Segmented temperature control charging current adjusting circuit of intelligent door lock battery pack

Abstract

The utility model relates to a segmented temperature control charging current adjusting circuit for a battery pack of an intelligent door lock. The segmented temperature control charging current adjusting circuit is used for charging the battery pack. The battery pack comprises two batteries which are connected in series. The charging circuit comprises a charging interface J1, a lithium battery protection circuit used for being connected with a battery pack and a charging management circuit used for equalizing current and being connected with the battery pack. The charging management circuit is connected with a charging interface J1 and an NTC (Negative Temperature Coefficient) resistor NTC1 for detecting the temperature of the charging management circuit; the temperature segmentation protection circuit is used for detecting the temperature of the battery pack and carrying out segmentation protection according to different temperatures of the detected battery pack; the temperature segmentation protection circuit is connected with the charging management circuit; the charging protection current requirement of the battery pack of the intelligent door lock at different temperature sections can be met, the temperature section quick charging function is achieved, and the charging time is shortened.

Description

Technical Field

[0001] This utility model relates to the technical field of segmented temperature control and charging current regulation circuits for intelligent door lock battery packs, and in particular to an intelligent door lock battery pack segmented temperature control and charging current regulation circuit. Background Technology

[0002] A door lock is a device that serves as an insurance and security device.

[0003] With the development of automation and intelligent technologies, and under the wave of smart homes, the intelligentization of door locks is also a development trend, leading to the emergence of smart door locks.

[0004] Because features such as facial recognition, peephole, and Wi-Fi connectivity are integrated into smart locks, the power consumption of smart locks is higher than that of traditional fingerprint locks, making them unsuitable for use with dry cell batteries.

[0005] Currently, most smart door locks are powered by rechargeable lithium batteries.

[0006] Existing smart door locks' lithium batteries have difficulty meeting the charging protection current requirements for different temperature ranges during charging, thus hindering fast charging.

[0007] Therefore, in this utility model patent application, the applicant has carefully researched a segmented temperature control and charging current regulation circuit for intelligent door lock battery packs to solve the above problems. Utility Model Content

[0008] This utility model addresses the shortcomings of the existing technology by providing a segmented temperature control charging current adjustment circuit for a smart door lock battery pack. This circuit can meet the charging protection current requirements of the smart door lock battery pack at different temperature ranges, achieving temperature-segmented fast charging and shortening the charging time.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A segmented temperature-controlled charging current regulation circuit for a smart door lock battery pack is provided for charging the battery pack, which includes two batteries connected in series. The circuit includes a charging interface J1, a lithium battery protection circuit for connecting the battery pack, and a charging management circuit for balancing the current and connected to the battery pack. The charging management circuit is connected to the charging interface J1.

[0011] The charging management circuit is connected to an NTC resistor NTC1 for detecting its temperature.

[0012] It also includes a temperature segment protection circuit for detecting the battery pack temperature and providing segmented protection based on different temperatures of the detected battery pack, the temperature segment protection circuit being connected to the charging management circuit.

[0013] The temperature segment protection circuit includes resistors R14, R15, R19, and R10, capacitor C10, MOSFET Q5, operational amplifier, resistors R12 and R18 connected in series, and NTC resistor NTC3 for detecting the battery pack temperature.

[0014] Resistor R14 and NTC resistor NTC3 are connected in series. The series connection point of resistor R14 and NTC resistor NTC3 is connected to pin 1 of the operational amplifier. The series connection point of resistor R12 and resistor R18 is connected to pin 3 of the operational amplifier.

[0015] Resistors R15 and R19 are connected in series. The non-series node of resistor R15 is connected to pin 4 of the operational amplifier. The series node of resistors R15 and R19 is connected to the gate of MOSFET Q5. The drain of MOSFET Q5 is connected to the charging management circuit through resistor R10.

[0016] One end of capacitor C10, the non-series node of resistor R12, the non-series node of resistor R14, and pin 5 of operational amplifier are all connected to pin B9 of charging interface J1.

[0017] The source of MOSFET Q5, the other end of capacitor C10, pin 2 of operational amplifier, the non-series node of resistor R19, the non-series node of NTC resistor NTC3, and the non-series node of resistor R18 are all connected to digital ground.

