JP2002234406A - Power control device for on-vehicle electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power control device for on-vehicle electronic equipment omitting a delay circuit in on-vehicle equipment for simplification of a circuit arrangement and cost reduction. SOLUTION: The power control device includes a communication circuit for transmitting and receiving information to and from road equipment; a CPU 2A for reading and writing security information from and to an IC card inserted; a first and second feeder terminals ACC and CR for feeding electricity from an on-vehicle battery 20 to the CPU 2A; an ignition switch 21 inserted into the input side of the first feeder terminal ACC; a relay circuit 22 inserted into the input side of the second feeder terminal CR; and a power supply IC 8A inserted between the second feeder terminal CR and the CPU 2A. The relay circuit 22 operates in response to a delay signal coming from another on-vehicle electronic equipment 23 and, after a predetermined delay time has elapsed since the electricity from the on-vehicle battery is cut off, the relay circuit is cut off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply control device for a vehicle-mounted electronic device supplied with power from a vehicle-mounted battery, and more particularly to a power supply control device for a vehicle-mounted electronic device capable of omitting a delay circuit when the vehicle-mounted battery is turned off. It is about.

[0002]

2. Description of the Related Art Generally, a vehicle-mounted electronic device is supplied with power from a vehicle-mounted battery. However, when power from the vehicle-mounted battery is turned off, a delay circuit is provided to execute a process after the power is turned off for a predetermined time. Have been.

[0003] In recent years, for example, an automatic toll collection (ETC) system for avoiding vehicle congestion by a toll collection procedure at a toll road has been well known.
Vehicles that use toll roads are equipped with on-board ETC devices that communicate with on-road units.

In this type of ETC system, microwave or millimeter wave radio communication is performed between an ETC road machine on the tollgate side and an ETC on-board device on the vehicle side to automatically charge a toll road usage fee. It is configured to collectively receive.

That is, in the vehicle-mounted device, the collected fee data is written in the memory in accordance with the communication information with the road device, and the fee based on the fee collected data is settled by a prepaid system or a postpaid system. It has become.

At this time, the power supply of the vehicle-mounted device is supplied from an ignition circuit or an accessory circuit of the vehicle. Only when the vehicle ignition switch is at the well-known ON position or accessory position, the vehicle-mounted battery supplies the power to the vehicle-mounted device. Is supplied.

However, if the ignition switch is turned to the off position while the vehicle-mounted device is accessing the memory, the data stored in the memory is destroyed due to the power-off of the vehicle-mounted device, or the operation of the vehicle-mounted device is not performed. May not be able to end normally.

In order to prevent such a situation,
For example, it is not practical to obtain the power supply of the vehicle-mounted device directly from the vehicle-mounted battery, because relatively large power is consumed even when the vehicle-mounted device does not need to operate.

It is also conceivable to incorporate a backup battery in the vehicle-mounted device, but in this case, there arises a problem that the life management and replacement maintenance of the backup internal battery become troublesome.

In view of the above, there has been proposed a power supply control device for a vehicle-mounted electronic device that performs delay cutoff when the power supply of a vehicle-mounted battery is turned off. FIG. 2 shows, for example, JP-A-2000-224.
FIG. 762 is a circuit configuration diagram showing a power supply control device of a conventional on-vehicle electronic device described in Japanese Patent Application Publication No.
The case where the in-vehicle device for TC is used is shown.

In FIG. 2, reference numeral 1 denotes an on-vehicle device, which includes a CPU 2 comprising a microcomputer and a power control device 7.
And a battery power supply terminal B and an accessory power supply terminal AC
C and a ground terminal GND. The CPU 2 has an output port P and an input port Q connected to the power control device 7.

The CPU 2 is connected to an RF unit 3, an IC card 4, an EEPROM 5, and a notification unit 6. RF unit 3 includes a communication circuit and an antenna for transmitting and receiving information to and from a roadside device (not shown).

1 for storing data relating to automatic toll settlement
The C card 4 is mounted on the vehicle-mounted device 1 by a driver during driving, and the SAM (Secure Application) is installed.
Reading and writing of security information and the like are performed with the CPU 2 via the (Module) function.

