An alternative power supply circuit and an alternative power supply system

Abstract

The present application discloses a backup power supply circuit, including a boost circuit, a buck circuit, and an electrolytic capacitor. Among them, the first end of the boost circuit is connected to a power source and is used to boost the voltage of the power source; the second end of the boost circuit is connected to the electrolytic capacitor and is used to charge the electrolytic capacitor. The second end of the boost circuit is also connected to the first end of the buck circuit and is used to reduce the voltage to the voltage required by the load; the second end of the buck circuit is connected to the load. Compared with the current technology, in a low-voltage environment, the electrolytic capacitor cannot store enough energy in the backup power supply circuit. By adopting the technical solution of the present application, the low voltage output by the power source is boosted by the boost circuit and then used to charge the electrolytic capacitor, and then the load is powered by the buck circuit, so that the electrolytic capacitor can still fully exert its energy storage effect in a low-voltage environment, realizing effective energy storage of the electrolytic capacitor in a low-voltage environment. In addition, the present application also discloses a backup power supply system, including the above-mentioned backup power supply circuit, and the effect is the same as above.

Description

Technical Field

[0001] The present application relates to the technical field of power supply circuits, and particularly to a backup power supply circuit and a backup power supply system. Background Art

[0002] With the development of technology, redundant power supply circuits are provided for power supply equipment in more and more places, so as to maintain the short-term operation of the system during power outages, such as storing important data. In an environment with good conditions, a backup battery is usually used as the backup power supply circuit. In an industrial site with harsh environment, electrolytic capacitors are usually used for backup power supply, which can provide backup power for a certain period of time only by being powered on for several milliseconds, and has the advantage of fast energy replenishment.

[0003] The disadvantage is that due to its characteristics, the electrolytic capacitor needs to work normally in a circuit with a higher voltage to store enough energy, and it cannot effectively store energy at low voltages, such as 5V, 3.3V, etc.

[0004] Therefore, how to make the electrolytic capacitor still effectively store energy in a low-voltage environment is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present application is to provide a backup power supply circuit and a backup power supply system.

[0006] To solve the above technical problems, the present application provides a backup power supply circuit, which includes: a boost circuit 11, a buck circuit 12, and an electrolytic capacitor 14;

[0007] The first end of the boost circuit 11 is connected to the power supply 10, and is used to increase the voltage of the power supply 10;

[0008] The second end of the boost circuit 11 is connected to the electrolytic capacitor 14 and is used to charge the electrolytic capacitor 14. The second end of the boost circuit 11 is also connected to the first end of the buck circuit 12 and is used to reduce the voltage to the voltage required by the load 13;

[0009] The second end of the buck circuit 12 is connected to the load 13.

[0010] Preferably, it further includes: a super capacitor 16 and a charge management circuit 15;

[0011] The first end of the charge management circuit 15 is connected to the third end of the buck circuit 12, the second end of the charge management circuit 15 is connected to the first end of the super capacitor 16, and the second end of the super capacitor 16 is connected to the first end of the boost circuit 11; the charge management circuit 15 includes at least one switching tube, and the switching tube is connected to the power supply 10 and disconnects the charge management circuit 15 when the power supply 10 has no output.

[0012] Preferably, the charging management circuit 15 includes:

[0013] A first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first diode, a second diode, an NPN-type triode, a PNP-type triode, a first capacitor, a second capacitor, and a reference voltage chip;

[0014] The first end of the first capacitor serves as the first end of the charging management circuit 15 and is connected to the third end of the buck circuit 12; the second end of the first capacitor is connected to the anode of the first diode and the cathode of the second diode; the anode of the second diode is grounded; the cathode of the first diode is connected to the first end of the first resistor and the emitter of the PNP-type triode; the second end of the first resistor is connected to the first end of the second resistor and the base of the PNP-type triode; the first end of the second resistor is connected to the collector of the NPN-type triode; the base of the NPN-type triode is connected to the first end of the third resistor and the first end of the fourth resistor; the second end of the third resistor is connected to the first end of the fifth resistor and the first end of the reference voltage chip; the second end of the fifth resistor is connected to the power supply 10; the emitter of the NPN-type triode, the second end of the fourth resistor, the second end of the reference voltage chip, and the first end of the sixth resistor are commonly grounded; the second end of the sixth resistor is connected to the third end of the reference voltage chip and the first end of the seventh resistor; the second end of the seventh resistor, the collector of the PNP-type triode, and the first end of the second capacitor together serve as the second end of the charging management circuit 15 and are connected to the first end of the supercapacitor 16; the second end of the second capacitor is grounded;

