Super-capacitor-based automatic charging and discharging circuit applied to intelligent terminal

Abstract

The invention provides an automatic charging and discharging circuit based on a super-capacitor applied to an intelligent terminal, the super-capacitor is an electric energy storage and release element and is used as a standby power supply when the intelligent terminal is temporarily powered down, and a boost module converts a discharging voltage provided by the super-capacitor into a temporary power supply voltage; the first voltage module and the second voltage module are respectively used for detecting a main power supply voltage and a temporary power supply voltage provided by the boosting module, and a detection result is used for controlling the conduction state of the gating module so as to realize automatic charging and discharging of the super capacitor; according to the invention, the charging and discharging functions of the super capacitor are automatically realized through a hardware circuit, and the problem of charging and discharging function failure caused by software faults and the like is avoided; moreover, when the super capacitor is in a charging state, a discharging path is automatically cut off, so that the power consumption is reduced; in addition, when the working voltage is lower than a limit value, the super-capacitor discharging circuit is automatically closed, so that the problem of repeated power-on and power-off or restart of the terminal equipment is prevented.

Description

Technical Field

[0001] The present invention relates to the field of electronic circuits, and more specifically, to an automatic charging and discharging circuit based on a supercapacitor applied to a smart terminal. Background Art

[0002] In smart terminal products, supercapacitors are widely used as backup power sources in emergency power outages, ensuring that data can be saved and reported in time when the device loses power unexpectedly. Currently, terminal products mainly use a combination of software and hardware to control the charging and discharging of supercapacitors. The program detects the operating voltage of the terminal, and based on different feedback results, the microcontroller processor outputs a control signal to switch the switch of the supercapacitor charging and discharging circuit, thereby controlling the charging and discharging of the supercapacitor.

[0003] However, in a control system that uses software programs as the core of control processing, if a program failure occurs, such as program anomalies or flight, the supercapacitor cannot perform normal charging and discharging. Therefore, there is an urgent need for a low-power positioning technology that can ensure the accuracy of positioning information while taking into account the power usage cycle of the equipment. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide an automatic charging and discharging circuit based on a supercapacitor for use in a smart terminal, which automatically realizes the charging and discharging function of the supercapacitor through a hardware circuit, provides a backup power supply for the smart terminal, and is used to avoid the problem of failure of the supercapacitor charging and discharging function due to software failure and the like; and, in the automatic charging and discharging circuit based on a supercapacitor, the discharge circuit of the supercapacitor will be automatically cut off when the supercapacitor is in a charging state, thereby reducing the power consumption of the automatic charging and discharging circuit; in addition, when the operating voltage is lower than a limited value, the supercapacitor discharge circuit is automatically turned off, thereby preventing the terminal device from repeatedly powering on and off or restarting.

[0005] The present invention provides an automatic charging and discharging circuit based on a supercapacitor applied to a smart terminal, the circuit comprising:

[0006] A supercapacitor, a boost module, a first voltage module, a second voltage module and a gating module;

[0007] The supercapacitor is an electric energy storage and release element, and is used as a backup power supply when the smart terminal temporarily loses power; the supercapacitor is connected to the main power supply and obtains the electric energy of the main power supply for charging; the supercapacitor is connected to the gating module and is discharged through the gating module;

[0008] The boost module is a voltage conversion module, which is used to convert the discharge voltage provided by the super capacitor into a temporary power supply voltage; the power input end of the boost module is connected to the gating module, and the output end of the boost module is connected to the smart terminal and the second voltage module;

[0009] The first voltage module is a voltage detection circuit, which is used to detect the main power supply voltage value provided by the main power supply; the input end of the first voltage module is connected to the positive electrode of the main power supply; the output end of the first voltage module connects the detection result as the first control level to the gating module;

[0010] The second voltage module is a voltage detection circuit, which is used for the temporary power supply voltage value provided by the boost module; the input end of the second voltage module is connected to the power supply output end of the boost module; the output end of the second voltage module connects the detection result as the second control level to the gating module;

[0011] The gating module is used as a discharge switch of the super capacitor, and controls the conduction state between the super capacitor and the boost module according to the first control level and the second control level.

