Protection circuit, power supply device and energy storage equipment

Abstract

The utility model provides a protection circuit, a power supply device and an energy storage device. The protection circuit comprises a first logic module, a sampling module, a switch module, a second logic module and a fault alarm module. The first logic module is used for being connected with the output end of the voltage conversion circuit and a control signal of the switching circuit, the first logic module is connected with the first input end of the second logic module, and the switching module is connected with the second input end of the second logic module, the first logic module and the sampling module. The output end of the second logic module is connected with the fault alarm module. In the circuit, the fault alarm module can be controlled to work when the switching circuit and / or the voltage conversion circuit in the power supply device is abnormal, and the current circuit fault is prompted, so that the safety and the reliability of the power supply device are improved.

Description

Technical Field

[0001] The embodiments of the utility model relate to the technical field of safety protection of energy storage products, and in particular to a protection circuit, a power supply device and an energy storage device. Background Art

[0002] With the rapid development of society, the demand for new energy products, such as energy storage products, is increasing. Nowadays, the population base using energy storage products is increasing, so the performance and safety requirements of products are also getting higher and higher.

[0003] As energy storage power supplies are increasingly used, DC output is an essential function, such as USB-A, USB-C, cigarette lighters, etc. These functions generally draw power from the output end of the battery, and the output voltage of the battery is higher than the output voltage of these functions, so these functions generally use a buck topology. The output end of the battery is connected to the buck circuit through a switch circuit, wherein when the switch circuit is turned on by a control signal, the buck circuit receives the output voltage of the battery to work, and when the switch circuit is disconnected by a control signal, the buck circuit does not work. Under this circuit structure, if the switch circuit is short-circuited, the buck circuit will always work, posing a safety hazard; if the buck circuit is short-circuited, when the control signal controls the switch circuit to turn on, the circuit will form a current loop, which is easy to damage the device, causing smoke or even fire. It can be seen that under this circuit structure, if there are faults in the buck circuit and the switch circuit, the safety and reliability of the energy storage power supply cannot be guaranteed. Utility Model Content

[0004] The embodiments of the utility model provide a protection circuit, a power supply device and an energy storage device, which can improve the safety and reliability of the product.

[0005] In a first aspect, an embodiment of the utility model provides a protection circuit, which is applied to a power supply device, wherein the power supply device includes a switching circuit and a voltage conversion circuit, wherein the switching circuit is respectively connected to the output end of a battery and the input end of the voltage conversion circuit, and the protection circuit includes: a first logic module, a sampling module, a switching module, a second logic module and a fault alarm module; the first logic module is respectively used to connect the output end of the voltage conversion circuit and the control signal of the switching circuit, the first logic module is connected to the first input end of the second logic module, the switch module is respectively connected to the second input end of the second logic module, the first logic module and the sampling module, and the output end of the second logic module is connected to the fault alarm module; the first logic module is used to output a first logic signal to the second logic module according to the output voltage of the voltage conversion circuit and the control signal The first input terminal of the block; wherein, when the output voltage is greater than or equal to the first preset voltage and the control signal is at the second level, the first logic signal is at the first level; when the output voltage is less than the first preset voltage or the control signal is at the first level, the first logic signal is at the second level; the sampling module is used to detect the current between the ground of the voltage conversion circuit and the ground of the switch circuit, and to turn on the switch module when the current is greater than or equal to the preset current so that the first logic signal is output to the second input terminal of the second logic module, and to turn off the switch module when the current is less than the preset current so that the second input terminal of the second logic module is at the first level; the second logic module is used to output a fault signal to the fault alarm module when the signals at the first input terminal and the second input terminal are both at the second level, so as to control the operation of the fault alarm module.

[0006] In some embodiments, the fault alarm module includes an alarm unit and a delay unit; the output end of the second logic module is connected to the alarm unit and the delay unit respectively, and the delay unit is also used to connect to the switch control circuit; the alarm unit is used to indicate a circuit fault when receiving the fault signal; the delay unit is used to delay the fault signal for a preset time and transmit it to the switch control circuit, so that the switch control circuit controls the battery to stop supplying power to the voltage conversion circuit.

[0007] In some embodiments, the delay unit includes a resistor R11, a capacitor C2, a resistor R12, a switch tube Q5 and a resistor R9; one end of the resistor R11 is respectively connected to the output end of the second logic module and the alarm unit, the other end of the resistor R11 is respectively connected to one end of the capacitor C2, one end of the resistor R12 and the control end of the switch tube Q5, the other end of the capacitor C2, the other end of the resistor R12 and the first end of the switch tube Q5 are all grounded, the second end of the switch tube Q5 is connected to one end of the resistor R9, and the other end of the resistor R9 is used to connect to the switch control circuit.

