Charging circuit and shaver

Abstract

The invention relates to a charging circuit and a shaver. The charging circuit comprises a signal module used for generating a charging reference signal according to current and / or voltage of a charging loop; the charging control module is electrically connected with the main controller and comprises a first MOS tube and a switch element, the drain electrode of the first MOS tube is connected with the positive electrode of the battery, and the switch element is electrically connected with the grid electrode of the first MOS tube; and the main controller is electrically connected with the signal module and the charging control module and is used for generating a charging control signal according to the charging reference signal, and the charging control signal is used for controlling the on-off of the switching element. According to the charging circuit and the shaver provided by the embodiment of the invention, the charging current can be dynamically adjusted according to the charging parameters, the energy loss can be reduced, and the charging efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of charging control, and particularly to a charging circuit and a shaver. Background Art

[0002] An electric shaver is equipped with a rechargeable battery. The electric energy of an external power source is used to charge the battery through a charging interface, enabling the user to use it without constantly connecting to the power source, thus enhancing the convenience of use. The charging circuit of the shaver generally consists of a power input section, a step-down and rectification section, a charging control section, and a status indication section. Among them, the power input section is used to introduce the electric energy of the external power source into the charging circuit. The step-down and rectification section is used to convert the input alternating current into stable direct current and adjust the voltage to a level suitable for charging the shaver battery, or to stabilize the input direct current within the range required for battery charging. The charging control section is used to control the charging current and voltage according to the status of the battery. The charging status indication section is used to display the charging progress or status.

[0003] In the prior art, the charging circuits of electric shavers mainly have two types: a linear charging circuit and a charging circuit based on a charging management chip. Among them, the linear charging circuit has a low energy conversion efficiency and a limited charging current magnitude, so the charging speed is slow. The charging circuit based on a charging management chip usually first performs constant current charging. When the battery voltage rises to a preset voltage, it then switches to a constant voltage charging mode. As the battery charge gradually increases, the charging current gradually decreases. When the charging current decreases to a preset current, the chip determines that the battery is fully charged and the charging ends. The current in the constant current charging mode is usually lower than the maximum charging current of the battery, and the gradually decreasing charging current in the constant voltage charging mode will both affect the charging speed. Therefore, the charging speed of electric shavers in the prior art is slow. Summary of the Invention

[0004] Based on this, it is necessary to provide a charging circuit and a shaver that can improve the charging speed.

[0005] In a first aspect, a charging circuit is provided, including:

[0006] A signal module, configured to generate a charging reference signal according to the current and / or voltage of the charging circuit;

[0007] A charging control module, electrically connected to the main controller, including a first MOS transistor and a switching element. The drain of the first MOS transistor is connected to the positive pole of the battery, and the switching element is electrically connected to the gate of the first MOS transistor;

[0008] A main controller, electrically connected to the signal module and the charging control module, configured to generate a charging control signal according to the charging reference signal, and the charging control signal is used to control the on / off of the switching element.

[0009] In one embodiment, the main controller includes a first signal generation unit configured to generate a charging enable signal. The switching element includes a first triode Q2. The base of the first triode is electrically connected to the first signal output terminal of the main controller to receive the charging enable signal, the collector is electrically connected to the source of the first MOS transistor, and the emitter is grounded.

[0010] In one embodiment, the signal module includes a sampling resistor. The first end of the sampling resistor is electrically connected to the source of the first MOS transistor and the first input terminal of the main controller, the second end of the sampling resistor is grounded, the charging reference signal includes the voltage of the sampling resistor, and the main controller includes a second signal generation unit configured to generate a charging current control signal according to the voltage of the sampling resistor.

[0011] In one embodiment, the switching element includes a second triode. The base of the second triode is electrically connected to the output terminal of the second signal generation unit, and the collector of the second triode is electrically connected to the gate of the first MOS transistor.

[0012] In one embodiment, the charging circuit further includes a power detection module. The power detection module includes a first resistor, a second resistor, and a third resistor. The first resistor is electrically connected to the power input terminal and then connected in series with the second resistor and the third resistor, and the third resistor is grounded. The connection point between the first resistor and the second resistor is electrically connected to the second input terminal of the main controller, and the connection point between the second resistor and the third resistor is electrically connected to the third input terminal of the main controller.

[0013] In one embodiment, a filter and voltage regulation module is further included. The filter and voltage regulation module includes a first capacitor, a second capacitor, and a third capacitor. Among them, the first end of the first capacitor is connected to the positive electrode of the battery, the second end of the first capacitor is grounded, the first end of the second capacitor is connected to the positive electrode of the battery, the second end of the second capacitor is grounded, the third capacitor is connected in parallel between the positive and negative electrodes of the battery, and the first capacitor and the second capacitor have different sizes.