[0012] In this solution, the gating module specifically includes:

[0013] The first switch unit switches the conduction state of the first switch according to the first control level output by the first voltage module;

[0014] The second switch unit switches the conduction state of the second switch according to the second control level output by the second voltage module and the conduction state of the first switch;

[0015] The conducting unit switches the conducting state of the conducting switch according to the conducting state of the second switch;

[0016] One end of the conduction switch is connected to the super capacitor;

[0017] The other end of the conduction switch is connected to the boost module.

[0018] In this solution, the gating module is specifically:

[0019] The first transistor Q1, the second transistor Q2, the first field effect transistor Q3, the first resistor R1, the second resistor R2 and the third resistor R3 form a gating circuit;

[0020] The first control level Mpwr is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the base of the first transistor Q1, the emitter of the first transistor Q1 is connected to the first reference level GND, the collector of the first transistor Q1 is connected to the second end of the second resistor R2 and the base of the second transistor Q2, the second control level Cpwr is connected to the first end of the second resistor R2, the emitter of the second transistor Q2 is connected to the first reference level GND, the collector of the second transistor Q2 is connected to the second end of the third resistor R3 and the gate of the first field effect transistor Q3, the first end of the third resistor R3 and the source of the first field effect transistor Q3 are connected to the positive electrode of the super capacitor, and the drain of the first field effect transistor Q3 is connected to the power input end of the boost module.

[0021] This plan also includes:

[0022] The detection input terminal of the first voltage module is connected to the positive electrode of the main power supply;

[0023] Determine whether the main power supply voltage value exceeds a set first voltage threshold;

[0024] If yes, the first control level of the first voltage module is the second reference level;

[0025] If not, the first control level of the first voltage module is the first reference level.

[0026] This plan also includes:

[0027] The detection input terminal of the second voltage module is connected to the power output terminal of the boost module;

[0028] Determine whether the output voltage value of the boost module exceeds a set second voltage threshold;

[0029] If yes, the second control level of the second voltage module is a second reference level;

[0030] If not, the second control level of the second voltage module is the first reference level;

[0031] The first voltage threshold is greater than the second voltage threshold.

[0032] In this solution, the voltage detection circuit includes:

[0033] a first voltage detector and a second voltage detector;

[0034] The detection input terminal of the first voltage detector is the detection input terminal of the first voltage module, and is connected to the positive electrode of the main power supply;

[0035] The output terminal of the first voltage detector outputs a first control level;

[0036] The detection input terminal of the second voltage detector is the detection input terminal of the second voltage module, and is connected to the power output terminal of the boost module;

[0037] The output terminal of the second voltage detector outputs a second control level.

[0038] In this solution, the voltage detection circuit is specifically:

[0039] including a first comparator and a second comparator;

[0040] The detection input terminal of the first comparator is the detection input terminal of the first voltage module, and is connected to the positive electrode of the main power supply;

[0041] The reference input terminal of the first comparator is connected to a first voltage divider circuit, and the first voltage divider circuit outputs the first voltage threshold;

[0042] The output terminal of the first comparator outputs a first control level;

[0043] The detection input terminal of the second comparator is the detection input terminal of the second voltage module, and is connected to the power output terminal of the boost module;

[0044] The reference input terminal of the second comparator is connected to a second voltage divider circuit, and the second voltage divider circuit outputs the second voltage threshold;

[0045] The output terminal of the second comparator outputs a second control level.

[0046] This plan also includes:

[0047] The first voltage dividing circuit includes a first variable resistor, and the first variable resistor is used to adjust the first voltage threshold;

[0048] The second voltage-dividing circuit includes a second variable resistor, and the second variable resistor is used to adjust the second voltage threshold.

[0049] This plan also includes:

[0050] The first anti-backflow circuit;

[0051] The first anti-backflow circuit at least includes a first diode;

[0052] The anode of the first diode is connected to the anode of the main power supply;

[0053] The cathode of the first diode is connected to the anode of the super capacitor.