[0008] In some embodiments, the first logic module includes a voltage sampling unit and a logic unit; the voltage sampling unit is used to connect the output end of the voltage conversion circuit, the first input end of the logic unit is used to connect the control signal, the second input end of the logic unit is also connected to the voltage sampling unit, and the output end of the logic unit is respectively connected to the first input end of the second logic module and the switch module; wherein the voltage sampling unit is used to output a sampling voltage to the logic unit based on the output voltage of the voltage conversion circuit; the logic unit is used to output the first logic signal to the first input end of the second logic module according to the sampling voltage and the control signal, wherein when the sampling voltage is greater than or equal to the second preset voltage and the control signal is the second level, the first logic signal is the first level, and when the sampling voltage is less than the second preset voltage or the control signal is the first level, the first logic signal is the second level.

[0009] In some embodiments, the logic unit includes a NAND gate U1; the first input end of the NAND gate U1 is used to connect the control signal, the second input end of the NAND gate U1 is connected to the voltage sampling unit, and the output end of the NAND gate U1 is respectively connected to the first input end of the second logic module and the switch module.

[0010] In some embodiments, the switch module includes a resistor R14, a switch tube Q6 and a resistor R10; one end of the resistor R14 is connected to the sampling module, the other end of the resistor R14 is connected to the control end of the switch tube Q6, one end of the resistor R10 is connected to the first logic module, the other end of the resistor R10 is connected to the first end of the switch tube Q6, and the second end of the switch tube Q6 is connected to the second input end of the second logic module.

[0011] In some embodiments, the second logic module includes an AND gate U2; a first input end of the AND gate U2 is connected to the first logic module, a second input end of the AND gate U2 is connected to the switch module, and an output end of the AND gate U2 is connected to the fault alarm module.

[0012] In some embodiments, the second logic module further includes a resistor R8; one end of the resistor R8 is connected to the first logic module, and the other end of the resistor R8 is connected to the first input end of the AND gate U2.

[0013] In a second aspect, an embodiment of the utility model provides a power supply device, which includes: a battery, a switching circuit, a voltage conversion circuit, and a protection circuit as described in any embodiment of the first aspect; the switching circuit is respectively connected to the output end of the battery and the input end of the voltage conversion circuit, the output end of the voltage conversion circuit is connected to the first logic module, and the sampling module is respectively connected to the negative pole of the voltage conversion circuit and the negative pole of the switching circuit; the switching circuit is used to receive a control signal, and establish or disconnect the connection between the battery and the voltage conversion circuit based on the control signal to control the operation of the voltage conversion circuit.

[0014] In a third aspect, an embodiment of the utility model provides an energy storage device, which includes: a load; a power supply device as described in the second aspect, wherein the output end of the voltage conversion circuit is connected to the load for supplying power to the load.

[0015] Compared with the prior art, the utility model has the following beneficial effects: Different from the prior art, the utility model provides a protection circuit, a power supply device and an energy storage device, wherein the protection circuit includes: a first logic module, a sampling module, a switch module, a second logic module and a fault alarm module; the first logic module is used to connect the output end of the voltage conversion circuit and the control signal of the switch circuit respectively, the first logic module is connected to the first input end of the second logic module, the switch module is connected to the second input end of the second logic module, the first logic module and the sampling module respectively, and the output end of the second logic module is connected to the fault alarm module. In this circuit, when an abnormal situation occurs in the switch circuit and / or the voltage conversion circuit in the power supply device, the first logic module and the second logic module can be used to perform a logical judgment on the current circuit status, so as to control the operation of the fault alarm module, perform a fault alarm, and prompt the current circuit fault, thereby improving the safety and reliability of the power supply device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements / modules and steps with the same reference numerals in the drawings are represented as similar elements / modules and steps. Unless otherwise specified, the figures in the drawings do not constitute proportional limitations.

[0017] Figure 1 It is a partial circuit structure diagram of a power supply device provided by an embodiment of the utility model;

[0018] Figure 2 It is a structural block diagram of a protection circuit provided by an embodiment of the utility model;

[0019] Figure 3 It is a circuit structure diagram of a protection circuit provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0020] The utility model is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be pointed out that for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the utility model. These all fall within the scope of protection of the utility model.

[0021] For ease of understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those generally understood by those skilled in the art of the present application. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not used to limit the present application. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0022] It should be noted that, if there is no conflict, the various features in the embodiments of the present utility model can be combined with each other, and all are within the scope of protection of this application. In addition, although the functional module division is performed in the device schematic, in some cases, the module division can be different from that in the device. In addition, the words "first", "second", etc. used in this article do not limit the data and execution order, but only distinguish the same items or similar items with basically the same functions and effects.

[0023] As energy storage power supplies are increasingly used, DC output is an essential function, such as USB-A, USB-C, cigarette lighter, etc. These functions generally draw power from the output end of the battery, and the output voltage of the battery is higher than the output voltage of these functions, so these functions generally use a buck topology. Its circuit is as follows Figure 1 As shown, the voltage conversion circuit 120 obtains power from the output terminal VBAT of the battery through the switch tube Q1 in the switch circuit 110. The switch tube Q1 is controlled by the DC_EN signal. When DC_EN is at a high level, the switch tube Q1 is turned on and the voltage conversion circuit 120 works; when DC_EN is at a low level, the switch tube Q1 is turned off and the voltage conversion circuit 120 does not work.

