Power supply control device and power supply control method

Abstract

To make it possible to use a backup battery even during IG off.SOLUTION: A power supply control device controls a vehicle's power supply and has a control unit. The control unit determines whether a backup battery has a connection abnormality when controlling the backup battery while the vehicle is IG off.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The disclosed embodiments relate to a power control device and a power control method.

Background Art

[0002] Conventionally, a TCU (Telematics Control Unit) mounted on a vehicle and provided to be capable of wireless communication with an external information system is known. In addition to functions such as vehicle theft tracking and tow truck movement notification, some TCUs have an automatic notification function called eCall that automatically reports vehicle position information and the like to a center when a collision accident occurs.

[0003] In addition, the TCU is equipped with a backup battery such as a lithium-ion secondary battery so that it can operate even if the power supply from the vehicle battery is cut off due to an impact at the time of an accident.

[0004] The backup battery is replaced when it becomes unusable due to deterioration over time or the like, and such replacement is assumed to be performed while the vehicle's IG (ignition) is off. Therefore, the control of the backup battery is premised on the vehicle's IG being on, and there is a restriction that the backup battery cannot be used when the IG is off.

[0005] Therefore, even if there is an abnormal connection of the backup battery, such as accidental reverse connection of the backup battery during the replacement work, it is impossible to detect such an abnormality until the IG is turned on. Patent Document 1 discloses a technique for cutting off power supply to a boost circuit in case of an abnormality such as battery reverse connection when the IG is turned on (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] Thus, there is room for further improvement in conventional technology to enable the use of the backup battery even when the ignition is off.

[0008] One embodiment, made in view of the above, aims to provide a power control device and a power control method that can enable the use of a backup battery even when the IG is off. [Means for solving the problem]

[0009] A power control device according to one embodiment is a power control device for controlling the power supply of a vehicle, and has a control unit. The control unit is Based on the detection result of the ignition switch of the aforementioned vehicle, In controlling the backup power supply while the vehicle's ignition is off, it is determined whether there is a connection abnormality in the backup power supply. If it is determined that there is no connection abnormality to the backup power supply, the boost circuit that increases the voltage of the backup power supply is turned on. do. [Effects of the Invention]

[0010] According to one embodiment, the backup battery can be used even when the ignition is off. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a block diagram showing an example configuration of a TCU according to an embodiment. [Figure 2] Figure 2 shows an example of the configuration of the BUB and circuit section according to the embodiment. [Figure 3] Figure 3 is a flowchart showing the processing procedure executed by the TCU according to the embodiment. [Figure 4] Figure 4 is a flowchart showing the processing procedure for the battery connection status check shown in Figure 3. [Figure 5] Figure 5 is a flowchart showing the processing procedure for the BATT voltage check process shown in Figure 3. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the power control device and power control method disclosed in this application will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described below.

[0013] Furthermore, the following explanation will use the case where the power control device according to the embodiment is TCU10 as an example. Also, the backup battery provided by TCU10 will be referred to as "BUB" (Back Up Battery) as appropriate. Also, the vehicle battery provided by the vehicle will be referred to as "BATT" as appropriate.

[0014] Figure 1 is a block diagram showing an example configuration of the TCU10 according to this embodiment. Note that Figure 1 shows only the components necessary to explain the features of this embodiment, and descriptions of general components are omitted.

[0015] In other words, each component shown in Figure 1 is a functional concept and does not necessarily need to be physically configured as shown. For example, the specific forms of distribution and integration of each block are not limited to those shown, and it is possible to configure all or part of them by functionally or physically distributing and integrating them in any unit according to various loads and usage conditions.

[0016] As shown in Figure 1, the TCU10 is connected to the BATT3, IG sensor 5, ECU (Electronic Control Unit) 7, emergency call button 8, and microphone speaker unit 9.

[0017] BATT3 is the vehicle battery mounted on the vehicle. The IG sensor 5 is a sensor that detects the state of the IG switch. The ECU 7 is various ECUs mounted on the vehicle. The ECU 7 includes an airbag ECU. When the TCU 10 is notified that the airbag has been deployed from the airbag ECU, it operates the eCall function. Also, the TCU 10 operates the eCall function by the user's operation. The TCU 10 operates the eCall function, for example, when the user presses the emergency call button 8.