The EEPROM 5 stores history data and the like obtained by communication with the road device. The notification unit 6 includes a display for displaying data, a buzzer for warning that the IC card 4 has been forgotten to be removed, and the like.

The power supply control device 7 in the vehicle-mounted device 1 includes a power supply IC.
8, an input voltage smoothing capacitor 8a and an output voltage smoothing capacitor 8b of the power supply IC 8, and a P-channel FE
T (switching means) 9 and resistors 10, 11, 12
a, 12b, 13, 14a, and 14b and an npn-type first
It has a transistor 12, a second transistor 14, and an integration circuit 15.

The accessory power supply terminal ACC is connected to the battery power supply terminal B via a relay switch when an ignition switch (not shown) is turned on. FET9 is
The power supply IC 8 is turned on with at least one of the transistors 12 and 14 turned on, and converts the battery voltage 12 V of the power supply terminal B into a desired voltage (rated output 5 V) for each circuit in the vehicle-mounted device 1.

The integrating circuit 15 includes a resistor 15a connected to the accessory terminal ACC, and a constant voltage diode 1 inserted in parallel between the resistor 15a and the ground terminal GND.
5b and a capacitor 15c. Integration circuit 15
Are connected to the input port Q of the CPU 2.

The vehicle-mounted device 1 is supplied via a power supply control device 7 from a power supply terminal B connected to a positive output terminal of a vehicle-mounted battery. The output voltage (5V) of the power supply 1C8 in the power supply control device 7 is applied to each power supply terminal of the CPU 2, the RF unit 3, the IC card 4, the EEPROM 5, and the notification unit 6.

In this case, the first transistor 12 has a CP
The transistor is turned on / off by a signal from the output port P of U2, and the second transistor 14 is turned on / off by a signal supplied from the accessory terminal ACC via the integration circuit 15.

More specifically, in the first transistor 12, a base bias resistor 12a is connected between the base and the emitter, and the base of the first transistor 12 is connected to the base via a resistor 12b.
It is connected to the output port P of PU2. In the second transistor 14, a base bias resistor 14a is connected between the base and the emitter, and the base of the second transistor 14 is connected to an output terminal of the integrating circuit 15 via a resistor 14b.

Next, the conventional power supply controller 7 shown in FIG.
Will be described. First, the driver mounts the IC card 4 in which the self information is stored in the vehicle-mounted device 1, and turns on the ignition switch.

Thus, the power supply terminal ACC is connected to the power supply terminal B.
(The positive output terminal of the vehicle-mounted battery), the voltage of the power supply terminal ACC rises to the battery voltage (ON level).

At this time, the output potential of the integrating circuit 15 rises to a level specified by the constant voltage diode 15b with a predetermined time constant, and the second transistor 14 and the FET 9 are sequentially turned on.

When the FET 9 is turned on, the power supply IC 8 is supplied with power, the potential level Vcc rises to a predetermined level, and the power supply of the vehicle-mounted device 1 rises. Thus, in a state where the power is turned on, the CPU 2 receives the power supply from the integration circuit 15 via the input port Q, and determines the ON operation of the ignition switch based on the input voltage level.

When the CPU 2 determines that the ignition switch is turned on, the CPU 2 outputs the output port P in a short time.
Output a high level signal to turn on the first transistor 12.

Hereinafter, in response to the ON operation of the first transistor 12, the ON state of the FET 9 changes to the second transistor 14.
Is maintained irrespective of the on / off state of the vehicle,
Is self-held.

When the power of the vehicle-mounted device 1 is turned on, the CPU 2 transmits and receives data via the RF unit 3 and executes a desired ETC function.

Thereafter, when the ignition switch is turned off and the potential of the power supply terminal ACC is disconnected from the power supply terminal B and falls to the ground level, the output voltage of the integrating circuit 15 becomes the ground level (off level) at a predetermined time constant.
Down to

However, while the output voltage of the integrating circuit 15 is falling, the first transistor 12 is kept on, so that the FET 9 is not turned off and the on-vehicle device 1 is not turned off.
Power supply to is continued.

Therefore, the CPU 2 can continue the processing for a time necessary for normally terminating the operation. Specifically, a process of writing backup data to IC card 4 and EEPROM 5 is executed.