[0024] However, this circuit and control method have safety risks when abnormalities occur. First, when the switch tube Q1 is damaged and short-circuited, the voltage conversion circuit 120 always has an output voltage Vout regardless of whether there is a DC_EN signal or not, which poses a safety hazard; second, when the voltage conversion circuit 120 is damaged, that is, the capacitor CE2 is short-circuited or the switch tube Q2 and the switch tube Q3 are short-circuited, when the user turns on the DC output, that is, the DC_EN signal controls the switch tube Q1 to turn on, the circuit forms a current loop, and the controller detects that there is no output voltage Vout within a certain period of time, and will turn off the DC_EN signal, so that the switch tube Q1 is cut off and there is no loop, but during this period, the damaged device may smoke or even catch fire; third, when the switch tube Q1 is damaged and short-circuited and the voltage conversion circuit 120 is damaged, that is, when the switch tube Q1 and the capacitor CE2 are short-circuited or the switch tubes Q1, Q2, and Q3 are short-circuited, as long as the energy storage power supply is activated, a current loop will be formed, and the device will be damaged, smoke or even catch fire, until the loop is burned out.

[0025] In summary, when the DC output circuit of the energy storage power supply has a switching circuit abnormality and / or a step-down circuit abnormality, the safety and reliability of the energy storage power supply cannot be guaranteed.

[0026] In order to improve the above technical problems, the utility model provides a protection circuit, a power supply device and an energy storage device. When a switch circuit and / or a step-down circuit fails, the second logic module in the circuit can control the operation of the fault alarm module, thereby improving the safety and reliability of the product.

[0027] In a first aspect, an embodiment of the present utility model provides a protection circuit, which is applied to a power supply device, see Figure 2 The power supply device includes a switch circuit 110 and a voltage conversion circuit 120. The switch circuit 110 is respectively connected to the output end of the battery and the input end of the voltage conversion circuit 120. The protection circuit includes: a first logic module 210, a sampling module 220, a switch module 230, a second logic module 240 and a fault alarm module 250.

[0028] The first logic module 210 is respectively used to connect the output end of the voltage conversion circuit 120 and the control signal of the switch circuit 110. The first logic module 210 is connected to the first input end of the second logic module 240. The switch module 230 is respectively connected to the second input end of the second logic module 240, the first logic module 210 and the sampling module 220. The output end of the second logic module 240 is connected to the fault alarm module 250.

[0029] The first logic module 210 is used to output a first logic signal to a first input terminal of the second logic module 240 according to the output voltage of the voltage conversion circuit 120 and the control signal; wherein, when the output voltage is greater than or equal to the first preset voltage and the control signal is at the second level, the first logic signal is at the first level; when the output voltage is less than the first preset voltage or the control signal is at the first level, the first logic signal is at the second level;

[0030] The sampling module 220 is used to detect the current between the ground of the voltage conversion circuit 120 and the ground of the switch circuit 110, and to turn on the switch module 230 when the current is greater than or equal to the preset current, so that the first logic signal is output to the second input terminal of the second logic module 240, and to turn off the switch module 230 when the current is less than the preset current, so that the second input terminal of the second logic module 240 is at the first level. The second logic module 240 is used to output a fault signal to the fault alarm module 250 when the signals at the first input terminal and the second input terminal are both at the second level, so as to control the operation of the fault alarm module 250.

[0031] The control signal of the switch circuit 110 can be output by a microcontroller unit (MCU). The switch circuit 110 is connected between the output terminal of the battery and the input terminal of the voltage conversion circuit 120. Figure 1 , the switch circuit 110 may include a resistor R3, a resistor R4, a switch tube Q4, a resistor R1, a resistor R2 and a switch tube Q1. In normal operation of the circuit, the switch circuit 110 may be turned on or off based on a control signal. When the switch circuit 110 is turned on, a connection between the output end of the battery and the input end of the voltage conversion circuit 120 is established. In this way, the voltage conversion circuit 120 will convert the voltage of the battery, and the subsequent circuit will be powered. When the switch circuit 110 is turned off, the connection between the output end of the battery and the input end of the voltage conversion circuit 120 will be disconnected. In this way, the voltage conversion circuit 120 does not work, and the subsequent circuit will not be powered. The specific structure of the switch circuit 110 can refer to the prior art and is not limited here.

[0032] The voltage conversion circuit 120 is a DC-to-DC step-down circuit, which can be used to step down the output voltage of the battery, and may include Figure 1 The capacitor CE2, the switch tube Q1, the inductor L1, the switch tube Q3 and the capacitor CE3, the specific structure of the voltage conversion circuit 120 can refer to the existing technology and is not limited here.