[0015] Preferably, it further includes: a charging current limiting circuit, connected to the second end of the boost circuit 11 and the electrolytic capacitor 14.

[0016] Preferably, the second end of the boost circuit 11 is connected to the third end of the boost circuit 11 to provide the working power supply 10 for the boost circuit 11.

[0017] Preferably, it further includes: a power supply 10 protection circuit, connected to the power supply 10, for preventing current from flowing into the power supply 10 when the load 13 is powered by the electrolytic capacitor 14 or the supercapacitor 16.

[0018] Preferably, it further includes: a filtering circuit, connected to the second end of the buck circuit 12 and the load 13.

[0019] Preferably, it further includes: a first display device;

[0020] The first display device is connected to the electrolytic capacitor 14 to give a first prompt when detecting that the electrolytic capacitor 14 outputs current.

[0021] Preferably, it further includes: a second display device;

[0022] The second display device is connected to the supercapacitor 16 to give a second prompt when detecting that the supercapacitor 16 outputs current.

[0023] To solve the above technical problems, the present application also provides a backup power supply system, including the above backup power supply circuit.

[0024] The backup power supply circuit provided by the present application includes a boost circuit, a buck circuit, and an electrolytic capacitor. Among them, the first end of the boost circuit is connected to the power supply and is used to increase the voltage of the power supply; the second end of the boost circuit is connected to the electrolytic capacitor and is used to charge the electrolytic capacitor. The second end of the boost circuit is also connected to the first end of the buck circuit and is used to reduce the voltage to the voltage required by the load; the second end of the buck circuit is connected to the load. Compared with the current technology, in a low-voltage environment, the electrolytic capacitor cannot store enough energy in the backup power supply circuit. With the technical solution of the present application, the low voltage output by the power supply is boosted by the boost circuit and then used to charge the electrolytic capacitor, and then the load is powered by the buck circuit, so that the electrolytic capacitor can still fully play its energy storage effect in a low-voltage environment, realizing effective energy storage of the electrolytic capacitor in a low-voltage environment.

[0025] In addition, the backup power supply system provided by the present application includes the above backup power supply circuit, and the effects produced are the same as those of the backup power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the embodiments of the present application, the following will briefly introduce the drawings required for the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 It is a structural diagram of a backup power supply circuit provided by an embodiment of the present application;

[0028] Figure 2 It is a circuit diagram of a boost circuit, a charging current limiting circuit, and a power supply protection circuit connected to an electrolytic capacitor provided by an embodiment of the present application;

[0029] Figure 3 It is a circuit diagram of a buck circuit and a filtering circuit connected to a supercapacitor provided by an embodiment of the present application;

[0030] Figure 4Structural diagram of another backup power supply circuit provided by an embodiment of the present application;

[0031] Figure 5 Circuit diagram of a charging management circuit provided by an embodiment of the present application;

[0032] The reference numerals are as follows: 10 is a power supply, 11 is a boost circuit, 12 is a buck circuit, 13 is a load, 14 is an electrolytic capacitor, 15 is a charging management circuit, and 16 is a super capacitor. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present application.

[0034] The core of the present application is to provide a backup power supply circuit and a backup power supply system, which are mainly used to enable the electrolytic capacitor to effectively store energy in a low-voltage environment.