[0018] The microphone speaker unit 9 is an input / output device for voice information such as a microphone and a speaker mounted on the vehicle. The microphone speaker unit 9 inputs or outputs voice information during the operation of the eCall function. Note that the microphone speaker unit 9 is not limited to being integrally configured, and the microphone and the speaker may be separate bodies.

[0019] The TCU 10 has a BUB 11, a circuit unit 12, a communication unit 13, a storage unit 14, and a control unit 15. The BUB 11 is a battery pack in which one or more secondary batteries 11a (see FIG. 2) described later are incorporated. The circuit unit 12 is a peripheral circuit of the BUB 11 related to the control of the BUB 11.

[0020] The communication unit 13 is a communication module that realizes wireless communication with an external information system via a C-V2X (Cellular Vehicle to Everything) communication network or the like. The communication unit 13 is realized by a network adapter and a SIM (Subscriber Identity Module) that records user identification information.

[0021] The storage unit 14 is realized by a storage device such as a RAM (Random Access Memory) and a flash memory (Flash Memory).

[0022] The control unit 15 is a controller and is realized by the execution of various programs stored in the memory unit 14 using RAM as the working area by a CPU (Central Processing Unit) or MPU (Micro Processing Unit), etc. Furthermore, the control unit 15 can be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

[0023] The control unit 15 realizes or executes the functions and operations of the power control processing according to the power control method according to the embodiment described below.

[0024] Figure 2 shows an example configuration of the BUB 11 and circuit section 12 according to the embodiment. The dashed arrows in the figure represent the content of the control signals input from the control unit 15 and the information output to the control unit 15.

[0025] As shown in Figure 2, BUB11 includes a secondary battery 11a and a first thermistor 11b. The secondary battery 11a is a secondary battery such as a lithium-ion secondary battery. The first thermistor 11b functions as a temperature sensor within BUB11. The first thermistor 11b is installed between the secondary battery 11a and the temperature measuring circuit 12i, which will be described later.

[0026] The circuit section 12 includes an audio power supply 12a, a step-down circuit 12b, a battery voltage boost circuit 12c, diodes 12d and 12e, a charging circuit 12f, a discharge circuit 12g, and a battery voltage / current measurement circuit 12h. The circuit section 12 also includes a temperature measuring circuit 12i, a second thermistor 12j, a battery reverse connection protection circuit 12k, an overvoltage detection circuit 12l, a cutoff circuit 12m, and a test discharge circuit 12n.

[0027] The audio power supply 12a is the power supply for the microphone speaker unit 9 mentioned above. The step-down circuit 12b steps down the power from the vehicle battery's constant power supply (+B) and supplies it to the inside of the product, for example, the communication unit 13 mentioned above.

[0028] The control unit 15 monitors the constant power supply (see "Vehicle Battery Monitoring" in the diagram) and, if power can be supplied from the constant power supply, operates the eCall function using the constant power supply.

[0029] On the other hand, if power cannot be supplied from the vehicle battery, the control unit 15 uses the BUB 11 to activate the eCall function.

[0030] BUB11 is connected to the microphone speaker unit 9 and the power supply line SL inside the product via a secondary battery 11a, a battery voltage boosting circuit 12c, and diodes 12d and 12e. Based on the control of the control unit 15, the battery voltage boosting circuit 12c boosts the voltage of the power from BUB11, rectifies it via diode 12d, and supplies it to the audio unit power supply 12a.

[0031] Furthermore, the battery voltage boosting circuit 12c supplies the boosted power to the inside of the product while rectifying it via the diode 12e. The battery voltage boosting circuit 12c also outputs the result of the boosted voltage measurement to the control unit 15.

[0032] The charging circuit 12f is provided on the charging line CL that branches off from the power supply line SL to the BUB 11. Based on the control of the control unit 15, the charging circuit 12f switches between supplying and stopping the charging current flowing through the charging line CL to the BUB 11.

[0033] The discharge circuit 12g is provided between the charging line CL and ground. Based on the control of the control unit 15, the discharge circuit 12g discharges the excess power charged to the BUB 11.

