JP2013230030A - Malfunction prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a malfunction prevention device which can prevent malfunction of a load during reverse connection of power supply, while minimizing heat generation normally with a relatively inexpensive configuration.SOLUTION: Since a current does not flow through a coil CL1 normally due to existence of a diode D2 for blocking a forward current, an upstream side terminal PU1 and a downstream side terminal PD1 of a switch SW1 are connected electrically, and a power source line L1 for a load is brought into a conduction state. Consequently, when a PMOS transistor Q1 is turned on, a power supply voltage VD is supplied via the switch SW1 (between PU1, PD1) to an electric load 2, and a load current I2 flows from a positive terminal P1 to a negative terminal P2. During reverse connection of power supply, the power supply path of the power source line L1 for a load is brought into an interruption state forcibly between the upstream side terminal PU1 and the downstream side terminal PD1, thus blocking a reverse current flowing from the negative terminal P2 to the positive terminal P1 in the power source line L1 for a load.

Description

  The present invention relates to a malfunction prevention device for preventing malfunction during reverse connection in which a vehicle-mounted battery is connected in positive and negative directions.

  The power supply of the automobile, that is, the battery is a part that can be removed for maintenance or replaced when overdischarged. There is a concern of reverse connection. When the power supply is reversely connected, a reverse current (reverse current) is supplied to the battery-operated electric system, and an electrical component in the electric system performs an unexpected operation (malfunction). For example, there is a battery reverse connection protection device disclosed in Patent Document 1 as a device that takes measures against such reverse connection of the power source.

  On the other hand, with the advancement of electrical component control, semiconductor elements tend to be used as switching means for power supply. In particular, MOS transistors, which are MOSFETs, are often used, but the parasitic diodes that inevitably occur due to the structure become reverse current paths in the reverse connection of the power supply, and there is a concern that electrical components may malfunction regardless of the control state. Therefore, measures against reverse power connection are essential.

  FIG. 7 is a circuit diagram showing problems in reverse connection of power when MOS transistors are used as power supply switching means.

  As shown in the figure, a fuse 3 and a PMOS transistor Q1 are inserted on a load power supply line L4 from a positive terminal P1 through an electric load 2 to a negative terminal P2. That is, the positive terminal P1 is connected to the source electrode of the PMOS transistor Q1 via the fuse 3, and the drain electrode of the PMOS transistor Q1 is connected to the negative terminal P2 via the electric load 2. At this time, the parasitic diode D1 of the PMOS transistor Q1 is provided with the negative terminal P2 side as an anode and the positive terminal P1 side as a cathode.

  In such a configuration, the battery is normally connected so that the power supply voltage VD is applied to the positive terminal P1 and the ground voltage VG is applied to the negative terminal P2, as shown in FIG.

  Therefore, at normal times, whether or not the power supply voltage VD supplied from the positive terminal P1 is supplied to the electric load 2 can be controlled by the on / off operation of the PMOS transistor Q1 based on the control signal SC. That is, when the PMOS transistor Q1 is in the ON state, the power supply voltage VD is supplied to the electric load 2, and the load current I2 flows from the positive terminal P1 to the negative terminal P2.

  On the other hand, as shown in FIG. 5B, when the power supply is reversely connected, the power supply voltage VD is applied to the negative terminal P2, and the ground voltage VG is applied to the positive terminal P1.

  Therefore, when the power supply is reversely connected, the reverse current I2R flows from the negative terminal P2 to the positive terminal P1 via the electric load 2, the parasitic diode D1, and the fuse 3 even if the PMOS transistor Q1 is turned off.

  At this time, there is a possibility that a malfunction that is not intended by the electrical load 2 may occur, and there is a concern that a phenomenon that cannot be ignored depends on the type of the electrical load 2.

  FIG. 8 is a circuit diagram showing a first conventional protection device provided with a reverse connection blocking diode D5. As shown in the figure, a reverse connection blocking diode D5 is inserted between the PMOS transistor Q1 and the electric load 2 on the load power supply line L4 with the anode side being the PMOS transistor Q1 and the cathode side being the electric load 2.

  In such a configuration, as shown in FIG. 6A, normally, when the PMOS transistor Q1 is in the ON state, the power supply voltage VD is supplied to the electric load 2 via the forward connection blocking diode D5. A load current I2 flows from the positive terminal P1 to the negative terminal P2.

  As shown in FIG. 5B, when the power supply is reversely connected, the reverse connection blocking diode D5 is disposed in the reverse direction to block the reverse current I2R, thereby preventing the reverse current I2R from being generated. .

  However, in the first conventional protection device, since a current also flows through the reverse connection blocking diode D5 in a normal state, there arises a problem that the reverse connection blocking diode D5 generates extra heat.

  In addition, since a current amount of about 10 A is assumed as the load current I2, there is a problem in that the cost increases because a relatively large capacity reverse connection blocking diode D5 capable of flowing a current of about 10 A is required. there were.