[0018] As a preferred embodiment, the charging management circuit is composed of a chip U2 of model ETA6072 and its peripheral circuits.

[0019] As a preferred embodiment, pin 7 of chip U2 is connected to a charging indicator circuit, which is connected to charging interface J1.

[0020] As a preferred embodiment, the charging indicator circuit includes resistor R6, resistor R11, a first charging status indicator LED1, a second charging status indicator LED2, and a MOSFET Q4;

[0021] The A5 pin of the charging interface J1 is connected to digital ground through resistor R17, and the B5 pin of the charging interface J1 is connected to digital ground through resistor R16.

[0022] The B9 pin of the charging interface J1 is connected to the positive terminal of the first charging status indicator LED1 through the resistor R6. The negative terminal of the first charging status indicator LED1 is connected to the drain of the MOSFET Q4. The source of the MOSFET Q4 is connected to digital ground.

[0023] The B9 pin of the charging interface J1 is also connected to the positive terminal of the second charging status indicator LED2 through resistor R11. The negative terminal of the second charging status indicator LED2 is connected to the gate of MOSFET Q4. The gate of MOSFET Q4 is connected to pin 7 of chip U2.

[0024] Compared with the prior art, this utility model has obvious advantages and beneficial effects. Specifically, it mainly adds a temperature segment protection circuit, which can realize the charging protection current requirements of the smart door lock battery pack in different temperature segments, achieve temperature segment fast charging function, and shorten charging time.

[0025] To more clearly illustrate the structural features and effects of the present invention, a detailed description is provided below in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0026] Figure 1 This is a circuit schematic diagram of an embodiment of the present invention.

[0027] Explanation of icon numbers:

[0028] 11. Lithium battery protection circuit

[0029] 12. Equalizing current amplification circuit

[0030] 13. Charging management circuit

[0031] 14. Charging indicator circuit. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1 As shown, a segmented temperature control charging current regulation circuit for a smart door lock battery pack is used to charge the battery pack, which includes two batteries connected in series. It includes a charging interface J1, a lithium battery protection circuit 12 for connecting the battery pack, a temperature segmentation protection circuit 13 for detecting the battery pack temperature and providing segmented protection based on different detected battery temperatures, and a charging management circuit 11 for balancing the current and connected to the battery pack. The charging management circuit 11 is connected to the charging interface J1. The charging management circuit 11 is also connected to an NTC resistor NTC1 for detecting its temperature.

[0034] In this embodiment, the charging management circuit 11 is composed of a chip U2 with model number ETA6072 and its peripheral circuits.

[0035] The temperature segment protection circuit 13 is connected to the charging management circuit 11. In this embodiment, the temperature segment protection circuit 13 includes resistors R14, R15, R19, and R10, capacitor C10, MOSFET Q5, operational amplifier U3, resistors R12 and R18 connected in series, and an NTC resistor NTC3 for detecting the battery pack temperature.

[0036] Resistor R14 and NTC resistor NTC3 are connected in series. The series connection point of resistors R14 and NTC resistor NTC3 is connected to pin 1 of operational amplifier U3. In this embodiment, the resistance of NTC resistor NTC3 changes with temperature. NTC resistor NTC3 and resistor R14 are connected in series between Vbusc (power supply) and GND (ground), and a voltage divider sampling point is obtained through the connection in the middle. Since the resistance of NTC resistor NTC3 changes with temperature, the voltage at this sampling point also changes with temperature. This sampled voltage is connected to pin 1 of operational amplifier U3. It should be noted that Vbusc (power supply) is pin B9 of charging interface J1.

[0037] The series connection of resistors R12 and R18 is connected to pin 3 of operational amplifier U3. In this embodiment, resistors R12 and R18 are connected in series between Vbusc (power supply) and GND (ground) to form a voltage divider circuit. The voltage at the midpoint is used as a reference, and this reference voltage is connected to pin 3 of operational amplifier U3.

[0038] Resistors R15 and R19 are connected in series. In this embodiment, resistors R15 and R19 enhance the switching stability of MOSFET Q5.