[0034] The battery voltage / current measurement circuit 12h is located on the charging line CL, between the charging circuit 12f and the BUB 11. The battery voltage / current measurement circuit 12h measures the voltage and current of the BUB 11 and outputs the voltage measurement results and current measurement results to the control unit 15.

[0035] The temperature measuring circuit 12i is connected to the first thermistor 11b of the BUB 11. Based on the control of the control unit 15, the temperature measuring circuit 12i uses the first thermistor 11b as a temperature sensor to measure the temperature inside the BUB 11 (hereinafter referred to as "battery temperature" as appropriate).

[0036] Furthermore, the temperature measuring circuit 12i measures the temperature of the circuit board of the circuit unit 12 (hereinafter referred to as "board temperature") using the second thermistor 12j as a temperature sensor, based on the control of the control unit 15. The second thermistor 12j is provided between the temperature measuring circuit 12i and ground. The temperature measuring circuit 12i also outputs the results of the battery temperature measurement and the board temperature measurement to the control unit 15.

[0037] The battery reverse connection protection circuit 12k is connected to BUB11. When the battery reverse connection protection circuit 12k detects a reverse connection in BUB11, it cuts off the power supply from BUB11 to protect the TCU10.

[0038] The overvoltage detection circuit 12l is provided between the charging line CL and the battery reverse connection protection circuit 12k. When the overvoltage detection circuit 12l detects an overvoltage in BUB 11, it outputs the detection result to the control unit 15.

[0039] The battery reverse connection protection circuit 12k also cuts off power from BUB11 if an overvoltage is detected in BUB11. The cutoff circuit 12m is provided between the battery reverse connection protection circuit 12k and ground. The cutoff circuit 12m cuts off power from BUB11 based on the control of the control unit 15 when a reverse connection of BUB11 is detected or when an overvoltage is detected in BUB11.

[0040] The test discharge circuit 12n is installed between the charging line CL and ground. Based on the control of the control unit 15, the test discharge circuit 12n performs a test discharge of the BUB 11. In other words, the test discharge is a degradation determination of the BUB 11. The test discharge circuit 12n also outputs the result of the test discharge current measurement to the control unit 15.

[0041] In the TCU10 configured as described above, the control unit 15, as a power control method according to the embodiment, checks whether there are any connection abnormalities such as reverse connection or disconnection in the BUB11 so that the BUB11 can be used even when the IG is off.

[0042] Then, the control unit 15 turns on the battery voltage boosting circuit 12c when it confirms that no connection abnormality has occurred.

[0043] Furthermore, even after turning on the battery voltage boosting circuit 12c, there is a risk that the secondary battery 11a may be replaced if the ignition is off. For this reason, the control unit 15 checks whether there is a connection abnormality in BUB 11 even after turning on the battery voltage boosting circuit 12c.

[0044] The processing procedure, including such control, will be explained using Figures 3 to 5. Figure 3 is a flowchart showing the processing procedure executed by the TCU according to this embodiment. Figure 4 is a flowchart showing the processing procedure for the battery connection status check process shown in Figure 3. Figure 5 is a flowchart showing the processing procedure for the BATT voltage check process shown in Figure 3. The processing procedure in Figure 3 is constantly repeated based on the detection result of the IG sensor 5.

[0045] Based on the detection result of the IG sensor 5, the control unit 15 determines whether the IG ON switch has been turned off or the IG OFF switch has been turned on, and if the IG ON switch has been turned off or the IG OFF switch has been turned on, it executes the processing procedure shown in Figure 3.

[0046] As shown in Figure 3, the control unit 15 performs an abnormality check when the battery voltage boosting circuit 12c is off (step S101). Then, the control unit 15 performs an abnormality check on the battery voltage / current measuring circuit 12h (step S102).

[0047] Next, the control unit 15 performs a battery connection status check process (step S103). In the battery connection status check process, as shown in Figure 4, the control unit 15 causes the battery voltage / current measurement circuit 12h to measure the battery voltage (step S201).

[0048] The control unit 15 then determines whether the measured battery voltage is below a threshold (step S202). If the battery voltage is above the threshold (step S202, No), the control unit 15 returns from the battery connection status check process and returns to the processing procedure shown in Figure 3.