  FIG. 9 is a circuit diagram showing a second conventional protection device provided with a reverse connection blocking PMOS transistor Q6. As shown in the figure, a reverse contact blocking PMOS transistor Q6 is inserted between the PMOS transistor Q1 on the load power supply line L4 and the electric load 2 with the drain electrode side as the PMOS transistor Q1 and the source electrode side as the electric load 2. Yes. At this time, the parasitic diode D6 of the reverse connection blocking PMOS transistor Q6 is provided with the negative terminal P2 side as a cathode and the positive terminal P1 side as an anode. The reverse connection blocking PMOS transistor Q6 receives the control signal SC at its gate electrode.

  In such a configuration, as shown in FIG. 5A, normally, when the PMOS transistor Q1 is on, the reverse connection blocking PMOS transistor Q6 is also turned on, and the power supply voltage VD is connected to the PMOS transistor Q1, reverse connection. The electric current is supplied to the electric load 2 through the blocking PMOS transistor Q6, and the load current I2 flows from the positive terminal P1 to the negative terminal P2.

  As shown in FIG. 5B, when the power supply is reversely connected, the parasitic diode D6 is arranged in a direction to block the reverse current I2R, thereby preventing the reverse current I2R from being generated.

  However, in the second conventional protection device, since a current flows through the reverse connection blocking PMOS transistor Q6 in a normal state, the reverse connection blocking PMOS transistor Q6 generates extra heat. In addition, there is a problem in that the reverse connection blocking PMOS transistor Q6 requires a MOS transistor in addition to the PMOS transistor Q1, which increases the cost.

JP 10-336905 A

  The first and second conventional protection devices at the time of reverse connection of the conventional power supply are configured as described above, and current flows through the countermeasure component (parasitic diode D6, reverse connection blocking PMOS transistor Q6) itself at the normal time. High-performance (low loss, large capacity) parts are required as countermeasure parts, resulting in high costs and the countermeasure parts themselves generate heat during normal operation. There was a problem of doing.

  Further, the protection device (third conventional protection device) disclosed in Patent Document 1 has a normally closed type electromagnetic relay (mechanical relay) grounded at the most upstream of the power supply system of the automobile, and is electromagnetic only when the power supply is reversely connected. This is based on the idea of blocking the reverse current by opening the relay.

  However, the third conventional protection device does not presuppose the existence of switching means (means corresponding to the PMOS transistor Q1 in FIGS. 7 to 9) for controlling whether or not the power supply voltage is supplied from the battery to the load. That is, it is assumed that the power supply voltage is always supplied from the battery to all electrical components (loads), and the contact capacity of the switch portion in the electromagnetic relay is required to be at least about 100A. Since an electromagnetic relay having a large capacity switch unit is relatively expensive, it becomes an obstacle for realizing the conventional third protection device.

  The present invention has been made to solve the above problems, and provides a malfunction prevention device capable of preventing a malfunction of a load when a power supply is reversely connected while minimizing heat generation in a normal state with a relatively inexpensive configuration. The purpose is to obtain.

  The malfunction prevention device according to claim 1 of the present invention is provided between a positive terminal and a negative terminal for battery connection, the negative terminal of the battery is connected to the positive terminal, and the positive terminal of the battery is connected to the negative terminal. A malfunction prevention device for preventing reverse current from being generated when a battery is reversely connected, wherein the positive terminal is connected to the positive terminal from the predetermined load on a power supply line for loading from the positive terminal to the negative terminal via the predetermined load. And an electromagnetic relay having a switch part and a coil part, and the coil part flows current only when the battery is reversely connected. The switch part is interposed on the load power line so that no current flows through the coil part. A malfunction difference prevention process is performed in which the power supply path of the load power supply line is in a conductive state in a normal state and the power supply path of the load power supply line is forcibly cut off in the event of an abnormal current flow in the coil section. Features.

  The invention according to claim 2 is the malfunction prevention device according to claim 1, wherein the switch portion of the electromagnetic relay is interposed between the MOS transistor and the predetermined load on the load power line.

  The invention according to claim 3 is the malfunction prevention device according to claim 1, wherein the switch portion of the electromagnetic relay is provided on the positive terminal side of the MOS transistor on the load power line.

  The invention according to claim 4 is the malfunction prevention device according to claim 3, wherein the predetermined load includes a plurality of loads, and the predetermined load power line is a plurality of load power sources corresponding to the plurality of loads. The MOS transistor includes a plurality of MOS transistors, and each of the plurality of MOS transistors is inserted on a corresponding power supply line for load, and the conductive state in the switch section of the electromagnetic coil is the plurality of the plurality of MOS transistors. The power supply paths of the load power supply lines include all conduction possible states, and the cut-off state includes all cut-off states of the power supply paths of the plurality of load power supply lines.

  A fifth aspect of the present invention is the malfunction prevention device according to the first aspect, wherein the switch portion of the electromagnetic relay is provided closer to the negative terminal side than the predetermined load on the load power line.

