Super capacitor fast charging circuit and electronic device

Abstract

The utility model relates to charging circuit technology discloses a kind of super capacitor fast charging circuit and electronic equipment, comprising: power input, charging chip, voltage reduction module, super capacitor and NTC thermistor;The power supply end of power input is electrically connected to the power supply end of charging chip, NTC thermistor is connected between the temperature sensing end of charging chip and ground pin, and the charging output end of charging chip is sequentially connected ground wire through voltage reduction module and super capacitor;Multiple seriesly arranged Schottky diodes are provided in voltage reduction module, and the conducting direction of each Schottky diode is the direction from the charging output end of charging chip to super capacitor;The charging output voltage of the charging output end of charging chip, minus the sum of the forward voltage drop of all Schottky diodes in voltage reduction module to obtain the remaining voltage, does not exceed the capacitor charging voltage.The utility model aims at realizing the safe, fast charging of super capacitor based on charging chip.

Description

Technical Field

[0001] This utility model relates to the field of charging circuit technology, and in particular to a supercapacitor fast charging circuit and electronic device. Background Technology

[0002] Currently, the charging output voltage of general charging chips is greater than that of supercapacitors (for example, the charging output voltage of lithium-ion charging chips is stable at around 4.2V, while the charging voltage of general lithium-ion supercapacitors is 3.6 / 3.8V). If a charging chip is used directly to charge a supercapacitor, it may cause damage to the supercapacitor.

[0003] Furthermore, since most charging chips are designed for lithium battery charging, there is a pre-charging process, or trickle charging, when the battery is at low voltage. This process is quite long, typically taking 20 to 30 minutes. Supercapacitors, however, do not require trickle charging due to their different operating principle and can directly enter constant current charging (fast charging) mode. But the presence of trickle charging significantly extends the charging time of supercapacitors (for example, if a direct fast charge takes 10 minutes to fully charge, adding the trickle charging time could result in an actual charging time of 30 to 40 minutes), which defeats the original purpose of using supercapacitors for rapid energy replenishment.

[0004] The above content is only used to help understand the technical solution of this utility model and does not represent an admission that the above content is prior art. Utility Model Content

[0005] This invention proposes a supercapacitor fast charging circuit and electronic device, aiming to achieve safe and fast charging of supercapacitors based on a charging chip.

[0006] To achieve the above objectives, this utility model proposes a supercapacitor fast charging circuit, comprising: a power input terminal, a charging chip, a step-down module, a supercapacitor, and an NTC (Negative Temperature Coefficient) thermistor; the power input terminal is electrically connected to the power supply terminal of the charging chip, the NTC thermistor is connected between the temperature sensing terminal of the charging chip and the ground pin, and the charging output terminal of the charging chip is connected to the ground wire in sequence via the step-down module and the supercapacitor; The step-down module is equipped with multiple Schottky diodes connected in series, and the conduction direction of each Schottky diode is from the charging output terminal of the charging chip to the supercapacitor. The charging output voltage at the charging output terminal of the charging chip is greater than the capacitor charging voltage of the supercapacitor; the remaining voltage obtained by subtracting the sum of the forward voltage drops of all Schottky diodes in the step-down module from the charging output voltage does not exceed the capacitor charging voltage.

[0007] Optionally, the charging output voltage is 4.2V, and the capacitor charging voltage is 3.6 / 3.8V; The step-down module contains two Schottky diodes connected in series, and the forward voltage drop of a single Schottky diode is 3.5~3.6V.

[0008] Optionally, the charging chip is a lithium-ion charging chip, and the supercapacitor is a lithium-ion supercapacitor.

[0009] Optionally, a temperature control switch is provided between the power input terminal and the power supply terminal of the charging chip, and the control terminal of the temperature control switch is electrically connected to the control output terminal of the charging chip.

[0010] This invention further proposes an electronic device, including the supercapacitor fast charging circuit described above.