[0033] After receiving the fault signal, the fault alarm module 250 considers that a fault occurs in the current circuit and triggers a corresponding alarm or indication.

[0034] In the present application, the low level is taken as the first level and the high level is taken as the second level as an example for explanation. In practical applications, the high level can be the first level and the low level can be the second level according to actual needs.

[0035] In the protection circuit, when the switch circuit 110 is damaged and short-circuited, and the voltage conversion circuit 120 works normally, that is, the control signal is at a low level and the output voltage is greater than or equal to the first preset voltage, the first logic module 210 outputs a high-level first logic signal. In addition, when the voltage conversion circuit 120 is connected to a load so that the current between the ground of the voltage conversion circuit 120 and the ground of the switch circuit 110 is greater than the preset current, the switch module 230 is turned on, and the first logic signal will be output to the second input terminal of the second logic module 240. Since the first logic signal is at a high level, the first input terminal and the second input terminal of the second logic module 240 are both at a high level, and the second logic module 240 will output a fault signal to the fault alarm module 250, and the fault alarm module 250 will work.

[0036] When the switch circuit 110 is normally turned on and the voltage conversion circuit 120 is damaged, that is, when the control signal is at a high level and the output voltage is less than the first preset voltage, the first logic module 210 outputs a high-level first logic signal. In addition, the damaged voltage conversion circuit 120 forms a current loop with the input source, so that the current between the ground of the voltage conversion circuit 120 and the ground of the switch circuit 110 is greater than the preset current, the switch module 230 is turned on, and the first logic signal will be output to the second input terminal of the second logic module 240. Since the first logic signal is at a high level, the first input terminal and the second input terminal of the second logic module 240 are both at a high level, and the second logic module 240 will output a fault signal to the fault alarm module 250, and the fault alarm module 250 will work.

[0037] When the switch circuit 110 and the voltage conversion circuit 120 are operating normally, that is, when the control signal is at a high level and the output voltage is greater than or equal to the first preset voltage, the first logic module 210 outputs a low level. At this time, regardless of the current condition detected by the sampling module 220, the second logic module 240 outputs a low level, and the second logic module 240 does not output a fault signal to the fault alarm module 250, and the fault alarm module 250 does not operate.

[0038] When the control signal is at a low level and the output voltage is less than the first preset voltage, the first logic module 210 outputs a high level. If the current detected by the sampling module 220 is less than the preset current at this time, the switch module 230 is disconnected, the second input terminal of the second logic module 240 is at a low level, the second logic module 240 does not output a fault signal to the fault alarm module 250, and the fault alarm module 250 does not work. If the switch circuit 110 and the voltage conversion circuit 120 are both short-circuited, the current detected by the sampling module 220 is greater than or equal to the preset current, that is, the switch module 230 is turned on, and the first logic signal will be output to the second input terminal of the second logic module 240. Since the first logic signal is at a high level, the first input terminal and the second input terminal of the second logic module 240 are both at a high level, and the second logic module 240 will output a fault signal to the fault alarm module 250, and the fault alarm module 250 will work.

[0039] It can be seen that the protection circuit provided in this embodiment can control the fault alarm module 250 to operate when an abnormal situation occurs in the switch circuit 110 and / or the voltage conversion circuit 120 in the power supply device, prompting the current circuit fault, thereby improving the safety and reliability of the power supply device.

[0040] In some of these examples, see Figure 3 The fault alarm module 250 includes an alarm unit 251 and a delay unit 252. The output end of the second logic module 240 is connected to the alarm unit 251 and the delay unit 252 respectively, and the delay unit 252 is also used to connect to the switch control circuit 130. The alarm unit 251 is used to indicate a circuit fault when receiving a fault signal; the delay unit 252 is used to delay the fault signal for a preset time and transmit it to the switch control circuit 130, so that the switch control circuit 130 controls the battery to stop supplying power to the voltage conversion circuit 120.

[0041] The alarm unit 251 may include a microcontroller and at least one of a buzzer, a display and a vibrator, so that when the microcontroller receives a fault signal, the above-mentioned devices are controlled to work to indicate the current circuit fault.

[0042] The switch control circuit 130 may include a driver chip, which is used to control the conduction or disconnection of the discharge tube of the battery. The delay unit 252 is used to transmit the fault signal to the switch control circuit 130 after a preset time, such as 3 seconds after receiving the fault signal. After receiving the fault signal, the switch control circuit 130 controls the battery to stop supplying power to the voltage conversion circuit 120, such as controlling the discharge tube of the battery to be turned off, so that the battery stops outputting electrical energy to the voltage conversion circuit 120, and the power supply device is powered off and shut down, so as to prevent the device from smoking or catching fire, thereby improving the safety and reliability of the circuit operation. Compared with the embodiment without the delay unit 252, this embodiment can delay the power supply device from being powered off after indicating the fault when a fault occurs, so that the user can understand the reason for the current power off and shutdown, thereby improving the user experience.

