the battery can be prevented from running out. It is to provide a load control circuit.

  Another object of the present invention is to reduce circuit sneak current that may occur when some of the power supply circuits are shut down to reduce battery power consumption when the vehicle is parked for long-term storage or transportation. It is an object of the present invention to provide a battery rising prevention method that eliminates or reduces the battery charging and prevents the battery from rising or extends the generation time.

  A load control circuit according to the present invention guides battery power, and in order from the battery side, a protection means for cutting off overcurrent, a first path in which a first load and a first switch are connected in series, and battery power The second load and the second switch are connected in series from the battery side, and one of the terminals of the controller that switches the first switch according to the state of the second switch, the second load, and the second switch And at least one second path having a detection line connecting between the two switches, and the controller causes a current to flow from the detection line and changes according to an ON / OFF switching operation of the second switch. In the vehicle load control circuit configured to detect the state of the second switch based on the voltage level of the detection line, the second path includes at least the second path. Characterized in that the said first load side of the protective means of the route is disconnected.

  In the present invention, the power of the battery is supplied / cut off to the first load by switching the first switch in a state where the protection means is not cutting off the first path. Further, by switching the second switch, the battery power is supplied to or cut off from the second load. The first switch is switched by the controller according to the switching state of the second switch. That is, when the battery power is supplied to the second load, the battery power is also supplied to the first load. Further, in the vehicle load control circuit in which the controller detects whether the second switch is on or off based on the level of the potential of the detection line. For example, when the second switch is off, the detection line is connected to the ground potential. The voltage level of the terminal of the controller connected to the detection line is in a high state. When the second switch is turned on, the detection line is connected to the ground potential, and the voltage level of the terminal of the controller is in a low state. The controller detects the state of the second switch based on such potential displacement. And the 2nd path | route in which a 2nd load and a 2nd switch are provided is unconnected in the 1st load side from the protection means of a 1st path | route.

  For this reason, when the second switch is turned on once and then turned off in a state in which the protection means blocks the first path, the current flowing through the detection line does not flow from the second load side to the first path. As a result, since no current flows through the detection line, the controller can normally detect the state of the second switch.

  The load control circuit according to the present invention is characterized in that the battery side of the second load on the second path is connected to the first path on the battery side of the protection means.

  In the present invention, the configuration in which the battery side from the second load on the second path is connected to the first path on the battery side from the protection means can prevent the wiring from becoming complicated.

  The load control circuit according to the present invention is characterized in that the second switch is configured to be switched in accordance with an opening / closing operation of an opening / closing member provided to be openable / closable in the vehicle.

  In the present invention, the second switch is switched according to an opening / closing operation of an opening / closing member provided in the vehicle so as to be opened / closed. Thereby, a 2nd switch can be used as a switch which switches according to opening / closing operation | movement, such as a front door or a door of a trunk room, for example.

  The load control circuit according to the present invention is characterized in that the first load is a room lamp and the second load is a courtesy lamp and / or a trunk lamp.

  In the present invention, the first load is a room lamp, and the second load is a courtesy lamp and / or a trunk lamp. Thereby, lighting of the lamp in the passenger compartment can be controlled according to the opening / closing operation of the opening / closing member of the vehicle.

  In the load control circuit according to the present invention, the protection means is a fuse that cuts off a current flowing through the first path when a current exceeding a predetermined current value flows.

  In the present invention, the overcurrent in the first path is simply cut off by using a fuse that cuts off the current when a current exceeding a predetermined current value is used as the protection means that cuts off the overcurrent in the first path. And can be protected.

  The load control circuit according to the present invention is characterized in that the first path, the detection line, and the second path are formed by a wire harness.

  In the present invention, the first route, the detection line, and the second route are formed by the wire harness, so that the wiring can be easily performed.

  The load control circuit according to the present invention is characterized in that the protection means is detachable.

  A battery run-off prevention method according to the present invention is a battery run-off prevention method in a vehicle including the load control circuit according to the present invention, and the route is electrically protected by the first path protection means of the load control circuit during parking. It is characterized by blocking.

  According to the present invention, when the second switch is turned on once and then turned off in a state where the first path is blocked by the protection means, the current flowing through the detection line flows from the second load side to the first path. There is nothing. That is, in order to prevent the current flowing through the detection line from flowing from the second load side to the first path, there is no need to provide a commutator such as a diode, and the number of components can be reduced. As a result, it is possible to save time and labor at the time of manufacturing the load control circuit, and it is possible to reduce the cost.

