Backup energy storage power supply circuit and vehicle-mounted equipment

Abstract

The present invention provides a backup energy storage power supply circuit and on-vehicle equipment, wherein the backup energy storage power supply circuit includes an energy storage element group, a first charging circuit, a second charging circuit, an overvoltage detection circuit, a short circuit detection circuit, and a trigger circuit. The second charging circuit outputs a test current to the energy storage element group to charge the energy storage element group. At the same time, the overvoltage detection circuit and the short circuit detection circuit detect the short circuit and overvoltage status of each energy storage element and feed back corresponding detection signals to the trigger circuit. When a short circuit or overcurrent is detected in any energy storage element, the trigger circuit triggers the output of a shutdown signal to control the first charging circuit to shut down, stopping the first charging circuit from charging the energy storage element group, avoiding overvoltage and short circuit problems, and improving the reliability and safety of the energy storage element group.

Description

Technical Field

[0001] The present invention belongs to the technical field of power supply, and in particular relates to a backup energy storage power supply circuit and a vehicle-mounted device. Background Art

[0002] Electrical devices, such as vehicle-mounted monitoring equipment, often use energy storage elements (e.g., farad capacitors) as short-term backup power sources. When the device's external power supply is unexpectedly disconnected, the energy storage element can provide a preset duration of continuous current to allow the device to perform data storage tasks. For example, an embedded CPU can flush video data from the cache to a storage device such as a hard drive or SD card.

[0003] To meet power supply requirements, energy storage elements are typically charged and discharged in series. However, due to variations in capacity and internal resistance between energy storage elements, when five energy storage elements are fully charged, the voltage of each element may not necessarily be equal to the standard voltage; some may be higher than the standard voltage, and some may be lower than the standard voltage.

[0004] Because the lifespan of energy storage components, such as farad capacitors, is closely related to the applied operating voltage, if the voltage of a certain energy storage component after charging is too high, the service life of this energy storage component will be much shorter than that of other energy storage components with standard voltage. After long-term use, this energy storage component will be the first to fail and suffer short-circuit damage. The short-circuit will cause the voltage to be borne by other energy storage components to increase, forming a vicious cycle and causing more capacitor damage. When the capacitor is damaged, it will cause the front-end capacitor charging part to short-circuit, and even affect the normal operation of the system power supply.

[0005] Therefore, it is very important to monitor the status of each energy storage element in the energy storage element group, detect related abnormalities in a timely manner, and take corresponding protection actions to reduce the impact of short circuits and overvoltages on the system. Summary of the Invention

[0006] The purpose of the present invention is to provide a backup energy storage power supply circuit, aiming to solve the short circuit and overvoltage problems existing in traditional energy storage element groups.

[0007] A first aspect of an embodiment of the present invention provides a backup energy storage power supply circuit, comprising:

[0008] an energy storage element group comprising a plurality of energy storage elements connected in series, the energy storage element group being configured to discharge when the main power supply circuit has no power output, so as to provide power supply for a first preset duration to the electrical device;

[0009] a first charging circuit, wherein a power input terminal of the first charging circuit is commonly connected to a power terminal of the main power supply circuit, a power output terminal of the first charging circuit is connected to a power terminal of the energy storage element group, and the first charging circuit is configured to convert an input power supply into a charging power supply in an on state to charge the energy storage element group;

[0010] a second charging circuit, wherein a power input terminal of the second charging circuit is connected to a power output terminal of the main power supply circuit, and a power output terminal of the second charging circuit is connected to a power terminal of the energy storage element group, and the second charging circuit is used to convert and output a test current of a second preset duration to the energy storage element group when the main power supply circuit is initially discharged;

[0011] an overvoltage detection circuit, the overvoltage detection circuit being connected to the power supply terminal of each of the energy storage elements, performing overvoltage detection on each of the energy storage elements and outputting a corresponding overvoltage detection signal;

[0012] a short-circuit detection circuit, the short-circuit detection circuit being connected to the power supply terminal of each of the energy storage elements, and performing short-circuit detection on each of the energy storage elements and outputting a corresponding short-circuit detection signal;

[0013] a trigger circuit, connected to the overvoltage detection circuit, the short-circuit detection circuit, and the first charging circuit, respectively, the trigger circuit being configured to trigger turning off the first charging circuit upon receiving a detection signal indicating a short circuit or overvoltage of the energy storage element, and trigger turning on the first charging circuit upon not receiving a detection signal indicating a short circuit or overvoltage of the energy storage element.

[0014] In one embodiment, the overvoltage detection circuit includes a plurality of overvoltage detection branches, each of which is connected to the energy storage element one by one, and each of the overvoltage detection branches includes:

[0015] a voltage conversion circuit, the voltage conversion circuit being connected to the two ends of the corresponding energy storage element and converting the terminal voltage of the energy storage element into a proportional output;

[0016] An overvoltage conversion circuit is connected to the power output terminal of the voltage conversion circuit. The overvoltage conversion circuit is used to compare the terminal voltage output by the proportional conversion of the energy storage element with a preset reference voltage and output a corresponding overvoltage detection signal to the trigger circuit.