[0011] Optionally, the electronic device further includes a charging interface and a power module; the charging interface is electrically connected to the power input terminal of the supercapacitor fast charging circuit, and the positive input terminal of the power module is electrically connected to the charging output terminal of the charging chip of the supercapacitor fast charging circuit.

[0012] Optionally, the charging interface is a USB interface.

[0013] Optionally, the power supply module is powered by a lithium battery.

[0014] The beneficial effects of this utility model are as follows: By using multiple Schottky diodes connected in series in the step-down module, the charging output voltage of the charging chip is reduced to a range suitable for the supercapacitor, ensuring that the voltage applied to the supercapacitor does not exceed its rated value, avoiding overvoltage damage, and effectively ensuring the safety and service life of the supercapacitor; at the same time, by utilizing the forward voltage drop of the Schottky diode, the charging chip can skip the trickle charging stage and directly enter the constant current charging stage when the supercapacitor is in a low voltage state, greatly shortening the charging time and giving full play to the advantages of the supercapacitor's rapid charging and discharging. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an embodiment of the supercapacitor fast charging circuit of this utility model.

[0016] Explanation of reference numerals in the attached figures: R1: NTC thermistor TSEN: Temperature sensor VBAT: Charging output terminal D1: Schottky diode VCC: Power supply terminal GND: Ground wire The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0017] The solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0018] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this utility model are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0019] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0020] Furthermore, descriptions involving terms such as "first" and "second" in this utility model are for descriptive purposes only (e.g., to distinguish identical or similar elements) and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include at least one of those features. Additionally, technical solutions from different embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed by this utility model.

[0021] This utility model proposes a supercapacitor fast charging circuit, referring to... Figure 1 The supercapacitor fast charging circuit includes: a power input terminal V1, a charging chip U1, a step-down module N1, a supercapacitor C1, and an NTC thermistor R1; the power input terminal V1 is electrically connected to the power supply terminal VCC of the charging chip U1, the NTC thermistor R1 is connected between the temperature sensing terminal TSEN of the charging chip U1 and the ground GND pin, and the charging output terminal VBAT of the charging chip U1 is connected to the ground GND in sequence through the step-down module N1 and the supercapacitor C1; The step-down module N1 is equipped with multiple Schottky diodes D1 connected in series, and the conduction direction of each Schottky diode D1 is from the charging output terminal VBAT of the charging chip U1 to the supercapacitor C1. The charging output voltage of the charging output terminal VBAT of the charging chip U1 is greater than the capacitor charging voltage of the supercapacitor C1; the remaining voltage obtained by subtracting the sum of the forward voltage drops of all Schottky diodes D1 in the step-down module N1 from the charging output voltage does not exceed the capacitor charging voltage.

[0022] In this embodiment, the power input terminal V1 is electrically connected to the power supply terminal VCC of the charging chip U1 to provide the necessary power to the entire charging circuit, ensuring that the charging chip U1 can work normally, thereby realizing the charging operation of the supercapacitor C1.

[0023] One end of the NTC thermistor R1 is connected to the temperature sensing terminal TSEN of the charging chip U1, and the other end of the NTC thermistor R1 is connected to the ground pin GND of the charging chip U1; at the same time, the ground pin GND of the charging chip U1 is grounded.

[0024] Meanwhile, the charging output terminal VBAT of the charging chip U1 is connected in sequence to the step-down module N1 and the supercapacitor C1, and finally connected to the ground wire GND.

[0025] The charging chip U1 is the core control component of the entire charging circuit. It is responsible for precisely controlling the charging process based on the power input, the state of the supercapacitor C1, and the temperature information fed back by the NTC thermistor R1. This includes outputting appropriate charging voltage and current to achieve fast and safe charging of the supercapacitor C1.