[0054] This plan also includes:

[0055] The second anti-backflow circuit;

[0056] The second anti-backflow circuit at least includes a second diode;

[0057] The anode of the second diode is connected to the anode of the main power supply;

[0058] The cathode of the second diode is connected to the power supply output end of the boost module.

[0059] The present invention provides an automatic charging and discharging circuit based on a supercapacitor for use in an intelligent terminal. The supercapacitor is an electric energy storage and release element and is used as a backup power supply when the intelligent terminal is temporarily powered off. A boost module converts a discharge voltage provided by the supercapacitor into a temporary power supply voltage. A first voltage module and a second voltage module are respectively used to detect a main power supply voltage and a temporary power supply voltage provided by the boost module, and the detection results are used to control the conduction state of a gating module to realize automatic charging and discharging of the supercapacitor. The present invention automatically realizes the charging and discharging function of the supercapacitor through a hardware circuit, thereby avoiding the problem of failure of the charging and discharging function caused by software failure and the like. Moreover, when the supercapacitor is in a charging state, the discharge path will be automatically cut off, thereby reducing power consumption. In addition, when the operating voltage is lower than a limit value, the supercapacitor discharge circuit is automatically closed, thereby preventing the terminal device from repeatedly powering on and off or restarting. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope.

[0061] Figure 1 A topological diagram of an automatic charging and discharging circuit based on a supercapacitor applied to a smart terminal of the present invention is shown;

[0062] Figure 2 A schematic diagram of a gating module provided by an embodiment of the present invention is shown;

[0063] Figure 3 A circuit diagram of a gating module provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0064] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] Unless otherwise defined, all terms (including technical and scientific terms) used in the embodiments of the present invention have the same meanings as commonly understood by those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless the embodiments of the present invention are clearly defined in this way.

[0066] The words "first", "second" and similar words used in the embodiments of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "one", "an" or "the" and similar words do not indicate a quantity limitation, but indicate the existence of at least one. Similarly, words such as "include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The steps before or after the method of the embodiment of the present invention are not necessarily carried out in order. On the contrary, various steps can be processed in reverse order or simultaneously. At the same time, other operations can also be added to these processes, or a step or several steps can be removed from these processes.

[0067] In addition, the functional modules in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0068] Figure 1 The present invention shows a flow chart of an automatic charging and discharging circuit based on a super capacitor applied to a smart terminal.

[0069] like Figure 1 As shown, the present invention discloses an automatic charging and discharging circuit based on a supercapacitor applied to a smart terminal, the circuit comprising:

[0070] Super capacitor 101, boost module 102, first voltage module 103, second voltage module 104 and gating module 105;

[0071] The supercapacitor is an electric energy storage and release element, and is used as a backup power supply when the smart terminal temporarily loses power; the supercapacitor is connected to the main power supply and obtains the electric energy of the main power supply for charging; the supercapacitor is connected to the gating module and is discharged through the gating module;

[0072] The boost module is a voltage conversion module, which is used to convert the discharge voltage provided by the super capacitor into a temporary power supply voltage; the power input end of the boost module is connected to the gating module, and the output end of the boost module is connected to the smart terminal and the second voltage module;

[0073] The first voltage module is a voltage detection circuit, which is used to detect the main power supply voltage value provided by the main power supply; the input end of the first voltage module is connected to the positive electrode of the main power supply; the output end of the first voltage module connects the detection result as the first control level to the gating module;

[0074] The second voltage module is a voltage detection circuit, which is used for the temporary power supply voltage value provided by the boost module; the input end of the second voltage module is connected to the power supply output end of the boost module; the output end of the second voltage module connects the detection result as the second control level to the gating module;

[0075] The gating module is used as a discharge switch of the super capacitor, and controls the conduction state between the super capacitor and the boost module according to the first control level and the second control level.