  According to the present invention, complication of wiring can be prevented.

  According to the present invention, a troublesome switch operation can be omitted by switching the second switch for supplying power to the second load according to an opening / closing operation of a front door or a trunk room door, for example. .

  According to the present invention, since the first load is a room lamp and the second load is a courtesy lamp and / or a trunk lamp, it is possible to control the lighting of the lamp in the passenger compartment according to the opening / closing operation of the opening / closing member of the vehicle.

  According to the present invention, by removing / installing the fuse, even if an overcurrent flows in the first path, it can be easily interrupted.

  According to the present invention, the first route, the detection line, and the second route can be easily arranged by forming the wire route with the wire harness.

  According to the present invention, by making the protective means detachable, the current flowing to the controller during parking for a long time or during transportation can be cut off and the battery can be prevented from rising when mounted on the vehicle.

  According to the present invention, when mounted on a vehicle, the current flowing to the controller during parking for a long time can be cut off, and the battery can be prevented from running out.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. The load control circuit according to the embodiment of the present invention includes, for example, a plurality of lamps such as a room lamp installed on a ceiling in a vehicle, a courtesy lamp installed on a door (for example, a front door), and a trunk lamp installed in a trunk room. Each lamp is turned on / off by supplying / cutting off power from the battery to the lamp.

  FIG. 1 is a schematic diagram showing a load control circuit according to the present embodiment. The same members as those described with reference to FIG.

  The load control circuit includes an ECU 11, various lamps (for example, a room lamp 10 and a courtesy lamp 20), fuses 14, 15, 16, 17, switches 22, 32, 42, and a wire harness that connects each element. ing.

  The ECU 11 is an electronic control unit including a transistor 12 and a microcomputer 13 and controls a load control circuit. For example, the ECU 11 performs vehicle security monitoring control, vehicle door lock control, window opening / closing control, and the like in addition to various lamps such as the room lamp 10 and the courtesy lamp 20.

  The ECU 11 is connected to a power supply line 101 that supplies power from the battery 100. The power supply line 101 is provided with a fuse 16 that interrupts overcurrent and protects the circuit. Note that the ECU 11 is supplied with a dark current for causing the backup memory provided in the built-in microcomputer 13 to perform a standby operation even after an ignition switch (not shown) is turned off.

  Further, a power supply line 102 that supplies electric power of the battery 100 is connected to the input side of the ECU 11. One end of the power supply line 102 is connected to the upstream side (battery side) of the fuse 16 of the power supply line 101, and the other end is connected to the ECU 11, specifically, the collector of the transistor 12 provided in the ECU 11. The power supply line 102 is provided with fuses 14 and 15 and a room lamp 10 from the upstream side. The fuses 14 and 15 are provided at positions that can be attached and detached by the user, for example, in a fuse box in the vehicle.

  The transistor 12 is grounded at the emitter, and the base is connected to the microcomputer 13. The transistor 12 is driven and controlled by the microcomputer 13 and functions as a switch. For example, when the transistor 12 is turned on, power is supplied from the battery 100 to the room lamp 10 via the power supply line 101 and the fuses 14 and 15 of the power supply line 102. Thereby, the room lamp 10 is turned on. When the transistor 12 is turned off, the power from the battery 100 is cut off and the room lamp 10 is turned off. As will be described later, the microcomputer 13 drives and controls the transistor 12 in accordance with the open / close states of the switches 22, 32, and 42.

  A first lamp line (hereinafter referred to as a first line) 103 is connected to the power supply line 101 upstream of the fuse 16. The first line 103 is provided with a fuse 17, a courtesy lamp 20, and a switch 22 for circuit protection in order from the upstream side. The downstream side of the first line 103 is grounded. The switch 22 is turned on / off according to the opening / closing of the door on which the courtesy lamp 20 is installed. For example, when the door is opened, the switch 22 is turned on, and power is supplied from the battery 100 to the courtesy lamp 20 via the power supply line 101 and the fuse 17 of the first line 103. As a result, the courtesy lamp 20 is turned on. When the door is closed, the switch 22 is turned off, the power from the battery 100 is cut off, and the courtesy lamp 20 is turned off. Thus, the courtesy lamp 20 is turned on and off as the door is opened and closed.

  The power supply line 102 and the first line 103 are connected to the upstream side of the fuse 16 of the power supply line 101, but are not connected to each other except for the contact in the power supply line 101.