[0026] The NTC thermistor R1 has a negative temperature coefficient, meaning its resistance decreases as temperature increases. In the circuit, the NTC thermistor R1 acts as a temperature sensor, sensing real-time temperature changes and feeding this information back to the charging chip U1 in the form of a resistance value. Based on this feedback, the charging chip U1 adjusts the charging process, for example, reducing the charging current or stopping charging if the temperature is too high, to prevent circuit damage due to overheating and ensure charging safety.

[0027] The step-down module N1 is located between the charging output terminal VBAT of the charging chip U1 and the supercapacitor C1. The step-down module N1 contains multiple Schottky diodes D1 connected in series. The conduction direction of each Schottky diode D1 is from the charging output terminal VBAT of the charging chip U1 to the supercapacitor C1.

[0028] The main function of the step-down module N1 is to reduce the charging voltage output by the charging chip U1. Since the charging output voltage of the charging chip U1 is greater than the charging voltage of the supercapacitor C1, multiple Schottky diodes D1 are connected in series. Utilizing the forward voltage drop characteristic of the Schottky diodes D1, the charging output voltage is reduced to a suitable range for charging the supercapacitor C1. Schottky diodes D1 have advantages such as low forward voltage drop and fast switching speed, which can reduce energy loss and improve charging efficiency while reducing voltage.

[0029] One end of the supercapacitor C1 is connected to the step-down module N1, and the other end is connected to ground GND. Supercapacitor C1 is the object being charged in the circuit, characterized by high energy density and rapid charging and discharging. During charging, supercapacitor C1 can quickly store the electrical energy output from the charging chip U1 and adjusted by the step-down module N1, achieving the purpose of fast charging.

[0030] The remaining voltage obtained by subtracting the sum of the forward voltage drops of all Schottky diodes D1 in the step-down module N1 from the charging output voltage does not exceed the charging voltage of the supercapacitor C1. This design ensures that the voltage applied to the supercapacitor C1 will not exceed its rated charging voltage, avoiding damage to the supercapacitor C1 due to overvoltage, thereby ensuring the safety of the charging process and the service life of the supercapacitor C1.

[0031] For example, taking a charging output voltage of 4.2V for the charging chip U1 (in the final constant voltage charging stage) and a charging voltage of 3.6V or 3.8V for the supercapacitor C1, if two Schottky diodes connected in series are placed in the step-down module N1 (both with their conduction direction from the charging output terminal VBAT of the charging chip U1 to the supercapacitor C1), the forward voltage drop of these two diodes is about 0.3V~0.35V when the current is less than 5mA. The voltage drop of the two diodes is approximately 0.6V~0.7V, which ensures that the voltage applied to the supercapacitor C1 during the constant voltage stage is 3.5V~3.6V, within the safe voltage range of the supercapacitor C1.

[0032] Meanwhile, the multiple Schottky diodes D1 connected in series in the step-down module N1 also accelerate the charging of the supercapacitor C1: whenever the supercapacitor C1 is in a low voltage state and needs to be charged (e.g., a 3.6V supercapacitor C1 will generally discharge to 2.0V and be marked as a low voltage state, and a 3.8V supercapacitor C1 will generally discharge to 2.5V and be marked as a low voltage state), under the action of the multiple Schottky diodes D1 connected in series in the step-down module N1, the charging chip U1 can directly skip the trickle charging stage and directly enter the constant current charging (fast charging) stage at startup, thereby accelerating the charging speed of the supercapacitor C1.

[0033] This is because the Schottky diode D1 has a forward voltage drop. When current flows through the series-connected Schottky diodes D1, a certain voltage drop is generated across each diode. Thus, from the perspective of the charging chip U1, the voltage of the equivalent load (supercapacitor C1 and step-down module N1) connected to its charging output terminal VBAT will increase due to the voltage drop of the Schottky diode D1.

[0034] When the supercapacitor C1 is in a low voltage state, the voltage drop of the Schottky diode D1 makes the voltage detected by the charging chip U1 meet the conditions for entering the constant current charging stage. As a result, the charging chip U1 skips the trickle charging stage and directly enters the constant current charging stage when it starts up.