  The invention according to claim 6 is the malfunction prevention device according to claim 5, wherein the predetermined load includes a plurality of loads, and the predetermined load power supply line corresponds to the plurality of loads. The MOS transistor includes a plurality of MOS transistors, and each of the plurality of MOS transistors is inserted on a corresponding power supply line for load, and the conductive state in the switch section of the electromagnetic coil is the plurality of the plurality of MOS transistors. The power supply paths of the load power supply lines include all conduction possible states, and the cut-off state includes all cut-off states of the power supply paths of the plurality of load power supply lines.

  A seventh aspect of the present invention is the malfunction prevention device according to the sixth aspect, wherein the first connector is connected to end portions of the plurality of load power lines located closer to the negative terminal than the plurality of loads. And a second connector having a connection terminal for connection to the negative terminal, wherein the first connector and the second connector include a plurality of load power lines. Are joined so as to be electrically connected to the connection terminal via the switch portion of the electromagnetic relay.

  In the malfunction prevention device of the present invention according to claim 1, since the switch portion of the electromagnetic relay is normally in a conductive state and the power supply path of the load power supply line functions effectively, it is applied from the positive terminal by the on / off operation of the MOS transistor. The supplied battery voltage can be supplied to a predetermined load without any trouble. On the other hand, since the current flows through the coil when the battery is reversely connected, the electromagnetic relay switch is shut off when an error occurs, and the power path of the load power line is forcibly disabled. Can be prevented from flowing.

  Furthermore, the transition from the continuable state to the cut-off state is performed by the switch part of the electromagnetic relay, and the coil part is connected to an auxiliary signal line different from the power supply line for the load, so the amount of current flowing through the coil part is required. Can be minimized.

  In addition, when the electromagnetic relay is in a conductive state (during normal operation), it is only necessary to generate heat at the relay contact due to the current flowing through the switch, so the electromagnetic relay generates heat during normal use of a given load. Nor.

  In addition, as the main configuration, an electromagnetic relay having a switch portion and a coil portion can be provided, so that the device can be realized at a relatively low cost with the simplification of the device configuration.

  In the present invention according to claim 2, the switch portion of the electromagnetic relay inserted between the MOS transistor and the predetermined load is turned on / off between the MOS transistor and the predetermined load. The power supply path of the power supply line can be controlled effectively / ineffectively.

  According to the third aspect of the present invention, since the switch portion of the electromagnetic relay is provided on the load power supply line on the positive terminal side from the MOS transistor, the power line formation portion between the electromagnetic relay and the positive terminal is used as the load power supply line and the auxiliary power supply line. Since it can be shared with signal lines relatively easily, efficient use of wiring (power supply lines, signal lines) can be achieved.

  Since the invention of claim 4 can perform the malfunction prevention processing by making the conductive state / interruptible state collectively for a plurality of load power lines with one electromagnetic relay, the space required for the electromagnetic relay and Cost can be reduced.

  In the invention of claim 5, since the switch portion of the electromagnetic relay is provided on the negative power terminal side of the predetermined load on the load power line, the power line forming portion between the electromagnetic relay and the negative terminal is connected to the load power line and the auxiliary power line. Therefore, the wiring (power supply line, signal line) can be used efficiently.

  According to the sixth aspect of the present invention, since a malfunction prevention process can be performed by a single electromagnetic relay at a time with respect to a plurality of power supply lines for load by means of a conductive state / means state, the space and cost required for the electromagnetic relay are reduced. Can be reduced.

  In this invention of Claim 7, the connection of the negative terminal via the switch part of the electromagnetic coil of several load power wires can be performed simply and accurately by joining the 1st connector and the 2nd connector. .

It is a circuit diagram which shows the structure of the malfunction prevention apparatus for power supply reverse connection which is Embodiment 1 of this invention. It is a circuit diagram which shows the structure of the malfunction prevention apparatus for power supply reverse connection which is Embodiment 2 of this invention. It is a circuit diagram which shows the structure of the malfunction prevention apparatus for power supply reverse connection which is Embodiment 3 of this invention. It is a circuit diagram which shows the structure of the malfunction prevention apparatus for power supply reverse connection which is Embodiment 4 of this invention. It is a circuit diagram which shows the structure of the malfunction prevention apparatus for power supply reverse connection which is Embodiment 5 of this invention. It is explanatory drawing which shows the application example of Embodiment 5 using an earth joint connector. It is a circuit diagram which shows the problem in the power supply reverse connection at the time of using a MOS transistor as a power supply switching means. It is a circuit diagram which shows the 1st conventional protection apparatus which provided the reverse connection prevention diode. It is a circuit diagram which shows the 2nd conventional protection apparatus which provided the reverse connection prevention PMOS transistor.

<Embodiment 1>
(principle)
1 is a circuit diagram showing a configuration of a malfunction prevention device for reverse power connection according to Embodiment 1 of the present invention.