[0017] In one embodiment, the backup energy storage power supply circuit further includes:

[0018] A reference voltage generating circuit is electrically connected to the overvoltage conversion circuit and the main power supply circuit respectively, and provides a preset reference voltage for the overvoltage conversion circuit.

[0019] In one embodiment, each of the voltage conversion circuits includes a first resistor, a second resistor, a third resistor, and a first operational amplifier;

[0020] The first end of the first resistor and the first end of the second resistor are respectively connected to the two ends of the corresponding energy storage element, the second end of the first resistor, the first end of the third resistor and the non-inverting input end of the first operational amplifier are interconnected, the second end of the second resistor is connected to the inverting input end of the first operational amplifier, and the output end of the first operational amplifier and the first end of the third resistor are commonly connected to form the power output end of the voltage conversion circuit.

[0021] In one embodiment, the overvoltage conversion circuit includes a second operational amplifier;

[0022] The inverting input terminal of the second operational amplifier is connected to the voltage output terminal corresponding to the voltage conversion circuit, the non-inverting input terminal of the second operational amplifier is used to input the preset reference voltage, and the output terminal of the second operational amplifier constitutes the signal output terminal of the overvoltage conversion circuit.

[0023] In one embodiment, the short-circuit detection circuit includes a plurality of short-circuit detection branches, each of which is connected to the energy storage element one by one and outputs a corresponding short-circuit detection signal to the trigger circuit, and each of the short-circuit detection branches is further connected to the reference voltage generating circuit.

[0024] Each of the short-circuit detection branches comprises:

[0025] a fourth resistor, a fifth resistor, a first diode and a first transistor;

[0026] The first end of the fourth resistor and the emitter of the first transistor are respectively connected to the two ends of the corresponding energy storage element, the second end of the fourth resistor is connected to the base of the first transistor, the collector of the first transistor, the first end of the fifth resistor and the anode of the first diode are commonly connected, the second end of the fifth resistor is used to input the preset reference voltage, and the cathode of the first diode constitutes the signal output end of the short-circuit detection branch.

[0027] In one embodiment, the trigger circuit is further connected to the reference voltage generating circuit, and the trigger circuit includes:

[0028] a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a second diode, a second transistor, and a third transistor;

[0029] The first end of the sixth resistor, the first end of the seventh resistor and the signal output end of the overvoltage conversion circuit are connected in common, the second end of the seventh resistor is connected to the base of the second transistor, the emitter of the second transistor is grounded, the collector of the second transistor, the first end of the eighth resistor and the anode of the second diode are interconnected, the cathode of the second diode, the first end of the ninth resistor and the base of the third transistor are interconnected, the second transistor, the emitter of the third transistor and the second end of the ninth resistor are grounded, the collector of the third transistor and the first end of the tenth resistor are connected in common to form the signal output end of the trigger circuit, and the second end of the sixth resistor, the second end of the eighth resistor and the second end of the tenth resistor are all used to input the preset reference voltage.

[0030] In one embodiment, the second charging circuit includes an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a voltage stabilizing diode, a first capacitor, a fourth transistor, a first field effect transistor, and a second field effect transistor;

[0031] The first end of the eleventh resistor and the drain of the first field-effect transistor are commonly connected to form a power input end of the second charging circuit. The second end of the eleventh resistor, the cathode of the voltage-stabilizing diode, and the first end of the first capacitor are commonly connected to form a power input end of the second charging circuit. The second end of the first capacitor, the first end of the twelfth resistor, and the second end of the thirteenth resistor are commonly connected to form a power input end of the second charging circuit. The second end of the thirteenth resistor, the second end of the fourteenth resistor, and the base of the fourth transistor are commonly connected to form a power output end of the second charging circuit. The anode of the voltage-stabilizing diode, the second end of the twelfth resistor, the second end of the fourteenth resistor, and the emitter of the fourth transistor are all grounded. The collector of the fourth transistor is connected to the first end of the fifteenth resistor. The second end of the fifteenth resistor, the gate of the first field-effect transistor, the gate of the second field-effect transistor, and the first end of the sixteenth resistor are commonly connected to form a power output end of the second charging circuit. The source of the first field-effect transistor, the second end of the sixteenth resistor, and the drain of the second field-effect transistor are commonly connected to form a power output end of the second charging circuit.

[0032] In one embodiment, the energy storage element includes a resistor and a capacitor connected in parallel.

[0033] The second aspect of an embodiment of the present invention proposes a vehicle-mounted device, including a vehicle-mounted monitoring device, a main power supply circuit and at least one backup energy storage power supply circuit as described above, wherein the power input end of the vehicle-mounted monitoring device is respectively connected to the power output end of the main power supply circuit and the power output end of at least one backup energy storage power supply circuit.

