Standby power supply circuit and fault recording equipment

Abstract

The embodiment of the utility model provides a standby power supply circuit and a fault recording device. The standby power supply device comprises a bias unit, a standby power supply unit, a discharge switch unit and a discharge switch control unit, a first input end of the bias unit is used for connecting a main power supply, a second input end of the bias unit is used for inputting a bias switch signal, an output end of the bias unit is connected with an input end of the standby power supply unit, and a grounding end of the bias unit is used for grounding; the grounding end of the standby power supply unit is grounded, the first output end of the standby power supply unit is used for connecting a first to-be-powered unit, and the second output end of the standby power supply unit is connected with the first input end of the discharge switch unit; the output end of the discharge switch unit is used for being connected with a second unit to be powered, and the second input end of the discharge switch unit is connected with the discharge switch control unit. The standby power supply device is simple in design structure, simple in logic and low in cost.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field, more particularly to a standby power supply circuit and fault recording equipment. BACKGROUND

[0002] With the continuous development of national economy and society, the power load is rapidly growing, the scale of power transmission and distribution is expanding, and the power system is increasingly complex. The fault recording device is an important device for recording electrical quantities in the power system, which reflects the operation status of each power equipment in the power system.

[0003] The fault recording device is generally powered by the main power supply, and in order to ensure the stable operation of the fault recording device, when the main power supply supplying power to the fault recording device fails, the standby power supply needs to supply power to the fault recording device. Therefore, how to design a simple and low-cost standby power supply is a problem to be solved. UTILITY MODEL CONTENT

[0004] The utility model aims at the deficiency in prior art, provides a standby power supply circuit, and provides a simple and low-cost standby power supply device.

[0005] To achieve the above purpose, the technical scheme adopted by the utility model embodiment is as follows:

[0006] The utility model provides a kind of standby power supply circuit, and the standby power supply circuit includes:

[0007] Including: bias unit, standby power supply unit, discharge switch unit and discharge switch control unit;

[0008] The first input end of the bias unit is used to connect the main power supply, the second input end of the bias unit is used to input bias switch signal, the output end of the bias unit is connected with the input end of the standby power supply unit and the first power supply unit respectively, and the ground end of the bias unit is used for grounding;

[0009] The ground end of the standby power supply unit is grounded, the first output end of the standby power supply unit is used to connect the first power supply unit, and the second output end of the standby power supply unit is connected with the first input end of the discharge switch unit;

[0010] The output end of the discharge switch unit is used to connect the second power supply unit, and the second input end of the discharge switch unit is connected with the discharge switch control unit.

[0011] Optionally, the bias unit includes a first diode and a voltage reduction module;

[0012] The positive electrode of the first diode is connected with the main power supply, and the negative electrode of the first diode is connected with the output end of the voltage reduction module and the input end of the backup power supply unit respectively.

[0013] The input end of the voltage reduction module is used for inputting the bias switch signal, and the ground end of the voltage reduction module is grounded.

[0014] Optionally, the voltage reduction module comprises a first resistor, a second resistor, a third resistor and a triode.

[0015] One end of the first resistor is connected with the negative electrode of the first diode, and the other end of the first resistor is connected with the second end of the triode.

[0016] One end of the second resistor is used for inputting the bias switch signal, and the other end of the second resistor is connected with one end of the third resistor and the first end of the triode respectively.

[0017] The other end of the third resistor and the third end of the triode are both grounded.

[0018] Optionally, the backup power supply unit comprises a current limiting module, a backup power supply module and a voltage stabilizing module.

[0019] The first input end of the current limiting module is connected with the output end of the bias unit, the second input end of the current limiting module is connected with the first end of the backup power supply module, the output end of the backup power supply module is connected with the first input end of the discharge switch unit, the output end of the current limiting module is connected with the input end of the voltage stabilizing module, and the output end of the voltage stabilizing module is used for connecting the first to-be-powered unit.