[0035] In order to enable those skilled in the art to better understand the solution of the present application, the present application will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0036] Figure 1 Structural diagram of a backup power supply circuit provided by an embodiment of the present application, as Figure 1 shown, the circuit includes: a boost circuit 11, a buck circuit 12, and an electrolytic capacitor 14;

[0037] The first end of the boost circuit 11 is connected to the power supply 10 and is used to increase the voltage of the power supply 10; the second end of the boost circuit 11 is connected to the electrolytic capacitor 14 and is used to charge the electrolytic capacitor 14. The second end of the boost circuit 11 is also connected to the first end of the buck circuit 12 and is used to reduce the voltage to the voltage required by the load 13; the second end of the buck circuit 12 is connected to the load 13.

[0038] Among them, the boost circuit 11 can be a BOOST circuit or a boost converter, etc. It can access the low voltage output by the power supply 10 and output the high voltage required for charging the electrolytic capacitor 14. Similarly, the buck circuit 12 can be a BUCK circuit or a buck converter, etc. Usually, the voltage output by the power supply 10 powers the load 13. In this solution, in order to charge the electrolytic capacitor 14 and boost the voltage, it is necessary to pass through the buck circuit 12 to reduce the voltage to the voltage required for the normal operation of the load 13. The electrolytic capacitor 14 is a type of capacitor. The metal foil is the positive electrode, the oxide film in contact with the positive electrode is the dielectric, and the cathode is composed of a conductive material, an electrolyte, and other materials. Among them, the electrolyte can be liquid or solid. The capacitance per unit volume of the electrolytic capacitor 14 is very large, dozens to hundreds of times larger than other types of capacitors. Moreover, the rated capacitance can be made very large, and it can easily reach tens of thousands of microfarads or even several farads. The electrolytic capacitor 14 is further divided into polarized capacitors and non-polarized capacitors. In this solution, since the power supply 10 outputs direct current, the electrolytic capacitor 14 can use a polarized capacitor. If the power supply 10 outputs alternating current, rectification is required.

[0039] Figure 2 The figure is a circuit diagram of a boost circuit 11, a charging current limiting circuit, and a power supply protection circuit connected to the electrolytic capacitor 14 provided by an embodiment of the present application. As Figure 2 shown, the boost circuit 11 includes: an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a first inductor L1, a third diode D3, and a DC / DC boost chip U2.

[0040] The first terminal of the eighth resistor R8, the first terminal of the first inductor L1, and the first terminal of the ninth resistor R9 are jointly used as the first terminal of the boost circuit 11 to connect to the power supply 10; the second terminal of the eighth resistor R8 and the first terminal of the tenth resistor R10 are commonly connected to the first terminal of the DC / DC boost chip U2; the second terminal of the tenth resistor R10 is grounded; the second terminal of the DC / DC boost chip U2 is connected to the first terminal of the third capacitor C3; the third terminal of the DC / DC boost chip U2 and the second terminal of the third capacitor C3 are commonly grounded; the fourth terminal of the DC / DC boost chip U2 is connected to the first terminal of the eleventh resistor R11; the second terminal of the eleventh resistor R11 is connected to the first terminal of the fourth capacitor C4; the second terminal of the fourth capacitor C4 is grounded; the fifth terminal of the DC / DC boost chip U2 and the first terminal of the fifth capacitor C5 are commonly connected to the output terminal of the boost circuit 11; the second terminal of the fifth capacitor C5 and the sixth terminal of the DC / DC boost chip U2 are commonly grounded; the seventh terminal of the DC / DC boost chip U2 and the second terminal of the first inductor L1 are commonly connected to the anode of the third diode D3; the cathode of the third diode D3, the second terminal of the ninth resistor R9, the first terminal of the twelfth resistor R12, and the first terminal of the sixth capacitor C6 are jointly used as the second terminal of the boost circuit 11 to connect to the positive electrode of the electrolytic capacitor 14, such as Figure 2 C24 in; the eighth terminal of the DC / DC boost chip U2 is connected to the second terminal of the twelfth resistor R12 and the first terminal of the thirteenth resistor R13; the second terminal of the thirteenth resistor R13 is grounded; the second terminal of the sixth capacitor C6 and the negative electrode of the electrolytic capacitor 14 are commonly grounded.