[0034] When the main power supply circuit initially supplies power, the backup energy storage power supply circuit of the embodiment of the present invention outputs a test current to the energy storage element group through the second charging circuit to charge the energy storage element group. At the same time, the overvoltage detection circuit and the short-circuit detection circuit detect the short-circuit and overvoltage status of each energy storage element, and feed back the corresponding detection signal to the trigger circuit. When all energy storage elements are not short-circuited or overcurrent occurs, the trigger circuit triggers the output conduction signal to control the first charging circuit to turn on, and the energy storage element group starts working and combines with the first charging circuit to realize backup power supply, forming redundant power supply with the main power supply point. When any energy storage element is detected to be short-circuited or overcurrent occurs, the trigger circuit triggers the output shutdown signal to control the first charging circuit to shut down, stopping the first charging circuit from charging the energy storage element group, avoiding overvoltage and short-circuit problems, and improving the reliability and safety of the energy storage element group. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of a first module structure of a backup energy storage power supply circuit provided in an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of a second module structure of a backup energy storage power supply circuit provided in an embodiment of the present invention;

[0037] Figure 3 A schematic diagram of the circuit structure of a backup energy storage power supply circuit provided in an embodiment of the present invention;

[0038] Figure 4 A schematic diagram of the module structure of the vehicle-mounted equipment provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0041] A first aspect of an embodiment of the present invention provides a backup energy storage power supply circuit 100 .

[0042] like Figure 1 As shown, in this embodiment, the backup energy storage power supply circuit 100 includes:

[0043] An energy storage element group 10 comprising a plurality of energy storage elements connected in series, the energy storage element group 10 being configured to discharge when the main power supply circuit 200 has no power output, so as to provide power supply of a first preset duration to the power-consuming device 300;

[0044] A first charging circuit 20, wherein the power input terminal of the first charging circuit 20 is connected to the power terminal of the main power supply circuit 200, and the power output terminal of the first charging circuit 20 is connected to the power terminal of the energy storage element group 10. The first charging circuit 20 is used to convert the input power into a charging power supply in the conductive state to charge the energy storage element group 10;

[0045] A second charging circuit 30, wherein the power input terminal of the second charging circuit 30 is connected to the power output terminal of the main power supply circuit 200, and the power output terminal of the second charging circuit 30 is connected to the power terminal of the energy storage element group 10. The second charging circuit 30 is used to convert and output a test current of a second preset duration to the energy storage element group 10 during initial discharge of the main power supply circuit 200;

[0046] An overvoltage detection circuit 40 is connected to the power supply terminal of each energy storage element, performs overvoltage detection on each energy storage element, and outputs a corresponding overvoltage detection signal;

[0047] A short-circuit detection circuit 50 is connected to the power supply terminal of each energy storage element, performs short-circuit detection on each energy storage element, and outputs a corresponding short-circuit detection signal;

[0048] The trigger circuit 60 is connected to the overvoltage detection circuit 40, the short-circuit detection circuit 50, and the first charging circuit 20, respectively. The trigger circuit 60 is used to trigger the first charging circuit 20 to be turned off when a detection signal indicating a short circuit or overvoltage of the energy storage element is received, and to trigger the first charging circuit 20 to be turned on when no detection signal indicating a short circuit or overvoltage of the energy storage element is received.

[0049] In this embodiment, the power-consuming device 300 is redundantly powered by the main power supply circuit 200 and the energy storage element group 10. That is, under normal circumstances, the main power supply circuit 200 converts the input power VIN into an operating power V1. At the same time, the input power VIN is converted into a charging power supply for charging the energy storage element group 10 via the first charging circuit 20. The energy storage element group 10 serves as a backup power supply. When the input power VIN loses power or the main power supply circuit 200 is damaged, the energy storage element group 10 discharges to provide the operating power V1 of a first preset duration to the power-consuming device 300, thereby ensuring that the power-consuming device 300 can perform data processing work before power failure, such as data storage, data writing, and data output operations.

[0050] To ensure that the energy storage element group 10 does not experience short circuit or overvoltage problems before it is put into operation and to ensure its normal operation during the subsequent redundant power supply process, during initial power-up, the second charging circuit 30 and the power-consuming device 300 are simultaneously connected to the working power V1 of the main power supply circuit 200. At the same time, the input working power V1 is converted into a test current and output to the energy storage element group 10. The first charging circuit 20 is controlled by the control signal output by the trigger circuit 60. Since it does not receive the corresponding control signal, the first charging circuit 20 remains in a stopped state, no charging power is output, and the test current continues for a second preset time period. During this period, the energy storage elements within the energy storage element group 10 are slowly charged. At the same time, the short-circuit detection circuit 50 and the overvoltage detection circuit 40 respectively detect the short-circuit and overvoltage conditions of each energy storage element and output multiple short-circuit detection signals and overvoltage detection signals to the trigger circuit 60. The trigger circuit 60 triggers the output of a control signal to the first charging circuit 20 based on the received short-circuit detection signal and overvoltage detection signal.