[0020] The ground end of the backup power supply module is grounded.

[0021] Optionally, the current limiting module comprises a fourth resistor, a fifth resistor, a sixth resistor and a seventh resistor.

[0022] One end of the fourth resistor, one end of the fifth resistor, one end of the sixth resistor and one end of the seventh resistor are connected with the output end of the bias unit and the input end of the voltage stabilizing module respectively.

[0023] The other end of the fourth resistor, the other end of the fifth resistor, the other end of the sixth resistor and the other end of the seventh resistor are connected with the first end of the backup power supply module.

[0024] Optionally, the backup power supply module comprises an energy storage element, an eighth resistor and a ninth resistor.

[0025] The positive electrode of the energy storage element is connected with the second input end of the current limiting module, one end of the eighth resistor and the first input end of the discharge switch unit respectively, the other end of the eighth resistor is connected with one end of the ninth resistor, and the other end of the eighth resistor is used for outputting a capacitor voltage detection result, and the negative electrode of the energy storage element is grounded together with the other end of the ninth resistor.

[0026] Optionally, the discharge switch unit comprises a switch module and a second diode.

[0027] The first end of the switch module is connected with the second output end of the backup power supply unit, the second end of the switch module is connected with the positive electrode of the second diode, and the third end of the switch module is connected with the discharge switch control unit.

[0028] The negative electrode of the second diode is connected with the second power supply unit.

[0029] Optionally, the switch module comprises a tenth resistor, an eleventh resistor, a third diode and a field effect tube.

[0030] One end of the tenth resistor is connected with the first end of the field effect tube and the second output end of the backup power supply unit respectively, the other end of the tenth resistor is connected with the positive electrode of the third diode and the second end of the field effect tube respectively, and the third end of the field effect tube is connected with the positive electrode of the second diode.

[0031] The negative electrode of the third diode is connected with one end of the eleventh resistor, and the other end of the eleventh resistor is connected with the discharge switch control unit.

[0032] Optionally, the discharge switch control unit comprises a comparator, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a second capacitor, a third capacitor and a fourth diode.

[0033] The positive input end of the comparator is connected with one end of the twelfth resistor, one end of the thirteenth resistor, one end of the second capacitor and the negative electrode of the fourth diode respectively, and the other end of the twelfth resistor is used for connecting the first voltage of the main power supply.

[0034] The other end of the thirteenth resistor, the other end of the second capacitor and the positive electrode of the fourth diode are all grounded.

[0035] The negative input end of the comparator is connected with one end of the fourteenth resistor and one end of the fifteenth resistor respectively, the other end of the fourteenth resistor is used for connecting the second voltage of the main power supply, and the other end of the fifteenth resistor is used for grounding.

[0036] The positive power input end of the comparator is connected with the main power supply, one end of the third capacitor and one end of the sixteenth resistor respectively, the other end of the third capacitor is grounded, and the negative power input end of the comparator is grounded.

[0037] The output end of the comparator is connected with the second input end of the discharge switch unit and the other end of the sixteenth resistor respectively.

[0038] The utility model also provides a fault recording equipment, and the fault recording equipment comprises the standby power supply circuit of the first aspect.

[0039] The utility model discloses beneficial effect is: through setting up bias unit, standby power supply unit, discharge switch unit and discharge switch control unit in standby power supply circuit, when the main power supply appears the fault, discharge switch unit can be based on the control of discharge switch control unit and turn on, thereby with discharge switch unit connected the standby power supply unit is discharged through the discharge switch unit, and through connecting bias unit with main power supply and standby power supply unit, can make when the main power supply charges standby power supply switch unit, avoid overcharging phenomenon. The design structure of this standby power supply device is simple, simple and low in cost. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the following will be briefly introduced the drawing needed to be used in the embodiment, and should understand, the following drawing only shows some embodiments of the utility model, therefore should not be regarded as the limitation to the range, for ordinary skilled person in the art, under the premise of not paying the creative labor, can also obtain other related drawings according to these drawings.

