Standby power supply switching circuit, recorder and vehicle

Abstract

The utility model discloses a standby power supply switching circuit, a recorder and a vehicle. The standby power supply switching circuit comprises a comparison module, a switch control module and a switch module. A first input end of the comparison module is connected with a reference voltage, a second input end of the comparison module is connected with the main power supply end, and the comparison module is used for comparing the voltage of the main power supply end with the reference voltage and outputting a level signal; the control end of the switch control module is connected with the output end of the comparison module; the switch control module is used for outputting a control signal according to the level signal; a control end of the switch module is connected with an output end of the switch control module, a first end of the switch module is connected with a standby power supply end, a second end of the switch module is connected with a system power supply end, and the switch module is used for switching on or switching off according to a control signal and switching on the standby power supply to supply power to a system after switching on; the reference voltage is not less than the operating voltage of the system. The standby power supply switching circuit provided by the utility model can ensure the normal operation of a system.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit design technical field especially relates to a standby power switching circuit, recording appearance and vehicle. BACKGROUND

[0002] The unmanned car needs to record the data before and after the fault completely and upload to the cloud when the fault occurs, and the vehicle data recorder is required not to be affected by the vehicle state to cause power failure when the fault occurs. Therefore, the vehicle data recorder is generally provided with a standby power supply, which automatically switches to the standby power supply for power supply when the power supply is abnormal due to the fault, so as to ensure that the data before and after the fault can be recorded completely.

[0003] At present, the standby power switching circuit adopts the parallel mode of diode and PMOS tube, wherein the PMOS tube is connected in series with the standby power supply, which can avoid the power loss caused by the tube voltage drop in the parallel mode of diode, however, this switching circuit usually needs to be switched to the standby power supply for power supply when the main power supply voltage is lower than the standby power supply voltage, which may cause the system to be unable to operate normally when the main power supply voltage is not reduced to the standby power supply voltage. SUMMARY

[0004] The utility model provides a kind of standby power switching circuit, recording appearance and vehicle, to solve the problem that system can not be normally operated when standby power switches in prior art.

[0005] According to an aspect of the utility model, a kind of standby power switching circuit is provided, including comparison module, switch control module and switch module;

[0006] The first input end of the comparison module is connected with reference voltage, and the second input end of the comparison module is connected with main power supply end, and the comparison module is used to compare the voltage of the main power supply end with the reference voltage and output level signal;

[0007] The control end of the switch control module is connected with the output end of the comparison module, and the switch control module is used to output control signal according to the level signal;

[0008] The control end of the switch module is connected with the output end of the switch control module, the first end of the switch module is connected with standby power supply end, the second end of the switch module is connected with system power supply end, and the switch module is used to be turned on or be turned off according to the control signal, and the standby power supply is connected after being turned on to supply power for system;

[0009] Wherein, the reference voltage is not less than the operating voltage of the system.

[0010] Optionally, the comparison module comprises a first operational amplifier, a first capacitor and a first resistor, a first input end of the first operational amplifier is connected to the first input end of the comparison module, a second input end of the first operational amplifier is connected to the second input end of the comparison module, a power supply end of the first operational amplifier is connected to a first power supply end and a first end of the first capacitor, a second end of the first capacitor is grounded, a ground end of the first operational amplifier is grounded, an output end of the first operational amplifier is connected to a first end of the first resistor, and a second end of the first resistor is connected to the output end of the comparison module.

[0011] Optionally, the switch control module comprises a second resistor, a third resistor and a first transistor, a first end of the second resistor is connected to the input end of the switch control module, a second end of the second resistor is connected to a first end of the third resistor and a control end of the first transistor, a first end of the first transistor is connected to the output end of the switch control module, and a second end of the third resistor and a second end of the first transistor are grounded.