If, for example, the CPU 2 determines that the IC card 4 has been forgotten to be removed during the above-described OFF processing, the CPU 2 drives the notification unit 6 to give an alarm to the driver.

As described above, in the conventional power supply control device 7, when the ignition switch is turned off from the power-on state of the vehicle-mounted device 1, the vehicle-mounted device 1 is turned off after a predetermined time necessary for normally ending the operation. The power supply is configured to be shut off.

[0033]

As described above, the power supply control device of the conventional in-vehicle electronic device is provided with the power supply IC 8 and the power supply IC 8 to enable the delay processing in the on-vehicle device 1 when the power is turned off by turning off the ignition switch. Multiple transistors 1
2, 14 and the integrating circuit 15 need to be provided,
There has been a problem that the circuit configuration becomes complicated and cost increases.

The present invention has been made in order to solve the above-mentioned problems, and a cost reduction is realized by omitting a delay circuit in a vehicle-mounted device and simplifying a circuit configuration. It is an object of the present invention to obtain a power supply control device.

[0035]

According to a first aspect of the present invention, there is provided a power supply control device for an on-vehicle electronic device, which is supplied with power from a vehicle-mounted battery. A communication circuit for transmitting and receiving information, a CPU mounted with a detachable IC card to read and write security information and the like between the IC card and a first circuit for supplying power to the CPU from a vehicle-mounted battery. And the second
Power supply terminal, an ignition switch inserted on the input side of the first power supply terminal, a relay circuit inserted on the input side of the second power supply terminal, and a power supply terminal inserted between the second power supply terminal and the CPU. The relay circuit operates in response to a delay signal from another in-vehicle electronic device including a delay circuit, and is turned off after a predetermined delay time has elapsed since power supply from the in-vehicle battery was turned off. Things.

According to a second aspect of the present invention, there is provided a power supply control device for an on-vehicle electronic device according to the first aspect, wherein
Includes alarm means for alarming that the user has forgotten to remove the IC card. The alarm means includes a delay time when the IC card is mounted when the power supply from the first power supply terminal is turned off. To drive the notification unit.

According to a third aspect of the present invention, there is provided a power supply control apparatus for an on-vehicle electronic device, wherein the other on-vehicle electronic device is a vehicle engine control circuit driven by an on-vehicle battery. It consists of

According to a fourth aspect of the present invention, there is provided a power supply control device for a vehicle-mounted electronic device according to the third aspect, wherein
Includes information input means for capturing engine information controlled by the vehicle engine control circuit, and the alarm means includes:
When the engine information indicates the vehicle stopped state, the notification unit is driven during the delay time.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a circuit diagram showing a first embodiment of the present invention. The same components as those described above (see FIG. 2) are denoted by the same reference numerals or are denoted by "A" after the reference numerals. The details will be omitted.

In FIG. 1, the vehicle-mounted device 1A includes a CPU 2A
And first and second power supply terminals CR and ACC (hereinafter simply referred to as “power supply terminals”), and a ground terminal GND.
, Power supply IC 8A, transistor 14, and resistor 14
a, 14b and 14c.

The CPU 2A includes input ports Q1, Q connected to output terminals (potential level Vcc) of the power supply IC 8A.
2 and the collector terminal of the transistor 14 is also connected to the input port Q1.

In the vehicle-mounted device 1A, the input terminal of the power supply IC 8A is connected to the power supply terminal CR,
Is connected to the power supply terminal ACC via the resistor 14b.

Reference numeral 20 denotes a vehicle battery, reference numeral 21 denotes an ignition switch connected to the vehicle battery 20, and reference numeral 22 denotes a control relay inserted between the vehicle battery 20 and the power supply terminal CR.

The input side of the power supply terminal ACC of the vehicle-mounted device 1A is connected to the vehicle-mounted battery 20 via an ignition switch 21. The input side of the power supply terminal CR of the vehicle-mounted device 1A is connected to the input side of the vehicle-mounted battery 20
Is connected.

Reference numeral 23 denotes another vehicle-mounted device (vehicle-mounted electronic device) driven by a vehicle-mounted battery, which is constituted by, for example, a vehicle engine control circuit such as an engine fuel injection control circuit.