[0041] Figure 1 It is the structure schematic diagram of the first standby power supply circuit provided by the utility model embodiment;

[0042] Figure 2 It is the structure schematic diagram of the second standby power supply circuit provided by the utility model embodiment;

[0043] Figure 3 It is the structure schematic diagram of the third standby power supply circuit provided by the utility model embodiment;

[0044] Figure 4 It is the structure schematic diagram of the fourth standby power supply circuit provided by the utility model embodiment;

[0045] Figure 5 It is the structure schematic diagram of the discharge switch control unit provided by the utility model embodiment. DETAILED DESCRIPTION

[0046] For the purpose, technical scheme and advantages of the embodiments of the present application to be clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of illustration and description, and are not used to limit the protection scope of the present application. In addition, it should be understood that the schematic drawings are not drawn to scale. The flowchart used in the present application shows the operations realized according to some embodiments of the present application. It should be understood that the operations of the flowchart can be realized in no order, and the steps without logical context relationship can be reversed in order or implemented simultaneously. In addition, one or more other operations can be added to the flowchart or removed from the flowchart under the guidance of the content of the present application.

[0047] In addition, the described embodiments are only some of the embodiments of the present application, not all. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art without creative labor based on the embodiments of the present application belong to the scope of protection of the present application.

[0048] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0049] In the description of the present application, it should be noted that if the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship of the product of the present application when it is usually placed, only for the convenience of describing the present application and simplifying the description, and it is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application.

[0050] In addition, if the terms "first", "second" and the like are used only to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0051] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0052] Please refer to Figure 1 is a structural schematic diagram of a first backup power supply circuit provided by the embodiments of the present application, like Figure 1As shown, the backup power supply circuit may include: a bias unit 10, a backup power supply unit 11, a discharge switch unit 12, and a discharge switch control unit 13.

[0053] like Figure 1 As shown, the first input terminal of the bias unit 10 can be used to connect to the main power supply, the second input terminal of the bias unit 10 can be used to input the bias switch signal, the output terminal of the bias unit 10 can be connected to the input terminal of the backup power supply unit 11, and the ground terminal of the bias unit 10 can be grounded.

[0054] The bias switch signal can be output by the bias switch circuit and can be a high-level signal or a low-level signal. When the bias switch signal is high, the bias unit is turned on, which can maintain the tube voltage drop, thereby preventing overcharging when the backup power supply unit 11 connected to the bias unit 10 is charging. When the bias switch signal is low, the bias unit 10 is turned off, that is, it does not work.

[0055] Continue as Figure 1 As shown, the grounding terminal of the backup power supply unit 11 can be grounded, and the first output terminal of the backup power supply unit 11 can be connected to the first unit to be powered. Simultaneously, the first unit to be powered can also be connected to the main power supply through the bias unit 10 and the backup power supply unit 11. The second output terminal of the backup power supply unit 11 can be connected to the first input terminal of the discharge switch unit 12. Specifically, the second output terminal of the backup power supply unit 11 can be connected to the first input terminal of the discharge switch unit 12 via a wire. The first unit to be powered can be a device requiring low power consumption and long-term operation, such as an RTC circuit. When the backup power supply unit 11 is working, it can output a supply voltage to the first unit to be powered through its first output terminal.

[0056] Continue as Figure 1 As shown, the output terminal of the discharge switch unit 12 can be connected to the second power supply unit, and the second input terminal of the discharge switch unit 12 can be connected to the discharge switch control unit 13. The discharge switch unit 12 can be turned on or off based on the control of the discharge switch control unit 13. Specifically, the discharge switch control unit 13 can send a discharge switch signal to the discharge switch unit 12, which can be a high-level signal or a low-level signal. The discharge switch unit can turn on or off based on the received discharge switch signal.