[0051] Among them, when all energy storage elements are not short-circuited or overcurrent occurs, the trigger circuit 60 triggers the output conduction signal to control the first charging circuit 20 to be turned on, and the first charging circuit 20 converts the output charging power to the energy storage element group 10. The energy storage element group 10 starts working and combines with the first charging circuit 20 to realize backup power supply, forming a redundant power supply with the main power supply point. When any energy storage element is detected to be short-circuited or overcurrent occurs, the trigger circuit 60 triggers the output shutdown signal to control the first charging circuit 20 to be turned off, and stops the first charging circuit 20 from charging the energy storage element group 10, avoiding overvoltage and short circuit problems, and improving the reliability and safety of the energy storage element group 10.

[0052] The test current is smaller than the charging current outputted by the charging power source to the energy storage element group 10 , thereby achieving a small current short-time test and preventing overcharging from damaging the energy storage element groups 10 .

[0053] Each energy storage element can adopt a structure such as energy storage battery, farad capacitor C11, etc. Figure 3 As shown, optionally, the energy storage element includes a resistor Rc and a farad capacitor C11 connected in parallel. At the same time, the number of each energy storage element can be set according to the power demand of the electrical device 300, and the specific number is not limited.

[0054] The first charging circuit 20 may adopt a switching power supply circuit with the same structure as the main power supply circuit 200 , such as a buck-boost circuit, a voltage stabilizing circuit, etc., and the specific structure is not limited.

[0055] The second charging circuit 30 may adopt a switch circuit with delayed shutdown, and the specific structure is not limited.

[0056] The short-circuit detection circuit 50 and the overvoltage detection circuit 40 may include multiple detection branches to independently detect each energy storage element to avoid interference. The specific detection structure can be set according to the corresponding energy storage element group 10.

[0057] The trigger circuit 60 may adopt a switch circuit with controlled on / off, and may also include a corresponding level conversion circuit. The specific structure is set according to the level signals output by the short circuit detection circuit 50 and the overvoltage detection circuit 40, and the on / off control signal required by the second charging circuit 30.

[0058] like Figure 2 As shown, in one embodiment, the overvoltage detection circuit 40 includes a plurality of overvoltage detection branches 41. The overvoltage detection branches 41 are connected to the energy storage elements one by one. Each overvoltage detection branch 41 includes:

[0059] A voltage conversion circuit 411 is connected to both ends of the corresponding energy storage element and converts the terminal voltage of the energy storage element into a proportional output;

[0060] The overvoltage conversion circuit 412 is connected to the power output terminal of the voltage conversion circuit 411. The overvoltage conversion circuit 412 is used to compare the terminal voltage output by the proportional conversion of the energy storage element with the preset reference voltage V2, and output the corresponding overvoltage detection signal to the trigger circuit 60.

[0061] In this embodiment, the voltage conversion circuit 411 performs a differential conversion on the voltages at both ends of the energy storage element group 10 and outputs the energy storage elements of each section according to the corresponding ratio, wherein the ratio can be set according to the detection requirements. At the same time, after the terminal voltage ratio is converted and output, it is compared with the preset reference voltage V2 in the overvoltage conversion circuit 412 to perform overvoltage detection on the terminal voltage of the energy storage element. The high and low levels of the comparison output represent the overvoltage state of the energy storage element. In the normal state, the overvoltage conversion circuit 412 outputs high and low level overvoltage detection signals to the trigger circuit 60, so that the trigger circuit 60 triggers the output of different control signals according to the high and low levels.

[0062] Similarly, the short-circuit detection circuit 50 includes multiple short-circuit detection branches 51, which are connected one by one to the energy storage elements and output corresponding short-circuit detection signals to the trigger circuit 60. The short-circuit detection branch 51 compares the voltages at both ends of each energy storage element. When the voltages at both ends are the same, it indicates that the energy storage element is short-circuited. When the voltage difference between the two ends is greater than a certain voltage value, it indicates that the energy storage element is not short-circuited.

[0063] The preset reference voltage V2 can be provided by an independent voltage source, or by a power conversion circuit connected to the main power supply circuit 200. The specific structure is not limited. In one embodiment, the backup energy storage power supply circuit 100 further includes:

[0064] The reference voltage generating circuit 70 is electrically connected to the overvoltage conversion circuit 412 and the main power supply circuit 200 respectively, and provides a preset reference voltage V2 for the overvoltage conversion circuit 412 .