Another on-vehicle device 23 includes a power supply terminal B and AC
C, an output terminal C, and a power control circuit 24 including a delay circuit.
And a transistor 25 with a common emitter. The transistor 25 operates in connection with a delay circuit in the power supply control circuit 24.

The power supply terminal B is connected to the vehicle-mounted battery 20, and the power supply terminal ACC is connected to the vehicle-mounted battery 20 via the ignition switch 21, and both supply power to the power supply control circuit 24.

The base of the transistor 25 is connected to the output terminal of the power supply control circuit 24, and the collector of the transistor 25 is connected to the exciting coil of the control relay 22 via the output terminal C.

Thus, even after the ignition switch 21 is turned off, the movable contact of the control relay 22 is turned on in response to a delay signal from another vehicle-mounted device 23, and the vehicle-mounted device 1 A is supplied with power from the vehicle-mounted battery 20. It is shut off after a predetermined delay time has elapsed since it was turned off.

Although omitted in FIG. 1, similarly to the above (see FIG. 2), an RF unit 3 for transmitting and receiving information and an EEP for reading and writing information are provided in the vehicle-mounted device 1A.
A ROM 5 is provided, and an IC card 4 and a notification unit 6 can be connected to the CPU 2A.

Further, the CPU 2A includes an alarm means for alarming that the user has forgotten to remove the IC card 4, and a power supply terminal ACC
When the IC card 4 is mounted when the power supply from the power supply is turned off, the notification unit 6 is driven during power supply from the power supply terminal CR (during the delay time).

Hereinafter, the operation according to the first embodiment of the present invention will be described. In FIG. 1, when the driver who has finished driving the vehicle turns off the ignition switch 21,
Power supply to each power supply terminal ACC of the vehicle-mounted device 1A and the other vehicle-mounted devices 23 is cut off.

At this time, the transistor 25 in the other vehicle-mounted device 23 keeps on for a predetermined time by the delay signal output from the power supply control circuit 24. Accordingly, the exciting coil of the control relay 22 is excited via the output terminal C, and the movable contact of the control relay 22 is turned on.

Thus, power is supplied from the vehicle-mounted battery 20 to the power supply terminal CR of the vehicle-mounted device 1A.

Then, after a predetermined delay time has elapsed since the ignition switch 21 was turned off, the transistor 2
By turning off 5, the control relay 22 is cut off,
The power supply to the power supply terminal CR of the vehicle-mounted device 1A is turned off.

As described above, in the normal engine control, the power supply to the vehicle-mounted device 1A can be performed for a predetermined time by using the power supply self-holding (delay) control function that is being executed.

Therefore, the CPU function of the vehicle-mounted device 1A can be maintained even after the ignition switch 21 is turned off, without complicating the circuit configuration in the vehicle-mounted device 1A.

For example, if the IC card 4 is attached to the vehicle-mounted device 1A when the ignition switch 21 is turned off, the alarm unit in the CPU 2A drives the notification unit 6 (sound generator, buzzer, lamp, etc.) for a predetermined time. Thus, a warning can be given to the driver, and forgetting to remove the IC card 4 can be reliably prevented.

Embodiment 2 In the first embodiment, the off state of the ignition switch 21 is used as a condition for enabling the alarm means for preventing the IC card 4 from being forgotten to be removed. However, another onboard device 23 including a vehicle engine control circuit and the like is used. May be used.

In this case, the CPU 2A in the vehicle-mounted device 1A
It includes information input means for taking in engine information controlled by the other on-vehicle device 23, and the alarm means is provided during the delay time if the IC card 4 is mounted when the engine information indicates the vehicle stopped state. The notification unit 6 is driven.

The engine information for determining whether the vehicle is stopped includes a parking brake signal, a brake switch signal, an engine speed, an ISC valve opening, a throttle opening, a coolant temperature, and the like. The vehicle stop state can be determined by an arbitrary combination or the like.

Further, the case where the vehicle-mounted electronic device is an ETC vehicle-mounted device has been described as an example, but the same applies to any vehicle-mounted electronic device having a communication function and to which an IC card is mounted. Needless to say, it has an effect.