[0041] In this embodiment, the model of the DC / DC boost chip U2 is MP1542, and the first terminal is the enable terminal, which accesses the voltage after being divided by the eighth resistor and the tenth resistor. The fifth terminal is used as the power input terminal and is also the third terminal of the boost circuit 11. It can access the voltage from the power supply 10 or from the second terminal of the boost circuit 11. The conversion pin at the seventh terminal can control the closing of the internal switch of the chip, causing the current passing through the first inductor L1 to increase. Opening the switch will cause the current to flow through the third diode D3 to the sixth capacitor C6. Due to storing the current from the first inductor L1, the voltage of the sixth capacitor C6 increases after multiple switching cycles, making the output voltage of the boost circuit 11 higher than the input voltage, and raising the input +5V power supply voltage to 15V to Figure 2 charge the electrolytic capacitor C24 in.

[0042] Figure 3 The circuit diagram of a buck circuit 12 and a filter circuit connected to the super capacitor 16 provided by the embodiment of the present application is shown in Figure 3 as follows, the buck circuit 12 includes:

[0043] The seventh capacitor C7, the eighth capacitor C8, the ninth capacitor C9, the tenth capacitor C10, the fourteenth resistor R14, the fifteenth resistor R15, the sixteenth resistor R16, the seventeenth resistor R17, the eighteenth resistor R18, the DC / DC buck chip U3, and the second inductor L2.

[0044] The first terminal of the seventh capacitor C7, the first terminal of the eighth capacitor C8, the first terminal of the fourteenth resistor R14, and the first terminal of the DC / DC buck chip U3 together serve as the first terminal of the buck circuit 12 and are connected to the second terminal of the boost circuit 11; the second terminals of the seventh capacitor C7 and the eighth capacitor C8 are grounded together; the second terminal of the fourteenth resistor R14 and the first terminal of the fifteenth resistor R15 are commonly connected to the second terminal of the DC / DC buck chip U3; the second terminal of the fifteenth resistor R15 is grounded; the third terminal of the DC / DC buck chip U3 is connected to the first terminal of the ninth capacitor C9; the second terminal of the ninth capacitor C9, the fourth terminal of the DC / DC buck chip U3, and the first terminal of the second inductor L2 are commonly connected and serve as the third terminal of the buck circuit 12; the fifth terminal of the DC / DC buck chip U3 is grounded; the second terminal of the second inductor L2, the first terminal of the sixteenth resistor R16, and the first terminal of the tenth capacitor C10 together serve as the second terminal of the buck circuit 12 and are connected to the load 13; the second terminal of the tenth capacitor C10 is connected to the first terminal of the seventeenth resistor R17; the sixth terminal of the DC / DC buck chip U3, the second terminal of the sixteenth resistor R16, and the second terminal of the seventeenth resistor R17 are commonly connected to the first terminal of the eighteenth resistor R18; the second terminal of the eighteenth resistor R18 is grounded.

[0045] In this embodiment, the model of the DC / DC buck chip U3 is JW5060TTSOTB. By closing the internal switch, the second inductor L2 is charged, and after the switch is disconnected, the second inductor L2 discharges as a power source, causing the voltage to decrease. The 15V voltage connected from the boost circuit is reduced to 3.3V to supply power to the load 13.

[0046] The backup power supply circuit provided by the embodiment of the present application includes a boost circuit, a buck circuit, and an electrolytic capacitor. Among them, the first terminal of the boost circuit is connected to the power source and is used to increase the voltage of the power source; the second terminal of the boost circuit is connected to the electrolytic capacitor and is used to charge the electrolytic capacitor. The second terminal of the boost circuit is also connected to the first terminal of the buck circuit and is used to reduce the voltage to the voltage required by the load; the second terminal of the buck circuit is connected to the load. Compared with the current technology, in a low-voltage environment, the electrolytic capacitor cannot store enough energy in the backup power supply circuit. By adopting this technical solution, the low voltage output by the power source is used to charge the electrolytic capacitor after passing through the boost circuit, and then the load is powered through the buck circuit, enabling the electrolytic capacitor to still fully exert its energy storage effect in a low-voltage environment and realizing effective energy storage of the electrolytic capacitor in a low-voltage environment.

