JP2016038598A - Electronic device and power source control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device and a power source control method that attain proper suppression of power consumption of internal power sources.SOLUTION: According to an embodiment, an electronic device comprises: a diode OR circuit; a switch circuit; and a controller. The diode OR circuit is configured to connect an external power source in parallel to an internal power source lower in a voltage than the external power source; and selectively output one of the power sources. The switch circuit is configured to be provided to lie between the internal power source and the diode OR circuit, and can switch a power supply to the diode OR circuit from the internal power source or shut down the power supply thereto. The controller is configured to actuate the switch circuit so as to shut down the power supply to the diode OR circuit from the internal power source when the power is turned on, and actuate the switch circuit so as to supply the power to the diode OR circuit from the internal power source when a sensor detects an impact.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to an electronic apparatus and a power supply control method.

  A drive recorder is a device that records the behavior of a driving vehicle. This device operates as much as possible even when the car encounters an accident and needs to do some processing.

  For example, it is assumed that emergency communication is required when a vehicle encounters an accident as a system request for this apparatus. Usually, the power for operation of this apparatus is supplied from the vehicle body. When a car encounters an accident, it can be expected that the power supply from the vehicle body will be cut off, so it may have an internal power supply (emergency power supply) for self-drive.

JP 2008-140376 A

  By the way, a secondary battery that can be repeatedly charged and discharged is difficult to use as an internal power source of a drive recorder from the viewpoint of a required charge amount. On the other hand, when applying a primary battery, it is required not to consume the power unnecessarily.

  For example, when the external power supply on the vehicle body side and the primary battery on the drive recorder side are simply selectively used by a diode OR circuit, the power of the primary battery is consumed each time the power supply from the external power supply is cut off. End up. This is because the interruption of the power supply from the external power supply is indistinguishable between when the car encounters an accident and when the car is stopped and the engine is stopped. is there.

  The problem to be solved by the present invention is to provide an electronic device and a power supply control method that can appropriately suppress power consumption of an internal power supply.

  According to the embodiment, the electronic device includes an input unit, a second power supply, a diode OR circuit, a switch circuit, a sensor, and a controller. The input means inputs power from the first power source. The second power supply outputs power having a voltage lower than that of the first power supply. The diode OR circuit connects the first power source and the second power source in parallel, and selectively outputs one of the power from the first power source and the power from the second power source. The switch circuit is provided between the second power supply and the diode OR circuit, and can switch the supply or cutoff of the power from the second power supply to the diode OR circuit. The sensor detects an impact. The controller drives the switch circuit so that power supply from the second power supply to the diode OR circuit is cut off when the power is turned on, and when the impact is detected by the sensor, the controller supplies the second circuit to the diode OR circuit. The switch circuit is driven so that electric power is supplied.

The figure which shows the hardware constitutions of the part regarding the power supply control of the drive recorder of embodiment. The figure which shows the relationship between the presence or absence of the electric power supply from the external power supply in the drive recorder of embodiment, and the output value from the GPIO terminal of a microcomputer. The flowchart which shows the operation | movement procedure of the drive recorder of embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a hardware configuration of a part related to power control of the electronic apparatus according to the present embodiment. Here, it is assumed that the electronic apparatus according to the present embodiment is realized as a drive recorder that is a device that records the behavior of a car during driving. Further, it is assumed that the drive recorder according to the present embodiment is configured to start image capturing when the power is turned on and to perform emergency communication when the vehicle encounters an accident.

  This drive recorder normally operates with electric power supplied from the vehicle body side. The power supply source from the vehicle body side is indicated as an external power source 1 in FIG. In addition, the drive recorder is equipped with a primary battery 2 as an internal power source (emergency power source) for self-drive in case the power supply from the external power source 1 is cut off. The drive recorder of this embodiment is configured to appropriately suppress the power consumption of the primary battery 2 that is an internal power supply, and this point will be described in detail below.