[0064]

As described above, according to the first aspect of the present invention, there is provided a power supply control device for a vehicle-mounted electronic device supplied with power from a vehicle-mounted battery, for transmitting and receiving information to and from a roadside device. A communication circuit, a CPU having a detachable IC card mounted thereon for reading and writing security information and the like between the IC card and first and second power supply terminals for supplying power to the CPU from a vehicle-mounted battery; An ignition switch inserted on the input side of the first power supply terminal;
And a power supply IC inserted between the second power supply terminal and the CPU, and the relay circuit is connected to the other power supply terminal including the delay circuit. It operates in response to the delay signal and is cut off after a predetermined delay time has elapsed since the power supply from the vehicle-mounted battery was turned off, so the delay circuit in the vehicle-mounted device was omitted to simplify the circuit configuration and reduce costs. There is an effect that a power supply control device for an in-vehicle electronic device that is down-mounted can be obtained.

According to a second aspect of the present invention, in the first aspect, the CPU includes an alarm unit for alarming that the user has forgotten to remove the IC card, and the alarm unit is configured to supply power from the first power supply terminal. When the IC card is mounted when the power is turned off, the notification unit is driven during the delay time, so that the cost can be reduced and the in-vehicle electronic device that prevents forgetting to remove the IC card is prevented. There is an effect that a power supply control device for the device can be obtained.

According to a third aspect of the present invention, in the first or second aspect, the other on-vehicle electronic device is:
Since it is configured by the vehicle engine control circuit driven by the on-vehicle battery, the delay circuit in the on-vehicle device is omitted, the circuit configuration is simplified, and the power supply control device for the on-vehicle electronic device which achieves cost reduction is obtained. .

According to a fourth aspect of the present invention, in the third aspect, the CPU includes information input means for taking in engine information controlled by the vehicle engine control circuit, and the alarm means includes: When the vehicle is in a stopped state, the notification unit is driven during the delay time, so that the cost can be reduced and the power supply control of the in-vehicle electronic device that has widened the design conditions of the IC card removal warning is widened. There is an effect that the device can be obtained.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram showing Embodiment 1 of the present invention.

FIG. 2 is a circuit configuration diagram showing a conventional power supply control device for a vehicle-mounted electronic device.

[Explanation of symbols]

1A On-board unit (electronic device for vehicle), 2A CPU, 3
RF unit (communication circuit), 4 IC card, 5 EE
PROM, 6 notification unit, 8A power supply IC, 20 vehicle battery, 21 ignition switch, 22 control relay (relay circuit), 23 other vehicle equipment (other vehicle electronic equipment), ACC, CR power supply terminal.

Claims (4)

[Claims] 1. A power supply control device for a vehicle-mounted electronic device supplied with power from a vehicle-mounted battery, comprising: a communication circuit for transmitting / receiving information to / from a roadside device; CP for reading and writing security information to and from the card
U and a first for supplying power to the CPU from the vehicle-mounted battery.
A second power supply terminal; an ignition switch inserted on the input side of the first power supply terminal; a relay circuit inserted on the input side of the second power supply terminal; And a power supply IC inserted between the CPU and the CPU, wherein the relay circuit operates in response to a delay signal from another vehicle-mounted electronic device including a delay circuit, and the power supply from the vehicle-mounted battery is turned off. A power supply control device for an in-vehicle electronic device, wherein the power supply control device is shut off after a predetermined delay time has elapsed. 2. The CPU includes alarm means for alarming that the user has forgotten to remove the IC card, and the alarm means mounts the IC card when power supply from the first power supply terminal is turned off. 2. The power supply control device for an in-vehicle electronic device according to claim 1, wherein the notification unit is driven during the delay time. 3. The power supply control device for an on-vehicle electronic device according to claim 1, wherein the other on-vehicle electronic device comprises a vehicle engine control circuit driven by the on-vehicle battery. . 4. The CPU includes information input means for taking in engine information controlled by the vehicle engine control circuit, and the alarm means sets the delay when the engine information indicates a vehicle stopped state. The power supply control device for an in-vehicle electronic device according to claim 3, wherein the notification unit is driven during time.