[0065] The reference voltage generating circuit 70 serves as a power conversion circuit. When the main power supply circuit 200 is initially powered on, it converts and outputs a preset reference voltage V2 to the overvoltage conversion circuit 412 to provide the preset reference voltage V2. The reference voltage generating circuit 70 may be a voltage stabilizing circuit, a voltage step-down circuit, etc., and the preset reference voltage V2 may be 5V, 2.5V, or other voltages that meet comparison requirements.

[0066] like Figure 3 As shown, in one embodiment, each voltage conversion circuit 411 includes a first resistor R1, a second resistor R2, a third resistor R3 and a first operational amplifier U1;

[0067] The first end of the first resistor R1 and the first end of the second resistor R2 are respectively connected to the two ends of the corresponding energy storage element, the second end of the first resistor R1, the first end of the third resistor R3 and the non-inverting input terminal of the first operational amplifier U1 are interconnected, the second end of the second resistor R2 is connected to the inverting input terminal of the first operational amplifier U1, and the output terminal of the first operational amplifier U1 and the first end of the third resistor R3 are connected together to form the power output terminal of the voltage conversion circuit 411.

[0068] In this embodiment, the first resistor R1 , the second resistor R2 , the third resistor R3 and the first operational amplifier U1 form a voltage follower to achieve a one-to-one real-time output of the voltage of each energy storage element.

[0069] Please continue reading Figure 3 , in one embodiment, the overvoltage conversion circuit 412 includes a second operational amplifier U2;

[0070] The inverting input terminal of the second operational amplifier U2 is connected to the voltage output terminal of the corresponding voltage conversion circuit 411, the non-inverting input terminal of the second operational amplifier U2 is used to input the preset reference voltage V2, and the output terminal of the second operational amplifier U2 constitutes the signal output terminal of the overvoltage conversion circuit 412.

[0071] In this embodiment, when the voltage of the energy storage element is greater than the preset reference voltage V2, the output of the second operational amplifier U2 is negative, indicating that the energy storage element is overvoltage. If the voltage of the energy storage element is less than the preset reference voltage V2, the output of the second operational amplifier U2 is positive, indicating that the voltage of the energy storage element is within the normal range. The second operational amplifiers U2 in other overvoltage conversion circuits 412 have the same function. The output of the second operational amplifier U2 is open-drain. The second operational amplifiers U2 can be connected in parallel. As long as any second operational amplifier U2 outputs low, the output of the overvoltage conversion circuit 412 is low. The appearance of a low level also means that an energy storage element in the energy storage element group 10 is overvoltage.

[0072] Please continue reading Figure 3 In one embodiment, each of the short-circuit detection branches 51 is further connected to the reference voltage generating circuit 70 , and each short-circuit detection branch 51 includes a fourth resistor R4 , a fifth resistor R5 , a first diode D1 , and a first transistor Q1 ;

[0073] The first end of the fourth resistor R4 and the emitter of the first transistor Q1 are respectively connected to the two ends of the corresponding energy storage element, the second end of the fourth resistor R4 is connected to the base of the first transistor Q1, the collector of the first transistor Q1, the first end of the fifth resistor R5 and the anode of the first diode D1 are commonly connected, the second end of the fifth resistor R5 is used to input a preset reference voltage V2, and the cathode of the first diode D1 constitutes the signal output end of the short-circuit detection branch 51.

[0074] In this embodiment, a preset reference voltage V2 is connected to the fifth resistor R5 as a pull-up voltage, and the fifth resistor R5 forms a pull-up resistor. If the voltage inputted by the fourth resistor R4 is higher than the threshold turn-on voltage of the first transistor Q1, for example, 0.7V, the first transistor Q1 is turned on, the first diode D1 is connected to the collector of the first transistor Q1, and its input is also low. If the input voltage of the fourth resistor R4 is consistently lower than the threshold turn-on voltage of the first transistor Q1, the first transistor Q1 is turned off, the first diode D1 is connected to the collector of the first transistor Q1 and the fifth resistor R5, and its input is high. If the energy storage element is damaged and its voltage does not rise to the threshold turn-on voltage during the timed test current charging control period, the input voltage of the fourth resistor R4 is consistently lower than the threshold turn-on voltage, causing the input of the first diode D1 to be high. Conversely, if the energy storage element is functioning properly, it can be guaranteed to charge to above 0.7V during the timed test current charging control period, and the input of the first diode D1 is low.