[0076] It should be noted that smart terminals include but are not limited to smart terminal products and equipment such as electric energy meters. Supercapacitors are used as backup power sources in the event of an emergency power outage of the device, ensuring that data can be saved and reported in a timely manner when the smart terminal device loses power unexpectedly. When the main power supply is in a normal state, the main power supply provides power to the smart terminal, and at the same time the main power supply charges the supercapacitor, which is in a charging state. At this time, the first voltage module detects that the main power supply is in a normal state, and outputs the corresponding first control level for controlling the gating module, so that the gating module disconnects the supercapacitor from the boost module, that is, cuts off the discharge path of the supercapacitor.

[0077] When the main power supply is in an abnormal state, that is, when the main power supply voltage is lower than the preset first voltage threshold, the first control level output by the first voltage module does not affect the conduction state of the gating module, and the conduction state of the gating module is determined by the second control level output by the second voltage module. The boost module boosts the voltage provided by the supercapacitor to obtain a temporary power supply voltage. When the temporary power supply voltage is higher than the preset second voltage threshold, the second control level output by the second voltage module is the second reference level, at which time the gating module can be driven to conduct the connection between the supercapacitor and the boost module, that is, the discharge path of the supercapacitor is conducted, at which time the supercapacitor is discharged to provide electrical energy for the smart terminal, that is, in a discharge state. When the temporary power supply voltage is not higher than the preset second voltage threshold, it means that the power value of the supercapacitor is insufficient, and the second control level output by the second voltage module is the first reference level, at which time the gating module is driven to disconnect the connection between the supercapacitor and the boost module, that is, the supercapacitor stops discharging, that is, it is in a power-off state, thereby avoiding the supply voltage being at a critical value, resulting in the problem of repeated power on and off or restart of the terminal device.

[0078] Figure 2 A flow chart showing a mode for obtaining positioning information when the battery is sufficient is shown.

[0079] According to an embodiment of the present invention, Figure 2 As shown, the gating module specifically includes:

[0080] The first switch unit 202 switches the conduction state of the first switch according to the first control level output by the first voltage module;

[0081] The second switch unit 203 switches the conduction state of the second switch according to the second control level output by the second voltage module and the conduction state of the first switch;

[0082] The conducting unit 201 switches the conducting state of the conducting switch according to the conducting state of the second switch;

[0083] One end of the conduction switch is connected to the super capacitor;

[0084] The other end of the conduction switch is connected to the boost module. It should be noted that, in the embodiment, the input control pin of the conduction unit is connected to the second switch of the second switch unit. When the second switch is in the conduction state, the conduction unit is in the conduction state, so that the supercapacitor is connected to the boost module; when the second switch is in the disconnection state, the conduction unit is in the disconnection state, so that the supercapacitor is disconnected from the boost module.

[0085] The input control pin of the second switch unit is connected to the output end of the second voltage module and the first switch of the first switch unit at the same time. When the first switch is in the on state, the second switch unit is not affected by the output end of the second voltage module, so that the second switch unit is in the on state. When the first switch is in the off state, the on state of the second switch depends on the output end of the second voltage module, that is, the second control level; when the second control level is the first reference level, the second switch is in the off state; when the second control level is the second reference level, the second switch is in the on state.

[0086] The input control pin of the first switch unit is connected to the output end of the first voltage module, that is, the first control level. When the first control level is the first reference level, the first switch is in the off state; when the first control level is the second reference level, the first switch is in the on state.

[0087] Figure 3 A flow chart of determining a mode for acquiring positioning information when the battery is low is shown.

[0088] According to an embodiment of the present invention, Figure 3 As shown, the gating module is specifically:

[0089] The first transistor Q1, the second transistor Q2, the first field effect transistor Q3, the first resistor R1, the second resistor R2 and the third resistor R3 form a gating circuit;

[0090] The first control level Mpwr is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the base of the first transistor Q1, the emitter of the first transistor Q1 is connected to the first reference level GND, the collector of the first transistor Q1 is connected to the second end of the second resistor R2 and the base of the second transistor Q2, the second control level Cpwr is connected to the first end of the second resistor R2, the emitter of the second transistor Q2 is connected to the first reference level GND, the collector of the second transistor Q2 is connected to the second end of the third resistor R3 and the gate of the first field effect transistor Q3, the first end of the third resistor R3 and the source of the first field effect transistor Q3 are connected to the positive electrode of the super capacitor, and the drain of the first field effect transistor Q3 is connected to the power input end of the boost module.