[0014] In one embodiment, the signal module further includes a filter capacitor connected in parallel with the sampling resistor.

[0015] In one embodiment, the charging control module further includes a battery protection unit. The power input pin of the battery protection unit is connected to the positive electrode of the battery, the ground pin is connected to the negative electrode of the battery, and the battery voltage detection pin is connected to the first end of the sampling resistor.

[0016] In one embodiment, an LED digital tube is further included. The LED digital tube is electrically connected to the main controller. The main controller is further configured to obtain the charging state of the battery, and the LED digital tube is configured to display the charging state.

[0017] In a second aspect, a razor is further provided, which is characterized by comprising a battery and the charging circuit as described in the first aspect or any embodiment of the first aspect. The charging circuit is configured to charge the battery.

[0018] For the above-mentioned charging circuit and razor, the signal module generates a charging reference signal according to the current and / or voltage of the charging loop, enabling the main controller to obtain key parameters during the charging process in real time. The main controller generates a charging control signal based on the charging reference signal, which can dynamically adjust the charging process. When the battery power is low, the charging current can be increased to improve the charging speed. It also helps to detect charging anomalies in a timely manner through the charging reference signal to avoid situations such as overcharging of the battery. The on-resistance of the MOS transistor is usually small, and it can achieve the conduction of the charging loop with low power consumption. When the switching element conducts according to the charging control signal, the first MOS transistor can achieve the conduction of the charging loop with low power consumption. The switching element can adjust the magnitude of the charging current by regulating the conduction time of the MOS transistor. The above charging circuit and razor can dynamically adjust the charging current according to the charging parameters, reduce energy loss, and improve charging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a schematic diagram of the charging circuit provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0023] It can be understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0024] It can be understood that for "connection" in the following embodiments, if there is an electrical signal or data transfer between the connected circuits, modules, units, etc., it should be understood as "electrical connection", "communication connection", etc.

[0025] It can be understood that "at least one" means one or more, and "a plurality" means two or more. "At least a part of an element" means part or all of the element.

[0026] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprise / include" or "have" etc. specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the related listed items.

[0027] As Figure 1 shown, in an embodiment of this application, a charging circuit is provided, including:

[0028] A signal module, configured to generate a charging reference signal according to the current and / or voltage of the charging circuit;

[0029] A charging control module, electrically connected to the main controller U3, includes a first MOS transistor Q1 and a switching element, the drain of the first MOS transistor Q1 is connected to the positive pole of the battery, and the switching element is electrically connected to the gate of the first MOS transistor Q1;

[0030] The main controller U3, electrically connected to the signal module and the charging control module, is configured to generate a charging control signal PWM_L according to the charging reference signal, and the charging control signal PWM_L is used to control the on / off of the switching element.

[0031] Among them, the charging circuit refers to the path through which current flows from the power source J1 into the battery during the charging process. The signal module refers to a functional module for collecting electrical parameters related to the charging circuit, such as current, voltage, or charging power, etc., and generating a charging reference signal based on these electrical parameters. It may include circuit structures such as a sampling resistor R5 or a voltage dividing circuit. The charging reference signal can be an analog signal or a digital signal related to the charging state generated by processing or converting the current or voltage. The charging control module is the module in the charging circuit that actually controls the charging process. It is electrically connected to the main controller U3 and adjusts the on / off of the charging circuit and the charging parameters according to the charging control signal PWM_L issued by the main controller U3. When the charging control signal PWM_L of the main controller U3 makes the switching element conduct, the gate of the first MOS transistor Q1 obtains an appropriate voltage and thus conducts, allowing current to flow into the battery. When the gate voltage drops to the cut-off voltage, the charging circuit is disconnected and charging stops. The main controller U3 may include a microprocessor or a chip. The charging control algorithm can be stored in the microprocessor or the chip. The main controller U3 compares the charging control signal PWM_L with the preset charging parameters according to the charging control algorithm and generates the corresponding charging control signal PWM_L based on the comparison result, thereby controlling the on / off of the switching element and realizing the dynamic adjustment of the charging process. In some embodiments, the main controller U3 may include the CS8M330-QFN28 chip. The MOS transistor refers to a metal-oxide-semiconductor field-effect transistor, which belongs to a voltage-controlled switching device and is used to control the on and off of the charging circuit. The drain of the first MOS transistor Q1 is connected to the positive pole of the battery and serves as the voltage output terminal, and the source is connected to the charging interface and serves as the voltage input terminal. When an appropriate voltage is applied between the gate and the source, a conductive channel is formed inside the MOS transistor, making the drain and the source conduct, thus connecting the charging circuit. By controlling the magnitude and level change of the gate voltage, the on and off states of the MOS transistor can be precisely controlled. When the conduction time of the first MOS transistor Q1 increases within the control period, the conduction time of the charging circuit increases and the average charging current increases. When the conduction time decreases, the average current decreases accordingly. Therefore, the above charging circuit can dynamically adjust the charging current and improve the charging speed and efficiency.