[0012] Optionally, the switch module comprises a second transistor, a third transistor and a fourth resistor, a control end of the second transistor, a control end of the third transistor and a first end of the fourth resistor are connected to the control end of the switch module, a second end of the fourth resistor is grounded, a first end of the second transistor is connected to the first end of the switch module, a second end of the second transistor is connected to a second end of the third transistor, and a first end of the third transistor is connected to a second end of the switch module.

[0013] Optionally, the backup power supply switching circuit further comprises a first voltage division module, a first end of the first voltage division module is connected to the backup power supply end, and a second end of the first voltage division module is connected to the first input end of the comparison module, and the first voltage division module is configured to output the reference voltage after voltage division of the backup power supply end.

[0014] Optionally, the first voltage division module comprises a fifth resistor, a sixth resistor and a second capacitor, a first end of the fifth resistor is connected to the first end of the first voltage division module, a second end of the fifth resistor is connected to a first end of the sixth resistor, a first end of the second capacitor and a second end of the first voltage division module, and a second end of the sixth resistor and a second end of the second capacitor are grounded.

[0015] Optionally, the backup power supply switching circuit further comprises a second voltage division module, a first end of the second voltage division module is connected to the main power supply end, and a second end of the second voltage division module is connected to the second input end of the comparison module, and the second voltage division module is configured to divide the voltage of the main power supply end.

[0016] Optionally, the second voltage dividing module comprises a seventh resistor, an eighth resistor and a third capacitor, a first end of the seventh resistor is connected with the first end of the second voltage dividing module, a second end of the seventh resistor is connected with a first end of the eighth resistor, a first end of the third capacitor and the second end of the second voltage dividing module, a second end of the eighth resistor and a second end of the third capacitor are grounded.

[0017] Optionally, the backup power supply switching circuit further comprises a first diode, a first end of the first diode is connected with the main power supply end, and a second end of the first diode is connected with the system power supply end.

[0018] According to another aspect of the present application, a recording instrument is provided, comprising the backup power supply switching circuit.

[0019] According to another aspect of the present application, a vehicle is provided, comprising the recording instrument.

[0020] The technical scheme of the present application provides a backup power supply switching circuit, comprising a comparison module, a switch control module and a switch module; a first input end of the comparison module is connected with a reference voltage, a second input end of the comparison module is connected with a main power supply end, and the comparison module is used for comparing the voltage of the main power supply end with the reference voltage to output a level signal; a control end of the switch control module is connected with an output end of the comparison module, and the switch control module is used for outputting a control signal according to the level signal; a control end of the switch module is connected with an output end of the switch control module, a first end of the switch module is connected with a backup power supply end, and a second end of the switch module is connected with a system power supply end; the switch module is used for being turned on or turned off according to the control signal, and the backup power supply is connected after being turned on to supply power to the system. The reference voltage can be set to be greater than or equal to the operating voltage of the system, and when the main power supply fails and needs to be switched to the backup power supply, the voltage of the main power supply can be ensured to be not less than the operating voltage of the system to smoothly switch to the backup power supply, and the normal operation of the system is ensured, and the problem that the system cannot normally operate when the backup power supply is switched in the prior art is solved.

[0021] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical scheme in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to these drawings without creative labor for those skilled in the art.

[0023] Figure 1 is a circuit diagram of a backup power supply switching provided in the related art;

[0024] Figure 2 is a structural schematic diagram of a backup power supply switching circuit provided in an embodiment of the present application;

[0025] Figure 3 is a circuit diagram of a backup power supply switching circuit provided in an embodiment of the present application;

[0026] Figure 4 is a structural schematic diagram of a recorder provided in an embodiment of the present application;

[0027] Figure 5 is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the personnel in the technical field better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by the person of ordinary skill in the art without making creative efforts should belong to the protection scope of the present application.

[0029] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be exchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0030] The unmanned vehicle has less human intervention during the whole operation period, and the data before and after the fault is recorded and uploaded to the cloud when the fault occurs. The technical personnel can remotely pull down the data to locate the vehicle fault reason, which can greatly improve the operation and maintenance efficiency. Therefore, the vehicle data recorder is generally provided with a backup power supply. When the fault occurs and the power supply is abnormal, the backup power supply is automatically switched to ensure that the data before and after the fault can be recorded completely.