  As shown in FIG. 1, before the power from the external power source 1 and the power from the primary battery 2 are input to the power circuit 4 that generates power for operation of various components in the drive recorder, the diode OR circuit 3 Is mixed. The diode OR circuit 3 is a circuit for connecting the external power source 1 and the primary battery 2 in parallel, and gives priority to the power having the higher voltage value of the power from the external power source 1 and the power from the primary battery 2. And a selection circuit for outputting. In the drive recorder of the present embodiment, when the voltage value of power from the external power source 1 is higher than the voltage value of power from the primary battery 2 and power is supplied from the external power source 1, the diode OR circuit 3 Therefore, it is assumed that the specification is such that the power from the external power source 1 is selected and output. Note that the backflow of power to the external power source 1 and the primary battery 2 is prevented by the diode in the diode OR circuit 3 and thus does not occur.

  Examples of various components in the drive recorder that operate with the operating power generated by the power supply circuit 4 include a camera 11, a sensor 12, a communication device 13, and the like. The camera 11 is a device for performing the above-described image shooting. The sensor 12 is a device that detects an impact. The communication device 13 is a wireless communication device for performing the above-described emergency communication.

  The drive recorder of the present embodiment firstly includes an FET 5 between the primary battery 2 and the diode OR circuit 3 for conducting (ON) or interrupting (OFF) a power supply line connecting them. Second, the FET 5 is turned on / off using a GPIO (General purpose input / output) terminal 6A of the microcomputer 6 that controls the operation of various components in the drive recorder. More specifically, the control is performed by switching the value of the output signal from the GPIO terminal 6A of the microcomputer 6 in accordance with the presence or absence of impact detection by the sensor 12. The microcomputer 6 has an operation control module 101 that is firmware, and the operation control module 101 has a GPIO terminal 6A when power is turned on, that is, when power supply from the power supply circuit 4 to the microcomputer 6 is started. The value of the output signal from is set to off [0]. In other words, the output value from the GPIO terminal 6A is defined as an initial value that indicates OFF.

  The microcomputer 6 monitors the presence or absence of power supply from the external power source 1 using the GPIO terminal 6B. More specifically, it is generated by appropriately dividing the power on the power supply line on the side of the external power supply 1 with respect to the diode in the diode OR circuit 3 (so as not to exceed the operating power voltage of the microcomputer 6). A detection signal is input through the GPIO terminal 6B and monitored. When power is supplied from the external power supply 1, the input value from the GPIO terminal 6B is on [1]. When power supply from the external power supply 1 is interrupted, the input value from the GPIO terminal 6B is Off [0].

  The motion control module 101 turns on the value of the output signal from the GPIO terminal 6A when the sensor 12 detects an impact that is equal to or greater than a threshold that can determine that the vehicle (equipped with the drive recorder of the present embodiment) has encountered an accident. 1]. That is, the drive recorder of this embodiment is controlled by the microcomputer 6 (operation control module 101) so that the power from the primary battery 2 is supplied to the diode OR circuit 3 only when the sensor 12 detects an impact. Is done. The output value from the GPIO terminal 6A also has a role of a flag indicating whether or not the sensor 12 has detected an impact. Hereinafter, switching the value of the output signal from the GPIO terminal 6A to ON may be referred to as setting a flag.

  Here, consider a case where the user has finished driving the vehicle (without encountering an accident) and stopped the engine. Normally, when the power supply from the external power supply 1 is cut off, the power from the primary battery 2 is selected and output by the diode OR circuit 3. That is, every time the power supply from the external power source 1 is cut off, the power of the primary battery 2 is consumed. On the other hand, in the drive recorder of this embodiment, when the sensor 12 does not detect an impact, the power supply from the primary battery 2 to the diode OR circuit 3 is interrupted by the FET 5, so that the external power supply The power consumption of the primary battery 2 due to the power supply from 1 being cut off can be suppressed.

  On the other hand, when the sensor 12 detects an impact, the output value from the GPIO terminal 6A of the microcomputer 6 is switched to a value indicating ON by the operation control module 101. As a result, the primary battery 2 to the diode OR circuit 3 is switched. Electric power will be supplied. Therefore, if the power supply from the external power source 1 is cut off, the diode OR circuit 3 selects and outputs the power from the primary battery 2. The power supply circuit 4 generates power for operation of various components in the drive recorder using the power from the primary battery 2, and the microcomputer 6 (operation control module 101) receives the power for operation, The emergency communication described above is executed. The drive recorder of the present embodiment is provided with a capacitor 7 for supplementing the power supply after the power supply from the external power supply 1 is interrupted until the power supply from the primary battery 2 is started. After execution of the emergency communication, the microcomputer 6 (operation control module 101) returns the value of the output signal from the GPIO terminal 6A to OFF [0]. Then, the microcomputer 6 stops the operation of the drive recorder.