  Between the fuse 17 and the courtesy lamp 20 of the first line 103, a second lamp line (hereinafter referred to as a second line) 104 and a third lamp line (hereinafter referred to as a third line) 105 are connected. Has been. The second line 104 is provided with a courtesy lamp 30 and a switch 32 in this order from the upstream side, and the third line 105 is provided with a trunk lamp 40 and a switch 42, respectively. In other words, the courtesy lamp 20 and the switch 22 connected in series, the courtesy lamp 30 and the switch 32, and the trunk lamp 40 and the switch 42 are connected in parallel.

  The downstream sides of the second line 104 and the third line 105 are grounded. The switches 32 and 42 are turned on / off in accordance with the opening / closing of the door on which the courtesy lamp 30 is installed and the trunk door, and are turned on / off in accordance with the opening / closing of the door.

  Each line 101, 102, 103, 104, 105 is formed by a wire harness and is easy to route in the vehicle. Further, in the present embodiment, the lamps are the courtesy lamps 20 and 30 and the trunk lamp 40, but other lamps can be added or reduced.

  A first detection line 110, a second detection line 111, and a third detection line 112 are connected between the ECU 11 and the lamps 20, 30, 40 and the switches 22, 32, 42. The first detection line 110 is connected between the ECU 11, the courtesy lamp 20 and the switch 22. The second detection line 111 is connected between the ECU 11 and the courtesy lamp 30 and the switch 32. Further, the third detection line 112 is connected between the ECU 11, the trunk lamp 40 and the switch 42.

  In the ECU 11, each of the detection lines 110, 111, and 112 is connected to a voltage source 11 a (12 V power source) included in the ECU 11 via resistors 200, 201, and 202, respectively. When a load is further connected in addition to the lamp, the load is connected to the voltage source 11a via the resistor 203. The microcomputer 13 detects the open / closed state of the switches 22, 32, 42 by detecting the voltage displacement of the terminals of the ECU 11 to which the detection lines 110, 111, 112 are connected.

  For example, when the switch 22 is turned on, a current flows from the voltage source 11 a via the first detection line 110 and the switch 22. As a result, the voltage level of the terminal to which the first detection line 110 of the ECU 11 is connected is in the low state. Further, when the switch 22 is turned off, no current flows through the first detection line 110, and the voltage level of the terminal of the ECU 11 is in a high state. That is, the microcomputer 13 can detect the state of each switch 22, 32, 42 by detecting whether the voltage level is a high state or a low state. Then, the microcomputer 13 performs drive control of the transistor 12 described above according to the detected result of the open / close state. Specifically, the microcomputer 13 drives the transistor 12 when any one of the switches 22, 32, and 42 is on, and stops driving the transistor 12 when all the switches are off. Accordingly, the room lamp 10 is turned on when any of the courtesy lamps 20, 30 and the trunk lamp 40 is turned on, and is turned off when all of the courtesy lamps 20, 30 and the trunk lamp 40 are turned off.

  Next, the operation when the courtesy lamp 20 is turned on and off in the load control circuit configured as described above will be described. Since the same applies to the case where the courtesy lamp 30 and the trunk lamp 40 are turned on and off, the description thereof is omitted.

  When the front door on which the courtesy lamp 20 is installed is opened, the switch 22 is turned on. Thereby, electric power is supplied from the battery 100 to the courtesy lamp 20, and the courtesy lamp 20 is turned on. Further, when the switch 22 is turned on, a current flows from the voltage source 11 a of the ECU 11 through the first detection line 110 and the switch 22. As a result, the voltage level of the terminal to which the first detection line 110 of the ECU 11 is connected becomes a low state, and the microcomputer 13 detects that the switch 22 is turned on. Then, the microcomputer 13 drives the transistor 12. As a result, electric power is supplied from the battery 100 to the room lamp 10 via the fuses 14 and 15, and the room lamp 10 is turned on.

  When the front door on which the courtesy lamp 20 is installed is closed, the switch 22 is turned off. Thereby, the electric power from the battery 100 is interrupted and the courtesy lamp 20 is turned off. Further, when the switch 22 is turned off, no current flows from the voltage source 11a of the ECU 11 to the first detection line 110. Thereby, the voltage level of the terminal to which the first detection line 110 of the ECU 11 is connected becomes a high state, and the microcomputer 13 detects that the switch 22 is turned off. Then, the microcomputer 13 stops driving the transistor 12. As a result, power from the battery 100 is cut off and the room lamp 10 is turned off.

  In the load control circuit configured and operated as described above, the fuse 14 or both the fuses 14 and 17 are removed when the vehicle equipped with the load control circuit is transported.