[0047] In a specific implementation, the electrolytic capacitor 14 can provide power supply for a short period of time and supply power when the power is off for the device to store important data, etc. However, usually the electrolytic capacitor 14 can only supply power for a few seconds and sometimes cannot meet the actual needs.

[0048] Figure 4 The structural diagram of another backup power supply circuit provided by the embodiment of the present application is shown in Figure 4 As shown, in order to enable the backup power supply circuit to supply power for a longer time, on the basis of the above embodiment, the backup power supply circuit provided by the embodiment of the present application further includes: a supercapacitor 16 and a charging management circuit 15.

[0049] The first end of the charging management circuit 15 is connected to the third end of the buck circuit 12, the second end of the charging management circuit 15 is connected to the first end of the supercapacitor 16, and the second end of the supercapacitor 16 is connected to the first end of the boost circuit 11; the charging management circuit 15 includes at least one switching tube, and the switching tube is connected to the power supply 10, and the charging management circuit 15 is disconnected when the power supply 10 has no output.

[0050] The supercapacitor 16 is different from traditional chemical power sources. It is a power source with special performance between traditional capacitors and batteries, and mainly stores electrical energy by relying on the electric double layer and redox pseudocapacitance. However, no chemical reaction occurs during its energy storage process, and this energy storage process is reversible. Just because of this, the supercapacitor 16 can be charged and discharged hundreds of thousands of times. Its basic principle is the same as that of other types of electric double layer capacitors, and it uses the electric double layer structure composed of activated carbon porous electrodes and electrolytes to obtain a large capacity. Its capacity range is usually from 0.1 farad to 1000 farads, and it can provide more power than the electrolytic capacitor 14 when the power is off.

[0051] The charging management circuit 15 is connected to the buck circuit 12 and the supercapacitor 16. It can be turned on when the power supply 10 has an output to charge the supercapacitor 16, and turned off when the power supply 10 has no output. At this time, the load 13 is powered by the supercapacitor 16. It can be understood that when the power supply 10 has no output, the supercapacitor 16 discharges. After passing through the boost circuit 11, the high potential generated at the second end of the boost circuit 11 will inhibit the electrolytic capacitor 14 from releasing power. At this time, the load 13 is powered by the supercapacitor 16. When the supercapacitor 16 is not discharging, it is powered by the electrolytic capacitor 14.

[0052] The backup power supply circuit provided by the present application adds a supercapacitor as an energy storage device, which can provide power for a longer time than the above embodiment when the power is off to meet the actual needs.

[0053] In the above embodiment, the charging management circuit 15 is simply described. In this embodiment, a specific charging management circuit 15 is provided. Figure 5The circuit diagram of a charging management circuit 15 provided by an embodiment of the present application is as follows Figure 5 shown. The circuit includes:

[0054] A first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a first diode D1, a second diode D2, an NPN transistor Q2, a PNP transistor Q1, a first capacitor C1, a second capacitor C2, and a reference voltage chip U1;

[0055] The first end of the first capacitor C1 is connected to the third end of the buck circuit 12 as the first end of the charging management circuit 15, as Figure 5 BUCK_SW in the figure; the second end of the first capacitor C1 is connected to the anode of the first diode D1 and the cathode of the second diode D2; the anode of the second diode D2 is grounded; the cathode of the first diode D1 is connected to the first end of the first resistor R1 and the emitter of the PNP transistor Q1; the second end of the first resistor R1 is connected to the first end of the second resistor R2 and the base of the PNP transistor Q1; the first end of the second resistor R2 is connected to the collector of the NPN transistor Q2; the base of the NPN transistor Q2 is connected to the first end of the third resistor R3 and the first end of the fourth resistor R4; the second end of the third resistor R3 is connected to the first end of the fifth resistor R5 and the first end of the reference voltage chip U1; the second end of the fifth resistor R5 is connected to the power supply 10; the emitter of the NPN transistor Q2, the second end of the fourth resistor R4, the second end of the reference voltage chip U1, and the first end of the sixth resistor R6 are commonly grounded; the second end of the sixth resistor R6 is connected to the third end of the reference voltage chip U1 and the first end of the seventh resistor R7; the second end of the seventh resistor R7, the collector of the PNP transistor Q1, and the first end of the second capacitor C2 are jointly used as the second end of the charging management circuit 15 to be connected to the first end of the super capacitor 16, as Figure 5 SC in the figure; the second end of the second capacitor C2 is grounded.

