JP2002218648A - Control device of power source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a power source which is capable of securely controlling on/off of the power source even if controlled by a CPU in the equipment. SOLUTION: This control device of the power source 1 comprises a power source circuit 101 which supplies power to an electrical equipment when a start signal is input, and turns off the equipment mounted on a vehicle when an input of the start signal stops, a control means 3 which outputs the start signal and inputs to the power source circuit 101 when a vehicle signal such as an accessory signal output from an ignition switch in accordance with on/off of the power source by the ignition switch is input, and which stops the output of the start signal a certain time after stop of the input of the vehicle signal if the input is interrupted, a runaway detecting means 5 which monitors if the output of the start signal from the control means 3 stops when the input of the vehicle signal to the control means 3 stops, and which decides it to be a runaway if it does not stop, and a forced stop means 7 which stops the start signal input to the power source circuit 101 from the control means 3 when the runaway detecting means 5 decides it to be the runaway.

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 which is incorporated in an electric device such as an in-vehicle device and controls the start / stop of a power supply of the electric device.

[0002]

2. Description of the Related Art A power supply control device of this type is applied to, for example, an on-vehicle device such as a navigation system.
It controls the start / stop of the power supply of the in-vehicle device in response to the stop operation. Particularly, when the power supply stop operation is performed, it is possible to prevent the power supply from being stopped immediately after that, and The power supply is stopped after a certain time for the device to perform the stop processing.

As shown in FIG. 2, a conventional power supply control device 100 of this type includes a power supply circuit 101 and an OR gate circuit 10.
3 and a control unit 105.

[0004] When the ignition switch is turned on, the power is turned on to output a vehicle signal such as an accessory signal.
03, the start signal is input from the OR gate circuit 103 to the power supply circuit 101, and the power supply circuit 101 is started by this input (that is, the power supply is started). Power supply is started to 105 and the in-vehicle device, and they are started.

[0005] Then, immediately after the start, the control section 105 starts inputting a maintenance signal (control signal) to the OR gate circuit 103 (in this state, the OR gate circuit 103 receives the vehicle signal and the maintenance signal). During the operation, it is constantly monitored whether the vehicle signal is stopped based on the vehicle signal branched and input to the control unit 105.

When the power is turned off by turning off the ignition switch, the OR gate circuit 1 is turned off.
The input of the vehicle signal to 03 is stopped. At this time, since the sustain signal from the control unit 105 is still input to the OR gate circuit 103, the start signal is input from the OR gate circuit 103 to the power supply circuit 101.

On the other hand, the stop of the vehicle signal is detected by the control unit 105 based on the vehicle signal branched and input, and after a lapse of a predetermined time after the detection, the stop is input from the control unit 105 to the OR gate circuit 103. The maintenance signal is stopped. As a result, the start signal input to the power supply circuit 101 from the OR gate circuit 103 is stopped, the power supply circuit 101 is stopped, and the power supply by the power supply circuit 101 is stopped (that is, the power supply is stopped).

[0008] As described above, in the power supply control device 100, when the power supply stop operation is performed, the control unit 105 stops the vehicle signal such as the accessory signal by the control unit 105 in order to secure the time for performing the stop processing of the vehicle-mounted device. The power supply circuit 101 is stopped after a delay of a certain time from the point in time when the power is supplied, and the power supply is stopped.

[0009]

The above-described power supply control device 1
In the case where 00 is incorporated in an in-vehicle device such as a normal navigation system, the control unit 105 is configured so that the control unit (CPU) of the in-vehicle device itself is also used. That is, the configuration is such that the start / stop of the power supply in the vehicle-mounted device is controlled by the CPU in the device.

[0010] In this case, when the CPU in the device falls into a runaway state for some reason, even if the vehicle signal is stopped by turning off the ignition switch in order to stop the power supply circuit 101, the CPU in the device stops the stop. There is a disadvantage that the state is no longer detected, so that the maintenance signal input from the control unit 105 to the OR gate circuit 103 cannot be stopped, and the power supply cannot be stopped (that is, the power supply cannot be stopped).

Therefore, an object of the present invention is to solve the problem even when the start / stop of the power supply in the device is controlled by the CPU in the device.
An object of the present invention is to provide a power supply control device that can reliably control the start / stop of a power supply.