[0049] If the battery voltage is below a threshold (step S202, Yes), the control unit 15 turns on the temperature measuring circuit 12i (step S203) and causes the temperature measuring circuit 12i to measure the substrate temperature (step S204). Then, the control unit 15 determines whether the measured substrate temperature is within a predetermined low temperature range (step S205).

[0050] If the substrate temperature is within the low temperature range (step S205, Yes), the control unit 15 masks the low temperature error (step S206). If the substrate temperature is not within the low temperature range (step S205, No), the control unit 15 does not mask the low temperature error (step S207).

[0051] Next, the control unit 15 causes the temperature measuring circuit 12i to measure the battery temperature (step S208). Then, the control unit 15 turns off the temperature measuring circuit 12i (step S209) and determines whether the measured battery temperature is within a predetermined low-temperature range (step S210).

[0052] If the battery temperature is within the low temperature range (step S210, Yes), the control unit 15 determines that there is a "connection abnormality" (step S211). That is, the control unit 15 determines that BUB11 is in a "connection abnormality" state, such as reverse connection or no connection, because the battery voltage is low and the battery temperature is low. Then, it terminates the process.

[0053] Furthermore, if the battery temperature is not within the low temperature range (step S210, No), the control unit 15 determines that it is "over-discharged" (step S212). In other words, the control unit 15 determines that, because the battery voltage is low and the battery temperature is not low, at least BUB11 is connected, but BUB11 is in an "over-discharged" state with an excessively low battery voltage. The process then terminates.

[0054] Returning to the explanation of Figure 3, after recovering from the battery connection status check process, the control unit 15 performs a battery overvoltage check (step S104). Then, the control unit 15 performs an abnormality check of the battery reverse connection protection circuit 12k (step S105). In addition, the control unit 15 performs an abnormality check of the overvoltage detection circuit 12l (step S106).

[0055] Next, the control unit 15 checks for short-circuit abnormalities at the terminals of the first thermistor 11b (step S107). The control unit 15 also checks for open-circuit abnormalities at the terminals of the first thermistor 11b (step S108).

[0056] Then, the control unit 15 performs an abnormality check on the temperature measuring circuit 12i (step S109) and a battery over-discharge check (step S110). Then, the control unit 15 performs an abnormality check on the battery voltage boosting circuit 12c when it is ON (step S111).

[0057] Next, the control unit 15 performs an abnormality check on the test discharge circuit 12n (step S112). Then, the control unit 15 turns on the cutoff circuit 12m (step S113). Then, the control unit 15 turns off the battery reverse connection protection circuit 12k (step S114) and turns off the temperature measurement circuit 12i (step S115).

[0058] Then, the control unit 15 turns off the test discharge circuit 12n (step S116) and the discharge circuit 12g (step S117). Also, the control unit 15 turns off the charging circuit 12f (step S118).

[0059] Next, the control unit 15 turns on the battery voltage boosting circuit 12c (step S119). Then, the control unit 15 checks the remaining charge of the secondary battery 11a (step S120). Then, the control unit 15 performs a BATT voltage check process (step S121).

[0060] In the BATT voltage check process, as shown in Figure 5, the control unit 15 measures the voltage of BATT3 (step S301). Then, the control unit 15 determines whether the measured voltage of BATT3 is less than a threshold (in this case, 8V) (step S302).

[0061] If the voltage of BATT3 is above the threshold (step S302, No), the control unit 15 returns from the BATT voltage check process, returns to the processing procedure shown in Figure 3, and then terminates the process.

[0062] If the voltage of BATT3 is below the threshold (step S302, Yes), the control unit 15 causes the battery voltage boosting circuit 12c to measure the boosted voltage (step S303). The control unit 15 also causes the battery voltage / current measuring circuit 12h to measure the battery voltage of BUB11 (step S304).

[0063] Then, the control unit 15 determines whether the difference between the measured boosted voltage and the battery voltage is large or not (step S305). If there is a connection problem with BUB11, the boosted voltage will not rise, so step S305 checks for a connection problem with BUB11.

[0064] If the difference between the boosted voltage and the battery voltage is large (step S305, Yes), the control unit 15 transitions to "discharge" by BUB11 (step S306) and terminates the process.