  As shown in the figure, in the first embodiment, one PMOS transistor Q1 is provided for one electric load 2 to control the supply of the power supply voltage VD.

  As described above, the configuration for protecting all loads at the time of reverse power connection as in the third conventional protection device is a relatively expensive configuration. As the electrical load 2, there are loads that are dangerous when operated when the power supply is reversely connected, while there are loads that do not have any particular problems such as lamps. Therefore, it cannot be said that a protective device with an excessive measure, like the third conventional protective device, is more preferable because it is more expensive than necessary. Therefore, in Embodiment 1 and Embodiments 2 to 5 described below, one MOS transistor is provided for at least one electrical load that requires reverse power connection.

  Further, as shown in FIG. 1, an electromagnetic relay (mechanical relay) 1 including a switch unit SW1 and a coil unit CL1 is used as the main configuration of the malfunction prevention device of the first embodiment.

  The coil part CL1 is inserted between the upstream terminal PU2 and the downstream terminal PD3. The switching unit SW1 is a switching operation for switching electrical connection between {upstream terminal PU1, downstream terminal PD1} / {upstream terminal PU1, downstream terminal PD2} based on the presence / absence of current to the coil unit CL1. I do. The configuration and operation of the electromagnetic relay 1 are the same in the second to fifth embodiments described below.

  Therefore, the first to fifth embodiments described below have been realized with low heat loss while keeping the cost low by providing the electromagnetic relay 1 for power supply reverse connection countermeasures in the power supply control of the PMOS transistor Q1. This is a malfunction prevention device.

(Constitution)
As shown in FIG. 1, a fuse 3, a PMOS transistor Q1, and a switch part SW1 of the electromagnetic relay 1 are passed over a load power line L1 from a positive terminal P1 to a negative terminal P2 via an electric load 2 (predetermined load). Inserted. That is, the positive terminal P1 is connected to the source electrode of the PMOS transistor Q1 via the fuse 3, the drain electrode of the PMOS transistor Q1 is connected to the upstream terminal PU1 of the switch part SW1 of the electromagnetic relay 1, and the downstream side of the switch part SW1. The load power line L1 is configured in such a manner that the terminal PD1 is connected to the negative terminal P2 via the electric load 2. At this time, the parasitic diode D1 of the PMOS transistor Q1 is provided with the negative terminal P2 side as an anode and the positive terminal P1 side as a cathode.

  Coil portion CL1 is inserted on auxiliary signal line LS1 different from load power supply line L1. That is, the positive terminal P1 is connected to the upstream terminal PU2 of the coil part CL1 through the fuse 3, the cathode of the diode D2 is connected to the downstream terminal PD3 of the coil part CL1, and the anode of the diode D2 is connected to the negative terminal P2. Thus, the auxiliary signal line LS2 is configured.

  The switch part SW1 is in a conductive state in which the upstream terminal PU1 and the downstream terminal PD1 are electrically connected when no current flows in the coil part CL1, and when the current flows in the coil part CL1, the upstream terminal PU1 and the downstream side A switching operation for electrically connecting the terminal PD2 (floating state) to electrically disconnect the upstream terminal PU1 and the downstream terminal PD1 is performed.

(Operation)
In such a configuration, the battery is normally connected normally such that the power supply voltage VD is applied to the positive terminal P1 and the ground voltage VG is applied to the negative terminal P2, as shown in FIG.

  Therefore, in normal times, current does not flow through the coil portion CL1 due to the presence of the diode D2 that blocks forward current, and therefore, the upstream side terminal PU1 and the downstream side terminal PD1 of the switch portion SW1 are electrically connected, and the load The power supply line L1 becomes conductive. Therefore, whether or not the power supply voltage VD supplied from the positive terminal P1 is supplied to the electric load 2 can be controlled by the on / off operation of the PMOS transistor Q1 based on the control signal SC. That is, when the PMOS transistor Q1 is in the ON state, the power supply voltage VD is supplied to the electric load 2 via the switch unit SW1 (between PU1 and PD1), and the load current I2 flows from the positive terminal P1 to the negative terminal P2. At this time, the switch unit SW1 only needs to supply current to one unit of the electric load 2 (about 30 A or less), so that a current supply capacity of 30 A is sufficient. This is because generally the load current required for one unit of the electric load 2 for in-vehicle use is almost 10 A or less, and is about 30 A at the maximum.

  On the other hand, as shown in FIG. 5B, when the power supply is reversely connected, the power supply voltage VD is applied to the negative terminal P2, and the ground voltage VG is applied to the positive terminal P1.

  Therefore, when the power supply is reversely connected, a current flows through the coil portion CL1 via the diode D2, so that the switch portion SW1 electrically connects the upstream terminal PU1 and the downstream terminal PD2. That is, the power supply path of the load power supply line L1 is forcibly cut off between the upstream terminal PU1 and the downstream terminal PD1.