[0035] According to actual test data, if multiple Schottky diodes D1 are connected in series between the supercapacitor C1 and the charging chip U1, the supercapacitor C1 will trickle charge for 20-30 minutes under low voltage conditions, and a full charge will take 30-40 minutes. However, if multiple Schottky diodes D1 are connected in series between the supercapacitor C1 and the charging chip U1, there is no trickle charging process, and the supercapacitor C1 can be fully charged in only about 10 minutes.

[0036] In one embodiment, multiple Schottky diodes D1 connected in series in the step-down module N1 reduce the charging output voltage of the charging chip U1 to a range suitable for the supercapacitor C1, ensuring that the voltage applied to the supercapacitor C1 does not exceed its rated value, avoiding overvoltage damage, and effectively protecting the safety and service life of the supercapacitor C1. At the same time, by utilizing the forward voltage drop of the Schottky diodes D1, the charging chip U1 can skip the trickle charging stage and directly enter the constant current charging stage when the supercapacitor C1 is in a low voltage state, significantly shortening the charging time and giving full play to the advantages of the supercapacitor C1 in fast charging and discharging.

[0037] This solves the problem of selecting the charging chip U1 for the supercapacitor C1. That is, this supercapacitor fast charging circuit can charge the supercapacitor C1 quickly and safely even when using a conventional lithium-ion charging chip U1.

[0038] Optionally, based on the above embodiments, the charging output voltage is 4.2V, and the capacitor charging voltage is 3.6 / 3.8V.

[0039] Optionally, the power supply voltage for the power input terminal V1 is 5V.

[0040] The step-down module N1 contains two Schottky diodes D1 connected in series, and the forward voltage drop of a single Schottky diode D1 is 3.5~3.6V.

[0041] Optionally, in one embodiment, based on the above embodiment, the charging chip U1 is a lithium-ion charging chip U1, and the supercapacitor C1 is a lithium-ion supercapacitor C1.

[0042] Alternatively, the lithium-ion charging chip U1 can be selected from SGM41566-405N21, TP4056, MCP73831, LTC4054, etc.

[0043] Alternatively, the lithium-ion supercapacitor C1 can be selected from MAXWELL BCAP0350, NESSCAP P270, EVERCAP EC-105, UCLIC3R8337N100035E, etc.

[0044] In one embodiment, based on the above embodiment, a temperature control switch is further provided between the power input terminal V1 and the power supply terminal VCC of the charging chip U1, and the control terminal of the temperature control switch is electrically connected to the control output terminal of the charging chip U1.

[0045] In this embodiment, the existing supercapacitor fast charging circuit is expanded by adding a key component: a temperature control switch. The temperature control switch is located between the power input terminal V1 and the power supply terminal VCC of the charging chip U1, and its control terminal is electrically connected to the control output terminal of the charging chip U1.

[0046] Normal operating condition: When the supercapacitor C1 charging circuit is within its normal operating temperature range, the charging chip U1 sends a specific signal to the control terminal of the temperature control switch through its control output terminal, keeping the temperature control switch in the conducting state. In this way, the electrical energy at the power input terminal V1 can be smoothly transferred to the power supply terminal VCC of the charging chip U1, providing the charging chip U1 with the power required for operation, thereby ensuring the normal progress of the entire charging process.

[0047] Abnormal Temperature Conditions: If an abnormal situation occurs during charging, such as a temperature rise due to high current charging or heat generated by circuit components, the NTC thermistor R1 will sense the temperature change and feed the temperature information back to the charging chip U1. When the temperature exceeds a preset safety threshold, the charging chip U1 will react quickly, sending a control signal to the temperature control switch via its control output, causing the temperature control switch to open. At this time, the circuit connection between the power input terminal V1 and the power supply terminal VCC of the charging chip U1 is broken, the charging chip U1 stops working, and thus stops charging the supercapacitor C1, avoiding potential safety problems caused by overheating, such as damage to the supercapacitor C1, burnout of circuit components, or even a fire.