[0065] If the difference between the boosted voltage and the battery voltage is not large (step S305, No), the control unit 15 returns from the BATT voltage check process without transitioning to "discharge" by BUB11, returns to the processing procedure in Figure 3, and then terminates the process. From steps S301, S303, and S304, it can be said that the TCU10 has a "voltage acquisition unit".

[0066] As described above, the TCU10 according to the embodiment (corresponding to an example of a "power control device") has a control unit 15. The control unit 15 determines whether there is a connection abnormality in the BUB11 (corresponding to an example of a "backup power supply") when the vehicle's IG is off.

[0067] Therefore, according to the TCU10 of the embodiment, the BUB11 can be used even when the IG is off.

[0068] Furthermore, if the control unit 15 determines that there is no connection abnormality in BUB11, it performs control to turn on the battery voltage boosting circuit 12c (corresponding to an example of a "boost circuit") which boosts the voltage of BUB11.

[0069] Therefore, according to the embodiment of the TCU10, the TOC10 can be protected by determining that there is no connection abnormality in the BUB11 and then turning on the battery voltage boosting circuit 12c.

[0070] Furthermore, the TCU10 has a temperature measuring circuit 12i. The temperature measuring circuit 12i acquires the battery temperature (corresponding to an example of the "first temperature"), which is the temperature of the BUB11, and the substrate temperature (corresponding to an example of the "second temperature"), which is the temperature of the substrate, to the circuit unit 12 related to the control of the BUB11. The control unit 15 determines whether there is a connection abnormality in the BUB11 based on the battery temperature or the substrate temperature.

[0071] Therefore, according to the TCU10 of this embodiment, it is possible to determine whether there is a connection abnormality in the BUB11 based on the battery temperature or the substrate temperature. Furthermore, the determination may also take into account the battery voltage in addition to the temperature.

[0072] Furthermore, the control unit 15 determines whether at least BUB 11 is reverse-connected or disconnected.

[0073] Therefore, according to the TCU10 of this embodiment, it is possible to determine that BUB11 is either reverse-connected or disconnected as a connection abnormality of BUB11.

[0074] Furthermore, the TCU10 includes a battery voltage / current measurement circuit 12h (corresponding to an example of a "backup power supply voltage acquisition unit") that acquires the voltage of the BUB11. The control unit 15 determines that the BUB11 is reverse-connected or unconnected when the voltage of the BUB11 is below a threshold and the battery temperature is within a predetermined low-temperature range.

[0075] Therefore, according to the TCU10 of this embodiment, it is possible to determine whether BUB11 is reverse-connected or unconnected based on the voltage and battery temperature of BUB11.

[0076] Furthermore, the control unit 15 determines that BUB11 is in an over-discharged state if the voltage of BUB11 is below a threshold and the battery temperature is not within the above low-temperature range.

[0077] Therefore, according to the TCU10 of the embodiment, it is possible to determine whether BUB11 is in an over-discharged state based on the voltage and battery temperature of BUB11.

[0078] Furthermore, after turning on the battery voltage boosting circuit 12c, the control unit 15 also determines whether there is a connection abnormality in the BUB 11.

[0079] Therefore, according to the TCU10 of this embodiment, after turning on the battery voltage boosting circuit 12c, the BUB11 is replaced while the IG is off, thus avoiding the risk of connection abnormalities.

[0080] Furthermore, the TCU10 has a voltage acquisition unit that acquires the voltage of the vehicle's constant power supply, the boosted voltage of the BUB11 by the battery voltage boost circuit 12c, and the voltage of the BUB11. The control unit 15 determines that a connection abnormality has occurred in the BUB11 when the voltage of the constant power supply is below a threshold and the difference between the boosted voltage of the BUB11 by the battery voltage boost circuit 12c and the voltage of the BUB11 is smaller than a predetermined value.

[0081] Therefore, according to the TCU10 of this embodiment, a connection abnormality in BUB11 can be determined by the difference between the boosted voltage of BUB11 and the voltage of BUB11.