[0043] In some of these embodiments, please continue to see Figure 2 The delay unit 252 includes a resistor R11, a capacitor C2, a resistor R12, a switch tube Q5 and a resistor R9. One end of the resistor R11 is connected to the output end of the second logic module 240 and the alarm unit 251 respectively, and the other end of the resistor R11 is connected to one end of the capacitor C2, one end of the resistor R12 and the control end of the switch tube Q5 respectively. The other end of the capacitor C2, the other end of the resistor R12 and the first end of the switch tube Q5 are all grounded GND, the second end of the switch tube Q5 is connected to one end of the resistor R9, and the other end of the resistor R9 is used to connect to the switch control circuit 130.

[0044] The switch tube Q5 can be an NMOS tube, the control end of the switch tube Q5 is the gate of the NMOS tube, the second end of the switch tube Q5 is the drain of the NMOS tube, and the first end of the switch tube Q5 is the source of the NMOS tube. In practical applications, the switch tube Q5 can also be other suitable switch devices.

[0045] In the delay unit 252, if the circuit fails, the output end of the second logic module 240 will output a high level, and the high level will be output to the capacitor C2 after passing through the resistor R11, and the capacitor C2 will start to charge. When the voltage at the first end of the capacitor C2 is charged to the conduction threshold of the switch tube Q5, the switch tube Q5 is turned on, and the switch control circuit 130 is connected to the ground at one end of the resistor R9, and the switch control circuit 130 will control the battery to stop outputting electrical energy to the voltage conversion circuit 120, so that the power supply device is powered off. If the circuit does not fail, the output end of the second logic module 240 will output a low level, and the low level will be output to the control end of the switch tube Q5 after passing through the resistor R11, and the switch tube Q5 is disconnected, which does not affect the operation of the switch control circuit 130. It can be seen that by setting the charging time of the capacitor C2, the preset time can be set.

[0046] In this embodiment, by setting a capacitor and a switch tube as the delay unit 252, it is possible to output a signal to the switch control circuit 130 after a preset delay time after receiving a fault signal.

[0047] In some of these embodiments, please continue to see Figure 3 The first logic module 210 includes a voltage sampling unit 211 and a logic unit 212. The voltage sampling unit 211 is used to connect to the output terminal Vout of the voltage conversion circuit 120, the first input terminal of the logic unit 212 is used to connect to the control signal DC_EN, the second input terminal of the logic unit 212 is also connected to the voltage sampling unit 211, and the output terminal of the logic unit 212 is respectively connected to the first input terminal of the second logic module 240 and the switch module 230.

[0048] The voltage sampling unit 211 is used to output a sampling voltage to the logic unit 212 based on the output voltage of the voltage conversion circuit 120. The logic unit 212 is used to output a first logic signal to the first input terminal of the second logic module 240 according to the sampling voltage and the control signal, wherein when the sampling voltage is greater than or equal to the second preset voltage and the control signal is at the second level, the first logic signal is at the first level, and when the sampling voltage is less than the second preset voltage or the control signal is at the first level, the first logic signal is at the second level.

[0049] In the first logic module 210, when the output voltage is greater than or equal to the first preset voltage, the sampling voltage will be greater than or equal to the second preset voltage, and when the output voltage is less than the first preset voltage, the sampling voltage will be less than the second preset voltage.

[0050] Specifically, the voltage sampling unit 211 includes a resistor R6 and a resistor R7, wherein a first end of the resistor R6 is connected to an output end of the voltage conversion circuit 120, a second end of the resistor R6 is respectively connected to a second input end of the logic unit 212 and a first end of the resistor R7, and a second end of the resistor R7 is grounded. In the voltage sampling unit 211, the resistor R6 and the resistor R7 form a voltage divider circuit, which divides the output voltage and outputs the sampled voltage to the logic unit 212.

[0051] In this embodiment, the output voltage is sampled by the voltage sampling unit 211, and the logic unit 212 performs logic judgment on the sampled voltage and the control signal to ensure the reliability of the circuit operation.

[0052] In some of these embodiments, please continue to see Figure 3 The logic unit 212 includes a NAND gate U1. The first input terminal of the NAND gate U1 is used to connect the control signal, the second input terminal of the NAND gate U1 is connected to the voltage sampling unit 211, and the output terminal of the NAND gate U1 is respectively connected to the first input terminal of the second logic module 240 and the switch module 230.

[0053] The NAND gate U1 outputs a high level when one or more of the two input terminal signals are at a low level, and outputs a low level when both input terminal signals are at a high level.

[0054] In this embodiment, by providing the NAND gate U1, the number of logic elements can be reduced, and the reliability and stability of the circuit operation can be improved.

