JP2002238135A - Power supply terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply terminal device which can avoid vehicle fires, caused by a short circuit of a power supply cable and a failure of a load- driving device itself, detect short circuiting and open circuit of a driven load, inform outside facility of the state, and reduce current consumption, when electrical components are not used. SOLUTION: A power supply distributor 4 which distributes a supplied power is provide on a power supply line 3 from a battery 1. Power supply lines 5, 6, and 7 of respective systems are wired from the power distributor 4. Furthermore, power supply terminals 8, 11, 14, 18, and 21 are provided at the ends of the power supply lines 5, 6, and 7 and powers are supplied to respective types of electrical load devices 9, etc., 12, etc., 15, etc., 17, etc., and 20, etc., from the power supply terminals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device in which a large number of electric components are arranged at various places in a vehicle, and power is supplied to these electric components from a common power supply. The present invention relates to a power supply terminal device of a power supply control device suitable for an automobile of a system.

[0002]

2. Description of the Related Art For various vehicles such as automobiles, it is indispensable to equip various lighting devices and various electric loads (electrical components) typified by various types of electric equipment. The numbers are only increasing, and consequently the connecting lines for them are also a step towards increasing complexity.

In order to cope with the complexity of the connection line, a controller for controlling each electric load is integrated, and control signals for a plurality of electric loads are calculated using a small number of controllers having a communication function and a calculation function. Then, by transmitting a control signal to a terminal device connected by a communication line, by controlling a plurality of electrical loads connected to the terminal device, so as to reduce the number of connection lines, a so-called aggregate wiring system, Conventionally known examples are described in U.S. Pat. Nos. 4,771,382, 5,113,410, 4,855,896, and 5,438,506. You can see.

Further, in such a system, security equipment for a power supply circuit is indispensable. However, in a conventional vehicle, a blowing fuse is provided in a power supply path from a power supply, and a short circuit (short circuit accident) occurs in a power supply line to an electric load. ), The method of disconnecting the electric load from the power supply by blowing the fuse is mainly employed.

[0005]

The above prior art does not take into account the increase in the number of connection lines for an electric load and the presence of a blown fuse, and the power line occupies space in a vehicle. There was a problem in terms of maintenance when a short circuit accident occurred.

That is, in the prior art, even if the centralized wiring system is applied, the power supply line is still linearly wired from the power supply to each electric load or the drive circuit of the electric load, so that only the number of electric loads or More power lines are required, which causes the floor and ceiling of the vehicle and the inside of the body to be filled with electric wires, causing a problem that a large space is occupied.

Further, in the prior art, when a short circuit occurs, the fuse is blown. Therefore, every time a transient short circuit occurs, maintenance work such as replacement of the fuse is required each time, which is preferable for operation of the vehicle. There is no effect.

[0008] An object of the present invention is basically to provide a new power supply device for a vehicle, and specifically to reduce the number of power lines required for power supply of the vehicle. Another object of the present invention is to provide a vehicle power supply device without a blown fuse, and still another object of the present invention is to provide a new power supply method for a vehicle.

Still another object of the present invention is to provide a new semiconductor circuit device used for power supply control.
Still another object of the present invention is to provide a new integrated wiring device integrated with a power supply control system, and still another object of the present invention is to provide a new electric power supply device for a specific electric load of an automobile. It is still another object of the present invention to provide a new device for detecting that a power supply line is short-circuited.

[0010]

The object of the present invention is to provide a control circuit having a power take-in terminal for taking in power for driving a load from a power supply line, a communication function for receiving a signal from a communication line, and an output signal of the control circuit. This is achieved by providing a load driving element for controlling the power of a load, and a power output terminal connected to the load driving element.

At this time, a contact circuit for breaking power wiring may be provided between the power take-in terminal and the load driving element, and may be operated by a signal of the control circuit. The element may be constituted by a semiconductor device having a self-protection function.