[0057] Specifically, when the main power supply fails, the discharge switch control unit 13 can send a low-level signal to the discharge switch unit 12, so as to control the discharge switch unit 12 to be turned on, at this time, the standby power supply unit 11 can output a power supply voltage to the second power supply unit through the output end of the discharge switch unit 12, wherein the second power supply unit is not limited in particular, and can be the circuit of the fault recording module or other loads that can meet the output voltage and current of the standby power supply unit. When the main power supply is normal, the discharge switch control unit 13 can send a high-level signal to the discharge switch unit, so as to control the discharge switch unit 12 to be turned off, at this time, the standby power supply unit 11 does not work, and the main power supply can charge the standby power supply unit 11.

[0058] In the embodiment, by arranging the bias unit, the standby power supply unit, the discharge switch unit and the discharge switch control unit in the standby power supply device, when the main power supply fails, the discharge switch unit can be turned on based on the control of the discharge switch control unit, so that the standby power supply unit connected with the discharge switch unit is discharged through the discharge switch unit, and by connecting the bias unit with the main power supply and the standby power supply unit, overcharging can be avoided when the main power supply charges the standby power supply switch unit. The design structure of the standby power supply device is simple, the logic is simple, and the cost is low.

[0059] Figure 2 is a structural schematic diagram of a second standby power supply circuit provided by the embodiment of the utility model, as Figure 2 shown, the bias unit 10 can include: a first diode 101 and a voltage reduction module 102.

[0060] As Figure 2 shown, the anode of the first diode 101 is connected with the main power supply, the cathode of the first diode 101 is connected with the output end of the voltage reduction module 102 and the input end of the standby power supply unit 11, the input end of the voltage reduction module 102 can be used to input a bias switch signal, specifically, the input end of the voltage reduction module 102 can be connected with the output end of the bias switch circuit, then the output end of the bias switch circuit can output the bias switch signal, and the grounding end of the voltage reduction module 102 can be grounded.

[0061] In the embodiment, when the main power supply charges the standby power supply unit, the first diode is used to realize the anti-reverse function, and the voltage reduction module is used to maintain the tube voltage drop, so that the standby power supply unit will not be overcharged.

[0062] Continuing as Figure 2 shown, the voltage reduction module 102 can include: a first resistor 1021, a second resistor 1022, a third resistor 1023 and a triode 1024.

[0063] As Figure 2As shown, one end of the first resistor 1021 can be connected with the negative electrode of the first diode 101, specifically, one end of the first resistor 1021 can be connected with the negative electrode of the first diode 101 through a wire, the other end of the first resistor 1021 can be connected with the second end of the triode 1024, one end of the second resistor 1022 can be used for inputting the bias switch signal, the other end of the second resistor 1022 can be connected with one end of the third resistor 1023 and the first end of the triode 1024 respectively, and the other end of the third resistor 1023 and the third end of the triode 1024 are both grounded. Wherein, the triode 1024 can be a semiconductor triode, also known as a bipolar transistor, specifically, it can be an NPN type triode, then the base of the triode 1024 is the first end, the emitter of the triode 1024 is the second end, and the collector of the triode 1024 is the third end.

[0064] Then, the base of the triode 1024 can be connected with the other end of the second resistor 1022 and one end of the third resistor 1023 respectively, the collector of the triode 1024 is grounded, and the emitter of the triode 1024 is connected with the other end of the first resistor 1021. When the bias switch signal of the base of the triode 1024 is pulled high, the triode 1024 is turned on, so that the first diode 101 connected with the first resistor 1021 always has current passing through, and the first resistor 1021 and the triode 1024 can maintain the tube voltage drop, so that the backup power supply unit 11 will not be overcharged.

[0065] Optionally, the triode can also be replaced by a MOS tube in the embodiment.

[0066] Figure 3 is a structural schematic diagram of a third backup power supply circuit provided by the embodiment of the utility model, as Figure 3 shown, the backup power supply unit 11 can include: a current limiting module 110, a backup power supply module 111 and a voltage stabilizing module 112.