  Even if the sensor 12 detects an impact, if the power supply from the external power source 1 continues, the diode OR circuit 3 selects the power from the external power source 1 (with a high voltage value).・ Output. The power supply circuit 4 generates power for operation of various components in the drive recorder using the power from the primary battery 2, and the microcomputer 6 (operation control module 101) receives the power for operation, The emergency communication described above is executed. Thus, in this case, power consumption of the primary battery 2 does not occur at all. After execution of the emergency communication, the microcomputer 6 (operation control module 101) returns the value of the output signal from the GPIO terminal 6A to OFF [0]. Then, the microcomputer 6 resumes the normal operation of the drive recorder.

  FIG. 2 is a diagram showing the relationship between the presence / absence of power supply from the external power source 1 and the output value from the GPIO terminal 6A of the microcomputer 6.

  As shown in FIG. 2, when power is supplied from the external power source 1 and the output value from the GPIO terminal 6A of the microcomputer 6 is a value indicating OFF (when the sensor 12 does not detect an impact) ) The power from the external power supply 1 is selected and output by the diode OR circuit 3. When the power is cut off from the external power source 1 and the output value from the GPIO terminal 6A of the microcomputer 6 is a value indicating OFF, the diode OR circuit 3 supplies the power from the external power source 1 and the primary battery 2. None of the power is output.

  When power is supplied from the external power source 1 and the output value from the GPIO terminal 6A of the microcomputer 6 is ON (when the sensor 12 detects an impact), the diode OR circuit 3 The power from the power source 1 is selected and output. Further, when power is cut off from the external power source 1 and the output value from the GPIO terminal 6A of the microcomputer 6 is a value indicating ON, the power from the primary battery 2 is selected and output by the diode OR circuit 3. The

  Thus, in the drive recorder of the present embodiment, the primary battery 2 is a value indicating that the output value from the GPIO terminal 6A of the microcomputer 6 is on even when the power is cut off from the external power source 1. Since it is controlled so as to be used only in the case, it is possible to appropriately suppress the power consumption of the primary battery 2 which is an internal power source.

  FIG. 3 is a flowchart showing an operation procedure of the drive recorder of the present embodiment.

  When the drive recorder is turned on, that is, when power supply from the external power supply 1 is started, the microcomputer 6 (operation control module 101) performs a process of setting the output value from the GPIO terminal 6A to off [0]. An initialization process including this is executed (block A1). When the initialization processing is completed, the microcomputer 6 executes normal processing including image capturing (block A2).

  When the sensor 12 detects an impact (it can be determined that the car has encountered an accident) (YES in block A3), the microcomputer 6 switches the output value from the GPIO terminal 6A to ON [1] (sets a flag). (Block A4).

  If the input value from the GPIO terminal 6B is off [0], that is, if the power supply from the external power source 1 is cut off (YES in block A5), if the output value from the GPIO terminal 6A is on [1] ( The power from the primary battery 2 is supplied to the diode OR circuit 3 and the power from the primary battery 2 is selected and output by the diode OR circuit 3 (block A7). The microcomputer 6 is supplied with operating power generated by the power supply circuit 4 using the power from the primary battery 2, and the microcomputer 6 performs emergency processing such as emergency communication (block A8). When the emergency process is completed, the microcomputer 6 switches the output value from the GPIO terminal 6A to OFF [0] (block A9).

  The microcomputer 6 checks whether the input value from the GPIO terminal 6B is OFF [0], that is, whether the power supply from the external power source 1 is cut off when performing emergency processing (block A10). If it is (YES in block A10), the operation of the drive recorder is stopped (block A11).