According to the present invention, the terminal control circuit has a power relay function, so that the power supply wiring in the vehicle is simplified, and the total amount of power supply lines can be reduced.

According to the second aspect of the present invention, when the load circuit is short-circuited, the power supply terminal can be disconnected from the power supply main line, and the influence of short-circuit failure of each power supply terminal on other power supply terminals can be suppressed. A short circuit accident due to vibration or pinching can be detected by a detection circuit capable of detecting the occurrence of a power failure, and a power cable having an abnormality can be disconnected to prevent a secondary disaster.

Further, according to the third aspect of the present invention, when an abnormality occurs in the load driving element itself, the current to the load is cut off.
No overcurrent continues to flow through the load.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a power supply terminal device according to the present invention will be described in detail with reference to the illustrated embodiments. Figure 1
Is an embodiment in which the present invention is applied to a power supply circuit of an automobile. This embodiment is roughly divided into a power supply system for supplying power to a load device and switches for operating an electric load of a vehicle. And a signal system for capturing the data.

One terminal (+ terminal) of the battery 1 is connected to the power cable 3 via the fusible link 2, whereby power is transmitted from the battery 1 to the power distributor 4 and the switch group input terminal 24. I will Here, the fusible link 2 is for protection in the event that the system falls into an abnormal state for some reason, and is well known.

The power guided to the power distributor 4 has a star shape.
The power cables 5, 6, and 7 are distributed to (radially) three power cables 5, 6, and 7, and the power cables 5 and 7 are branched and wired in a tree shape. , 14, 18, 21 are supplied with power.

Each of the power terminals 8 (11, 14, 18, 21) has various devices 9, 10, 12, 13, 15, 16, 1
7, 19, 20, and 22 are connected. These devices 9 and the like may be electric loads such as motors and lamps, or may be some control devices arranged in the vehicle.

Lamp 23 connected to power distributor 4
Is provided to warn an abnormal operation situation, and is turned on when an abnormality occurs in this system or when any trouble occurs, and is provided to give a warning to a driver or the like.

The power distributor 4 and the switch group input terminal 24
Are connected by a communication line 27, and perform data communication between them.

FIG. 2 is a diagram showing the internal structure of the power cables 5, 6, and 7, as shown in FIG.
Are provided with two electric wires, a power supply line 25 and a communication line 26, and play a role of transmitting power from the power distributor 4 to each power terminal and a role of transmitting control data. ing.

Here, an example of the operation will be described.
For example, if an ignition key switch status signal is received from the switch group input terminal 24 and it is located at a position (ACC position) for supplying power to the vehicle accessories, each power supply is transmitted from the power distributor 4 through the communication line 26 via the communication line 26. Notify the terminal that the ignition key is in the ACC position,
The power supply terminals 8 to 8 that have been notified connect the power supply circuit to the corresponding load device and operate to supply power.

FIG. 3 is a diagram showing the internal configuration of the power distributor 4, and the power guided from the battery 1 is supplied to the power circuit 31 and the switching circuit 33 via the power cable 3.

Here, the power supply circuit 31 functions to supply power to the circuit inside the power distributor 4, and the switching circuit 33
Functions to cut off the power supply from the power supply cable 3 to the power supply cables 5, 6, and 7.

The power supply circuit 31 is composed of a stabilized power supply, and the stabilized power is supplied to the microcomputer 30 and the communication IC 32 via power supply lines 34 and 35, respectively, to enable these operations.

The communication IC 32 is connected to the microcomputer 30 via a data bus 36, and exchanges data on the communication line 27 to the switch group input terminal 24 and the communication line 26 to each power supply terminal.

A signal line 39 from the microcomputer 30 is used to turn on the alarm lamp 23 (FIG. 1).

The switching circuit 33 includes the microcomputer 30 and the signal line 3
7, whereby the microcomputer 30 controls the contact points A, B, and C for disconnection incorporated in the switching circuit 33, and issues a connection state and a disconnection instruction.

