JPH10271676A - Start signal generator for vehicles - Google Patents

Abstract

(57) [Problem] To provide a vehicle start signal generating device capable of reducing power consumption of a battery and appropriately preventing running out of the battery. SOLUTION: Switches SW1 to SW4 are low-side switches, and when turned on, inverters 61 to 6 respectively.
4, the input signals of the pulse generators 51 to 54 are switched to the high level, and the pulse signals including the pulses of the predetermined time width are changed according to the switching.
4 is output to NAND3 via inverters 41-44. That is, when at least one of the switches SW1 to SW4 is turned on, a pulse having a predetermined time width is generated at the output terminal 3a of the NAND3. The CPU 2 monitors the interrupt terminal 2a, and upon receiving the pulse, switches the power supply state from the unnecessary current cutoff mode to the normal mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting signal generator for a vehicle, which can reduce the power consumption of a battery and properly prevent the battery from running down.

[0002]

2. Description of the Related Art In a vehicle such as an automobile, for example, when a user forgets to turn off a room light or a headlamp and leaves it for a long time, the battery runs out and the battery needs to be replaced. Even if there is no negligence of the user, power is always supplied to the in-vehicle computer. Therefore, when the vehicle is not used for a long time, the battery may run down due to dark current. To prevent such a battery rise,
2. Description of the Related Art A power supply control system has been developed which automatically shuts off a power supply when a predetermined condition is satisfied or controls power supply to only a minimum necessary part.

In such a power supply control system, for example, an ignition key is turned off (ACC OF).
F) After entering the state, if there is no switch input such as door lock release or door release for a predetermined period of time, power supply to unnecessary parts such as AV equipment and headlamps is stopped, for example, door lock release Power is supplied only to the minimum necessary parts such as devices. Here, the state in which the power supply to the unnecessary parts is stopped is called an unnecessary current cutoff mode, and the normal power supply state is called a normal mode. In addition, the process of shifting from the normal mode to the unnecessary current cutoff mode is called a sleep process, and the process of shifting from the unnecessary current cutoff mode to the normal mode is called a wake-up process.

[0004] In the sleep process, while operating in the normal mode,
For example, a process of shifting from the normal mode to the unnecessary current cutoff mode when a transition condition such as a predetermined time has elapsed since the ignition key is turned off and power supply to all loads is turned off. It is. Here, the load is, for example, a room light or a headlight. The sleep processing is performed by the CPU (C
The processing is performed based on CPU control software in the central processing unit.

In the wake-up process, for example, when an operation such as door lock release or door release is generated during operation in the unnecessary current cutoff mode and a return condition is satisfied, the unnecessary current cutoff mode is switched to the normal mode. This is the process of shifting. Since the wake-up process is performed in the unnecessary current cutoff mode, the CPU monitors only the interrupt terminal. That is, the output terminal or the like of the switch to be monitored is connected to the interrupt terminal of the CPU, and when the state of the interrupt terminal becomes high level, the CPU starts (wakes up) to the normal mode by software.

For example, in the conventional power supply control system 1, as shown in FIG.
The output terminal 3a of the AND circuit 3 is connected to the four input terminals 3b, 3c, 3d, and 3e of the NAND circuit 3, and the switches SW1, SW2, SW3, and SW4 to be monitored are respectively provided.
Is connected. Switches SW1, SW2, SW3
SW4 is a low-side switch that outputs a signal that is low in the on state and high in the off state.
It outputs to the input terminal of ND circuit 3, respectively. In the power supply control system 1, the switches SW1, SW2, SW
3, when all the input signals from the SW4 to the NAND circuit 3 are at the high level, that is, when the switches SW1, SW2,
When all of the switches SW3 and SW4 are off, the output terminal of the NAND circuit 3 goes low. On the other hand, switch S
When any one of W1, SW2, SW3, and SW4 is turned on, the signal from the output terminal 3a of the NAND3 goes high.

The CPU 2 has switches SW1, SW2, S
Any one of W3 and SW4 is turned on,
When the interrupt terminal 2a becomes high level, the wake-up process is performed, and the mode is switched from the unnecessary current cutoff mode to the normal mode.

[0008]

However, in the power supply control system 1 described above, for example, 10 minutes have passed since the ignition key was turned off and all the loads were turned off, or the load or the load was turned off. When the condition for performing the sleep process is that 15 minutes have elapsed since the load switch was last turned on, the load switch is included in the monitoring target when determining whether to perform the wake-up process. May have been For example, this is a case where the load switch is a courtesy switch that is turned on / off in response to opening and closing of a door.