  On the other hand, in block A5, when the input value from the GPIO terminal 6B is on [1], that is, when the power supply from the external power source 1 is not cut off (NO in block A5), the diode OR circuit 3 causes the external power source 1 to Will continue to be selected and output (block A12). The microcomputer 6 checks whether or not the output value from the GPIO terminal 6A is switched on [1] (block A13). If the microcomputer 6 is switched on [1] (YES in block A13), the microcomputer A starts from block A8. Execute the process. That is, emergency processing such as emergency communication is performed (block A8), and the output value from the GPIO terminal 6A is switched off [0] (block A9). In this case, since the input value from the GPIO terminal 6B is ON [1], that is, the power supply from the external power source 1 is not cut off (NO in block A10), the microcomputer 6 performs processing from block A2. To resume.

  The input value from the GPIO terminal 6B is on [1], that is, the power supply from the external power supply 1 is not cut off (NO in block A5), and the output value from the GPIO terminal 6A is also switched off [0]. If not (NO in block A13), the microcomputer 6 continues normal processing as it is (block A14) and repeats the processing from block A2. On the other hand, the input value from the GPIO terminal 6B is off [0], that is, the power supply from the external power source 1 is cut off (YES in block A5), and the output value from the GPIO terminal 6A is switched to off [0]. If not (NO in block A6), since the power from the primary battery 2 is not supplied to the diode OR circuit 3, neither the power from the external power source 1 nor the power from the primary battery 2 is output from the diode OR circuit 3. As a result, the drive recorder forcibly stops the operation (block A15).

  As described above, the drive recorder according to the present embodiment conducts (turns on) the power line connecting between the diode OR circuit 3 and the primary battery 2 that connect the external power source 1 and the primary battery 2 in parallel. Alternatively, the FET 5 for shutting off (off) is provided, and the on / off of the FET 5 is controlled by using the GPIO terminal 6A of the microcomputer 6 in accordance with the presence or absence of the impact detection by the sensor 12, thereby providing an internal power supply. It implement | achieves suppressing appropriately the power consumption of the primary battery 2 which is.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... External power supply, 2 ... Primary battery, 3 ... Diode OR circuit, 4 ... Power supply circuit, 5 ... FET, 6 ... Microcomputer, 6A, 6B ... GPIO terminal, 7 ... Capacitor, 11 ... Camera, 12 ... Sensor, 13 ... Communication device, 101 ... Operation control module

Claims (7)

Input means for inputting power from the first power source;
A second power source that outputs power having a lower voltage than the first power source;
A diode OR circuit that connects the first power source and the second power source in parallel, and selectively outputs one of the power from the first power source and the power from the second power source;
A switch circuit provided between the second power supply and the diode OR circuit, and capable of switching supply or cutoff of power from the second power supply to the diode OR circuit;
A sensor to detect the impact;
The switch circuit is driven so that power supply from the second power supply to the diode OR circuit is cut off when the power is turned on, and power is supplied from the second power supply to the diode OR circuit when an impact is detected by the sensor. A controller for driving the switch circuit to be
An electronic device comprising:   The controller drives the switch circuit so that power is supplied from the second power source to the diode OR circuit, and then executes a first process. After the first process is performed, the controller performs the first process from the second power source. The electronic device according to claim 1, wherein the switch circuit is driven so that power supply to the diode OR circuit is interrupted.   The electronic device according to claim 1, wherein the controller is configured as a one-chip microcomputer having a GPIO (General purpose input / output) terminal, and drives the switch circuit using the GPIO terminal.   The electronic device according to claim 1, wherein the second power source is a primary battery.   2. The capacitor according to claim 1, further comprising a capacitor for supplementing power supply until the power from the second power source is output from the diode-or circuit when the input of power from the first power source is interrupted. Electronic equipment. A power control method for an electronic device having an internal power supply,
When the power is turned on, the power line between the internal power supply and the diode OR circuit that selectively outputs one of the power from the external power supply and the power from the internal power supply is cut off,
When the impact is detected, the power supply line between the diode OR circuit and the internal power supply is made conductive.
Power control method.   The power line between the diode OR circuit and the internal power supply is cut off after the first process is performed after the power supply line between the diode OR circuit and the internal power supply is made conductive. The power supply control method described in 1.

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