A current detector 38 is provided at the output of the switching circuit 33. The current detector 38 detects the current flowing through the power cables 5, 6, and 7, and the detected current value is taken into the microcomputer 30. It is used to monitor the current flowing through the power cables 5, 6, 7.

FIG. 4 is a diagram showing the internal configuration of the power supply terminals 8 to 8. Here, the power supply terminal 8 will be described as a representative, but basically all power supply terminals have the same internal configuration.

The power supply circuit 40 is a stabilized power supply for supplying power to the internal circuit of the power supply terminal. The power supply circuit 40 receives power supply from the power supply line 25,
2 is supplied with stabilized power.

The power from the power supply line 25 is guided to IPDs 48 and 49, which will be described later, via a contact circuit 41 for disconnection, and is used as power supplied from the power supply terminal 8 to a load device.

The data bus 45 is for performing data used for communication with the power distributor 4 through the communication IC 43.

A signal line 46 extending from the microcomputer 42 to the contact circuit 41 is used to transmit a signal for controlling power supply to a load device connected to the power supply terminal 8, thereby starting or stopping power supply. Can be controlled.

When no electric power is supplied, the contact circuit 41 is normally released (power supply is stopped), so that the dark current can be reduced when the load device is not used, and the electric current in the IPD described later can be reduced. Used as a safety circuit in the event of a major failure.

As described above, the power line 47 from the contact circuit 41 is connected to the IPDs 48 and 49. The IPD is an abbreviation of an intelligent power device, which is a kind of load driving element. It is a device that diagnoses short-circuit and disconnection of a load, outputs information to the microcomputer 42, and also has a protection circuit so as not to be destroyed by itself, and has recently been widely used. Things.

The signal lines 51 and 53 output from each of the IPDs 48 and 49 to the microcomputer 42 detect whether each electric load is in a short-circuit state or a released (disconnected) state by the function of the IPD. For transmitting a diagnostic signal for notification, the microcomputer 42 captures this signal, grasps the function state of the IPD, and performs an abnormality warning process.

The signals 50 and 52 input from the microcomputer 42 to the respective IPDs 48 and 49 are signals for driving the IPD. The signals 54 and 55 input from the outputs of the respective IPDs 48 and 49 to the microcomputer 42 are described above. This is a failure diagnosis signal for detecting a failure of the IPD element itself.

Next, the operation for detecting when the load connected to the power supply terminal is short-circuited or released, or when the IPD element has failed will be described.

First, FIG. 5 is a detailed view of a portion where power is supplied to the load device 9 of the block diagram shown in FIG.

As described above, the IPDs 48 and 49 have a function of judging the state of the connected electric load.
As shown in FIG. 6, "load release" and "load short-circuit" can be determined.

On the other hand, if the elements constituting the IPD have failed, the load diagnosis signals 51 and 53 cannot be relied on. In this case, as shown in FIG.
The D output signals 54 and 55 are configured to be monitored by the microcomputer 42.

After all, by monitoring the voltage applied to the load device 9 and monitoring the three signals of the drive signal 51, the load diagnosis signal 51, and the element failure diagnosis signal 54, all the states shown in FIG. Can be grasped. In FIG. 6, the portion marked “-” (slant) is “H”,
This indicates that any of “L” may be used.

Therefore, for example, if the drive signal is "H" and the diagnostic signal is "H", and if the failure diagnostic signal is "L" in this state, in this case, the output state of the IPD Indicates that the output is not performed in spite of the judgment that it is normal.

For example, if the drive signal is "L" and the failure diagnosis signal at this time is "H", in this case, the output from the IPD is output even though the IPD is not driven. This shows what is happening.

In this case, since both are in an abnormal state,
It can be determined that the IPD has failed. When such a situation occurs, the driver or the like is notified that an abnormality has occurred, and the disconnection circuit 41 of FIG. 4 is opened to prevent a secondary disaster from occurring.