[0032] In the above charging circuit and the shaver, the signal module generates a charging reference signal based on the current and / or voltage of the charging circuit, enabling the main controller U3 to obtain key parameters during the charging process in real time. The main controller U3 generates a charging control signal PWM_L based on the charging reference signal, which can dynamically adjust the charging process. When the battery power is low, the charging current can be increased to improve the charging speed. It also helps to detect charging anomalies in a timely manner through the charging reference signal to avoid situations such as overcharging of the battery. The on-resistance of the MOS transistor is usually small, and it can achieve the conduction of the charging circuit with low power consumption. When the switching element conducts according to the charging control signal PWM_L, the first MOS transistor Q1 can achieve the conduction of the charging circuit with low power consumption. The switching element can adjust the magnitude of the charging current by regulating the conduction time of the MOS transistor. The above charging circuit and shaver can dynamically adjust the charging current according to the charging parameters, reducing energy loss and improving charging efficiency.

[0033] In an exemplary embodiment, the main controller U3 includes a first signal generation unit for generating a charging enable signal. The switching element includes a first triode Q3. The base of the first triode Q3 is electrically connected to the first signal output terminal of the main controller U3 and receives the charging enable signal, the collector is electrically connected to the source of the first MOS transistor Q1, and the emitter is grounded. Among them, the first signal generation unit can be a functional module inside the main controller U3 and can include components such as logic circuits. When the battery meets the charging conditions, it can generate a high-level or low-level signal as the charging enable signal and transmit it to the external circuit through the first signal output terminal to provide a control signal for switching elements such as the first triode Q3. The high-level or low-level signal is transmitted to the base of the first triode Q3 to turn on the triode, thereby controlling the conduction of the first MOS transistor Q1. When charging needs to be stopped, the charging enable signal changes to the opposite level state, causing the triode to cut off, thus disconnecting the charging circuit. The base is the control electrode of the triode, and the base current controls the conduction state between the collector and the emitter. By using the first triode Q3 to control the first MOS transistor Q1, the on-off of the charging circuit can be flexibly controlled, and the influence of external interference signals on the first MOS transistor can also be reduced, ensuring that the MOS transistor operates stably in the on or off state and improving the stability of the entire charging circuit.

[0034] In an exemplary embodiment, the signal module includes a sampling resistor R5. The first end of the sampling resistor R5 is electrically connected to the source of the first MOS transistor Q1 and the first input terminal of the main controller U3. The second end of the sampling resistor R5 is grounded. The charging reference signal includes the voltage of the sampling resistor R5. The main controller U3 includes a second signal generation unit, and the second signal generation unit is configured to generate a charging current control signal according to the voltage of the sampling resistor R5. Among them, the sampling resistor R5 is connected in series in the charging circuit, and the magnitude of the current in the charging circuit is indirectly obtained by measuring the voltage across its own two ends. The second signal generation unit can be a functional module inside the main controller U3, which is configured to receive the voltage signal across the sampling resistor R5 and generate a charging current control signal according to the voltage signal, and adjust working parameters such as the conduction time or duty cycle of the switching element, so as to achieve precise regulation of the charging current. The feedback control mechanism composed of the sampling resistor R5 and the second signal generation unit can also effectively suppress the fluctuation of the charging current and improve the stability and reliability of the charging circuit.

[0035] In an exemplary embodiment, the switching element includes a second triode Q2. The base of the second triode Q2 is electrically connected to the output terminal of the second signal generation unit. The collector of the second triode Q2 is electrically connected to the gate of the first MOS transistor Q1. The second triode Q2 can be an NPN-type triode. When the second signal generation unit outputs a high-level charging current control signal, the signal is applied to the base of the second triode Q2, so that the voltage between the base and the emitter exceeds the conduction threshold of the triode, and a suitable voltage is transmitted to the gate of the first MOS transistor Q1, causing the first MOS transistor Q1 to conduct, turning on the charging circuit and starting to charge.