[0056] Figure 5 In the shown charging management circuit, the PNP transistor Q1 is used as the switching transistor of the charging circuit and is connected to the power supply 10, and this circuit is disconnected when the power supply 10 has no output. The reference voltage chip U1 can determine whether the super capacitor 16 is fully charged by comparing the input voltage with its own comparison voltage. When it is fully charged, it can control the NPN transistor Q2 to disconnect, realizing the charging management of the super capacitor.

[0057] For the charging management circuit provided by this embodiment, while controlling the conduction and disconnection of the circuit, the first diode, the second diode, and the first capacitor cooperate with the SW signal of the BUCK circuit to provide a relatively constant current power supply to charge the super capacitor. The reference voltage chip cooperates with the peripheral circuit to turn off the charging circuit when it detects that the super capacitor is fully charged.

[0058] In a specific implementation, in order to mitigate the impact on the power supply 10 caused by a large inrush current generated when the electrolytic capacitor 14 starts to charge instantaneously when the power supply 10 is just turned on, based on the above embodiment, in this embodiment, it further includes: a charging current limiting circuit, connected to the second end of the boost circuit 11 and the electrolytic capacitor 14.

[0059] The embodiment of the present application provides a specific charging current limiting circuit, as Figure 2 shown, this circuit includes:

[0060] The fourth diode D4, the nineteenth resistor R19, and the twentieth resistor R20.

[0061] The cathode of the fourth diode D4, the first end of the nineteenth resistor R19, and the first end of the twentieth resistor R20 are commonly connected to the second end of the boost circuit 11, and the anode of the fourth diode D4, the second end of the nineteenth resistor R19, and the second end of the twentieth resistor R20 are commonly connected to the positive electrode of the electrolytic capacitor 14.

[0062] The charging current limiting circuit provided by the embodiment of the present application can mitigate the impact on the power supply caused by a large inrush current generated when the electrolytic capacitor starts to charge instantaneously when the power supply is just turned on.

[0063] In a specific implementation, the power input pin of the DC / DC boost chip U2 is usually connected to the power supply 10. When the supercapacitor 16 discharges and the voltage drops below the minimum operating voltage of the DC / DC boost chip U2, it cannot discharge, resulting in a part of the energy of the supercapacitor 16 not being released and the utilization rate being reduced.

[0064] To solve the above problem, in this embodiment, the second end of the boost circuit 11 is connected to the third end of the boost circuit 11 to provide a working power supply for the boost circuit 11.

[0065] The backup power supply circuit provided by the embodiment of the present application uses the boosted voltage to supply power to the DC / DC boost chip. Compared with the current technology, where the DC / DC boost chip is powered by the power supply, the discharge threshold of the supercapacitor is 2.5V to 5V. With this technical solution, the boosted voltage is used to supply power to the DC / DC boost chip, broadening the discharge threshold of the supercapacitor to 1.8V to 5.5V, expanding the discharge threshold of the supercapacitor and achieving full utilization of the energy stored in the supercapacitor.

[0066] In a specific implementation, in order to prevent current from flowing into the power supply 10 and causing damage when the load 13 is powered by the supercapacitor 16 or the electrolytic capacitor 14, based on the above embodiment, in this embodiment, it further includes: a power supply protection circuit, connected to the power supply 10, for preventing current from flowing into the power supply 10 when the load 13 is powered by the electrolytic capacitor 14 or the supercapacitor 16.