[0067] As shown in Figure 3 , the first input end of the current limiting module 110 can be connected with the output end of the bias unit 10, specifically, the first input end of the current limiting module 110 can be connected with the negative electrode of the first diode 101 in the bias unit 10 through a wire, the second input end of the current limiting module 110 can be connected with the first end of the backup power supply module 111 respectively, wherein the first end of the backup power supply module 111 can be a charging input end or a discharging output end. The output end of the backup power supply module 111 can be connected with the first input end of the discharging switch unit 12, the output end of the current limiting module 110 can be connected with the input end of the voltage stabilizing module 112, and the output end of the voltage stabilizing module 112 can be connected with the first power supply unit. The ground end of the backup power supply module 111 is grounded.

[0068] The backup power module 111 can be charged and discharged. When the main power supply is in normal operation, the main power supply charges the backup power module 111. When the main power supply fails, the backup power module 111 starts to work and discharges.

[0069] Optionally, the current limiting module 110 can be used to limit the current when the main power supply charges the backup power module 111, preventing excessive current when charging the backup power module 111. When the main power supply is supplying power normally, the main power supply can supply power to the first unit to be powered connected to the voltage regulator module 112 through the voltage regulator module 112; when the backup power module 111 is discharging, the backup power module 111 can supply power to the first unit to be powered through the voltage regulator module 112.

[0070] Optionally, the voltage regulator module 112 may include a fifth diode 1120 and a seventeenth resistor 1121. The positive terminal of the fifth diode 1120 can be connected to the output terminal of the current limiting module 110, the negative terminal of the fifth diode 1120 can be connected to one end of the seventeenth resistor 1121, and the other end of the seventeenth resistor 1121 can be connected to the first unit to be powered. Then, the main power supply or backup power supply unit 11 can discharge to the first unit to be powered through the fifth diode 1120 and the seventeenth resistor 1121.

[0071] Continue as Figure 3 As shown, the current limiting module 110 may include: a fourth resistor 1101, a fifth resistor 1102, a sixth resistor 1103, and a seventh resistor 1104.

[0072] Optionally, one end of the fourth resistor 1101, one end of the fifth resistor 1102, one end of the sixth resistor 1103, and one end of the seventh resistor 1104 are respectively connected to the output terminal of the bias unit 10 and the input terminal of the voltage regulator module 112. Specifically, one end of the fourth resistor 1101, one end of the fifth resistor 1102, one end of the sixth resistor 1103, and one end of the seventh resistor 1104 can be connected to the negative terminal of the first diode 101 in the bias unit 10 through wires, and one end of the fourth resistor 1101, one end of the fifth resistor 1102, one end of the sixth resistor 1103, and one end of the seventh resistor 1104 can be connected to the positive terminal of the fifth diode in the voltage regulator module 112 through wires.

[0073] Optionally, the other ends of the fourth resistor 1101, the fifth resistor 1102, the sixth resistor 1103, and the seventh resistor 1104 are all connected to the first end of the backup power module 111. Therefore, the fourth resistor 1101, the fifth resistor 1102, the sixth resistor 1103, and the seventh resistor 1104 are all current-limiting resistors.

[0074] It is worth mentioning that the resistance value and the like of the current limiting resistor in the current limiting module 110 in the embodiment are selected according to the size of the backup power supply module 111, and can be increased or decreased according to the actual circuit condition.

[0075] Continuing as shown in Figure 3 , the backup power supply module 111 can include an energy storage element 1110, an eighth resistor 1111, and a ninth resistor 1112.

[0076] Among them, the energy storage element can be a capacitor element.