[0031] A common switching circuit is a circuit in which a main power supply and a diode are connected in series, and a backup power supply and a diode are connected in parallel. Due to the existence of the diode voltage drop, even the Schottky diode will have a voltage drop of zero point several volts, which is relatively large power loss for the backup power supply. Figure 1 A backup power supply switching circuit provided in the related art is a circuit diagram in which a diode and a PMOS tube are connected in parallel. The PMOS tube is connected in series with a backup power supply LI_5V, and the power loss caused by the diode voltage drop can be avoided. The PMOS tube includes a gate G, a source S, and a drain D. The diode D is connected in series with a main power supply DC_5V, and then connected in parallel with the circuit composed of the backup power supply and the PMOS tube. The backup power supply switching circuit further includes capacitors C01, C02, C03, C04, C05, a resistor R01, and a resistor R02. The circuit usually needs to be switched to the backup power supply to supply power to the system power supply VSYS_5V when the main power supply voltage drops below the backup power supply voltage (i.e., the gate-source voltage Vgs of the PMOS tube is less than the threshold voltage Vth). This may cause the main power supply voltage to drop below the backup power supply voltage, and the entire system cannot be maintained, resulting in data loss.

[0032] To solve the above problems, an embodiment of the present application provides a backup power supply switching circuit, Figure 2 A structural schematic diagram of a backup power supply switching circuit provided by an embodiment of the present application is shown in FIG. 1. Figure 2As shown, the backup power supply switching circuit 100 comprises a comparison module 110, a switch control module 120 and a switch module 130; a first input end of the comparison module 110 is connected to a reference voltage Vsw, a second input end of the comparison module 110 is connected to a main power supply end DC, the comparison module 110 is used to compare the voltage of the main power supply end DC with the reference voltage Vsw to output a level signal; a control end of the switch control module 120 is connected to an output end of the comparison module 110, the switch control module 120 is used to output a control signal according to the level signal; a control end of the switch module 130 is connected to an output end of the switch control module 120, a first end of the switch module 130 is connected to a backup power supply end LI, a second end of the switch module 130 is connected to a system power supply end VSYS, the switch module 130 is used to be turned on or turned off according to the control signal, and after being turned on, the backup power supply is connected to supply power to the system, wherein the reference voltage is not less than the operating voltage of the system.

[0033] In the embodiment, the backup power supply switching circuit 100 is a circuit for automatically switching the backup power supply to continue to supply power to the system when the main power supply fails. The comparison module 110 is a module for comparing the main power supply voltage with the reference voltage, and the switching time of the backup power supply is controlled according to the set reference voltage, for example, the reference voltage can be set to be greater than or equal to the operating voltage of the system. The switch control module 120 is a module for being turned on or turned off according to the level signal output by the comparison module 110, and outputting a control signal when being turned on. The switch module 130 is a module for controlling the connection or disconnection between the backup power supply end and the system power supply end.

[0034] In the embodiment, the comparison module 110 compares the main power supply voltage and the reference voltage, when the main power supply voltage drops to the reference voltage, the comparison module 110 outputs a high level signal, the switch control module 120 is turned on according to the received high level signal, and outputs a control signal, for example, the control signal is a low level signal, the switch module 130 is turned on according to the low level signal, and after the switch module 130 is turned on, the backup power supply end LI is connected to the system power supply end VSYS, and the backup power supply supplies power to the system.