[0067] As shown Figure 2 in the figure, the power protection circuit is the fifth diode D5.

[0068] In addition, as shown Figure 2 in the figure, the backup power supply circuit provided in this embodiment further includes a sixth diode D6 and an eleventh capacitor C11. The sixth diode D6 is a discharge channel for the super capacitor, and the eleventh capacitor C11 is used to perform preliminary filtering on the voltage output by the power supply.

[0069] The anode of the fifth diode D5 is connected to the power supply 10; the cathode of the fifth diode D5, the cathode of the sixth diode D6, and the first end of the eleventh capacitor C11 are commonly connected to the first end of the boost circuit 11; the anode of the sixth diode D6 is connected to the second end of the super capacitor 16; the second end of the eleventh capacitor C11 is grounded.

[0070] The power protection circuit provided in the embodiment of the present application prevents current from flowing into the power supply when the load is powered by an electrolytic capacitor or a super capacitor, thereby realizing the protection of the power supply.

[0071] In a specific implementation, in order to prevent the supply voltage from changing due to the change of the load 13 and to obtain a relatively stable DC voltage, on the basis of the above embodiment, in this embodiment, it further includes: a filtering circuit, which is connected to the second end of the buck circuit 12 and the load 13.

[0072] As shown Figure 3 in the figure, in this embodiment, the filtering circuit includes: a twelfth capacitor C12, a thirteenth capacitor C13, a fourteenth capacitor C14, and a fifteenth capacitor C15.

[0073] The first end of the twelfth capacitor C12, the first end of the thirteenth capacitor C13, the first end of the fourteenth capacitor C14, the first end of the fifteenth capacitor C15, and the second end of the buck circuit 12 are commonly connected to the load 13; the second end of the twelfth capacitor C12, the second end of the thirteenth capacitor C13, the second end of the fourteenth capacitor C14, and the second end of the fifteenth capacitor C15 are commonly grounded.

[0074] The filtering circuit provided in the embodiment of the present application filters the voltage and can obtain a relatively stable DC voltage.

[0075] In a specific implementation, when the power supply 10 has no output, in order to confirm whether the load 13 is powered by the electrolytic capacitor 14, in this embodiment, it further includes: a first display device.

[0076] The first display device is connected to the electrolytic capacitor 14 to issue a first prompt when detecting the output current of the electrolytic capacitor 14.

[0077] The backup power supply circuit provided in this embodiment uses a first display device to give a first prompt when the electrolytic capacitor outputs current, enabling the operator to know that the load is powered by the electrolytic capacitor at this time, and it can also be deduced that the supercapacitor has released its power.

[0078] In a specific implementation, when the power supply 10 has no output, in order to confirm whether the load 13 is powered by the supercapacitor 16, in this embodiment, it further includes: a second display device.

[0079] The second display device is connected to the supercapacitor 16 to give a second prompt when detecting that the supercapacitor 16 outputs current.

[0080] The backup power supply circuit provided in this embodiment uses a second display device to give a second prompt when the supercapacitor outputs current, enabling the operator to know that the load is powered by the supercapacitor at this time.

[0081] The embodiment of the present application also provides a backup power supply system, including the backup power supply circuit mentioned in the above embodiment. Since the above embodiment has described each component in detail, this embodiment will not be elaborated here.

[0082] The backup power supply system provided by the embodiment of the present application includes a backup power supply circuit, which includes a boost circuit, a buck circuit, and an electrolytic capacitor. Among them, the first end of the boost circuit is connected to the power supply and is used to increase the voltage of the power supply; the second end of the boost circuit is connected to the electrolytic capacitor and is used to charge the electrolytic capacitor, and the second end of the boost circuit is also connected to the first end of the buck circuit and is used to reduce the voltage to the voltage required by the load; the second end of the buck circuit is connected to the load. Compared with the current technology, in a low-voltage environment, the electrolytic capacitor cannot store enough energy in the backup power supply circuit. With this technical solution, the low voltage output by the power supply is boosted by the boost circuit and then used to charge the electrolytic capacitor, and then the load is powered by the buck circuit, enabling the electrolytic capacitor to still fully exert its energy storage effect in a low-voltage environment and realizing effective energy storage of the electrolytic capacitor in a low-voltage environment.