[0091] It should be noted that, as an implementation mode, the selection module is a selection circuit composed of a first transistor Q1, a second transistor Q2, a first field effect transistor Q3, a first resistor R1, a second resistor R2 and a third resistor R3; wherein the first reference level is a low level and the second reference level is a high level.

[0092] When the first control level Mpwr is the second reference level, the base of the first transistor Q1 is the second reference level, so that the first transistor Q1 is in the on state, and then the base of the second transistor Q2 is the first reference level, so that the second transistor Q2 is in the off state. At this time, the voltage difference between the gate and the source of the first field effect transistor Q3 is lower than the on threshold of the field effect transistor, that is, the first field effect transistor Q3 is in the off state, that is, the super capacitor is disconnected from the boost module, and the super capacitor is in a state of only charging but not discharging.

[0093] When the first control level Mpwr is the first reference level, the conduction state of the second transistor Q2 is determined by the second control level Cpwr. When the second control level Cpwr is the first reference level, the base of the second transistor Q2 is the first reference level, so that the second transistor Q2 is in the cut-off state; at this time, the voltage difference between the gate and the source of the first field effect transistor Q3 is lower than the conduction threshold of the field effect transistor, that is, the first field effect transistor Q3 is in the cut-off state, that is, the super capacitor is disconnected from the boost module, and the super capacitor is in a state of neither charging nor discharging. When the second control level Cpwr is the second reference level, the base of the second transistor Q2 is the second reference level, so that the second transistor Q2 is in the conduction state; at this time, the voltage difference between the gate and the source of the first field effect transistor Q3 is higher than the conduction threshold of the field effect transistor, that is, the first field effect transistor Q3 is in the conduction state, that is, the super capacitor is connected to the boost module, and the super capacitor is in the discharge state.

[0094] According to an embodiment of the present invention, it also includes:

[0095] The detection input terminal of the first voltage module is connected to the positive electrode of the main power supply;

[0096] Determine whether the main power supply voltage value exceeds a set first voltage threshold;

[0097] If yes, the first control level of the first voltage module is the second reference level;

[0098] If not, the first control level of the first voltage module is the first reference level.

[0099] It should be noted that the first voltage module is used to detect the voltage value of the main power supply. As an implementation mode, when the voltage value of the main power supply exceeds the set first voltage threshold, it is determined that the main power supply is in a normal state, and at this time, the first control level output by the first voltage module is the second reference level; when the voltage value of the main power supply does not exceed the set first voltage threshold, it is determined that the main power supply is in an abnormal state, and at this time, the first control level output by the first voltage module is the first reference level.

[0100] According to an embodiment of the present invention, it also includes:

[0101] The detection input terminal of the second voltage module is connected to the power output terminal of the boost module;

[0102] Determine whether the output voltage value of the boost module exceeds a set second voltage threshold;

[0103] If yes, the second control level of the first voltage module is a second reference level;

[0104] If not, the second control level of the first voltage module is the first reference level;

[0105] The first voltage threshold is greater than the second voltage threshold.

[0106] It should be noted that the second voltage module is used to detect the output voltage value of the boost module. As an implementation mode, when the output voltage value of the boost module exceeds the set second voltage threshold, it is determined that the power of the supercapacitor meets the power supply demand and is in a discharging state. At this time, the second control level of the output of the second voltage module is the second reference level; when the output voltage value of the boost module does not exceed the set second voltage threshold, it is determined that the power of the supercapacitor cannot meet the power supply demand and is in a power-off state. At this time, the second control level of the output of the second voltage module is the first reference level.

[0107] It is worth mentioning that, in practical applications, the first voltage threshold is higher than the second voltage threshold.