[0077] As shown in Figure 3 , the positive electrode of the energy storage element 1110 can be connected with the second input end of the current limiting module 110, one end of the eighth resistor 1111, and the first input end of the discharge switch unit 12 respectively, specifically, the positive electrode of the energy storage element 1110 can be connected with the other end of the fourth resistor 1101, the other end of the fifth resistor 1102, the other end of the sixth resistor 1103, and the other end of the seventh resistor 1104 in the current limiting module 110 respectively.

[0078] Optionally, the other end of the eighth resistor 1111 can be connected with one end of the ninth resistor 1112, the negative electrode of the energy storage element 1110 and the other end of the ninth resistor 1112 are both grounded, and the other end of the eighth resistor 1111 can output the capacitor voltage detection result of the energy storage element 1110. Specifically, the eighth resistor 1111 and the ninth resistor 1112 can be two resistors with the same resistance value, and the resistor with a larger resistance value can perform a voltage dividing function and collect the voltage of the energy storage element 1110 to obtain the capacitor voltage detection result, and through the collected capacitor voltage detection result, it can be judged whether the energy storage element 1110 is full.

[0079] Figure 4 is a structural diagram of a fourth backup power supply circuit provided by the embodiment of the utility model, as shown in Figure 4 , the discharge switch unit 12 can include a switch module 120 and a second diode 121.

[0080] As shown in Figure 4 , the first end of the switch module 120 can be connected with the second output end of the backup power supply unit 11, specifically, the first end of the switch module 120 can be connected with one end of the eighth resistor 1111 in the backup power supply unit 11, the second end of the switch module 120 can be connected with the positive electrode of the second diode 121, and the third end of the switch module 120 can be connected with the discharge switch control unit 13. The negative electrode of the second diode 121 is connected with the second power supply unit.

[0081] Optionally, when the switch module 120 is turned on, the backup power supply unit 11 can discharge to the second power supply unit through the switch module 120 and the second diode 121.

[0082] Continue as Figure 4 As shown, the switch module 120 may include: a tenth resistor 1201, an eleventh resistor 1202, a third diode 1203, and a field-effect transistor 1204.

[0083] like Figure 4 As shown, one end of the tenth resistor 1201 can be connected to the first terminal of the field-effect transistor 1204 and the second output terminal of the backup power supply unit 11, respectively. Specifically, one end of the tenth resistor 1201 can be connected to one end of the eighth resistor 1111 in the backup power supply unit 11. The other end of the tenth resistor 1201 can be connected to the anode of the third diode 1203 and the second terminal of the field-effect transistor 1204, respectively. The third terminal of the field-effect transistor 1204 can be connected to the anode of the second diode 121. The cathode of the third diode 1203 is connected to one end of the eleventh resistor 1202, and the other end of the eleventh resistor 1202 can be connected to the discharge switch control unit 13.

[0084] The field-effect transistor 1204 can be a P-MOS field-effect transistor. The drain of the field-effect transistor 1204 is the first terminal, the gate is the second terminal, and the source is the third terminal. The second terminal of the field-effect transistor 1204 can be pulled low or high under the control of the discharge switch control unit 13. When the second terminal of the field-effect transistor 1204 is pulled low to GND, the field-effect transistor 1204 is turned on, and the energy storage element 1110 in the backup power unit 11 discharges. Simultaneously, the third diode 1203 prevents reverse power flow. When the second terminal of the field-effect transistor 1204 is pulled high, the field-effect transistor 1204 is turned off, and the main power supply charges the energy storage element 1110.

[0085] Figure 5 This is a schematic diagram of the structure of a discharge switch control unit provided in an embodiment of this application, as shown below. Figure 5 As shown, the discharge switch control unit 13 may include: a comparator 130, a twelfth resistor 131, a thirteenth resistor 132, a fourteenth resistor 133, a fifteenth resistor 134, a sixteenth resistor 135, a second capacitor 136, a third capacitor 137, and a fourth diode 138.