[0083] The above has introduced the backup power supply circuit and the backup power supply system provided by the present application in detail. Each embodiment in the specification is described in a progressive manner, and the key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present application, several improvements and modifications can still be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

[0084] It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

Claims

1. A backup power supply circuit, characterized in that, Comprising: A boost circuit (11), a buck circuit (12), an electrolytic capacitor (14), a super capacitor (16), and a charging management circuit (15); A first end of the boost circuit (11) is connected to a power supply (10) for boosting the voltage of the power supply (10); A second end of the boost circuit (11) is connected to the electrolytic capacitor (14) for charging the electrolytic capacitor (14), and the second end of the boost circuit (11) is further connected to a first end of the buck circuit (12) for reducing the voltage to a voltage required by a load (13); A second end of the buck circuit (12) is connected to the load (13); A first end of the charging management circuit (15) is connected to a third end of the buck circuit (12), a second end of the charging management circuit (15) is connected to a first end of the super capacitor (16), and a second end of the super capacitor (16) is connected to a first end of the boost circuit (11); the charging management circuit (15) includes at least one switching transistor, and the switching transistor is connected to the power supply (10) to disconnect the charging management circuit (15) when the power supply (10) has no output The charging management circuit (15) includes: A first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first diode, a second diode, an NPN-type transistor, a PNP-type transistor, a first capacitor, a second capacitor, and a reference voltage chip; A first end of the first capacitor serves as a first end of the charging management circuit (15) and is connected to a third end of the buck circuit (12); a second end of the first capacitor is connected to an anode of the first diode and a cathode of the second diode; an anode of the second diode is grounded; a cathode of the first diode is connected to a first end of the first resistor and an emitter of the PNP-type transistor; a second end of the first resistor is connected to a first end of the second resistor and a base of the PNP-type transistor; a first end of the second resistor is connected to a collector of the NPN-type transistor; a base of the NPN-type transistor is connected to a first end of the third resistor and a first end of the fourth resistor; a second end of the third resistor is connected to a first end of the fifth resistor and a first end of the reference voltage chip; a second end of the fifth resistor is connected to the power supply (10); an emitter of the NPN-type transistor, a second end of the fourth resistor, a second end of the reference voltage chip, and a first end of the sixth resistor are commonly grounded; a second end of the sixth resistor is connected to a third end of the reference voltage chip and a first end of the seventh resistor; a second end of the seventh resistor, a collector of the PNP-type transistor, and a first end of the second capacitor jointly serve as a second end of the charging management circuit (15) and are connected to a first end of the super capacitor (16); a second end of the second capacitor is grounded; Further comprising: a charging current limiting circuit connected to a second end of the boost circuit (11) and the electrolytic capacitor (14).

2. The backup power supply circuit according to claim 1, characterized in that, The second terminal of the boost circuit (11) is connected to the third terminal of the boost circuit (11) to provide a working power supply (10) for the boost circuit (11).

3. The backup power supply circuit according to claim 1, wherein Further comprising: A power supply (10) protection circuit, connected to the power supply (10), for preventing current from flowing into the power supply (10) when the load (13) is powered by the electrolytic capacitor (14) or the supercapacitor (16).

4. The backup power supply circuit according to any one of claims 1 to 3, characterized in that Further comprising: A filter circuit, connected to the second terminal of the buck circuit (12) and the load (13).

5. The backup power supply circuit according to claim 1, wherein Further comprising: A first display device; The first display device is connected to the electrolytic capacitor (14) to give a first prompt when the output current of the electrolytic capacitor (14) is detected.

6. The backup power supply circuit according to claim 1, characterized in that, Further comprising: A second display device; The second display device is connected to the supercapacitor (16) to give a second prompt when the output current of the supercapacitor (16) is detected.

7. A backup power supply system, characterized in that, Comprising the backup power supply circuit according to any one of claims 1 to 6.

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