  In this state, for example, when the front door is opened and the switch 22 is turned on, the courtesy lamp 20 is not lit, but current flows from the ECU 11 via the first detection line 110 and the switch 22. At this time, the potential of the terminal of the ECU 11 is lowered and the voltage level becomes a low state, and as a result, the transistor 12 is driven. At this time, since the fuse 14 (or both of the fuses 14 and 17) is removed, the room lamp 10 is not lit because the power from the battery 100 is not supplied to the room lamp 10.

  When the front door is closed and the switch 22 is turned off, no current flows from the first detection line 110 via the switch 22. Further, since the fuse 14 (or both of the fuses 14 and 17) is removed and the power supply line 102 (or the lines 102 and 103) is disconnected, as described with reference to FIG. No current flows through the ECU 11 via the lamp 20 and the room lamp 10. For this reason, the voltage level of the terminal of ECU11 will be in a High state, and the drive of transistor 12 will be stopped.

  Thereby, ECU11 can suppress the power consumption of the battery 100, without driving wastefully. Further, it is not necessary to provide a rectifying element (for example, a diode) for preventing current from flowing from the detection lines 110, 111, 112 to the upstream side of the lines 103, 104, 105. As a result, the number of parts can be reduced in comparison with the conventional circuit (FIG. 2). Further, since each line 103, 104, 105 is formed by a wire harness, the number of parts can be reduced, so that it is possible to eliminate the time and labor-consuming element mounting operation as described in FIG. Thus, the production efficiency can be improved and the cost can be reduced.

  In the present embodiment, the load control circuit of the present invention has been described as a control circuit for lighting / extinguishing the lamp. However, the present invention can also be applied to loads other than the lamp. In the present embodiment, the first path of the present invention is one of the load control circuits including the room lamp 10, but a plurality of circuits, loads other than the lamp, and both are mixed. The same applies.

  Further, in the present embodiment, it is assumed that the circuit interruption / connection in the present invention is mainly performed by attaching and detaching the fuses 14 and 17, but a fuse holder connected in series with the fuse is provided and the fuse type short piece is attached and detached. In the same way, it is also possible to provide a switch circuit in series, or to perform on / off control of the switch circuit by a program in the ECU, which is performed by attaching / detaching a connector of a harness forming the series circuit. Take as an example.

  The preferred embodiment of the present invention has been specifically described above. However, each configuration, processing operation, and the like can be changed as appropriate, and are not limited to the above-described embodiment.

It is the schematic which shows the load control circuit which concerns on this Embodiment. It is the schematic of the control circuit which turns on and off an illuminating device. It is a schematic diagram which shows the state which assembles | attaches a diode to a wire harness.

Explanation of symbols

10 Room lamp 11 ECU
12 transistor 13 microcomputer 14 fuse 20 courtesy lamp 100 battery 102 power supply line 103 first line 110, 111, 112 detection line 200, 201, 202, 203 resistance

Claims (8)

A first path that guides the power of the battery and, in order from the battery side, blocks the overcurrent, the first load and the first switch are connected in series;
A second load and a second switch are connected in series from the battery side to guide battery power, and one of the terminals of the controller that switches the first switch according to the state of the second switch; And at least one second path having a detection line connecting between the load and the second switch,
The controller is
In a vehicle load control circuit configured to detect a state of the second switch based on a voltage level of the detection line that flows according to a switching operation of turning on / off the second switch by passing a current from the detection line.
The second route is
A load control circuit, wherein the load control circuit is not connected to at least the first load side of the protection means of the first path. 2. The load control circuit according to claim 1, wherein a battery side of the second load on the second path is connected to the first path on a battery side of the protection unit. The second switch is
The load control circuit according to claim 1, wherein the load control circuit is configured to be switched according to an opening / closing operation of an opening / closing member provided to be openable / closable in the vehicle. The first load is a room lamp;
The load control circuit according to claim 3, wherein the second load is a courtesy lamp and / or a trunk lamp. The protective means is
The load control circuit according to any one of claims 1 to 4, wherein the fuse is a fuse that cuts off a current flowing through the first path when a current exceeding a predetermined current value flows.   The load control circuit according to claim 1, wherein the first path, the detection line, and the second path are formed by a wire harness.   The load control circuit according to claim 1, wherein the protection unit is detachable.   8. A method for preventing a battery from running out in a vehicle comprising the load control circuit according to claim 1, wherein the route is electrically protected by a protection means for the first route of the load control circuit during parking. A battery rising prevention method characterized by blocking.

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