[0086] like Figure 5As shown, the positive input end of the comparator 130 can be connected with one end of the twelfth resistor 131, one end of the thirteenth resistor 132, one end of the second capacitor 136 and the negative electrode of the fourth diode 138 respectively, the other end of the twelfth resistor 131 can be connected with the first voltage of the main power supply, wherein the first voltage can be the voltage Vin of the input end of the main power supply, the other end of the thirteenth resistor 131, the other end of the second capacitor 136 and the positive electrode of the fourth diode 138 are all grounded.

[0087] Optionally, the negative input end of the comparator 130 can be connected with one end of the fourteenth resistor 133 and one end of the fifteenth resistor 134 respectively, the other end of the fourteenth resistor 133 can be connected with the second voltage of the main power supply, wherein the second voltage can be the voltage Vcc of the output end of the main power supply, the other end of the fifteenth resistor 134 is grounded.

[0088] Optionally, the positive power supply input end of the comparator 130 can be connected with the main power supply, one end of the third capacitor 137 and one end of the sixteenth resistor 135 respectively, specifically, the positive power supply input end of the comparator 130 can be connected with the output end of the main power supply, the negative power supply input end of the comparator 130 is grounded. The output end of the comparator 130 can be connected with the second input end of the discharge switch unit 12 and the other end of the sixteenth resistor 135 respectively. Specifically, the output end of the comparator 130 can be connected with the other end of the eleventh resistor 1202 in the discharge switch unit 12.

[0089] Optionally, when the main power supply is normally powered, the voltage Vin of the input end of the main power supply is less than the voltage Vcc of the output end of the main power supply, then when the first voltage connected with the positive input end of the comparator 130 is higher than the second voltage connected with the negative input end of the comparator 130, the output end of the comparator 130 can output a high level signal, then the field effect transistor 1204 in the discharge switch unit 12 is turned off, and the energy storage element 1110 in the backup power supply unit 11 is not discharged; when the first voltage connected with the positive input end of the comparator 130 is lower than the second voltage connected with the negative input end of the comparator 130, the output end of the comparator 130 can output a low level signal, then the field effect transistor 1204 in the discharge switch unit 12 is turned on, and the energy storage element 1110 in the backup power supply unit 11 starts to discharge.

[0090] The utility model uses common resistance and capacity devices, diodes, triodes and other components, reduces circuit cost, and the control logic of the discharge switch control unit is simple and reliable, and the discharge switch unit is triggered to be turned on when the main power supply is powered off, so that the energy storage element in the backup power supply unit is discharged, and the whole process is simple and convenient.

[0091] The utility model also provides a fault recording equipment, and the fault recording equipment comprises the backup power supply circuit in the foregoing specific embodiment.

[0092] The above merely illustrates the specific implementation of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A backup power supply circuit, characterized by comprising: The application relates to a power supply device. The bias unit, the standby power supply unit, the discharge switch unit and the discharge switch control unit are connected in series. The first input end of the bias unit is used for connecting a main power supply, the second input end of the bias unit is used for inputting a bias switch signal, the output end of the bias unit is connected with the input end of the standby power supply unit, and the ground end of the bias unit is used for grounding. The ground end of the standby power supply unit is used for grounding, the first output end of the standby power supply unit is connected with a first power supply unit, and the second output end of the standby power supply unit is connected with the first input end of the discharge switch unit. The output end of the discharge switch unit is used for connecting a second power supply unit, and the second input end of the discharge switch unit is connected with the discharge switch control unit.

2. The backup power supply circuit according to claim 1, characterized by The bias unit comprises a first diode and a voltage reduction module. The positive pole of the first diode is connected with the main power supply, the negative pole of the first diode is connected with the output end of the voltage reduction module and the input end of the standby power supply unit respectively, and the input end of the voltage reduction module is used for inputting the bias switch signal. The voltage reduction module comprises a first resistor, a second resistor, a third resistor and a triode.