[0055] In some of these examples, see Figure 1 and Figure 3 The sampling module 220 includes a resistor R5, a resistor R15, a resistor R16, a resistor R13, a resistor C1, an operational amplifier U3, a capacitor C3 and a resistor R17, wherein one end of the resistor R15 is respectively connected to one end of the resistor R5 and the ground GND_BUCK of the voltage conversion circuit 120, one end of the resistor R16 is respectively connected to the other end of the resistor R5 and the ground GND of the switch circuit, the other end of the resistor R15 is respectively connected to one end of the resistor R13, one end of the capacitor C1 and the first input end of the operational amplifier U3, the other end of the resistor R13 and the other end of the capacitor C1 are both grounded GND, the other end of the resistor R16 is respectively connected to the second input end of the operational amplifier U3, one end of the capacitor C3 and one end of the resistor R17, and the output end of the operational amplifier U3 is respectively connected to the other end of the capacitor C3, the other end of the resistor R17 and the switch module 230.

[0056] In the sampling module 220, by converting the current of the resistor R5 into a voltage and amplifying it, the current flowing through the resistor R5 can be obtained to implement current sampling. The specific working process of the sampling module 220 can refer to the existing technology and will not be elaborated here.

[0057] In some of these examples, see Figure 3 The switch module 230 includes a resistor R14, a switch tube Q6, and a resistor R10. One end of the resistor R14 is connected to the sampling module 220, the other end of the resistor R14 is connected to the control end of the switch tube Q6, one end of the resistor R10 is connected to the first logic module 210, the other end of the resistor R10 is connected to the first end of the switch tube Q6, and the second end of the switch tube Q6 is connected to the second input end of the second logic module 240.

[0058] The switch tube Q6 can be an NPN transistor, the control end of the switch tube Q6 is the base of the NPN transistor, the first end of the switch tube Q6 is the collector of the NPN transistor, and the second end of the switch tube Q6 is the emitter of the NPN transistor. In practical applications, the switch tube Q6 can also use other suitable switching devices. Specifically, one end of the resistor R10 is connected to the output end of the NAND gate U1.

[0059] In the switch module 230, when the sampling module 220 outputs a high level, the switch tube Q6 will be turned on, thereby establishing a connection between the first logic module 210 and the second input terminal of the second logic module 240; when the sampling module 220 outputs a low level, the switch tube Q6 will be turned off, thereby disconnecting the connection between the first logic module 210 and the second input terminal of the second logic module 240, making the second input terminal of the second logic module 240 a low level.

[0060] In some of these examples, see Figure 3 The second logic module 240 includes an AND gate U2 . A first input end of the AND gate U2 is connected to the first logic module 210 , a second input end of the AND gate U2 is connected to the switch module 230 , and an output end of the AND gate U2 is connected to the fault alarm module 250 .

[0061] The AND gate U2 outputs a low level when one or more of the two input terminal signals are at a low level, and outputs a high level when both of the two input terminal signals are at a high level.

[0062] In this embodiment, by providing the AND gate U1, the number of logic elements can be reduced, and the reliability and stability of the circuit operation can be improved.

[0063] In some of these embodiments, please continue to see Figure 3 The second logic module 240 further includes a resistor R8. One end of the resistor R8 is connected to the first logic module 210, and the other end of the resistor R8 is connected to the first input end of the AND gate U2.

[0064] Specifically, one end of the resistor R8 is connected to the output end of the NAND gate U1 , and the output end of the AND gate U2 is connected to one end of the resistor R11 .

[0065] In this embodiment, the resistor R8 can be used to limit the signal size input from the NAND gate U1 to the AND gate U2, thereby protecting circuit components and improving the reliability of circuit operation.

[0066] Combine the following Figure 1 and Figure 3 The illustrated embodiment describes in detail the specific working process of the protection circuit provided by the utility model.

[0067] In this protection circuit, when the switch circuit 110 is damaged and short-circuited (such as the switch tube Q1 is damaged and short-circuited) and the voltage conversion circuit 120 works normally, that is, the control signal is at a low level and the sampling voltage is greater than or equal to the second preset voltage, the first input terminal of the NAND gate U1 is at a low level and the second input terminal receives a high level, then the NAND gate U1 outputs a first logic signal of a high level. In addition, when the voltage conversion circuit 120 is connected to a load so that the current between the ground of the voltage conversion circuit 120 and the ground of the switching circuit 110 is greater than a preset current, the sampling module 220 outputs a high level to the switch tube Q6, the switch tube Q6 is turned on, and the first logic signal will be output to the second input terminal of the AND gate U2. Since the first logic signal is a high level, the first input terminal and the second input terminal of the AND gate U2 are both high levels, and the AND gate U2 will output a high-level fault signal to the alarm unit 251 and the delay unit 252. The alarm unit 251 will indicate the current alarm, and after the delay unit 252 delays for a preset time, the switch tube Q5 will be turned on, and the switch control circuit 130 will control the battery to stop supplying power to the voltage conversion circuit 120, and the voltage conversion circuit 120 will not be powered by the battery.