[0012]

According to a first aspect of the present invention, there is provided a power supply control device for controlling the power supply of an electric device corresponding to a start / stop operation of a power supply by a predetermined operation unit. A power supply control device for controlling start / stop, wherein a power supply circuit for starting power supply to the electric device by input of a start signal, and stopping power supply to the electric device by stop of input of the start signal; When a signal for instructing power supply start is input as an operation signal in response to the operation of starting / stopping the power supply by the unit, the start signal is output to the power supply circuit to maintain the output state, and the power supply stop is performed. When a signal to instruct is input, after a lapse of a predetermined time from the input, control means for stopping the output of the start signal,
When a signal for instructing a power supply stop is input as the operation signal to the control unit, the control unit monitors whether the start signal output from the control unit is shifted to an output stop state, and sets the predetermined time period. Runaway detection means for determining runaway if the output has not been shifted to the stop state even after elapse,
Forcibly stopping means interposed between the control means and the power supply circuit, and stopping the input of the start signal from the control means to the power supply circuit when the runaway is determined by the runaway detection means, It is provided with.

According to a second aspect of the present invention, when the operation signal is input to one input terminal of the control means and a signal for instructing power-on is input as the operation signal,
An OR gate circuit that outputs the start signal from the output terminal thereof, and power supply is started via the power supply circuit, and when a signal indicating power supply start is input as the operation signal, the output state of the start signal is changed. And a control unit for inputting a maintenance signal to maintain to the other input terminal of the OR gate circuit and outputting the same as the start signal from an output terminal of the OR gate circuit.

According to a third aspect of the present invention, the forcible stop means is provided by A
An input terminal and an output terminal thereof are respectively connected to an output terminal of the OR gate circuit and the power supply circuit, and a control signal from the runaway detection means is input to the other input terminal; The input / stop of the start signal to the power supply circuit is controlled by the control signal.

According to a fourth aspect of the present invention, the runaway detecting means includes:
It consists of an AND gate circuit and a NOT gate circuit.
By inputting the operation signal via the NOT gate circuit to one input terminal of the ND gate circuit and inputting the sustain signal output from the control unit to the other input terminal, the output terminal of the AND gate circuit is output. From the time when the signal to instruct the stop of the power is input as the operation signal, the period during which the maintenance signal is output, a monitoring circuit that outputs a detection signal, and the detection period of the detection signal is measured. And a timer circuit that determines that a runaway has occurred when the counted time reaches the predetermined time.

According to a fifth aspect of the present invention, the electric device is a car navigation device mounted on a vehicle, and the operation unit is an ignition switch.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a configuration diagram of a power supply control device according to a first embodiment of the present invention.

The power supply control device 1 according to the present embodiment
In-vehicle equipment (electric equipment) such as car navigation systems
It is used to control the start / stop of the power supply of the in-vehicle device according to the on / off operation of the start / stop of the power of an ignition switch (operation unit), for example, as shown in FIG. A power supply circuit 101 for driving start / stop of power supply from the power supply 107 such as a battery mounted on the vehicle to the in-vehicle device, and activation of the power supply circuit 101 in response to input of a vehicle signal such as an accessory signal from an ignition switch. Control means 3 for controlling stop; runaway detection means 5 for detecting runaway of control means 3;
Forcibly stopping the power supply circuit 101 when a runaway of the control means 3 is detected.

The power supply circuit 101 is activated by a later-described activation signal input from the control means 3 via the forced stop means 7 and uses the electric power from the power supply 107 to control the on-vehicle equipment and a control unit in the control means 3 which will be described later. 105 and the entire on-vehicle device. When the input of the activation signal is stopped, the supply of power to the vehicle-mounted device and the control unit 105 is stopped.

When a vehicle signal such as an accessory signal output by the operation of turning on the power of the ignition switch is input, the control means 3 starts to output a start signal to the power supply circuit 101 via the forcible stop means 7 to start the power supply. The circuit 101 is started. Then, when the input of the vehicle signal is stopped by the operation of stopping the power of the ignition switch, the output of the start signal is maintained for a certain period of time required for the vehicle-mounted device to complete the stop process, The power supply circuit 101 is stopped by stopping the output of the start signal, and includes an OR gate circuit 103 and a control unit 105.