[0035] The embodiment provides a kind of standby power switching circuit, including comparison module, switch control module and switch module;The first input end of comparison module is accessed reference voltage, the second input end of comparison module is connected main power end, and comparison module is used to compare the voltage of main power end with reference voltage and output level signal;The control end of switch control module is connected the output end of comparison module, and switch control module is used to control signal according to level signal output;The control end of switch module is connected the output end of switch control module, the first end of switch module is connected standby power end, the second end of switch module is connected system power end, and switch module is used to switch on or shut off according to control signal, and after switch on, the standby power is connected to the system power supply.Wherein, reference voltage can be set to greater than or equal to the operating voltage of system, when main power fails and needs to be switched to standby power, it can be guaranteed that the voltage of main power is not less than the operating voltage of system when switching to standby power smoothly, ensure normal operation of system, solve the problem that standby power switching may cause system unable to operate normally in prior art.

[0036] Figure 3 It is the circuit diagram of the standby power switching circuit provided by the utility model embodiment, as shown in Figure 3 The comparison module 110 includes the first operational amplifier U1, the first capacitor C1 and the first resistor R1, the first input end of the first operational amplifier U1 is connected with the first input end of the comparison module 110, the second input end of the first operational amplifier U1 is connected with the second input end of the comparison module 110, the power supply end of the first operational amplifier U2 is connected with the first end of the first capacitor C1 and the first power supply end V1, the second end of the first capacitor C1 is grounded, the ground end of the first operational amplifier U1 is grounded, the output end of the first operational amplifier U1 is connected with the first end of the first resistor R1, and the second end of the first resistor R1 is connected with the output end of the comparison module 110.

[0037] On the basis of the above embodiment, the first operational amplifier U1 compares main power voltage and reference voltage, when main power voltage drops to reference voltage, the first operational amplifier U1 outputs high level signal, and the voltage of high level signal is equal to the voltage of the first power supply end V1.Wherein, the voltage of the first power supply end V1 is equal to the voltage of standby power end, and the first operational amplifier U1 is high-speed comparator, can replace the control of software logic, only uses hardware to realize switching, maximum degree increases the stability of switching and avoids the influence caused by time delay.

[0038] Continue to refer to Figure 3The switch control module 120 includes a second resistor R2, a third resistor R3 and a first transistor Q1. The first end of the second resistor R2 is connected to the input end of the switch control module 120. The second end of the second resistor R2 is connected to the first end of the third resistor R3 and the control end of the first transistor Q1. The first end of the first transistor Q1 is connected to the output end of the switch control module 120. The second end of the third resistor R3 and the second end of the first transistor Q1 are grounded.

[0039] Based on the above embodiment, when the level signal received by the switch control module 120 is a high level signal, the high level signal is transmitted to the control end of the first transistor Q1 after being divided by the second resistor R2 and the third resistor R3. The first transistor Q1 is turned on, and the first end of the first transistor Q1 outputs a low level signal, that is, the switch control module 120 outputs a low level signal.

[0040] Continuing to refer to Figure 3 The switch module 130 includes a second transistor Q2, a third transistor Q3 and a fourth resistor R4. The control end of the second transistor Q2, the control end of the third transistor Q3 and the first end of the fourth resistor R4 are connected to the control end of the switch module 130. The second end of the fourth resistor R4 is grounded. The first end of the second transistor Q2 is connected to the first end of the switch module 130. The second end of the second transistor Q2 is connected to the second end of the third transistor Q3. The first end of the third transistor Q3 is connected to the second end of the switch module 130.

[0041] Based on the above embodiment, the switch module 130 is turned on or turned off according to the received control signal. When the control signal is a low level signal, the second transistor Q2 is turned on, that is, the switch module 130 is turned on. The standby power supply end LI is connected to the system power supply end VSYS, and the standby power supply supplies power to the system. The second transistor Q2 is a PMOS tube. The PMOS tube includes a gate G, a source S and a drain D. The third transistor Q3 has an anti-backflow function.

[0042] Continuing to refer to Figure 3 The standby power supply switching circuit further includes a first voltage dividing module 310. The first end of the first voltage dividing module 310 is connected to the standby power supply end LI. The second end of the first voltage dividing module 310 is connected to the first input end of the comparison module 110. The first voltage dividing module 310 is used to divide the voltage of the standby power supply end LI and output a reference voltage Vsw.