[0036] In an exemplary embodiment, the charging circuit further includes a power supply J1 detection module. The power supply J1 detection module includes a first resistor R24, a second resistor R25, and a third resistor R26. The first resistor R24 is electrically connected to the input terminal of the power supply J1 and then connected in series with the second resistor R25 and the third resistor R26, and the third resistor R26 is grounded. The connection point of the first resistor R24 and the second resistor R25 is electrically connected to the second input terminal of the main controller U3, and the connection point of the second resistor R25 and the third resistor R26 is electrically connected to the third input terminal of the main controller U3. Among them, the power supply J1 detection module is used to detect the parameters of the charging voltage. The first resistor R24, the second resistor R25, and the third resistor R26 obtain the voltage information of the power supply J1 through voltage division. Among them, the connection point of the first resistor R24 and the second resistor R25 outputs the WIN_WP signal, and the connection point of the second resistor R25 and the third resistor R26 outputs the WIN_DET signal. The WIN_WP signal is used to detect whether the input voltage exceeds the safe range, and the WIN_DET signal can be used to detect whether the power supply J1 is connected and whether the voltage of the power supply J1 is within the charging range. The main controller U3 can judge whether to start the charging process by detecting the VIN_WP signal and the WIN_DET signal, and monitor the status of the power supply J1 in real time during the charging process.

[0037] In an exemplary embodiment, a filter and voltage regulator module is further included. The filter and voltage regulator module includes a first capacitor C2, a second capacitor C3, and a third capacitor C6. Among them, the first end of the first capacitor C2 is connected to the positive electrode of the battery, the second end of the first capacitor C2 is grounded, the first end of the second capacitor C3 is connected to the positive electrode of the battery, the second end of the second capacitor C3 is grounded, the third capacitor C6 is connected in parallel between the positive and negative electrodes of the battery, and the sizes of the first capacitor C2 and the second capacitor C3 are different. Among them, the filter and voltage regulator module is a module for stabilizing the voltage in the circuit and filtering out noise. Through the combined action of the first capacitor C2, the second capacitor C3, and the third capacitor C6, filtering of different frequency noises is achieved. The first capacitor C2 and the second capacitor C3 can be used to filter out high-frequency noise and low-frequency noise respectively, and the third capacitor C6 is connected in parallel between the positive and negative electrodes of the battery to stabilize the voltage across the battery.

[0038] In an exemplary embodiment, the signal module further includes a filter capacitor C10, and the filter capacitor C10 is connected in parallel with the sampling resistor R5. Among them, the filter capacitor C10 can filter the voltage signal across the sampling resistor R5, improve the signal quality, help the main controller U3 generate a charging current control signal more accurately, and improve the accuracy of the charging process control.

[0039] In an exemplary embodiment, the charging control module further includes a battery protection unit, wherein the power supply J1 input pin of the battery protection unit is connected to the positive electrode of the battery, the ground pin is connected to the negative electrode of the battery, and the battery voltage detection pin is connected to the first end of the sampling resistor R5. The battery protection unit is used to monitor the voltage and current of the battery in real time and take protective measures when the battery is abnormal. The power supply J1 input pin is used to connect the positive electrode of the battery to the internal circuit of the battery protection unit, so that the electric energy output by the battery can be input into the protection unit, and the power supply J1 is provided for the normal operation of the protection unit. The output voltage and other information of the battery can also be monitored in real time through the pin. The ground pin is used to provide a zero potential reference point for the battery protection unit to ensure that the potential difference between the internal circuit of the protection unit and the battery is within the normal range, so that the protection unit can work stably. The battery voltage detection pin is connected to the first end of the sampling resistor R5, and the real-time voltage information of the battery is indirectly obtained by detecting and analyzing the voltage on the sampling resistor R5. The battery protection unit determines whether the battery is in the normal operating voltage range according to the detected battery voltage, so that protective measures can be taken in time when the battery is overcharged or over-discharged. In some embodiments, the battery protection unit may be a XB5606AJ chip.

[0040] In an exemplary embodiment, it further comprises an LED digital tube, which is electrically connected to the main controller U3. The main controller U3 is also used to obtain the charging status of the battery, and the LED digital tube is used to display the charging status. Figure 1 As shown, the LED digital tube may include multiple light-emitting diodes, which may be seven-segment digital tubes or eight-segment digital tubes. The signal line for controlling each LED light and the bit selection line of the digital tube are respectively connected to an input / output port of the main controller U3. The main controller U3 can control the bit selection line of each digital tube in turn by time-sharing and send the corresponding segment selection signal, so as to realize static or dynamic display, so that the user can know the charging status at any time.