FIG. 7 shows the internal configuration of the switching circuit 33 shown in FIG. 3. In this embodiment, in order to supply power to the three power cables 5, 6, and 7, an electromagnetic switch (relay) is provided. ) 60, 61, 62, which are used in a normal state with the contacts A, B, C closed, the so-called N
These are C (normally closed contact) type switches, which are driven by switching elements 66, 67, and 68, respectively, to perform intermittent power supply.

The diodes 63, 64, and 65 inserted in parallel with the switching elements 66 to are provided for protection when the present system is reversely connected to the battery 1.

If the polarity of the battery 1 is reversed (+) or (-), the current flows in a direction opposite to the normal current direction, and there is a possibility that a failure occurs in the electric load in the system.

Therefore, when the battery is reversely connected, current is passed through these diodes 63 to
Force the contacts A, B, and C of the electromagnetic switch 60 to OF
By performing the F operation, the reverse current flowing to the power supply terminal side is prevented, and the electric load is protected.

The switching elements 66, 67, 68 are provided with signals 37b, 37d, 37f supplied from the microcomputer 30.
The microcomputer 30 simultaneously checks the voltage levels of the signal lines 37a, 37c, and 37e, and controls the driving state and the driving signal. Collation is used to ensure accurate control.

For example, if the contact A is now closed, the switching element 66 is off in this case, and the signal 37b is "low".
a should show "high". Conversely, if the contact A is open, in this case, the switching element 66
Is on, the signal 37b should be at "high" level and the signal 37a should be at "low" level.

Here, if the switching element 66 fails, the relationship between the signals 37a and 37b is broken, so that the microcomputer 30 can detect the failure of the switching element 66.

FIG. 8 is a diagram showing the internal structure of the contact circuit built in each of the power supply terminals 8. In FIG. 8, only the contact circuit 41 is extracted as a representative of the power supply terminal 8 shown in FIG. Shown.

As described above, this contact circuit 41
It functions to shut off the power to the PDs 48 and 49, and the shut-off conditions are as described above.

The normally open electromagnetic switch 70 is off (open) when power is not supplied.
(NO) type relay.
The switching element 73 is turned on / off by the signal line 46 from the second, and the electromagnetic switch 70 is turned on / off.

The diodes 71 and 72 are provided to prevent the current from flowing through the electromagnetic switch 70 and automatically turning on when the battery 1 is reversely connected. Since there is no possibility that a reverse current flows through the electric load device and the IPD, there is an advantage that a failure can be prevented.

Next, a series of operations performed by the system according to this embodiment until the battery 1 is connected to the system and the function is started will be described with reference to a startup processing flow 100 shown in FIG.

When the system is turned on in step 101, the system is ready for operation (step 102).

Thereafter, if a change occurs in any of the switches connected to the switch group input terminal 24, the switch group input terminal 24 transmits information of the changed switch to the power distributor 4. (Step 103).

In step 104, based on the received switch information, it is determined which electric load device of the target power supply terminal is to be supplied with power, and the result is transmitted to the corresponding power supply terminal by data communication. Send to

Thereafter, each power supply terminal includes an electric load device which controls power supply by itself, and a power supply element (IPD).
Is constantly monitored by the microcomputer, and based on the table in FIG. 6, it is checked whether or not any abnormality has occurred (step 105).

If it is determined that an abnormality has occurred, at step 106, the fact that an abnormality has occurred is transmitted to the power distributor 4 by data communication.

Then, the power distributor 4 receives this data and turns on the warning lamp 23 as necessary so that the driver is notified of the abnormality.

When no abnormality is detected,
In step 107, the warning lamp is turned off, and thereafter, these processes are repeated from step 103.

By the way, the electric load to which the power supply terminal supplies electric power may be any control unit, any motor or lamp.

For example, upon receiving the ON of the opening switch of the driver's seat power window from the switch group input terminal 24,
The motor may be operated to open the power window from the power supply terminal built into the driver's door,
The ignition key accessory power supply position (ACC position) signal is fetched from the switch group input terminal 24,
Power may be supplied from a power supply terminal to supply power to a device (such as a radio) that operates on an accessory power supply.