[0068] When the switch circuit 110 is normally turned on and the voltage conversion circuit 120 is damaged (capacitor CE2 is short-circuited, switch tube Q2 or switch tube Q3 is short-circuited), that is, when the control signal is at a high level and the sampling voltage is less than the second preset voltage, the second input terminal of the NAND gate U1 is at a low level, and the NAND gate U1 outputs a high-level first logic signal. In addition, the damaged voltage conversion circuit 120 forms a current loop with the input source, so that the current between the ground of the voltage conversion circuit 120 and the ground of the switch circuit 110 is greater than the preset current, the sampling module 220 outputs a high level to the switch tube Q6, the switch tube Q6 is turned on, and the first logic signal will be output to the second input terminal of the AND gate U2. Since the first logic signal is at a high level, the first input terminal and the second input terminal of the AND gate U2 are both at a high level, and the AND gate U2 will output a fault signal to the fault alarm module 250, and the fault alarm module 250 works.

[0069] When the switch circuit 110 and the voltage conversion circuit 120 are operating normally, that is, the control signal is at a high level and the output voltage is greater than or equal to the first preset voltage, the first input terminal and the second input terminal of the NAND gate U1 are both at a high level, and the NAND gate U1 outputs a low level. At this time, regardless of the current condition detected by the sampling module 220, the AND gate U2 outputs a low level, and the AND gate U2 does not output a fault signal to the fault alarm module 250, and the fault alarm module 250 does not operate.

[0070] When the control signal is at a low level and the output voltage is less than the first preset voltage, the first input terminal and the second input terminal of the NAND gate U1 are both at a low level, and the NAND gate U1 outputs a high level. If the current detected by the sampling module 220 is less than the preset current at this time, the sampling module 220 outputs a low level to the switch tube Q6, the switch tube Q6 is turned off, the second input terminal of the AND gate U2 is at a low level, and the AND gate U2 does not output a fault signal to the fault alarm module 250, and the fault alarm module 250 does not work. If the switch circuit 110 and the voltage conversion circuit 120 are both short-circuited, such as the switch tube Q1 and the capacitor CE2 are both short-circuited and the switch tube Q1, the switch tube Q2 or the switch tube Q3 is short-circuited, then the current detected by the sampling module 220 is greater than or equal to the preset current, that is, the sampling module 220 outputs a high level to the switch tube Q6, the switch tube Q6 is turned on, and the first logic signal will be output to the second input terminal of the AND gate U2. Since the first logic signal is a high level, the first input terminal and the second input terminal of the AND gate U2 are both high levels, and the AND gate U2 will output a fault signal to the fault alarm module 250, and the fault alarm module 250 will work.

[0071] In summary, in this embodiment, if the switch circuit 110 and / or the voltage conversion circuit 120 is abnormal, a fault signal can be output to the fault alarm module 250 through the logic module and the sampling module, indicating the current circuit fault and powering off the circuit, reducing device damage and preventing it from smoking or catching fire, thereby improving the safety and reliability of the circuit.

[0072] In the second aspect, the embodiment of the utility model further provides a power supply device, which includes: a battery, a switch circuit 110, a voltage conversion circuit 120, and a protection circuit as described in any embodiment of the first aspect. The switch circuit 110 is respectively connected to the output end of the battery and the input end of the voltage conversion circuit 120, the output end of the voltage conversion circuit 120 is connected to the first logic module 210, and the sampling module 220 is respectively connected to the negative electrode of the voltage conversion circuit 120 and the negative electrode of the switch circuit 110. The switch circuit 110 is used to receive a control signal, and establish or disconnect the connection between the battery and the voltage conversion circuit 120 based on the control signal to control the operation of the voltage conversion circuit 120.

[0073] In this embodiment, the protection circuit has the same structure and function as the protection circuit described in any one of the embodiments of the first aspect, which will not be described in detail here. In the power supply device, when the switch circuit 110 and / or the voltage conversion circuit 120 is abnormal, the fault alarm module 250 can be controlled to work to indicate the current circuit fault, thereby improving the safety and reliability of the circuit.

[0074] In a third aspect, an embodiment of the utility model further provides an energy storage device, which includes: a load and a power supply device as described in the embodiment of the second aspect, wherein the output end of the voltage conversion circuit 120 is connected to the load for supplying power to the load.

[0075] In this embodiment, the power supply device has the same structure and function as the power supply device described in any embodiment of the second aspect, which will not be described in detail. The load may be a variety of electronic devices that can be used to consume the power supply from the voltage conversion circuit 120.