In this embodiment, the input of the vehicle signal means the "input of a signal for instructing the start of power supply" described in claim 1, and the stop of the input of the vehicle signal is described in claim 1. Means "input of a signal to instruct to stop the power supply". Further, as used below, input of an H level signal as a vehicle signal also means “input of a signal to instruct power activation” according to claim 1, and an H level signal as the vehicle signal 2. The "input of a signal for instructing to stop the power supply" according to claim 1, wherein the switching to the L level signal is also performed.
Means

The OR gate circuit 103 outputs a start signal in response to an input of a vehicle signal to start the power supply circuit 101. That is, when an H-level signal as a vehicle signal is input, an H-level signal as a start signal is output to the power supply circuit 101 via the forced stop means 7 and the power supply circuit 10
Start 1 Then, the H level signal as the vehicle signal and the H level as a later-described maintenance signal from the control unit 105 are output.
When at least one of the level signals is input,
The H level signal as a start signal is continuously output to the power supply circuit 101 side during the input. When both the input vehicle signal and the maintenance signal are switched to the L level signal (that is, when both are stopped), the activation signal is switched to the L level signal (that is, the output of the activation signal is stopped).
The power supply circuit 101 is stopped.

When the vehicle signal input to the OR gate circuit 103 is stopped, the control unit 105 maintains the output of the start signal from the OR gate circuit 103 for the above-mentioned fixed time after the stop. OR gate circuit 103
Control.

Here, the control unit 105 controls the power supply circuit 10
1 starts and stops according to the start and stop of the power supply from the power supply 107 by the start and stop of 1. Also, immediately after the start,
By starting to output the H level signal as the above-mentioned sustain signal to the OR gate circuit 103, the OR gate circuit 10
3 is held, the vehicle signal input to the OR gate circuit 103 is suddenly set to L level (ie, stop), and the start signal from the OR gate circuit 103 is set to L level (ie, stop). , So that the power supply circuit 101 is not suddenly stopped.

During the operation, the vehicle signal input to the OR gate circuit 103 is always branched and input, and the H level as the vehicle signal input to the OR gate circuit 103 is input based on the branched input vehicle signal. It monitors whether the signal has been switched to the L level signal (ie, whether the vehicle signal input to the OR gate circuit 103 has been stopped), and has switched to the L level signal (ie, that the vehicle signal has been stopped).
When the detection is performed, after the above-described predetermined time has elapsed after the detection, the sustain signal is switched to the L level signal (that is, the output of the sustain signal is stopped), and the activation signal output from the OR gate circuit 103 is stopped. The power supply circuit 101 is stopped.

When the power supply control device 1 is incorporated in the vehicle-mounted device, the control unit 105 also serves as a control unit (not shown) including a CPU and the like of the vehicle-mounted device itself. That is, the operation of the above-described control unit 105 is set in the CPU of the in-vehicle device itself, and based on this setting, the in-vehicle device itself switches the power supply of the in-vehicle device in response to input of a vehicle signal such as an accessory signal from an ignition switch. It is configured to start and stop.

The forced stopping means 7 is configured as an AND gate circuit. An H-level signal as an output permission signal (control signal) and an L-level signal as an output stop signal (control signal), which are described later, are alternately input to the one input terminal from the runaway detection unit 5. When an H level signal (output permission signal) is input, an H level signal as a start signal from the OR gate circuit 103 input to the other input terminal is output to the power supply circuit 101, while an L level signal is output. When a signal (output stop signal) is input, the start signal is cut off (stopped) and output to the power supply circuit 101 is stopped.

Runaway detection means 5 includes OR gate circuit 103
Is stopped, and after the stop, after the above-mentioned fixed time has elapsed, the OR gate circuit 10
The output of the start signal from the control unit 105 is stopped (that is, the runaway of the control unit 105 occurs). If not, the runaway of the control unit 105 is determined. ) 9 and a timer circuit 11.

Runaway detection circuit 9 includes control unit 105 (and O
The input of the vehicle signal to the R gate circuit 103) is stopped,
In addition, a maintenance signal is output from control section 105 (that is, OR signal).
A state in which a start signal is output from the gate circuit 103) is detected.

Here, runaway detection circuit 9 includes an AND gate circuit 9a and a NOT gate circuit 9b connected to one input terminal of AND gate circuit 9a. And
The vehicle signal input to the control unit 105 is branched and NOT
The sustain signal that is input to one input terminal of the AND gate circuit 9a via the gate circuit 9b and that is input from the control unit 105 to the OR gate circuit 103 is branched and AND
The signal is input to the other input terminal of the gate circuit 9a. As a result, the H level signal as a sustain signal is input from the control unit 105 to the OR gate circuit 103, and the control unit 10
When the vehicle signal input to the input terminal 5 is stopped, that is, when the signal is changed to an L level signal, both input terminals of the AND gate circuit 9a are set to H level.
A level signal is input. As a result, the input of the vehicle signal to the control unit 105 is stopped, and the state in which the maintenance signal is output from the control unit 105 is detected. Continue to output the H level signal.