[0108] According to an embodiment of the present invention, the voltage detection circuit includes:

[0109] a first voltage detector and a second voltage detector;

[0110] The detection input terminal of the first voltage detector is the detection input terminal of the first voltage module, and is connected to the positive electrode of the main power supply;

[0111] The output terminal of the first voltage detector outputs a first control level;

[0112] The detection input terminal of the second voltage detector is the detection input terminal of the second voltage module, and is connected to the power output terminal of the boost module;

[0113] The output terminal of the second voltage detector outputs a second control level.

[0114] It should be noted that, as an implementation method, the voltage detection circuit is composed of a voltage detector, that is, a voltage detection chip. For example, in the case of the voltage detection chip S-80140, when the voltage value at the detection input end of the voltage detection chip exceeds the detection voltage 4.0 volts set by the voltage detection chip S-80140, the output end of the voltage detection chip S-80140 outputs a high level; when the voltage value at the detection input end of the voltage detection chip does not exceed the detection voltage 4.0 volts set by the voltage detection chip S-80140, the output end of the voltage detection chip S-80140 outputs a low level.

[0115] In this embodiment, the input end of the first voltage detector is connected to the positive electrode of the main power supply, and is used to detect the voltage value of the main power supply; the output end of the first voltage detector outputs a first control level, and is connected to the first switch unit. The input end of the second voltage detector is connected to the power output end of the boost module, and is used to detect the output voltage value of the boost module; the output end of the second voltage detector outputs a second control level, and is connected to the second switch unit.

[0116] According to an embodiment of the present invention, the voltage detection circuit is specifically:

[0117] including a first comparator and a second comparator;

[0118] The detection input terminal of the first comparator is the detection input terminal of the first voltage module, and is connected to the positive electrode of the main power supply;

[0119] The reference input terminal of the first comparator is connected to a first voltage divider circuit, and the first voltage divider circuit outputs the first voltage threshold;

[0120] The output terminal of the first comparator outputs a first control level;

[0121] The detection input terminal of the second comparator is the detection input terminal of the second voltage module, and is connected to the power output terminal of the boost module;

[0122] The reference input terminal of the second comparator is connected to a second voltage divider circuit, and the second voltage divider circuit outputs the second voltage threshold;

[0123] The output terminal of the second comparator outputs a second control level.

[0124] It should be noted that, as an implementation method, the voltage detection circuit is composed of a voltage comparator. The voltage comparator includes a detection input terminal and a reference input terminal. When the voltage value of the detection input terminal exceeds the voltage value of the reference input terminal, the output terminal of the voltage comparator outputs a high level; when the voltage value of the detection input terminal does not exceed the voltage value of the reference input terminal, the output terminal of the voltage comparator outputs a low level.

[0125] In this embodiment, the detection input of the first comparator is connected to the positive electrode of the main power supply, and the reference input of the first comparator is connected to the first voltage divider circuit, which is used to detect whether the voltage value of the main power supply exceeds the voltage divider value of the first voltage divider circuit; the output of the first comparator outputs a first control level and is connected to the first switch unit. The detection input of the second comparator is connected to the power output of the boost module, and the reference input of the second comparator is connected to the second voltage divider circuit, which is used to detect whether the output voltage value of the boost module exceeds the voltage divider value of the second voltage divider circuit; the output of the second comparator outputs a second control level and is connected to the second switch unit.

[0126] According to an embodiment of the present invention, it also includes:

[0127] The first voltage dividing circuit includes a first variable resistor, and the first variable resistor is used to adjust the first voltage threshold;

[0128] The second voltage-dividing circuit includes a second variable resistor, and the second variable resistor is used to adjust the second voltage threshold.

[0129] It should be noted that, as an implementation mode, a variable resistor is provided in the voltage divider circuit, and the voltage divider value of the voltage divider circuit is adjusted by adjusting the resistance value of the variable resistor. In this embodiment, the first voltage threshold is adjusted by adjusting the resistance value of the first variable resistor of the first voltage divider circuit; and the second voltage threshold is adjusted by adjusting the resistance value of the second variable resistor of the second voltage divider circuit.

[0130] According to an embodiment of the present invention, it also includes:

[0131] The first anti-backflow circuit;

[0132] The first anti-backflow circuit at least includes a first diode;

[0133] The anode of the first diode is connected to the anode of the main power supply;

[0134] The cathode of the first diode is connected to the anode of the super capacitor.