[0075] Therefore, according to the output level of the overvoltage conversion circuit 412 and the output level of the short-circuit detection branch 51, in order to meet the detection requirements, such as Figure 3As shown, in one embodiment, the trigger circuit 60 is further connected to the reference voltage generating circuit 70, and the trigger circuit 60 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a second diode D2, a second transistor Q2, and a third transistor Q3;

[0076] A first end of the sixth resistor R6, a first end of the seventh resistor R7, and a signal output end of the overvoltage conversion circuit 412 are connected in common. A second end of the seventh resistor R7 is connected to the base of the second transistor Q2. The emitter of the second transistor Q2 is grounded. The collector of the second transistor Q2, the first end of the eighth resistor R8, and the anode of the second diode D2 are interconnected. The cathode of the second diode D2, the first end of the ninth resistor R9, and the base of the third transistor Q3 are interconnected. The emitters of the second transistor Q2, the third transistor Q3, and the second end of the ninth resistor R9 are grounded. The collector of the third transistor Q3 and the first end of the tenth resistor R10 are connected in common to form a signal output end of the trigger circuit 60. The second end of the sixth resistor R6, the second end of the eighth resistor R8, and the second end of the tenth resistor R10 are all used to input a preset reference voltage V2.

[0077] In this embodiment, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the second diode D2 and the second transistor Q2 constitute an overvoltage judgment circuit. If the output of the overvoltage conversion circuit 412 is low, the second transistor Q2 is turned off, and the second diode D2 is connected to the collector of the second transistor Q2 and the eighth resistor R8. The input of the second diode D2 is high, which means that there is an overvoltage in the capacitor in the energy storage element group 10.

[0078] The eighth resistor R8 and the tenth resistor R10 constitute a pull-up resistor, and the first diode D1 in the short-circuit detection branch 51 and the second diode D2 in the trigger circuit 60 constitute an OR circuit. When the input of any one of the diodes is high, the output of the OR circuit is high. As input, the high level is output to the level inversion circuit composed of the ninth resistor R9, the third transistor Q3 and the tenth resistor R10. Then, the output EN of the level inversion circuit is low. At this time, the enable of the first charging circuit 20 is low, and the first charging circuit 20 is turned off. By setting the trigger circuit 60, the first charging circuit 20 is turned off when any energy storage element is short-circuited or overvoltage occurs, thereby improving power supply reliability.

[0079] Please continue reading Figure 2 In one embodiment, the second charging circuit 30 includes an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a Zener diode ZD1, a first capacitor C1, a fourth transistor Q4, a first field effect transistor Q5, and a second field effect transistor Q6;

[0080] The first end of the eleventh resistor R11 and the drain of the first field effect transistor Q5 are connected together to form a power input end of the second charging circuit 30. The second end of the eleventh resistor R11, the cathode of the voltage-stabilizing diode ZD1 and the first end of the first capacitor C1 are connected together. The second end of the first capacitor C1, the first end of the twelfth resistor R12 and the second end of the thirteenth resistor R13 are connected together. The second end of the thirteenth resistor R13, the second end of the fourteenth resistor R14 and the base of the fourth transistor Q4 are connected together. The anode of the voltage-stabilizing diode ZD1 and the second end of the twelfth resistor R12 are connected together. The second end of the fourteenth resistor R14 and the emitter of the fourth transistor Q4 are both grounded, the collector of the fourth transistor Q4 is connected to the first end of the fifteenth resistor R15, the second end of the fifteenth resistor R15, the gate of the first field effect transistor Q5, the gate of the second field effect transistor Q6 and the first end of the sixteenth resistor R16 are commonly connected, the source of the first field effect transistor Q5, the second end of the sixteenth resistor R16 and the drain of the second field effect transistor Q6 are commonly connected, and the source of the second field effect transistor Q6 constitutes the power output end of the second charging circuit 30.

[0081] In this embodiment, the eleventh resistor R11 and the voltage-stabilizing diode ZD1 generate a fixed voltage, the first capacitor C1, the twelfth resistor R12, the thirteenth resistor R13, the fourteenth resistor R14, and the fourth transistor Q4 constitute a time-adjustable switch control circuit, and the fifteenth resistor R15, the sixteenth resistor R16, the first field-effect transistor Q5, and the second field-effect transistor Q6 constitute a power-controlled part.

[0082] When the main power supply circuit 200 is discharged for the first time, the voltage generated by the voltage-stabilizing diode ZD1 is applied across the first capacitor C1 and the twelfth resistor R12. The first capacitor C1 and the twelfth resistor R12 form a resistor-capacitor circuit. When the power is just turned on, the voltage of the first capacitor C1 cannot change suddenly. At this time, the fourth transistor Q4 is turned on, the first field-effect transistor Q5 and the second field-effect transistor Q6 are controlled to be turned on, and the working power supply V1 charges the energy storage element group 10.

[0083] The first capacitor C1 is gradually charged. When the first capacitor C1 is fully charged, the fourth transistor Q4 is turned off, the first field effect transistor Q5 and the second field effect transistor Q6 are disconnected, the system power is cut off, and the energy storage element group 10 stops supplying power.

[0084] The second charging circuit 30 will only run for a second preset time when the system is powered on. The second preset time can be adjusted according to the power supply demand, for example, set to 30s. Therefore, if the energy storage element is short-circuited, it will not cause a lasting impact on the system power supply, thereby improving reliability.