In other cases, that is, the control unit 1
When the maintenance signal input to the OR gate circuit 103 from L05 is low, that is, when the signal is stopped, and when the H level signal as the vehicle signal is input to the control unit 105, AN
Since the H level signal is not simultaneously input to both input terminals of the D gate circuit 9a, the detection signal output from the AND gate circuit 9a to the timer circuit 11 is at the L level, that is, stopped.

When an H-level signal as a detection signal is input from runaway detection circuit 9, timer circuit 11 counts the duration of the input state. It is determined that a runaway has occurred, and an L level signal as an output stop signal is input to the forced stop means 7 to stop the output of the start signal from the forced stop means 7 to the power supply circuit 101.

On the other hand, when the runaway of the control unit 105 is not detected (that is, when the H level as a detection signal is not continuously input from the runaway detection circuit 9 for a predetermined time or more, or when the detection signal input to the timer circuit 11 is L level). In the case of the level (ie, stop), an H level signal as an output permission signal is input to the forced stop means 7, the output of a start signal from the forced stop means 7 to the power supply circuit 101 is permitted, and the power supply circuit 101 is activated. To maintain.

The runaway detecting means 5 is provided with a power supply 107
Thus, an H level signal as an output permission signal can be input from the timer circuit 11 to the forcible stop means 7 even before the power supply circuit 101 is started.

Next, the operation of the power supply control device 1 will be described.

First, the operation at the time of starting the power supply control device 1 will be described. In a state before the power supply control device 1 is activated, the runaway detection unit 5 directly supplied with power from the power supply 107 is operating.
The control unit 105 and the in-vehicle device to which power is not supplied from 7 are stopped. In the runaway detection means 5, the start-up of the power supply circuit 101
Regardless of the stop state, the input state of the vehicle signal input to the control unit 105 and the OR gate circuit 103 from the control unit 105
Monitoring the output state of the maintenance signal output to the control unit 10
5 is monitored, but in this state, at least a sustain signal is not output from the control unit 105, so that a runaway of the control unit 105 is not detected. When a start signal is input to the forced stopping means 7, the start signal is transmitted to the power supply circuit 101.
Is controlled to output.

When the power switch is turned on by operating the ignition switch, a vehicle signal such as an accessory signal is output from the ignition switch. When the vehicle signal is input to the OR gate circuit 103, the OR gate circuit 103 outputs the signal. A start signal is output, and the start signal is input to the power supply circuit 101 via the forced stop unit 7. The power supply circuit 101 is activated by this input, and the activated power supply circuit 101 supplies the power supply 107 to the control unit 105 and the vehicle-mounted device.
Is started.

The control unit 105 started by the power supply starts inputting the maintenance signal to the OR gate circuit 103 immediately after the start, thereby holding the output of the start signal output from the OR gate circuit 103, and Circuit 1
03 is stopped when the vehicle signal input to 03 is stopped.
The start signal output from the R gate circuit 103 is suddenly stopped so that the power supply circuit 101 is not suddenly stopped.
During the operation, the vehicle signal input to the OR gate circuit 103 is always branched and input, and it is monitored whether the vehicle signal input to the OR gate circuit 103 is stopped based on the branched input vehicle signal. At the same time, when it is also used as a control unit of the in-vehicle device itself, it also performs control processing of the in-vehicle device.

At this point, runaway detecting means 5
The vehicle signal input to the control unit 105 is branched and input, and the maintenance signal input to the OR gate circuit 103 from the control unit 105 is input and branched. Based on these two signals, the vehicle signal is stopped. Sometimes, the occurrence of the runaway of the control unit 105 is continuously monitored by monitoring whether or not the output of the maintenance signal is stopped after a lapse of a predetermined time after the stop.

Next, the operation when the power supply control device 1 is stopped will be described. When the power supply is stopped by operating the ignition switch, the vehicle signal from the ignition switch input to the OR gate circuit 103 is stopped. At this point, since the sustain signal from the control unit 105 is still input to the OR gate circuit 103, the power supply circuit 1 is output from the OR gate circuit 103 via the forced stop unit 7.
01, a start signal is input, and the power supply circuit 101 is started.