[0039] The non-series node of resistor R15 is connected to pin 4 of operational amplifier U3, and the series node of resistors R15 and R19 is connected to the gate of MOSFET Q5. The drain of MOSFET Q5 is connected to charging management circuit 11 through resistor R10.

[0040] One end of capacitor C10, the non-series node of resistor R12, the non-series node of resistor R14, and pin 5 of operational amplifier U3 are all connected to pin B9 of charging interface J1.

[0041] The source of MOSFET Q5, the other end of capacitor C10, pin 2 of operational amplifier U3, the non-series node of resistor R19, the non-series node of NTC resistor NTC3, and the non-series node of resistor R18 are all connected to digital ground.

[0042] Pin 5 of operational amplifier U3 is filtered by capacitor C10. Pin 2 is grounded. Operational amplifier U3 analyzes and compares the sampled voltage at pin 1 with the reference voltage at pin 3, and based on the analysis and comparison result, it outputs a high or low level at pin 4 to control the MOSFET Q5 to turn on or off, thereby controlling the charging current of chip U2.

[0043] When MOSFET Q5 is turned off, its on-resistance is extremely high and can be treated as an open circuit, which is equivalent to leaving resistor R10 floating. At this time, the total resistance of the external grounding resistor at pin 9 of chip U2 is the same as the resistance of resistor R9.

[0044] When MOSFET Q5 is turned on, its on-resistance is negligible, which is equivalent to grounding resistor R10 and forming a parallel circuit with resistor R9. At this time, the total resistance of the external grounding resistor at pin 9 of chip U2 is equivalent to the parallel value of resistors R9 and R10. When the two resistors are connected in parallel, the resistance value decreases, thereby achieving the function of regulating the charging current.

[0045] Pin 7 of chip U2 is connected to a charging indicator circuit 14, which is connected to the charging interface J1. The charging indicator circuit 14 includes resistors R6 and R11, a first charging status indicator LED1, a second charging status indicator LED2, and a MOSFET Q4.

[0046] The A5 pin of the charging interface J1 is connected to digital ground through resistor R17, and the B5 pin of the charging interface J1 is connected to digital ground through resistor R16.

[0047] The B9 pin of the charging interface J1 is connected to the positive terminal of the first charging status indicator LED1 through the resistor R6. The negative terminal of the first charging status indicator LED1 is connected to the drain of the MOSFET Q4. The source of the MOSFET Q4 is connected to digital ground.

[0048] The B9 pin of the charging interface J1 is also connected to the positive terminal of the second charging status indicator LED2 through resistor R11. The negative terminal of the second charging status indicator LED2 is connected to the gate of MOSFET Q4. The gate of MOSFET Q4 is connected to pin 7 of chip U2.

[0049] In this embodiment, the lithium battery protection circuit 1211 includes a chip U1, a capacitor C1, a resistor R1, a resistor R3, a capacitor C2, a resistor R2, a capacitor C6, a capacitor C12, and a MOS chip Q1.

[0050] Pin 3 of chip U1 is connected to digital ground through resistor R3, and pin 5 of chip U1 is connected to analog ground through capacitor C1. Pin 5 of chip U1 is also connected to one end of resistor R1, and the other end of resistor R1 is used to connect to the B+ terminal of the battery pack.

[0051] Pin 4 of chip U1 is connected to analog ground through capacitor C2, and pin 6 of chip U1 is used to connect to the B- terminal of the battery pack and is also connected to analog ground; pin 4 of chip U1 is also connected to one end of resistor R2, and the other end of resistor R2 is used to connect to the VC terminal of the battery pack.

[0052] Pin 6 of MOS chip Q1 is connected to pin 1 of chip U1. Pin 3 of pin 1 of MOS chip Q1 is connected to digital ground. Pin 3 of the third MOS chip Q4 is connected to pin 1 of the third MOS chip Q4 through capacitors C6 and C12. Pin 1 of MOS chip Q1 is connected to analog ground.