[0085] It is understandable that if Figure 3As shown, when the electrical device 300 has only a single power input port, in order to prevent current from flowing back to other modules and causing damage, a corresponding unidirectional conduction circuit needs to be added between the main power supply circuit 200 and the energy storage discharge circuit, such as a fifth diode D5 and a sixth diode D6 between the main power supply circuit 200 and the first charging circuit 20. At the same time, in order to prevent current from flowing back between the first charging circuit 20, the second charging circuit 30 and the energy storage element group 10, the first charging circuit 20, the second charging circuit 30 and the energy storage element group 10 are further provided with a third diode D3 and a fourth diode D4, thereby improving circuit safety and operating reliability.

[0086] The present invention uses components such as resistors, capacitors, transistors, diodes, and operational amplifiers to form a backup energy storage power supply circuit 100, which has a simple structure and low cost. At the same time, it can be adapted and configured according to the number of energy storage elements.

[0087] In the first embodiment, the first transistor Q1 , the second transistor Q2 , the third transistor Q3 and the fourth transistor Q4 are all NPN transistors, and the first field effect transistor Q5 and the second field effect transistor Q6 are both PMOS transistors.

[0088] The present invention also provides an on-vehicle device, comprising an on-vehicle monitoring device 310, a main power supply circuit 200, and at least one backup energy storage power supply circuit 100. The specific structure of the backup energy storage power supply circuit 100 is similar to the above-described embodiments. Since the present on-vehicle device utilizes all the technical solutions of all the above-described embodiments, it at least possesses all the beneficial effects brought about by the technical solutions of the above-described embodiments, and thus will not be further described here. The power input terminal of the on-vehicle monitoring device 310 is connected to the power output terminal of the main power supply circuit 200 and the power output terminal of the at least one backup energy storage power supply circuit 100, respectively.

[0089] In this embodiment, the power-consuming device 300 is a vehicle-mounted monitoring device 310, and the main power supply circuit 200 and the backup power supply circuit are redundantly powered. Among them, the backup energy storage power supply circuit 100 can be set as one or more independent modules to play a redundant backup power function. When any module has an abnormality, it will not affect the functions of other modules, thereby improving the robustness of the system.

[0090] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A backup energy storage power supply circuit, characterized in that: include: an energy storage element group comprising a plurality of energy storage elements connected in series, the energy storage element group being configured to discharge when the main power supply circuit has no power output, so as to provide power supply for a first preset duration to the electrical device; a first charging circuit, wherein a power input terminal of the first charging circuit is commonly connected to a power terminal of the main power supply circuit, a power output terminal of the first charging circuit is connected to a power terminal of the energy storage element group, and the first charging circuit is configured to convert an input power supply into a charging power supply in an on state to charge the energy storage element group; a second charging circuit, wherein a power input terminal of the second charging circuit is connected to a power output terminal of the main power supply circuit, and a power output terminal of the second charging circuit is connected to a power terminal of the energy storage element group, and the second charging circuit is used to convert and output a test current of a second preset duration to the energy storage element group when the main power supply circuit is initially discharged; an overvoltage detection circuit, the overvoltage detection circuit being connected to the power supply terminal of each of the energy storage elements, performing overvoltage detection on each of the energy storage elements and outputting a corresponding overvoltage detection signal; a short-circuit detection circuit, the short-circuit detection circuit being connected to the power supply terminal of each of the energy storage elements, and performing short-circuit detection on each of the energy storage elements and outputting a corresponding short-circuit detection signal; a trigger circuit, connected to the overvoltage detection circuit, the short-circuit detection circuit, and the first charging circuit, respectively, the trigger circuit being configured to trigger turning off the first charging circuit upon receiving a detection signal indicating a short circuit or overvoltage of the energy storage element, and trigger turning on the first charging circuit upon not receiving a detection signal indicating a short circuit or overvoltage of the energy storage element; When the power is initially turned on, the first charging circuit remains in a stopped state and no charging power is output; The backup energy storage power supply circuit further includes: a third diode and a fourth diode, wherein the anode of the third diode is connected to the output end of the first charging circuit, the anode of the fourth diode is connected to the output end of the second charging circuit, and the cathode of the third diode and the cathode of the fourth diode are connected to the power supply end of the energy storage element group; The second charging circuit includes an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a voltage stabilizing diode, a first capacitor, a fourth transistor, a first field effect transistor, and a second field effect transistor; The first end of the eleventh resistor and the drain of the first field-effect transistor are commonly connected to form a power input end of the second charging circuit. The second end of the eleventh resistor, the cathode of the voltage-stabilizing diode, and the first end of the first capacitor are commonly connected to form a power input end of the second charging circuit. The second end of the first capacitor, the first end of the twelfth resistor, and the second end of the thirteenth resistor are commonly connected to form a power input end of the second charging circuit. The second end of the thirteenth resistor, the second end of the fourteenth resistor, and the base of the fourth transistor are commonly connected to form a power output end of the second charging circuit. The anode of the voltage-stabilizing diode, the second end of the twelfth resistor, the second end of the fourteenth resistor, and the emitter of the fourth transistor are all grounded. The collector of the fourth transistor is connected to the first end of the fifteenth resistor. The second end of the fifteenth resistor, the gate of the first field-effect transistor, the gate of the second field-effect transistor, and the first end of the sixteenth resistor are commonly connected to form a power output end of the second charging circuit. The source of the first field-effect transistor, the second end of the sixteenth resistor, and the drain of the second field-effect transistor are commonly connected to form a power output end of the second charging circuit.