[0076] It should be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Under the idea of ​​the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A protection circuit, characterized in that: The protection circuit is applied to a power supply device, the power supply device includes a switch circuit and a voltage conversion circuit, the switch circuit is respectively connected to the output end of the battery and the input end of the voltage conversion circuit, and the protection circuit includes: a first logic module, a sampling module, a switch module, a second logic module and a fault alarm module; The first logic module is used to connect the output end of the voltage conversion circuit and the control signal of the switch circuit respectively, the first logic module is connected to the first input end of the second logic module, the switch module is respectively connected to the second input end of the second logic module, the first logic module and the sampling module, and the output end of the second logic module is connected to the fault alarm module; The first logic module is used to output a first logic signal to a first input terminal of the second logic module according to the output voltage of the voltage conversion circuit and the control signal; wherein, when the output voltage is greater than or equal to the first preset voltage and the control signal is at the second level, the first logic signal is at the first level; when the output voltage is less than the first preset voltage or the control signal is at the first level, the first logic signal is at the second level; The sampling module is used to detect the current between the ground of the voltage conversion circuit and the ground of the switch circuit, and to turn on the switch module when the current is greater than or equal to a preset current so that the first logic signal is output to the second input end of the second logic module, and to turn off the switch module when the current is less than the preset current so that the second input end of the second logic module is at the first level; The second logic module is used for outputting a fault signal to the fault alarm module to control the operation of the fault alarm module when the signals at the first input terminal and the second input terminal are both at the second level.

2. The protection circuit according to claim 1, characterized in that: The fault alarm module includes an alarm unit and a delay unit; The output end of the second logic module is respectively connected to the alarm unit and the delay unit, and the delay unit is also used to connect to the switch control circuit; The alarm unit is used to indicate a circuit fault when receiving the fault signal; The delay unit is used to delay the fault signal for a preset time and transmit it to the switch control circuit, so that the switch control circuit controls the battery to stop supplying power to the voltage conversion circuit.

3. The protection circuit according to claim 2, characterized in that: The delay unit includes a resistor R11, a capacitor C2, a resistor R12, a switch tube Q5 and a resistor R9; One end of the resistor R11 is respectively connected to the output end of the second logic module and the alarm unit, the other end of the resistor R11 is respectively connected to one end of the capacitor C2, one end of the resistor R12 and the control end of the switch tube Q5, the other end of the capacitor C2, the other end of the resistor R12 and the first end of the switch tube Q5 are all grounded, the second end of the switch tube Q5 is connected to one end of the resistor R9, and the other end of the resistor R9 is used to connect to the switch control circuit.

4. The protection circuit according to claim 1, characterized in that: The first logic module includes a voltage sampling unit and a logic unit; The voltage sampling unit is used to connect the output end of the voltage conversion circuit, the first input end of the logic unit is used to connect the control signal, the second input end of the logic unit is also connected to the voltage sampling unit, and the output end of the logic unit is respectively connected to the first input end of the second logic module and the switch module; Wherein, the voltage sampling unit is used to output a sampling voltage to the logic unit based on the output voltage of the voltage conversion circuit; The logic unit is used to output the first logic signal to the first input end of the second logic module according to the sampling voltage and the control signal, wherein when the sampling voltage is greater than or equal to the second preset voltage and the control signal is at the second level, the first logic signal is at the first level, and when the sampling voltage is less than the second preset voltage or the control signal is at the first level, the first logic signal is at the second level.

5. The protection circuit according to claim 4, characterized in that: The logic unit includes a NAND gate U1; The first input end of the NAND gate U1 is used to connect the control signal, the second input end of the NAND gate U1 is connected to the voltage sampling unit, and the output end of the NAND gate U1 is respectively connected to the first input end of the second logic module and the switch module.

6. The protection circuit according to claim 1, characterized in that: The switch module includes a resistor R14, a switch tube Q6 and a resistor R10; One end of the resistor R14 is connected to the sampling module, the other end of the resistor R14 is connected to the control end of the switch tube Q6, one end of the resistor R10 is connected to the first logic module, the other end of the resistor R10 is connected to the first end of the switch tube Q6, and the second end of the switch tube Q6 is connected to the second input end of the second logic module.

7. The protection circuit according to claim 1, characterized in that: The second logic module includes an AND gate U2; The first input end of the AND gate U2 is connected to the first logic module, the second input end of the AND gate U2 is connected to the switch module, and the output end of the AND gate U2 is connected to the fault alarm module.

8. The protection circuit according to claim 7, characterized in that: The second logic module also includes a resistor R8; One end of the resistor R8 is connected to the first logic module, and the other end of the resistor R8 is connected to the first input end of the AND gate U2.

9. A power supply device, characterized in that: include: A battery, a switch circuit, a voltage conversion circuit, and a protection circuit as claimed in any one of claims 1 to 8; The switch circuit is respectively connected to the output end of the battery and the input end of the voltage conversion circuit, the output end of the voltage conversion circuit is connected to the first logic module, and the sampling module is respectively connected to the negative electrode of the voltage conversion circuit and the negative electrode of the switch circuit; The switch circuit is used to receive a control signal, and establish or disconnect the connection between the battery and the voltage conversion circuit based on the control signal, so as to control the operation of the voltage conversion circuit.

10. An energy storage device, characterized in that: include: load; According to the power supply device as claimed in claim 9, the output end of the voltage conversion circuit is connected to the load for supplying power to the load.

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