Therefore, the operation of the present invention will be described below with reference to a flow chart, limited to the input of the ignition key.

By the way, the electric load to which the power supply terminal supplies electric power may be any control unit, any motor or lamp.

For example, when the ON switch of the driver's seat power window is received from the switch group input terminal 24,
The motor may be operated to open the power window from the power supply terminal built into the driver's door,
Ignition key accessory power supply location (AC
The power supply terminal may supply power to a device (such as a radio) that receives a signal (position C) and operates with an accessory power supply.

The operation of this embodiment will now be described with reference to the input of an ignition key.

First, the operation of the part where the switch group input terminal 24 captures the signal of the ignition key switch will be described with reference to FIG.

The switch group input terminal 24 includes a power supply circuit 80 for generating an internal power supply, a communication IC 81, and a microcomputer 82. The microcomputer 82 captures all input signals. In particular, an accessory switch 83 of an ignition key switch (ignition key cylinder switch) and an ignition ON switch 84 are shown as representatives.

FIG. 11 is a flowchart of the switch signal fetching process 200 performed by the microcomputer 82 of FIG. 10. This process is performed in a fixed time interrupt process that is repeatedly executed at regular intervals. I have.

The reason why the processing is performed in a fixed time is that, according to this, the filter processing for removing the chattering of the switch is easily performed.

First, at step 201, it is determined whether or not the accessory switch is ON. Then, if the result is YES (affirmative), in step 202, "IGN (AC
C)) flag is set to “1”, NO
If (No), this flag is set to “0” in step 203.
Is performed.

Subsequently, at step 204, it is determined whether or not the ignition ON switch is ON.

At this time, the switch is also set to O
If it is N, the flag "IGN (ON)" is set to "1", and if not, it is cleared to "0" and the process ends.

FIG. 12 is a flowchart of the data transmission process 300 performed by the microcomputer 82 of FIG.

In step 301, first, the previously transmitted data is compared with the data fetched by the above-mentioned fixed-time interrupt processing.

Then, the result is determined in step 302,
First, when the data match (there is no change in the input of the switch), the process is terminated as it is, and no data transmission is performed.

If there is a change in the input of the switch, the process proceeds to step 303, where the data fetched this time is set as transmission data in the communication IC 81. Send command.

Subsequently, the data (transmitted data) fetched in step 305 is stored as previously transmitted data, and the processing is terminated.

Next, the data transmitted by the switch group input terminal 24 is transmitted to the power distributor 4 or the power terminals 8, 11, 1 and 2.
The processing received by 4, 18, 21 will be described.

The communication IC used in this embodiment includes:
As a basic function, when data is received, there is a function of notifying that data has been received.

Therefore, in this embodiment, a signal notifying the reception of the data is used, thereby executing an interrupt process and executing a process of collecting the data received by the communication IC. Is a data reception process 400 shown in FIG.

First, in step 401, the address of the transmitting station is obtained from the received data in order to determine where the data is transmitted.

Subsequently, in step 402, the received data is obtained. In step 403, the address of the RAM in which the received data is to be stored is decoded based on the address obtained in step 401.
The data is stored in the AM, and the process ends.

As described above, by securing an area for storing data in the RAM exclusively for each transmitting station,
In other processes, the necessary data can be immediately obtained by referring to the RAM.

Next, FIG. 14 is a flowchart in which each power supply terminal collectively describes processing for operating the IPD which is a switching element. For example, the processing of the power supply terminal 8 is described in steps 501, 520, and 530. , Power terminal 11
Is described in steps 502, 503, and 504, and the processing of each power supply terminal continues from step 505 to step 513, respectively.

First, in step 501, it is checked whether or not an abnormality is found in the power supply terminal 8. If there is no abnormality, the power supply process is performed in step 520. If there is an abnormality, the power is shut off in step 530. Processing is performed.