[0135] It should be noted that the present embodiment provides a first anti-backflow circuit for preventing the output current of the supercapacitor from backflowing to the main power supply. As an implementation mode, the first anti-backflow circuit includes at least a first diode, the anode of the first diode is connected to the anode of the main power supply, and the cathode of the first diode is connected to the anode of the supercapacitor, so as to limit the current from flowing from the supercapacitor end to the main power supply end.

[0136] According to an embodiment of the present invention, it also includes:

[0137] The second anti-backflow circuit;

[0138] The second anti-backflow circuit at least includes a second diode;

[0139] The anode of the second diode is connected to the anode of the main power supply;

[0140] The cathode of the second diode is connected to the power supply output end of the boost module.

[0141] It should be noted that the second anti-backflow circuit is provided in this embodiment to prevent the output current of the boost module from backflowing to the main power supply. As an implementation mode, the second anti-backflow circuit includes at least a second diode, the anode of the second diode is connected to the anode of the main power supply, and the cathode of the second diode is connected to the anode of the boost module, so as to limit the current from flowing from the boost module end to the main power supply end.

[0142] In summary, the present invention provides an automatic charging and discharging circuit based on a supercapacitor for use in a smart terminal. The supercapacitor is an energy storage and release element, and is used as a backup power supply when the smart terminal is temporarily powered off. The boost module converts the discharge voltage provided by the supercapacitor into a temporary power supply voltage. The first voltage module and the second voltage module are respectively used to detect the main power supply voltage and the temporary power supply voltage provided by the boost module, and the detection results are used to control the conduction state of the selection module to realize automatic charging and discharging of the supercapacitor. The present invention automatically realizes the charging and discharging function of the supercapacitor through a hardware circuit, avoiding the problem of failure of the charging and discharging function caused by software failure and the like. Moreover, when the supercapacitor is in a charging state, the discharge path will be automatically cut off, thereby reducing power consumption. In addition, when the operating voltage is lower than a limit value, the supercapacitor discharge circuit is automatically turned off, thereby preventing the terminal device from repeatedly powering on and off or restarting.

[0143] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An automatic charging and discharging circuit based on supercapacitor applied to a smart terminal, characterized in that: The circuit comprises: A supercapacitor, a boost module, a first voltage module, a second voltage module and a gating module; The supercapacitor is an electric energy storage and release element, and is used as a backup power supply when the smart terminal is temporarily powered off; the supercapacitor is connected to the main power supply and obtains the electric energy of the main power supply for charging; the supercapacitor is connected to the gating module and is discharged through the gating module; The boost module is a voltage conversion module, which is used to convert the discharge voltage provided by the super capacitor into a temporary power supply voltage; the power input end of the boost module is connected to the gating module, and the output end of the boost module is connected to the smart terminal and the second voltage module; The first voltage module is a voltage detection circuit, which is used to detect the main power supply voltage value provided by the main power supply; the input end of the first voltage module is connected to the positive electrode of the main power supply; the output end of the first voltage module uses the detection result as the first control level to connect to the selection module; The second voltage module is a voltage detection circuit, which is used for the temporary power supply voltage value provided by the boost module; the input end of the second voltage module is connected to the power supply output end of the boost module; the output end of the second voltage module connects the detection result as the second control level to the gating module; The gating module is used as a discharge switch of the super capacitor, and controls the conduction state between the super capacitor and the boost module according to the first control level and the second control level.

2. According to claim 1, an automatic charging and discharging circuit based on supercapacitor applied to a smart terminal is characterized in that: The gating module specifically includes: The first switch unit switches the conduction state of the first switch according to the first control level output by the first voltage module; The second switch unit switches the conduction state of the second switch according to the second control level output by the second voltage module and the conduction state of the first switch; The conducting unit switches the conducting state of the conducting switch according to the conducting state of the second switch; One end of the conduction switch is connected to the super capacitor; The other end of the conduction switch is connected to the boost module.