On the other hand, if the control unit 105 is not running out of control, the stop of the vehicle signal is detected from the branching input vehicle signal. After continuously outputting the sustain signal to the circuit 103, the output of the sustain signal is stopped, and the OR gate circuit 10
3 to stop the start signal output from the power supply circuit 1
01 is stopped. With this stop, power supply to the control unit 105 and the on-vehicle device is stopped, and these are stopped. When the control unit 105 is also used as the control unit of the in-vehicle device itself, the control unit 105 performs a process of stopping the in-vehicle device during the predetermined time.

On the other hand, when the control unit 105 runs away, the control unit 105 does not detect the stoppage of the vehicle signal even if the vehicle signal is stopped. The sustain signal is continuously output to the gate circuit 103.

On the other hand, runaway detecting means 5 continuously outputs the maintenance signal for a certain period of time or more from the time when the control unit 105 stops the vehicle signal, based on the vehicle signal and the maintenance signal which are branched and input. When the state is detected, the output permission signal input to the forced stop means 7 is switched to the output stop signal at the time of detection, and the start signal input to the forced stop means 7 is output to the power supply circuit 101. Control not to.

As a result, the input of the start signal to the power supply circuit 101 is forcibly stopped, the power supply circuit 101 is stopped, and the power supply to the control unit 105 and the vehicle-mounted equipment is stopped.
05 and the in-vehicle device are stopped. And this control unit 1
With the stop of 05, the maintenance signal output from the control unit 105 is stopped, and the runaway of the control unit 105 is released.

The runaway detection means 5 detects the runaway of the control unit 105 based on the input status of the vehicle signal input to the control unit 105 and the output status of the maintenance signal output from the control unit 105 to the OR gate circuit 103. The release state is detected, and at the time of detection, the output permission signal is input to the forced stop means 7 again, and when the start signal is input to the forced stop means 7, the start signal is supplied to the power supply. Control is performed so as to output to the circuit 101.

According to the power supply control device 1 configured as described above, the runaway detection means 5 and the forced stop means 7 interposed between the OR gate circuit 103 and the power supply circuit 101 are provided. 5, the vehicle signal input to the control unit 105 is branched and input, the maintenance signal input from the control unit 105 to the OR gate circuit 103 is input and branched, and the control unit 105 When the runaway of the control unit 105 is detected by the forced stop means 7 and the runaway detection means 5 by the forced stop means 7, the power supply circuit 1 is detected.
01 is forcibly stopped, the stop signal output from the control unit 105 cannot be controlled even if the control unit 105 goes out of control. This prevents a stop operation from becoming inoperable, and ensures that the power supply can be stopped. Therefore, even when the start / stop of the power supply in the vehicle-mounted device is controlled by the control unit (CPU) of the vehicle-mounted device itself, the start / stop of the power supply can be reliably controlled.

The runaway detecting means 5 includes a timer circuit 11
The timer circuit 11 measures the time during which the maintenance signal is continuously output from the control unit 105 from the time when the vehicle signal is stopped, and determines that the control unit 105 is running out of control when the time is maintained for a predetermined time or more. Therefore, the control unit 105 continues to output the maintenance signal for a certain period of time from the time when the vehicle signal is stopped for the stop processing of the on-vehicle device, The runaway of the control unit 105 can be detected by discriminating between the cases where there is no mistake.

Further, since the forcible stop means 7 is constituted as an AND gate circuit, and the runaway detection circuit 9 is constituted by the AND gate circuit 9a and the NOT gate circuit 9b, both can be constituted by a simple structure. .

[0049]

According to the first, second and fifth aspects of the present invention, there is provided a runaway detecting means and a forced stopping means,
When the runaway detection means receives a signal to instruct the control means to stop power supply as an operation signal to the control means, it is monitored whether or not the state has been shifted to the state in which the output of the start signal from the control means has been stopped. If the transition has not been made, a runaway is determined, and the forced stop means stops the input of the start signal from the control means to the power supply circuit when the runaway detection means determines that the runaway has occurred. Even if the power supply goes out of control, it is possible to prevent the stop of the maintenance signal output from the control unit from becoming uncontrollable and the operation of stopping the power supply of the electric device from becoming inoperable, and the power supply can be reliably stopped. Therefore, even when the start / stop of the power in the electric device is controlled by the control unit of the electric device itself, the start / stop of the power can be reliably controlled.