[0041] In an exemplary embodiment, a charging circuit is provided, such as Figure 1 As shown, when the power supply J1 is connected to the charger for charging, the second transistor Q2 is turned on, and the first MOS tube Q1 is turned on. At this time, the current flows through the battery to the sampling resistor R5, and then to the ground, forming a charging loop. The chip U3 reads the voltage of the sampling resistor R5, adjusts the PWM_L signal, and makes the first MOS tube Q1 continuously turned on and off through the first diode Q3, so that the voltage of R5 and PWM_L form a closed-loop regulation, so that it can charge the battery at a flash speed. The LED digital tube displays the amount of flash charging.

[0042] In an exemplary embodiment, a razor is further provided, which includes a battery and a charging circuit as described in the above embodiments, and the charging circuit is used to charge the battery.

[0043] In an exemplary embodiment, the charging circuit can also be used for other electrical devices, and the other electrical devices include but are not limited to various life care devices.

[0044] In the description of this specification, the descriptions referring to terms such as "some embodiments", "other embodiments", etc. mean that the specific features, structures, materials or features described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0045] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0046] The above-described embodiments only represent several implementation manners of the present application. The descriptions are relatively specific and detailed, but should not be construed as a limitation on the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A charging circuit, characterized in that: include: A signal module, used for generating a charging reference signal according to the current and / or voltage of the charging circuit; A charging control module, electrically connected to the main controller, comprising a first MOS tube and a switch element, wherein the drain of the first MOS tube is connected to the positive electrode of the battery, and the switch element is electrically connected to the gate of the first MOS tube; A main controller is electrically connected to the signal module and the charging control module, and is used to generate a charging control signal according to the charging reference signal, wherein the charging control signal is used to control the on and off of the switch element.

2. The charging circuit according to claim 1, characterized in that: The main controller includes a first signal generating unit, which is used to generate a charging enable signal. The switching element includes a first transistor, the base of which is electrically connected to the first signal output terminal of the main controller and receives the charging enable signal, the collector is electrically connected to the source of the first MOS tube, and the emitter is grounded.

3. The charging circuit according to claim 1, characterized in that: The signal module includes a sampling resistor, a first end of the sampling resistor is electrically connected to the source of the first MOS tube and the first input end of the main controller, a second end of the sampling resistor is grounded, the charging reference signal includes the voltage of the sampling resistor, and the main controller includes a second signal generating unit, and the second signal generating unit is used to generate a charging current control signal according to the voltage of the sampling resistor.

4. The charging circuit according to claim 3, characterized in that: The switch element comprises a second triode, a base of the second triode is electrically connected to the output end of the second signal generating unit, and a collector of the second triode is electrically connected to the gate of the first MOS tube.

5. The charging circuit according to claim 3, characterized in that: The charging circuit also includes a power detection module, which includes a first resistor, a second resistor and a third resistor. The first resistor is electrically connected to the power input terminal and then connected in series with the second resistor and the third resistor, and the third resistor is grounded. The connection point between the first resistor and the second resistor is electrically connected to the second input terminal of the main controller, and the connection point between the second resistor and the third resistor is electrically connected to the third input terminal of the main controller.

6. The charging circuit according to claim 1, characterized in that: It also includes a filtering and voltage stabilizing module, which includes a first capacitor, a second capacitor and a third capacitor, wherein the first end of the first capacitor is connected to the positive electrode of the battery, the second end of the first capacitor is grounded, the first end of the second capacitor is connected to the positive electrode of the battery, the second end of the second capacitor is grounded, the third capacitor is connected in parallel between the positive and negative electrodes of the battery, and the first capacitor and the second capacitor are different in size.

7. The charging circuit according to claim 3, characterized in that: The signal module further includes a filter capacitor, and the filter capacitor is connected in parallel with the sampling resistor.

8. The charging circuit according to claim 2, characterized in that: The charging control module also includes a battery protection unit, a power input pin of the battery protection unit is connected to the positive electrode of the battery, a ground pin is connected to the negative electrode of the battery, and a battery voltage detection pin is connected to the first end of the sampling resistor.

9. The charging circuit according to claim 1, characterized in that: It also includes an LED digital tube, which is electrically connected to the main controller. The main controller is also used to obtain the charging status of the battery, and the LED digital tube is used to display the charging status.

10. A razor, characterized in that: The invention comprises a battery and a charging circuit according to any one of claims 1 to 9, wherein the charging circuit is used for charging the battery.

Images