In this case, the user turns off the ignition key, forgets to turn off the room light, leaves the vehicle,
After 15 minutes, the condition for performing the sleep process is satisfied,
Attempt to shift to unnecessary current cutoff mode. However, a courtesy switch is included in the monitoring target when determining whether or not to perform the wake-up process. In the power supply control system 1 shown in FIG.
Since the output terminal 3a is at a high level, immediately after shifting to the unnecessary current cutoff mode by the sleep process,
Wake-up processing is performed and the mode returns to the normal mode. Therefore, in the above-described conventional power supply control system 1, there is a problem that the unnecessary current cutoff mode does not function effectively.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a vehicle start signal generating device capable of reducing power consumption of a battery and appropriately preventing running out of the battery. And

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art and achieve the above-mentioned object, a vehicle start signal generating device according to the present invention is used for switching a power supply state of a vehicle. A vehicle start signal generating apparatus for generating a vehicle start signal, wherein the plurality of switch means generate a switch signal having a level corresponding to an on / off state of a switch, and each of the plurality of switch means is provided. Pulse signal generating means for generating a pulse signal that generates a pulse having a predetermined time width at a timing when the switch signal switches from a first level to a second level; and the plurality of pulse signal generating means. , A pulse signal is input from each of the above. If at least one of the input pulse signals includes a pulse, the pulse is input. And a vehicle start signal generating means for generating an activation signal for no vehicles.

[0012] Preferably, the vehicle start signal generating device of the present invention further comprises control means for switching a power supply state from an unnecessary current cutoff mode to a normal mode in accordance with a pulse included in the vehicle start signal. Have.

In the vehicle start signal generating apparatus according to the present invention, preferably, the on / off state of at least one of the plurality of switch means is such that the control means controls the power supply state to the normal mode. To the unnecessary current cut-off mode.

In the vehicle start signal generating apparatus according to the present invention, for example, one of the plurality of switch means is a switch of a room light, and the switch of the room light is in an ON state. When one of the conditions for switching the supply state from the normal mode to the unnecessary current cutoff mode is satisfied, the operation is performed as follows. That is, in the vehicle start signal generation device of the present invention, when the user switches the switch of the room light to the ON state, and then leaves the vehicle for a long time while keeping the switch ON, the control unit changes the power supply state. The condition for switching from the normal mode to the unnecessary current cutoff mode is satisfied, and the power supply state is switched to the unnecessary current cutoff mode. The control means monitors the vehicle start signal input to the interrupt terminal. By the way, when the control means starts monitoring the interrupt terminal, the pulse generated in the vehicle start signal when the room light switch is turned on has already disappeared, and the room light switch remains on. However, the control unit does not switch the power supply state from the unnecessary current cutoff mode to the normal mode, and keeps the unnecessary current cutoff mode.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a vehicle start signal generating apparatus according to an embodiment of the present invention. FIG. 1 is a configuration diagram of a power supply control system 10 according to the present embodiment. As shown in FIG. 1, the power supply control system 10 includes a CPU 2, a wake-up processing start signal generator 11, and switches SW1 to SW4.

Wake-up process start signal generator 11
Are NAND circuit 3, inverters 41-44, 61-6
4 and pulse generators 51 to 54. The vehicle start signal generator 11 includes a CPU 2 and a switch SW.
1 to SW4.

The interrupt terminal 2a of the CPU 2 is connected to the output terminal 3a of the NAND circuit 3. The four input terminals 3b, 3c, 3d, 3e of the NAND circuit 3 are connected to the output terminals of the inverters 41, 42, 43, 44, respectively. The input terminals of the inverters 41, 42, 43, 44 are connected to pulse generators 51, 52, 53, 54, respectively. Further, the inverters 61, 62, 63, 6
4 are connected to pulse generators 51, 52, 5 respectively.
3, 54. Inverters 61, 62, 6
3 and 64 are connected to switches SW1 and SW, respectively.
2, SW3 and SW4.

The switches SW1 to SW4 are low-side switches, which output signals that are low in the on state and high in the off state, respectively.
Output to 64 input terminals. Switches SW1 to SW4
Are, for example, a switch for unlocking a door, a courtesy switch for turning on / off in response to opening / closing of a door, a switch for a headlight, and a switch for opening / closing a window.

The inverters 61 to 64 invert the levels of the input signals from the switches SW1 to SW4, respectively, and output the inverted level output signals to the pulse generator 5 respectively.
1 to 54. The pulse generators 51 to 54 are configured using, for example, one-shot multivibrators, and when the levels of the signals from the inverters 61 to 64 rise from a low level to a high level as shown in FIG. , As shown in FIG.
And outputs a pulse signal including the pulse. Here, the time width t of the pulse is a unit of several μsec or several msec.

The inverters 41 to 44 include a pulse generator 5
The output signals of the level obtained by inverting the pulse signal from the input terminal 1 are input to the input terminals 3b, 3c, 3d, and 3 of the NAND circuit 3, respectively.
e.