  As a result, as shown in FIG. 4B, when the power supply is reversely connected, the reverse switch I2R can be prevented from being generated by the switch part SW1 in the cut-off state.

  At this time, in the malfunction preventing apparatus of the first embodiment, since no current flows through the coil part CL1 during normal time, no heat is generated by the coil part CL1. Slightly, the contact of the switch part SW1 can be kept to a certain extent to generate heat.

  Moreover, since the electromagnetic relay 1 is provided corresponding to the electric load 2, the current supply capability to other loads that require the power supply voltage VD from the battery is not required. Therefore, since the current supply capability of the switch unit SW1 is only required to be able to supply current to the electric load 2, it can be suppressed to a sufficiently low capacity.

(effect)
As described above, in the malfunction preventing apparatus of the first embodiment, the switch part SW1 of the electromagnetic relay 1 makes the power supply path of the load power supply line L1 conductive when it is normal, so that the positive terminal is turned on by the on / off operation of the PMOS transistor Q1. The power supply voltage VD applied from P1 can be supplied to the electric load 2 without any trouble. On the other hand, since a current flows through the coil part CL1 when the power supply is reversely connected, the switch part SW1 of the electromagnetic relay 1 puts the load power supply line L1 into a cut-off state when an abnormality occurs. As a result, the power supply path of the load power supply line L1 is forcibly invalidated, so that a reverse current can be prevented from flowing through the electric load 2.

  Furthermore, the transition from the conductive state to the cut-off state in the load power line L1 is performed by the switch part SW1 of the electromagnetic relay 1, and the coil part CL1 is connected to the auxiliary signal line LS2 different from the load power line L1. Therefore, the amount of current flowing through the coil portion CL1 can be minimized.

  In addition, when the electromagnetic relay 1 is in the conductive state (normal time), only the heat generated at the relay contact due to the current flowing in the switch unit SW1 can be generated. As it does not generate heat.

  In addition, since the main configuration of the malfunction prevention device can be the configuration of providing the electromagnetic relay 1 having the switch portion SW1 and the coil portion CL1, the device can be configured with a relatively inexpensive configuration with the simplification of the device configuration. Can be realized.

  Then, by electrically connecting / disconnecting the PMOS transistor Q1 and the electric load 2 by the switch part SW1 of the electromagnetic relay 1 provided between the PMOS transistor Q1 and the electric load 2, the power supply path of the load power supply line L1 is changed. Effective / invalid can be controlled efficiently.

<Embodiment 2>
(Constitution)
FIG. 2 is a circuit diagram showing a configuration of a malfunction prevention device for reverse power connection according to Embodiment 2 of the present invention. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  As shown in the figure, a fuse 3, a switch part SW1 of an electromagnetic relay 1, and a MOS transistor Q1 are inserted on a load power line L2 extending from a positive terminal P1 through an electric load 2 to a negative terminal P2. That is, the positive terminal P1 is connected to the upstream terminal PU1 of the switch part SW1 of the electromagnetic relay 1 via the fuse 3, the downstream terminal PD1 of the switch part SW1 is connected to the source electrode of the PMOS transistor Q1, and the PMOS transistor Q1 The load power supply line L2 is configured in such a manner that the drain electrode is connected to the negative terminal P2 via the electric load 2.

  The coil part CL1 of the electromagnetic relay 1 is inserted on an auxiliary signal line LS2 different from the load power line L2. That is, the positive terminal P1 is connected to the upstream terminal PU2 of the coil part CL1 through the fuse 3, the cathode of the diode D2 is connected to the downstream terminal PD3 of the coil part CL1, and the anode of the diode D2 is connected to the negative terminal P2. Thus, the auxiliary signal line LS2 is configured. The load power supply line L2 and the auxiliary signal line LS2 are connected at the node N1 on the positive terminal P1 side of the electromagnetic relay 1, and the node N1 and the positive terminal P1 are shared.

(Operation)
In such a configuration, in the normal state, as in the first embodiment, when the PMOS transistor Q1 is in the ON state, the power supply voltage VD is supplied to the electric load 2, and the load current is directed from the positive terminal P1 to the negative terminal P2. I2 flows.

  On the other hand, when the power supply is reversely connected, the generation of reverse current can be prevented by the switch part SW1 in the cut-off state, as in the first embodiment.

(effect)
Thus, the malfunction prevention device of the second embodiment has the same effects as those of the first embodiment. That is, it is possible to prevent a reverse current from flowing through the electric load 2 when the power supply is reversely connected without any trouble during normal operation. Further, similarly to the first embodiment, the amount of current flowing through the coil portion CL1 is minimized, and the electric load 2 does not generate heat as the electromagnetic relay 1 is normally used.