[0043] In this embodiment, the first voltage dividing module 310 is a module for dividing the voltage of the standby power supply end LI and obtaining the reference voltage Vsw. According to the above embodiment, the reference voltage Vsw can be set according to the operating voltage of the system, so as to ensure smooth switching to the standby power supply when the voltage of the main power supply is not less than the operating voltage of the system, and ensure normal operation of the system.

[0044] Specifically, the first voltage divider module 310 includes a fifth resistor R5, a sixth resistor R6, and a second capacitor C2. The first end of the fifth resistor R5 is connected to the first end of the first voltage divider module 310, and the second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6, the first end of the second capacitor C2, and the second end of the first voltage divider module 310. The second end of the sixth resistor R6 and the second end of the second capacitor C2 are grounded.

[0045] Referring to the above embodiment, the voltage at the backup power supply terminal LI is divided by the fifth resistor R5 and the sixth resistor R6 to obtain the reference voltage Vsw. The fifth resistor R5 and the sixth resistor R6 can be selected according to the operating voltage of the system. The second capacitor C2, as a filter capacitor, can improve the stability of the circuit.

[0046] Continue to refer to Figure 3 The backup power switching circuit also includes a second voltage divider module 320. The first end of the second voltage divider module 320 is connected to the main power supply DC, and the second end of the second voltage divider module 320 is connected to the second input terminal of the comparator module 110. The second voltage divider module 320 is used to divide the voltage of the main power supply DC.

[0047] In this embodiment, the second voltage divider module 320 is a module that divides the voltage of the DC power supply terminal. Referring to the above embodiment, the comparison module 110 compares the voltage after the main power supply voltage is divided by the second voltage divider module 320 with the reference voltage Vsw, which can ensure that when the main power supply voltage is greater than the system operating voltage, the system switches to the backup power supply, thereby further ensuring the normal operation of the system.

[0048] Specifically, the second voltage divider module 320 includes a seventh resistor R7, an eighth resistor R8, and a third capacitor C3. The first end of the seventh resistor R7 is connected to the first end of the second voltage divider module 320, and the second end of the seventh resistor R7 is connected to the first end of the eighth resistor R8, the first end of the third capacitor C3, and the second end of the second voltage divider module 320. The second ends of the eighth resistor R8 and the second ends of the third capacitor C3 are grounded.

[0049] Referring to the above embodiment, the voltage of the main power supply terminal DC (i.e., the main power supply voltage) is divided by the seventh resistor R7 and the eighth resistor R8 and then transmitted to the second input terminal of the comparison module 110. The comparison module 110 compares the voltage after dividing the main power supply voltage with the reference voltage. The third capacitor C3, as a filter capacitor, can improve the stability of the circuit.

[0050] Continue to refer to Figure 3 The backup power switching circuit also includes a first diode D1. The first end of the first diode D1 is connected to the main power supply terminal DC, and the second end of the first diode D1 is connected to the system power supply terminal VSYS. When the main power supply is operating normally without faults, the main power supply terminal DC is connected to the system power supply terminal VSYS, and the main power supply supplies power to the system.

[0051] In the embodiment, the backup power supply switching circuit further comprises a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8 and a ninth resistor R9. When the main power supply fails, due to capacitor discharge, the voltage at the main power supply end and the voltage at the system power supply end will not disappear immediately, but follow the basic characteristics of capacitor discharge. Referring to the above embodiment, during the main power supply voltage drop, the comparison module 110 compares the main power supply voltage and the reference voltage, and when the main power supply voltage drops to the reference voltage, the comparison module 110 outputs a high level signal, the switch control module 120 is turned on according to the received high level signal, and outputs a low level signal, the switch module 130 is turned on according to the low level signal, and the switch module 130 is turned on to connect the backup power supply end LI and the system power supply end VSYS, and the backup power supply supplies power to the system. Since the first operational amplifier U1 in the comparison module 110 adopts a high-speed comparator, the propagation delay is in nanoseconds, and the capacitance in the circuit is several hundred microfarads, so the capacitor discharge is in microseconds, and sufficient time margin ensures the stable flip of the output of the high-speed comparator and the stable conduction of the second transistor Q2 in the switch module 130, and the stable access of the backup power supply is ensured.