The NAND circuit 3 has input terminals 3b, 3c,
When the levels of the signals input to 3d and 3e are all high, that is, when the switches SW1, SW2, SW3,
When all of the switches SW4 are off, the output signal from the output terminal 3a is set to low level. On the other hand, the switches SW1,
When any one of SW2, SW3, and SW4 is turned on, the output signal from the output terminal 3a of the NAND3 is set to a high level.

When the signal input to the interrupt terminal 2a rises from a low level to a high level based on software for performing the wake-up process, the CPU 2 activates the wake-up process, and the normal power-off mode is switched from the unnecessary power-off mode. Transition to mode. That is, the state is changed from a state in which power supply to unnecessary parts is stopped to a state in which power can be supplied to all normal loads. CPU2
Monitors only the level of the interrupt terminal 2a in the unnecessary power cutoff mode. For example, the CPU 2 determines that, for example, 10 minutes have elapsed since the ignition key was turned off and all the loads were turned off, or 15 minutes after the load or the load switch was last turned on.
The elapse of minutes is a condition for activating sleep processing. That is, when this condition is satisfied, the CPU 2 performs a sleep process and shifts from the normal mode to the unnecessary power cutoff mode.

Hereinafter, one operation of the vehicle start signal generator 11 will be described. For example, when the CPU 2 is in the unnecessary power cutoff mode, for example, when the switch SW1 for unlocking the door is switched from off to on, the input signal of the inverter 61 is switched from high level to low level, and the inverter is accordingly switched. The output signal of 61 is shown in FIG.
Switching from low level to high level as shown in FIG. Then, a pulse signal including a pulse having a time width t shown in FIG.
Is output to Accordingly, the output signal of the inverter 41 also becomes low for the time width t shown in FIG. 2B, and the level of the output terminal 3a of the NAND circuit 3 also becomes high for the time width t. As a result, the wake-up process is performed in the CPU 2, and the mode shifts from the unnecessary power cutoff mode to the normal mode.

After that, for example, when the user turns off the ignition key, forgets to turn off the room light and leaves the vehicle, and 15 minutes have passed, the CPU 2 satisfies the transition condition, performs sleep processing, and transitions to an unnecessary current cutoff mode. . At this time, the courtesy switch SW2 for turning on / off the room light is turned on, and this switch SW2 is monitored by the wake-up processing start signal generator 11 shown in FIG. However, since the pulse signal from the pulse generator 53 is already at the low level after the completion of the sleep process in the CPU 2, the wake-up process is not started. As a result, C
In the PU2, the unnecessary current cutoff mode is appropriately held.

As described above, according to the power supply control system 10, as in the power supply control system 1 described in the related art, the wake-up process is started at an inappropriate timing, and the unnecessary current mode is not properly maintained. Can be effectively avoided.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, four switches S
Although the case where W is provided is illustrated, the switches to be monitored by the wake-up process activation signal generator 11 and the functions of the switches are arbitrary.

[0027]

As described above, according to the vehicle start signal generating apparatus of the present invention, when at least one of the plurality of switch means is turned on, the vehicle generates a pulse having a predetermined time width. An activation signal can be generated. Therefore, even when the switch unit is a monitoring target at the time of activating the sleep process, it is possible to effectively prevent the wake-up process from being inappropriately activated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a power supply control system according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the pulse generator shown in FIG. 1;

FIG. 3 is a configuration diagram of a conventional power supply control system.

[Explanation of symbols]

2 ... CPU, 3 ... NAND circuit, 11 ... Vehicle start signal generator, 41-44, 61-64 ... Inverter, 51
~ 54 ... Pulse generator, SW1 ~ SW4 ... Switch (low side switch)

Claims (3)

[Claims] 1. A vehicle start signal generator for generating a vehicle start signal used for switching a power supply state of a vehicle, wherein a plurality of switches for generating a switch signal having a level corresponding to an on / off state of the switch. Means for generating a pulse signal which generates a pulse having a predetermined time width at a timing when the switch signal is switched from a first level to a second level, provided in correspondence with each of the plurality of switch means. A pulse signal generation unit, and a pulse signal input from each of the plurality of pulse signal generation units, and when at least one of the input pulse signals includes a pulse, a vehicle start including the pulse A vehicle start signal generating device having a vehicle start signal generating means for generating a signal. 2. The vehicle start signal generator according to claim 1, further comprising control means for switching a power supply state from an unnecessary current cutoff mode to a normal mode in accordance with a pulse included in the vehicle start signal. 3. An on / off state of at least one of the plurality of switch means is included in a condition when the control means switches the power supply state from the normal mode to the unnecessary current cutoff mode. The vehicle start signal generator according to claim 2, wherein