[0048] In one embodiment, by introducing a temperature control switch, the temperature changes during the charging process can be monitored and responded to in real time. When the temperature is abnormal, the power supply can be cut off in time, effectively preventing various safety hazards caused by overheating and greatly improving the safety and reliability of the supercapacitor fast charging circuit.

[0049] This utility model further proposes an electronic device, which includes a supercapacitor fast charging circuit. The specific structure of the supercapacitor fast charging circuit is as described in the above embodiments. Since this electronic device adopts all the technical solutions of all the above embodiments, it has at least all the technical effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0050] Optionally, the electronic device further includes a charging interface and a power module; the charging interface is electrically connected to the power input terminal V1 of the supercapacitor fast charging circuit, and the positive input terminal of the power module is electrically connected to the charging output terminal VBAT of the charging chip U1 of the supercapacitor fast charging circuit.

[0051] The charging interface is used to connect to an external power source to provide input power to the supercapacitor fast charging circuit; the supercapacitor fast charging circuit is responsible for fast charging of the supercapacitor C1 and charging the power module; the power module can provide stable power support for other functional modules of the electronic device.

[0052] Optionally, the charging interface is a USB interface.

[0053] Optionally, the power supply module is powered by a lithium battery.

[0054] The above description is only a part or preferred embodiment of this utility model. Neither the text nor the drawings should limit the scope of protection of this utility model. All equivalent structural transformations made using the content of this utility model specification and drawings under the overall concept of this utility model, or direct / indirect applications in other related technical fields, are included within the scope of protection of this utility model.

Claims

1. A supercapacitor fast charging circuit, characterized in that, include: The system consists of a power input terminal, a charging chip, a step-down module, a supercapacitor, and an NTC thermistor. The power input terminal is electrically connected to the power supply terminal of the charging chip. The NTC thermistor is connected between the temperature sensing terminal and the ground pin of the charging chip. The charging output terminal of the charging chip is connected to the ground wire via the step-down module and the supercapacitor. The step-down module is equipped with multiple Schottky diodes connected in series, and the conduction direction of each Schottky diode is from the charging output terminal of the charging chip to the supercapacitor. The charging output voltage at the charging output terminal of the charging chip is greater than the capacitor charging voltage of the supercapacitor; the remaining voltage obtained by subtracting the sum of the forward voltage drops of all Schottky diodes in the step-down module from the charging output voltage does not exceed the capacitor charging voltage.

2. The supercapacitor fast charging circuit as described in claim 1, characterized in that, The charging output voltage is 4.2V, and the capacitor charging voltage is 3.6 / 3.8V; The step-down module contains two Schottky diodes connected in series, and the forward voltage drop of a single Schottky diode is 3.5~3.6V.

3. The supercapacitor fast charging circuit as described in claim 1 or 2, characterized in that, The charging chip is a lithium-ion charging chip, and the supercapacitor is a lithium-ion supercapacitor.

4. The supercapacitor fast charging circuit as described in claim 1, characterized in that, A temperature control switch is also provided between the power input terminal and the power supply terminal of the charging chip, and the control terminal of the temperature control switch is electrically connected to the control output terminal of the charging chip.

5. An electronic device, characterized in that, Includes a supercapacitor fast charging circuit as described in any one of claims 1-4.

6. The electronic device as claimed in claim 5, characterized in that, The electronic device also includes a charging interface and a power module; the charging interface is electrically connected to the power input terminal of the supercapacitor fast charging circuit, and the positive input terminal of the power module is electrically connected to the charging output terminal of the charging chip of the supercapacitor fast charging circuit.

7. The electronic device as claimed in claim 6, characterized in that, The charging interface is a USB interface.

8. The electronic device as claimed in claim 6, characterized in that, The power module is powered by a lithium battery.

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