[0052] The utility model embodiment further provides a kind of recorder, Figure 4 It is the structure schematic diagram of a kind of recorder provided in the utility model embodiment, as Figure 4 As shown, recorder 10 includes backup power supply switching circuit 100 in the above embodiment. Recorder is an important component in vehicle, can record the speed, time, image, sound etc. Data in the process of vehicle driving, provide important analysis basis when vehicle fault. Backup power supply switching circuit in the above embodiment is applied in recorder, can guarantee that recorder normally operates, and records the data before and after fault completely.

[0053] The utility model embodiment further provides a kind of vehicle, Figure 5 It is the structure schematic diagram of a kind of vehicle provided in the utility model embodiment, as Figure 5 As shown, vehicle 20 includes recorder 10 in the above embodiment. Vehicle 20 is unmanned car, unmanned car is less human intervention during the whole operation period, when fault occurs, it needs to record the data before and after fault completely and upload cloud, technical personnel are positioned vehicle fault reason by data analysis, recorder in the above embodiment is applied in unmanned car, can ensure that complete data information is recorded when vehicle fault, can more accurately analyze fault, improve operation and maintenance efficiency.

[0054] It should be understood that the various forms of flow shown above can be used to reorder, add or delete steps. For example, the steps described in the present application can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, which is not limited herein.

[0055] The above specific embodiments do not constitute a limitation on the scope of protection of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A backup power supply switching circuit, characterized by comprising: The switching circuit comprises a comparison module, a switch control module and a switch module. The first input end of the comparison module is connected to a reference voltage, and the second input end of the comparison module is connected to a main power supply end. The control end of the switch control module is connected to the output end of the comparison module. The control end of the switch module is connected to the output end of the switch control module. The first end of the switch module is connected to a backup power supply end, and the second end of the switch module is connected to a system power supply end. The reference voltage is not less than the operating voltage of the system.

2. The backup power switching circuit of claim 1, wherein, The first voltage dividing module is connected to the backup power supply end.

3. The backup power switching circuit of claim 1, wherein, The comparison module comprises a first operational amplifier, a first capacitor and a first resistor.

4. The backup power switching circuit of claim 1, wherein, The switch control module comprises a second resistor, a third resistor and a first transistor.

5. The backup power switching circuit of claim 1, wherein, The switch module comprises a second transistor, a third transistor and a fourth resistor. The first voltage dividing module comprises a fifth resistor, a sixth resistor and a second capacitor.

6. The backup power switching circuit of claim 1, wherein, The second voltage dividing module is further connected with the first end of the main power supply end, and the second end of the second voltage dividing module is connected with the second input end of the comparison module, and the second voltage dividing module is used for voltage division of the voltage of the main power supply end.

7. The backup power switching circuit of claim 6, wherein, The second voltage dividing module comprises a seventh resistor, an eighth resistor and a third capacitor, the first end of the seventh resistor is connected with the first end of the second voltage dividing module, the second end of the seventh resistor is connected with the first end of the eighth resistor, the first end of the third capacitor and the second end of the second voltage dividing module, and the second end of the eighth resistor and the second end of the third capacitor are grounded.

8. The backup power switching circuit of claim 1, wherein, The first diode is further connected with the first end of the main power supply end, and the second end of the first diode is connected with the system power supply end.

9. A recording instrument characterized by The backup power supply switching circuit comprises the backup power supply switching circuit according to any one of claims 1-8.

10. A vehicle characterized by comprising: The recorder comprises the recorder according to claim 9.

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