Hereinafter, the details of the power supply process in step 520 will be described with reference to FIG. 15, and the details of the power supply shutdown process in step 530 will be described with reference to FIG.

In the power supply process of the power supply terminal 8 in FIG.
First, at step 521, it is checked by a flag "IGN (ACC)" whether or not the accessory power switch of the ignition key switch is ON.
This flag is set to the switch group input terminal 24 described above.
Is data obtained by data communication.

If the flag "IGN (ACC)" is "1", the IPD 48 is turned on in step 522.
The drive signal 50 is set to “high” in order to perform the operation.

When the flag "IGN (ACC)" is "0", the drive signal 50 is set to "low" in step 523.

Therefore, IPD 48
When the key switch is in the accessory position, it is understood that the switching element is a switching element that supplies power to the electric load device 9 to which power is to be supplied.

Next, in step 524, it is determined whether or not the ignition key switch has been turned on by the flag "IGN (ON)". This flag is also obtained by data communication, which is the data set by the switch group input terminal 24, similarly to the above-mentioned "IGN (ACC)".

If the flag "IGN (ON)" is "1", the drive signal 52 is set to "high" in step 525 to turn on the IPD 49.

On the other hand, when the flag "IGN (ON)" is "0", the drive signal 52 is set to "low" in step 526, and the process is terminated.

From this, it is understood that the IPD 49 is a switching element for supplying power to the electric load device 9 to which power is supplied when the ignition key switch is in the ON position.

FIG. 16 shows a power supply cutoff process 53 of the power supply terminal 8.
0 is a flowchart.

First, in step 531, an abnormality of the IPD 48 is checked based on FIG.
At 32, the drive signal 50 of the IPD 48 is canceled.

Subsequently, at step 533, an abnormality of the IPD 49 is detected, and if there is an abnormality, at step 534, the IPD 49 is detected.
That is, the drive signal 52 of 49 is canceled.

Next, the process of monitoring the current of the power cables 5, 6, 7 executed by the power distributor 4 in this embodiment will be described.

Here, first, when a vehicle is put on the general market, the current capacity consumed by the vehicle is known at the stage of designing the vehicle.

On the other hand, which of the electric loads mounted on the vehicle is operating can be recognized if the operation status from the switch group input terminal 24 and each power supply terminal can be grasped.

In this embodiment, as described above, data transmission / reception is performed between the terminals, so that the operation status of the electric load can be easily grasped. By comparing the data from the current detector 38 built in the power distributor 4 with the capacity of the currently operating electric load, it is possible to detect an abnormality in the power supply line including the power cable.

The method of detecting the abnormality and the method of warning the driver will be described with reference to the flowchart of the current detection warning process 600 shown in FIG.

First, in step 601, how much electric load is currently in operation and how much current (power)
It is investigated and estimated whether or not is consumed. For example, if the electric load is a power window motor, the current is 10 A
It is a degree.

Next, at step 602, the current detector 3
8, it is calculated how much current is flowing through the power cable 5. In step 603, the current value estimated and estimated is compared with the current value detected by the current detector 38. If the data at the detector is within 50% of the estimated value (within 1.5 times), the process of turning off the warning lamp 23 is executed in step 604, and the switch A of the switching circuit 33 is executed in step 608. Connection is made.

If it is 50% or more, the lighting process of the warning lamp 23 is performed in step 605, and in the following step 606, the detected current is increased by 100% or more (two times) of the estimated value. Is checked.

If it is 100% or more, the contact A of the switching circuit 33 is opened (blocked) at step 607, and the power supply to the power cable 5 is stopped.

As a result, even if the power supply cable is short-circuited to the vehicle body ground or the power supply terminal is short-circuited for some reason and a large current flows through the power supply cable, it is possible to prevent the possibility of vehicle fire. , Safety can be kept securely.

Therefore, the configuration of the above embodiment can be summarized as follows.