  In addition, in the second embodiment, the switch section SW1 of the electromagnetic relay 1 has an upstream setting configuration in which the positive terminal P1 side is provided from the PMOS transistor Q1 on the load power supply line L2. Therefore, without considering the presence of the PMOS transistor Q1 or the electric load 2, the power line forming portion between the electromagnetic relay 1 and the positive terminal P1 is connected between the load power line L3 and the auxiliary signal line LS3 (the positive line in FIG. 2). Since the common use is relatively easy between the terminal P1 and the node N1, the wiring (power supply line, signal line) can be used efficiently.

<Embodiment 3>
(Constitution)
FIG. 3 is a circuit diagram showing a configuration of a malfunction prevention device for reverse power connection according to Embodiment 3 of the present invention. Note that in the third embodiment, the same components as those in the second embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  As shown in the figure, in the malfunction prevention device of the third embodiment, PMOS transistors Q11 to Q13 are provided corresponding to the electric loads 21 to 23, respectively. PMOS transistors Q11-Q13 are controlled to be turned on / off by control signals SC1-SC3. Therefore, there are three load power lines L21 to L23 extending from the positive terminal P1 to the negative terminal P2 via the electric loads 21 to 23, respectively.

  That is, the positive terminal P1 is connected to the upstream terminal PU1 of the switch unit SW1 of the electromagnetic relay 1 via the fuse 3, the downstream terminal PD1 of the switch unit SW1 is connected to the source electrode of the PMOS transistor Q11, and the PMOS transistor Q11 The load power supply line L21 is configured in such a manner that the drain electrode is connected to the negative terminal P2 via the electric load 21.

  The positive terminal P1 is connected to the upstream terminal PU1 of the switch part SW1 of the electromagnetic relay 1 via the fuse 3, the downstream terminal PD1 of the switch part SW1 is connected to the source electrode of the PMOS transistor Q12, and the PMOS transistor Q12 The load power supply line L22 is configured in such a manner that the drain electrode is connected to the negative terminal P2 via the electric load 22.

  Further, the positive terminal P1 is connected to the upstream terminal PU1 of the switch part SW1 of the electromagnetic relay 1 via the fuse 3, the downstream terminal PD1 of the switch part SW1 is connected to the source electrode of the PMOS transistor Q13, and the PMOS transistor Q13 The load power supply line L23 is configured in such a manner that the drain electrode is connected to the negative terminal P2 via the electric load 23.

(Operation)
In such a configuration, during normal times, as in the first and second embodiments, when the PMOS transistors Q11 to Q13 are on, the power supply voltage VD is supplied to the electric loads 21 to 23, and the load power supply A load current flows through each of the lines L21 to L23. That is, the supply / cutoff of the power supply voltage VD to the electric load 2i is controlled by the on / off operation of the PMOS transistor Q1i (i = 1 to 3). However, since the switch unit SW1 needs to supply current to three units of the electrical loads 21 to 23 (total of about 100A or less), the current supply capability needs to be set to about 100A.

  On the other hand, at the time of reverse power connection, all the power paths of the load power lines L21 to L23 are forcibly cut off between the upstream terminal PU1 and the downstream terminal PD1. As a result, the generation of reverse current to the electrical loads 21 to 23 can be collectively prevented by the cut-off switch unit SW1.

(effect)
As described above, in the malfunction prevention device of the third embodiment, as in the first embodiment, there is no problem during normal time, and it is possible to prevent a reverse current from flowing through the electric load 2 when the power supply is reversely connected. The amount of current flowing through the electric relay 2 is kept to a minimum, and the electric load 2 does not generate heat as the electromagnetic relay 1 during normal use.

  Further, in the third embodiment, as in the second embodiment, it is not necessary to provide the auxiliary signal line LS2 by avoiding the PMOS transistor Q1, and the wiring (power supply line, signal line) can be used efficiently.

  In addition, the malfunction prevention device according to the third embodiment malfunctions with respect to the electrical loads 21 to 23 in a state in which the electromagnetic relay 1 can conduct / cut off the three power supply lines L21 to L23 all at once. Since the prevention process can be performed, the space and cost required for the electromagnetic relay 1 can be reduced.

<Embodiment 4>
(Constitution)
FIG. 4 is a circuit diagram showing a configuration of a malfunction prevention device for reverse power connection according to Embodiment 4 of the present invention. Note that in the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  As shown in the figure, a fuse 3, a MOS transistor Q1, and a switch part SW1 of the electromagnetic relay 1 are inserted on a load power supply line L3 from the positive terminal P1 to the negative terminal P2 through the electric load 2. That is, the positive terminal P1 is connected to the source electrode of the PMOS transistor Q1 through the fuse 3, the drain electrode of the PMOS transistor Q1 is connected to the upstream terminal PU1 of the switch unit SW1 of the electromagnetic relay 1 through the electric load 2, The load power supply line L3 is configured in such a manner that the downstream terminal PD1 of the switch unit SW1 is connected to the negative terminal P2.