3. The backup power supply circuit of claim 2, wherein One end of the first resistor is connected with the negative pole of the first diode, and the other end of the first resistor is connected with the second end of the triode. One end of the second resistor is used for inputting the bias switch signal, and the other end of the second resistor is connected with one end of the third resistor and the first end of the triode respectively. The other end of the third resistor and the third end of the triode are grounded. The standby power supply unit comprises a current limiting module, a standby power supply module and a voltage stabilizing module.

4. The backup power supply circuit of claim 1, wherein The first input end of the current limiting module is connected with the output end of the bias unit, the second input end of the current limiting module is connected with the first end of the standby power supply module, the output end of the standby power supply module is connected with the first input end of the discharge switch unit, the output end of the current limiting module is connected with the input end of the voltage stabilizing module, and the output end of the voltage stabilizing module is used for connecting the first power supply unit. The ground end of the standby power supply module is grounded. The current limiting module comprises a fourth resistor, a fifth resistor, a sixth resistor and a seventh resistor.

5. The backup power supply circuit of claim 4, wherein, One end of the fourth resistor, one end of the fifth resistor, one end of the sixth resistor and one end of the seventh resistor are connected with the output end of the bias unit and the input end of the voltage stabilizing module respectively. The other end of the fourth resistor, the other end of the fifth resistor, the other end of the sixth resistor and the other end of the seventh resistor are connected with the first end of the standby power supply module. The standby power supply module comprises an energy storage element, an eighth resistor and a ninth resistor.

6. The backup power supply circuit of claim 4, wherein, ​ The positive electrode of the energy storage element is connected with the second input end of the current limiting module, one end of the eighth resistor and the first input end of the discharge switch unit respectively, the other end of the eighth resistor is connected with one end of the ninth resistor, and the other end of the eighth resistor is used for outputting a capacitor voltage detection result, and the negative electrode of the energy storage element is grounded together with the other end of the ninth resistor.

7. The backup power supply circuit of claim 1, wherein The discharge switch unit comprises a switch module and a second diode. The first end of the switch module is connected with the second output end of the backup power supply unit, the second end of the switch module is connected with the positive electrode of the second diode, and the third end of the switch module is connected with the discharge switch control unit. The negative electrode of the second diode is connected with the second power supply unit.

8. The backup power supply circuit of claim 7, wherein, The switch module comprises a tenth resistor, an eleventh resistor, a third diode and a field effect tube. One end of the tenth resistor is connected with the first end of the field effect tube and the second output end of the backup power supply unit respectively, the other end of the tenth resistor is connected with the positive electrode of the third diode and the second end of the field effect tube respectively, and the third end of the field effect tube is connected with the positive electrode of the second diode. The negative electrode of the third diode is connected with one end of the eleventh resistor, and the other end of the eleventh resistor is connected with the discharge switch control unit.

9. The backup power supply circuit of claim 1, wherein, The discharge switch control unit comprises a comparator, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a second capacitor, a third capacitor and a fourth diode. The positive input end of the comparator is connected with one end of the twelfth resistor, one end of the thirteenth resistor, one end of the second capacitor and the negative electrode of the fourth diode respectively, and the other end of the twelfth resistor is used for connecting the first voltage of the main power supply. The other end of the thirteenth resistor, the other end of the second capacitor and the positive electrode of the fourth diode are all grounded. The negative input end of the comparator is connected with one end of the fourteenth resistor and one end of the fifteenth resistor respectively, the other end of the fourteenth resistor is used for connecting the second voltage of the main power supply, and the other end of the fifteenth resistor is used for grounding. The positive power supply input end of the comparator is connected with the main power supply, one end of the third capacitor and one end of the sixteenth resistor respectively, the other end of the third capacitor is grounded, and the negative power supply input end of the comparator is grounded. The output end of the comparator is connected with the second input end of the discharge switch unit and the other end of the sixteenth resistor respectively.

10. A fault recording device, characterized by, The backup power supply circuit comprises the backup power supply circuit according to any one of claims 1-9.

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