Also, when a signal to instruct the control means to stop power supply is input to the control means as an operation signal to the runaway detection means, is the start signal output from the control means shifted to the output stop state? Is monitored, and when the output is not shifted to the stop state after a certain period of time, it is determined that a runaway has occurred. It is possible to detect the runaway of the control unit by discriminating between the case where the maintenance signal is continuously output for a certain period of time and the case where the maintenance signal is continuously output after the runaway.

According to the third aspect of the present invention, the forcible stopping means is constituted as an AND gate circuit, one input terminal and one output terminal of which are connected to the output terminal of the OR gate circuit and the power supply circuit, respectively. Since a control signal from the runaway detection means is input to the input terminal, and input / stop of the start signal to the power supply circuit is controlled by the control signal, a simple configuration can be achieved.

According to the fourth aspect of the present invention, the runaway detecting means comprises an AND gate circuit and a NOT gate circuit, and inputs an operation signal to one input terminal of the AND gate circuit via the NOT gate circuit. By inputting the sustain signal output from the control unit to the other input terminal, the output of the AND gate circuit outputs a sustain signal when a signal to instruct power stop is input as an operation signal. A monitoring circuit that outputs a detection signal during the
Since it is provided with a timer circuit that measures the detection period of the detection signal and determines that a runaway occurs when the measured time reaches a predetermined time, the configuration can be made with a simple configuration.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram of a conventional power supply control device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 power supply control device 3 control means 5 runaway detection means 7 forcible stop means (AND gate circuit) 9 a AND gate circuit 9 b NOT gate circuit 11 timer circuit 101 power supply circuit 107 power supply

Continuation of the front page (72) Inventor Susumu Takeshima 1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi F-term in the Auto Network Engineering Laboratory Co., Ltd. 5G065 BA00 EA02 GA06 GA09 JA02 JA07 KA01 KA06 LA01 MA07 MA10 PA01

Claims (5)

[Claims] 1. A power supply control device for controlling a start / stop of a power supply of a corresponding electric device in response to a start / stop operation of a power supply by a predetermined operation unit, wherein a start signal is input to the electric device. Start feeding,
A power supply circuit for stopping power supply to the electric device by stopping input of the start signal, and a signal for instructing power start as an operation signal in response to a start / stop operation of power by the operation unit is input. While outputting the start signal to the power supply circuit and holding the output state, when a signal instructing to stop the power is input, after a lapse of a certain time from the input, the output of the start signal is stopped. And a control unit that monitors whether or not the start signal output from the control unit has been shifted to an output stop state when a signal to instruct power stop is input as the operation signal to the control unit. A runaway detection unit that determines that a runaway has occurred when the output has not been shifted to the stop state after the lapse of the predetermined time; and a control unit that is interposed between the power supply circuit and the runaway detection unit. Ri when it is determined that the runaway, power supply control device, characterized in that it comprises a forced stop means for stopping the input of the start signal to the power supply circuit from the control means. 2. The control means outputs the activation signal from an output terminal thereof when the operation signal is input to one input terminal and a signal to instruct power activation is input as the operation signal. An OR gate circuit for performing power supply start via the power supply circuit; and a maintenance signal for maintaining the output state of the start signal when a signal for instructing power start is input as the operation signal.
A control unit that inputs the other input terminal of the gate circuit and outputs the start signal from the output terminal of the OR gate circuit;
The power supply control device according to claim 1, further comprising: 3. The forcible stopping means is configured as an AND gate circuit, one input terminal and one output terminal of which are connected to the output terminal of the OR gate circuit and the power supply circuit, respectively.
3. The power supply according to claim 2, wherein a control signal from the runaway detection means is input to the other input terminal, and input / stop of the start signal to the power supply circuit is controlled by the control signal. Control device. 4. The runaway detection means comprises an AND gate circuit and a NOT gate circuit.
By inputting the operation signal via the NOT gate circuit to one input terminal of the ND gate circuit and inputting the sustain signal output from the control unit to the other input terminal, the output terminal of the AND gate circuit is output. From, when a signal to instruct power stop is input as the operation signal, a period in which the maintenance signal is output, a monitoring circuit that outputs a detection signal, and a detection period of the detection signal is measured. 4. The power supply control device according to claim 2, further comprising: a timer circuit that determines that a runaway has occurred when the measured time reaches the predetermined time. 5. The power supply control device according to claim 1, wherein the electric device is a car navigation device mounted on a vehicle, and the operation unit is an ignition switch.