[0053] It also includes a discharge interface J2. Pin 5 of the discharge interface J2 is connected to pin B9 of the charging interface J1. Pin 5 of the discharge interface J2 is connected to pin 4 of the discharge interface J2 through a bidirectional TVS diode ESD1. Pin 5 of the discharge interface J2 is also connected to pin 4 of the discharge interface J2 through a capacitor C11. Pin 4 of the discharge interface J2 is connected to digital ground. Pin 4 of the discharge interface J2 and the discharge interface 2 are connected to pin 1 of the discharge interface J2 through a bidirectional TVS diode ESD2. Pin 1 of the discharge interface J2 is used to connect to the B+ terminal of the battery pack.

[0054] The key design feature of this invention is the addition of a temperature segmentation protection circuit, which enables the smart door lock's battery pack to meet the charging protection current requirements at different temperature ranges, achieving temperature-segmented fast charging and shortening charging time.

[0055] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A battery pack segmented temperature control regulation charging current circuit for charging a battery pack, the battery pack comprising two series connected batteries; the battery pack charging circuit comprising a charging interface J1, a lithium battery protection circuit for connecting the battery pack, and a charging management circuit for balancing current and connecting the battery pack; the charging management circuit being connected to the charging interface J1, characterized in that: the charging management circuit is connected to an NTC resistor NTC1 for detecting the temperature thereof; the battery pack further comprising a temperature segmented protection circuit for detecting the temperature of the battery pack and performing segmented protection according to different detected temperatures of the battery pack, the temperature segmented protection circuit being connected to the charging management circuit; the temperature segmented protection circuit comprising a resistor R14, a resistor R15, a resistor R19, a resistor R10, a capacitor C10, a MOS transistor Q5, an operational amplifier, a resistor R12 and a resistor R18 connected in series, and an NTC resistor NTC3 for detecting the temperature of the battery pack; the resistor R14 and the NTC resistor NTC3 are connected in series, the series connection node of the resistor R14 and the NTC resistor NTC3 being connected to pin 1 of the operational amplifier, the series connection node of the resistor R12 and the resistor R18 being connected to pin 3 of the operational amplifier; the resistor R15 and the resistor R19 are connected in series, the non-series connection node of the resistor R15 being connected to pin 4 of the operational amplifier, the series connection node of the resistor R15 and the resistor R19 being connected to the gate of the MOS transistor Q5, the drain of the MOS transistor Q5 being connected to the charging management circuit through the resistor R10; one end of the capacitor C10, the non-series connection node of the resistor R12, the non-series connection node of the resistor R14, and pin 5 of the operational amplifier are collectively connected to pin B9 of the charging interface J1; the source of the MOS transistor Q5, the other end of the capacitor C10, pin 2 of the operational amplifier, the non-series connection node of the resistor R19, the non-series connection node of the NTC resistor NTC3, and the non-series connection node of the resistor R18 are collectively connected to a digital ground. the charging management circuit is composed of a chip U2 of model ETA6072 and its peripheral circuit.

2. The smart door lock battery pack section temperature control regulated charging current circuit according to claim 1, wherein: pin 7 of the chip U2 is connected to a charging indication circuit, the charging indication circuit being connected to the charging interface J1.

3. The smart door lock battery pack section temperature control regulated charging current circuit according to claim 2, wherein: the charging indication circuit comprises a resistor R6, a resistor R11, a first charging state indicator LED1, a second charging state indicator LED2, and a MOS transistor Q4; 4. The smart door lock battery pack section temperature control regulated charging current circuit according to claim 3, wherein: pin A5 of the charging interface J1 is connected to a digital ground through the resistor R17, pin B5 of the charging interface J1 is connected to a digital ground through the resistor R16; pin B9 of the charging interface J1 is connected to the positive electrode of the first charging state indicator LED1 through the resistor R6, the negative electrode of the first charging state indicator LED1 is connected to the drain of the MOS transistor Q4, and the source of the MOS transistor Q4 is connected to a digital ground; pin B9 of the charging interface J1 is also connected to the positive electrode of the second charging state indicator LED2 through the resistor R11, the negative electrode of the second charging state indicator LED2 is connected to the gate of the MOS transistor Q4, and the gate of the MOS transistor Q4 is connected to pin 7 of the chip U2. ​

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