First, a power distributor 4 for distributing power is provided on the power line 3 from the battery 1, and power lines 5, 6, and 7 of each system are wired from the power distributor 4. Power supply terminals 8, 11, 1 before the power supply lines 5, 6, 7
4, 18 and 21 from which various electric load devices 9 are provided.
, 12 to 15, 15 to 17, to 20 to be supplied with electric power.

As a result, by performing the distribution of the power supply and the control of the power supply to the electric load by multiplex communication, not only the wires for the control signal but also the wires for the power supply can be reduced.

Further, since the magnitude of the current that would flow through the operating electric load is compared with the current value that is actually flowing, a large current caused by a short circuit in the power supply harness can be detected. Even if the cable is short-circuited to the body ground of the vehicle, or if the power supply terminal breaks down for some reason, it is possible to construct a system that does not cause a vehicle fire, and it is possible to sufficiently secure safety.

In the above embodiment, the case where the present invention is applied to a power supply device of an automobile has been described.
The present invention is not limited to power supply devices for automobiles, but can be used for various vehicles such as railway vehicles, aircraft, ships, etc., as long as the system receives a common power supply from a power supply and has a large number of electric load devices installed at different locations. It goes without saying that the present invention is applicable regardless of the type.

[0119]

According to the present invention, a terminal device suitable for use in a vehicle power supply system is obtained.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an example of an embodiment when the present invention is applied to an automobile.

FIG. 2 is a configuration diagram showing an example of a power cable used in an embodiment of the present invention.

FIG. 3 is a block diagram showing details of a power distributor in one embodiment of the present invention.

FIG. 4 is a block diagram illustrating details of a power supply terminal according to an embodiment of the present invention.

FIG. 5 is a block diagram showing details of an IDP according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram showing operating conditions of an embodiment of the present invention.

FIG. 7 is a block diagram showing details of a switching circuit in one embodiment of the present invention.

FIG. 8 is a block diagram showing details of a contact circuit according to an embodiment of the present invention.

FIG. 9 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 10 is a block diagram illustrating functions of a switch group input terminal according to an embodiment of the present invention.

FIG. 11 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 12 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 13 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 14 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 15 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 16 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 17 is a flowchart for explaining the operation of the embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 battery 2 fusible link 3 power cable 4 power distributor 5, 6, 7 power cable 8, 11, 14, 18, 21 power terminal 9, 10, 12, 13, 15, 16, 17, 19, 2
0, 22 Load device 24 Switch group input terminal 27 Communication line

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroyuki Saito 2520 Oita Takaba, Hitachinaka City, Ibaraki Prefecture Inside the Automotive Equipment Division of Hitachi, Ltd. (72) Tatsuya Yoshida 2520 Oita Takaba Hitachida City, Ibaraki Prefecture Stock Company Hitachi, Ltd. Automotive Equipment Division (72) Inventor Shinichi Sakamoto 2520 Oji Takaba, Hitachinaka City, Ibaraki Prefecture Hitachi, Ltd. Automotive Equipment Division (72) Inventor Kiyoshi Horibe 4-6-6 Kanda Surugadai Chiyoda-ku, Tokyo Stock Hitachi, Ltd. (72) Inventor: Mitsuaki Kurosawa, Hitachi, Ibaraki, 2520 Oji Takaba Co., Ltd. Manufacturing Equipment Division

Claims (3)

[Claims] 1. A control circuit having a power input terminal for receiving load driving power from a power supply line, a communication function for receiving a signal from a communication line, and a load drive for controlling load power by an output signal of the control circuit. A power supply terminal device comprising: an element; and a power output terminal connected to the load driving element. 2. The power supply terminal device according to claim 1, wherein a power circuit disconnecting contact circuit is provided between the power take-in terminal and the load driving element, and is operated by a signal of the control circuit. 3. The power supply terminal device according to claim 1, wherein the load driving element is formed of a semiconductor device having a self-protection function.