2. The backup energy storage power supply circuit according to claim 1, characterized in that: The overvoltage detection circuit includes a plurality of overvoltage detection branches, each of which is connected to the energy storage element in a one-to-one manner, and each of the overvoltage detection branches includes: a voltage conversion circuit, the voltage conversion circuit being connected to the two ends of the corresponding energy storage element and converting the terminal voltage of the energy storage element into a proportional output; An overvoltage conversion circuit is connected to the power output terminal of the voltage conversion circuit. The overvoltage conversion circuit is used to compare the terminal voltage output by the proportional conversion of the energy storage element with a preset reference voltage and output a corresponding overvoltage detection signal to the trigger circuit.

3. The backup energy storage power supply circuit according to claim 2, characterized in that: The backup energy storage power supply circuit also includes: A reference voltage generating circuit is electrically connected to the overvoltage conversion circuit and the main power supply circuit respectively, and provides a preset reference voltage for the overvoltage conversion circuit.

4. The backup energy storage power supply circuit according to claim 3, characterized in that: Each of the voltage conversion circuits includes a first resistor, a second resistor, a third resistor and a first operational amplifier; The first end of the first resistor and the first end of the second resistor are respectively connected to the two ends of the corresponding energy storage element, the second end of the first resistor, the first end of the third resistor and the non-inverting input end of the first operational amplifier are interconnected, the second end of the second resistor is connected to the inverting input end of the first operational amplifier, and the output end of the first operational amplifier and the first end of the third resistor are commonly connected to form the power output end of the voltage conversion circuit.

5. The backup energy storage power supply circuit according to claim 4, characterized in that: The overvoltage conversion circuit includes a second operational amplifier; The inverting input terminal of the second operational amplifier is connected to the voltage output terminal corresponding to the voltage conversion circuit, the non-inverting input terminal of the second operational amplifier is used to input the preset reference voltage, and the output terminal of the second operational amplifier constitutes the signal output terminal of the overvoltage conversion circuit.

6. The backup energy storage power supply circuit according to claim 5, characterized in that: The short-circuit detection circuit includes a plurality of short-circuit detection branches, each of which is connected to the energy storage element one by one and outputs a corresponding short-circuit detection signal to the trigger circuit, and each of the short-circuit detection branches is also connected to the reference voltage generating circuit. Each of the short-circuit detection branches comprises: a fourth resistor, a fifth resistor, a first diode and a first transistor; The first end of the fourth resistor and the emitter of the first transistor are respectively connected to the two ends of the corresponding energy storage element, the second end of the fourth resistor is connected to the base of the first transistor, the collector of the first transistor, the first end of the fifth resistor and the anode of the first diode are commonly connected, the second end of the fifth resistor is used to input the preset reference voltage, and the cathode of the first diode constitutes the signal output end of the short-circuit detection branch.

7. The backup energy storage power supply circuit according to claim 6, characterized in that: The trigger circuit is also connected to the reference voltage generating circuit, and the trigger circuit includes: a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a second diode, a second transistor, and a third transistor; The first end of the sixth resistor, the first end of the seventh resistor and the signal output end of the overvoltage conversion circuit are connected in common, the second end of the seventh resistor is connected to the base of the second transistor, the emitter of the second transistor is grounded, the collector of the second transistor, the first end of the eighth resistor and the anode of the second diode are interconnected, the cathode of the second diode, the first end of the ninth resistor and the base of the third transistor are interconnected, the second transistor, the emitter of the third transistor and the second end of the ninth resistor are grounded, the collector of the third transistor and the first end of the tenth resistor are connected in common to form the signal output end of the trigger circuit, and the second end of the sixth resistor, the second end of the eighth resistor and the second end of the tenth resistor are all used to input the preset reference voltage.

8. The backup energy storage power supply circuit according to any one of claims 1 to 7, characterized in that: The energy storage element includes a resistor and a farad capacitor connected in parallel.

9. A vehicle-mounted device, characterized in that: It includes a vehicle-mounted monitoring device, a main power supply circuit and at least one backup energy storage power supply circuit as described in claims 1 to 8, and the power input end of the vehicle-mounted monitoring device is respectively connected to the power output end of the main power supply circuit and the power output end of at least one backup energy storage power supply circuit.

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