3. The automatic charging and discharging circuit based on supercapacitor applied to a smart terminal according to claim 2, characterized in that: The gating module is specifically: The first transistor Q1, the second transistor Q2, the first field effect transistor Q3, the first resistor R1, the second resistor R2 and the third resistor R3 form a gating circuit; The first control level Mpwr is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the base of the first transistor Q1, the emitter of the first transistor Q1 is connected to the first reference level GND, the collector of the first transistor Q1 is connected to the second end of the second resistor R2 and the base of the second transistor Q2, the second control level Cpwr is connected to the first end of the second resistor R2, the emitter of the second transistor Q2 is connected to the first reference level GND, the collector of the second transistor Q2 is connected to the second end of the third resistor R3 and the gate of the first field effect transistor Q3, the first end of the third resistor R3 and the source of the first field effect transistor Q3 are connected to the positive electrode of the super capacitor, and the drain of the first field effect transistor Q3 is connected to the power input end of the boost module.

4. The automatic charging and discharging circuit based on supercapacitor applied to a smart terminal according to claim 1, characterized in that: Also includes: The detection input terminal of the first voltage module is connected to the positive electrode of the main power supply; Determine whether the main power supply voltage value exceeds a set first voltage threshold; If yes, the first control level of the first voltage module is the second reference level; If not, the first control level of the first voltage module is the first reference level.

5. The automatic charging and discharging circuit based on supercapacitor applied to a smart terminal according to claim 4, characterized in that: Also includes: The detection input terminal of the second voltage module is connected to the power output terminal of the boost module; Determine whether the output voltage value of the boost module exceeds a set second voltage threshold; If yes, the second control level of the second voltage module is a second reference level; If not, the second control level of the second voltage module is the first reference level; The first voltage threshold is greater than the second voltage threshold.

6. The automatic charging and discharging circuit based on supercapacitor applied to a smart terminal according to claim 5, characterized in that: The voltage detection circuit comprises: a first voltage detector and a second voltage detector; The detection input terminal of the first voltage detector is the detection input terminal of the first voltage module, and is connected to the positive electrode of the main power supply; The output terminal of the first voltage detector outputs a first control level; The detection input terminal of the second voltage detector is the detection input terminal of the second voltage module, and is connected to the power output terminal of the boost module; The output terminal of the second voltage detector outputs a second control level.

7. The automatic charging and discharging circuit based on supercapacitor applied to a smart terminal according to claim 5, characterized in that: The voltage detection circuit is specifically: including a first comparator and a second comparator; The detection input terminal of the first comparator is the detection input terminal of the first voltage module, and is connected to the positive electrode of the main power supply; The reference input terminal of the first comparator is connected to a first voltage divider circuit, and the first voltage divider circuit outputs the first voltage threshold; The output terminal of the first comparator outputs a first control level; The detection input terminal of the second comparator is the detection input terminal of the second voltage module, and is connected to the power output terminal of the boost module; The reference input terminal of the second comparator is connected to a second voltage divider circuit, and the second voltage divider circuit outputs the second voltage threshold; The output terminal of the second comparator outputs a second control level.

8. The automatic charging and discharging circuit based on supercapacitor applied to a smart terminal according to claim 7, characterized in that: Also includes: The first voltage dividing circuit includes a first variable resistor, and the first variable resistor is used to adjust the first voltage threshold; The second voltage-dividing circuit includes a second variable resistor, and the second variable resistor is used to adjust the second voltage threshold.

9. The automatic charging and discharging circuit based on supercapacitor applied to a smart terminal according to claim 1, characterized in that: Also includes: The first anti-backflow circuit; The first anti-backflow circuit at least includes a first diode; The anode of the first diode is connected to the anode of the main power supply; The cathode of the first diode is connected to the anode of the super capacitor.

10. The automatic charging and discharging circuit based on supercapacitor applied to a smart terminal according to claim 1, characterized in that: Also includes: The second anti-backflow circuit; The second anti-backflow circuit at least includes a second diode; The anode of the second diode is connected to the anode of the main power supply; The cathode of the second diode is connected to the power supply output end of the boost module.

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