[0082] Furthermore, the control unit 15 has an eCall function (corresponding to an example of an "automatic notification function") that automatically notifies an external information system by receiving power from the BUB 11 when the power supply from the constant power source is interrupted.

[0083] Therefore, according to the embodiment of the TCU10, even if the vehicle battery becomes unusable due to the impact of a vehicle collision, the TCU10 can be operated by receiving power from the BUB11 and the eCall function can be implemented.

[0084] Furthermore, the power control method executed by the TCU10 includes determining whether there is a connection abnormality in the BUB11 when the vehicle's ignition is off.

[0085] Therefore, according to the power control method according to the embodiment, the BUB11 can be used even when the IG is off.

[0086] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of Symbols]

[0087] 10 TCU 11 BUB 11a secondary battery 11b Thermistor No. 1 12 Circuit section 12a Audio section power supply 12b Step-down circuit 12C battery voltage boost circuit 12d diode 12e diode 12f charging circuit 12g discharge circuit 12h Battery Voltage / Current Measurement Circuit 12i temperature measuring circuit 12J Thermistor No. 2 12k battery reverse connection protection circuit 12L Overvoltage Detection Circuit 12m break circuit 12N Test Discharge Circuit 13 Communications Department 14 Storage section 15 Control Unit

Claims

1. A power control device for controlling the power supply of a vehicle, comprising a control unit, The control unit, Based on the detection result of the vehicle's ignition switch, when controlling the backup power supply while the vehicle's ignition is off, it is determined whether there is a connection abnormality in the backup power supply, and if it is determined that there is no connection abnormality in the backup power supply, the boost circuit that increases the voltage of the backup power supply is turned on. Power supply control device.

2. A power control device for controlling the power supply of a vehicle, Control unit and It has a temperature measuring circuit that acquires a first temperature, which is the temperature of the backup power supply, and a second temperature, which is the temperature of the circuit board of the circuit section related to the control of the backup power supply. The control unit, In controlling the backup power supply while the vehicle's ignition is off, the system determines whether there is a connection abnormality in the backup power supply based on the first temperature or the second temperature, and if it determines that there is no connection abnormality in the backup power supply, it turns on a boost circuit that increases the voltage of the backup power supply. Power supply control device.

3. The control unit, At least determine whether the backup power supply is reverse-connected or disconnected, The power control device according to claim 2.

4. The system further includes a backup power supply voltage acquisition unit that acquires the voltage of the aforementioned backup power supply, The control unit, If the voltage of the backup power supply is below a threshold and the first temperature is within a predetermined low-temperature range, it is determined that the backup power supply is in the reverse-connected or unconnected state. The power control device according to claim 3.

5. The control unit, If the voltage of the backup power supply is below a threshold and the first temperature is not within the low temperature range, it is determined that the backup power supply is in an over-discharge state. The power control device according to claim 4.

6. A power control device for controlling the power supply of a vehicle, comprising a control unit, The control unit, In controlling the backup power supply while the vehicle's ignition is off, it is determined whether there is a connection abnormality in the backup power supply, and if it is determined that there is no connection abnormality in the backup power supply, the boost circuit that increases the voltage of the backup power supply is turned on, After turning on the boost circuit, it is further determined whether there is a connection abnormality in the backup power supply. Power supply control device.

7. The system further includes a voltage acquisition unit that acquires the voltage of the vehicle's constant power supply, the boosted voltage of the backup power supply by the boost circuit, and the voltage of the backup power supply. The control unit, If the voltage of the constant power supply is below a threshold, and the difference between the boosted voltage of the backup power supply by the boost circuit and the voltage of the backup power supply is smaller than a predetermined value, it is determined that a connection abnormality has occurred in the backup power supply. The power control device according to claim 6.

8. It has an automatic notification function that, if the power supply from the constant power source is interrupted, receives power from the backup power source and automatically notifies an external information system. The power control device according to claim 7.

9. A power control method performed by a power control device that controls the power supply of a vehicle, Based on the detection result of the vehicle's ignition switch, when controlling the backup power supply while the vehicle's ignition is off, it is determined whether there is a connection abnormality in the backup power supply, and if it is determined that there is no connection abnormality in the backup power supply, the boost circuit that increases the voltage of the backup power supply is turned on. A power control method including

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