  The coil portion CL1 of the electromagnetic relay 1 is inserted on an auxiliary signal line LS3 different from the load power supply line L3. That is, the positive terminal P1 is connected to the upstream terminal PU2 of the coil part CL1 through the fuse 3, the cathode of the diode D2 is connected to the downstream terminal PD3 of the coil part CL1, and the anode of the diode D2 is connected to the negative terminal P2. Thus, the auxiliary signal line LS3 is configured. The load power supply line L3 and the auxiliary signal line LS3 are connected at the node N2 on the negative terminal P2 side of the electromagnetic relay 1, and the node N2 and the negative terminal P2 are shared.

(Operation)
In such a configuration, during normal times, as in the first and second embodiments, when the PMOS transistor Q1 is in the ON state, the power supply voltage VD is supplied to the electric load 2 and the positive terminal P1 to the negative terminal P2 The load current I2 flows in the direction of.

  On the other hand, when the power supply is reversely connected, the occurrence of reverse current can be prevented by the switch part SW1 in the cut-off state, as in the first and second embodiments.

  Thus, the malfunction prevention device of the fourth embodiment has the same effects as those of the first embodiment. That is, it is possible to prevent a reverse current from flowing through the electric load 2 when the power supply is reversely connected without any trouble during normal operation. Further, similarly to the first embodiment, the amount of current flowing through the coil portion CL1 is minimized, and the electric load 2 does not generate heat as the electromagnetic relay 1 is normally used.

  In addition, in the fifth embodiment, the switch unit SW1 of the electromagnetic relay 1 has a downstream setting configuration in which the negative terminal P2 side is provided from the electric load 2 on the load power line L2. Therefore, without considering the presence of the PMOS transistor Q1 and the electric load 2, the power line forming portion of the electromagnetic relay 1 and the negative terminal P2 is connected between the load power line L3 and the auxiliary signal line LS3 (the negative line in FIG. 4). Since the common use is relatively easy between the terminal P2 and the node N2, the wiring (power supply line, signal line) can be used efficiently.

<Embodiment 5>
(Constitution)
FIG. 5 is a circuit diagram showing a configuration of a malfunction prevention device for reverse power connection according to Embodiment 5 of the present invention. Note that in the fifth embodiment, the same components as those in the fourth embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  As shown in the figure, in the malfunction prevention device of the fifth embodiment, PMOS transistors Q11 to Q13 are provided corresponding to the electric loads 21 to 23, as in the third embodiment. PMOS transistors Q11-Q13 are controlled to be turned on / off by control signals SC1-SC3. Therefore, there are load power lines L31 to L33 extending from the positive terminal P1 to the negative terminal P2 through the electric loads 21 to 23, respectively.

  That is, the positive terminal P1 is connected to the source electrode of the PMOS transistor Q11 via the fuse 3, the drain electrode of the PMOS transistor Q11 is connected to the upstream terminal PU1 of the switch unit SW1 of the electromagnetic relay 1 via the electric load 21, The load power supply line L31 is configured in such a manner that the downstream terminal PD1 of the switch unit SW1 is connected to the negative terminal P2.

  The positive terminal P1 is connected to the source electrode of the PMOS transistor Q12 via the fuse 3, the drain electrode of the PMOS transistor Q12 is connected to the upstream terminal PU1 of the switch unit SW1 of the electromagnetic relay 1 via the electric load 22, The load power supply line L32 is configured in such a manner that the downstream terminal PD1 of the switch unit SW1 is connected to the negative terminal P2.

  In addition, the positive terminal P1 is connected to the source electrode of the PMOS transistor Q13 via the fuse 3, the drain electrode of the PMOS transistor Q13 is connected to the negative terminal P2 via the electric load 23, and upstream of the switch unit SW1 of the electromagnetic relay 1. The load power supply line L33 is configured in such a manner that it is connected to the side terminal PU1 and connected to the downstream side terminal PD1 of the switch unit SW1.

(Operation)
In such a configuration, in the normal state, as in the third embodiment, when the PMOS transistors Q11 to Q13 are in the ON state, the power supply voltage VD is supplied to the electric loads 21 to 23, and the load power supply lines L31 to L33, respectively. Load current flows in That is, the supply / cutoff of the power supply voltage VD to the electric load 2i is controlled by the on / off operation of the PMOS transistor Q1i (i = 1 to 3).

  On the other hand, when the power supply is reversely connected, all the power paths of the load power supply lines L31 to L33 are forcibly cut off between the upstream terminal PU1 and the downstream terminal PD1. As a result, the generation of reverse current to the electrical loads 21 to 23 can be collectively prevented by the cut-off switch unit SW1.

(effect)
As described above, in the malfunction prevention device of the fifth embodiment, similarly to the first embodiment, it is possible to prevent a reverse current from flowing through the electric load 2 when the power supply is reversely connected without any trouble during normal operation, and the coil portion CL1. The amount of current flowing through the electric relay 2 is kept to a minimum, and the electric load 2 does not generate heat as the electromagnetic relay 1 during normal use.

  Further, in the fifth embodiment, as in the fourth embodiment, the power line forming portion (between the negative terminal P2 and the node N2 in FIG. 5) between the electromagnetic relay 1 and the negative terminal P2 is connected to the load power lines L31 to L33. Since it can be used relatively easily with the signal line LS3, the wiring (power supply line, signal line) can be used efficiently.

  In addition, the malfunction prevention device of the fifth embodiment is required for the electromagnetic relay 1 because the malfunction prevention processing can be collectively performed on the plurality of load power lines L31 to L33 by one electromagnetic relay 1. Space and cost can be reduced.

(Utilization of earth joint connector 12)
FIG. 6 is an explanatory view showing an application example of the fifth embodiment using an earth joint connector. As shown in the figure, the end of the power supply line including the load power supply lines L31 to L33 on the negative terminal P2 side is connected to the connector 11.

  On the other hand, the ground joint connector 12 has a ground connection terminal 13 for connection to the negative terminal P <b> 2 and can be joined to the connector 11. Therefore, the electromagnetic relay 1 and the diode D2 are inserted into the earth joint connector 12 so that the load power lines L31 to L33 and the electromagnetic relay 1 are connected as shown in FIG. The connection is made.

  As described above, in the application example of the fifth embodiment, the switch portion SW1 of the electromagnetic relay 1 of the load power supply lines L31 to L33 is obtained by joining the connector 11 (first connector) and the ground joint connector 12 (second connector). The negative terminal P2 can be easily and accurately connected via the terminal.

<Others>
In the above-described embodiment, an example in which a PMOS transistor is used as the MOSFET has been described. However, it goes without saying that an NMOS transistor may be used instead of the PMOS transistor.

  Also, within the scope of the present invention, the embodiments can be freely combined, or the embodiments can be appropriately modified or omitted.

Q1, Q11 to Q13 PMOS transistor 1 Electromagnetic relay SW1 Switch part CL1 Coil part L1 to L3, L21 to L23, L31 to L33 Load power line LS1 to LS3 Auxiliary signal line 11 Connector 12 Earth joint connector 13 Earth connection terminal

Claims (7)

It is provided between a positive terminal and a negative terminal for battery connection, and a negative current of the battery is connected to the positive terminal and a positive electrode of the battery is connected to the negative terminal to prevent a reverse current from being generated when the battery is reversely connected. A malfunction prevention device,
A MOS transistor inserted on the positive terminal side from the predetermined load on the load power line extending from the positive terminal via the predetermined load to the negative terminal, and turned on / off based on a predetermined control signal; ,
An electromagnetic relay having a switch portion and a coil portion;
The coil part is provided on an auxiliary signal line different from the load power line so that a current flows only when the battery is reversely connected,
The switch unit is inserted on the power supply line for the load, makes the power path of the power supply line for the load power supply conductive when the current does not flow to the coil unit, and the load at the time of an abnormal current flow to the coil unit. It is characterized by executing a malfunction difference prevention process for forcibly shutting off the power path of the power line for power.
Malfunction prevention device. The malfunction prevention device according to claim 1,
The switch portion of the electromagnetic relay is interposed between the MOS transistor and the predetermined load on the load power line.
Malfunction prevention device. The malfunction prevention device according to claim 1,
The switch portion of the electromagnetic relay is provided on the positive terminal side from the MOS transistor on the load power line.
Malfunction prevention device. The malfunction prevention device according to claim 3,
The predetermined load includes a plurality of loads,
The predetermined load power line includes a plurality of load power lines corresponding to the plurality of loads,
The MOS transistor includes a plurality of MOS transistors,
Each of the plurality of MOS transistors is inserted on a corresponding power supply line for load,
The conductive state in the switch section of the electromagnetic coil includes all conductive states of the power paths of the plurality of load power lines, and the cutoff state includes all of the power paths of the plurality of load power lines. Including blocking status,
Malfunction prevention device. The malfunction prevention device according to claim 1,
The switch part of the electromagnetic relay is provided on the negative terminal side from the predetermined load on the load power line.
Malfunction prevention device. The malfunction prevention device according to claim 5,
The predetermined load includes a plurality of loads,
The predetermined load power line includes a plurality of load power lines corresponding to the plurality of loads,
The MOS transistor includes a plurality of MOS transistors,
Each of the plurality of MOS transistors is inserted on a corresponding power supply line for load,
The conductive state in the switch section of the electromagnetic coil includes all conductive states of the power paths of the plurality of load power lines, and the cutoff state includes all of the power paths of the plurality of load power lines. Including blocking status,
Malfunction prevention device. The malfunction prevention device according to claim 6,
A first connector connected to an end portion of the plurality of load power lines on the negative terminal side from the plurality of loads;
The electromagnetic relay is housed inside, and further includes a second connector having a connection terminal for connection at the negative terminal,
The first connector and the second connector are joined so that end portions of a plurality of load power lines are electrically connected to the connection terminal via the switch portion of the electromagnetic relay.
Malfunction prevention device.

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