Low-loss dual-charging circuit for tablet personal computer
By introducing filtering noise reduction circuits and one-way conducting circuits into the dual-charging circuits of tablet computers, instead of diodes, the voltage difference and heat problems caused by diodes are solved, and lower heat generation is achieved.
Patent Information
- Application Number
- CN202420080249.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-12
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2034-01-12
AI Technical Summary
When the dual charge circuit used in the prior art is isolated and conducts through diodes, a large pressure difference leads to the generation of additional heat.
A low-loss dual-charging circuit is designed, using filtering and noise reduction circuits and one-way conducting circuits to cooperate with each other. The one-way conducting circuit replaces the diodes to reduce voltage difference and reduce heat generation.
It effectively reduces the voltage difference between the two ends of the one-way conduction circuit, reduces heat generation, and solves the problem of high additional heat caused by diodes.
Smart Images
Figure CN222355994U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of circuits, and in particular to a low-loss dual-charging circuit for a tablet computer. Background Art
[0002] In many smart electronic devices, such as tablet computers, dual charging circuits are often used, that is, both the USB interface and the DC power socket have charging functions. The main purpose is that when using USB to connect peripherals, the tablet can also be charged through the DC power socket. This is very practical for tablet computers with keyboards. However, when using the DC power socket for charging, the current is relatively large, generally about 2A, so it is necessary to separate the USB interface charging circuit from the DC power socket charging circuit.
[0003] At present, the most commonly used design in the prior art is to isolate and conduct through diodes, but this circuit has a major disadvantage, that is, there is a large voltage difference. Due to the voltage difference, the voltage will also fluctuate to a certain extent when the current is different, which will lead to the generation of higher additional heat. Utility Model Content
[0004] In order to solve the problems in the prior art, the utility model provides a low-loss dual charging circuit for a tablet computer. By arranging a filtering noise reduction circuit and a unidirectional conduction circuit that cooperate with each other in the low-loss dual charging circuit for a tablet computer, the unidirectional conduction circuit can separate the USB interface charging circuit from the DC power socket charging circuit, and make the DC power socket charging circuit have a higher priority than the USB interface charging circuit. The unidirectional conduction circuit as a whole can replace a single diode to prevent reverse voltage input, and the overall resistance of the unidirectional conduction circuit is much lower than that of the diode, which can reduce the voltage difference between the two ends of the unidirectional conduction circuit and reduce the heat generated by the unidirectional conduction circuit, thereby solving the problem in the prior art that the dual charging circuit for tablet computers using diodes has a large voltage difference and generates high additional heat.
[0005] The utility model provides a low-loss dual charging circuit for a tablet computer, comprising a USB interface charging circuit and a DC power socket charging circuit, wherein the input end of the USB interface charging circuit is connected to the USB charging interface of the tablet computer, the input end of the DC power socket charging circuit is connected to the DC power socket of the tablet computer, the output end of the USB interface charging circuit and the output end of the DC power socket charging circuit are connected to a main control circuit board of the tablet computer for charging, the DC power socket charging circuit comprises a filtering noise reduction circuit and a unidirectional conduction circuit, the input end of the filtering noise reduction circuit is connected to the DC power socket of the tablet computer, the output end of the filtering noise reduction circuit is connected to the input end of the unidirectional conduction circuit, the output end of the unidirectional conduction circuit is connected to the main control circuit board of the tablet computer, and the unidirectional conduction circuit as a whole can replace a single diode to prevent reverse voltage input.
[0006] The utility model is further improved, the unidirectional conduction circuit is provided with a field effect tube Q1, a resistor R2, a resistor R3 and a diode D1, wherein the gate of the field effect tube Q1 is connected to one end of the resistor R2 and one end of the resistor R3, the drain of the field effect tube Q1 is connected to the DC power socket of the tablet computer, the output end of the filtering and noise reduction circuit, and the positive electrode of the diode D1, the source of the field effect tube Q1 is connected to the other end of the resistor R3 and the main control circuit board of the tablet computer, and the other end of the resistor R2 is connected to the negative electrode of the diode D1.
[0007] The utility model is further improved, the unidirectional conduction circuit is further provided with a transistor Q2, a resistor R4, a resistor R5 and a resistor R6, wherein the base of the transistor Q2 is connected to one end of the resistor R4 and one end of the resistor R6, the other end of the resistor R4 is connected to the DC power socket of the tablet computer, the output end of the filtering and noise reduction circuit, the positive electrode of the diode D1, and the drain of the field effect transistor Q1, the collector of the transistor Q2 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to the gate of the field effect transistor Q1, one end of the resistor R2, and one end of the resistor R3, and the other end of the resistor R6 and the emitter of the transistor Q2 are grounded.
[0008] The utility model is further improved, the filtering and noise reduction circuit is provided with a resistor R1 and a capacitor C1, wherein one end of the resistor R1 is connected to one end of the capacitor C1, the drain of the field effect transistor Q1, the DC power socket of the tablet computer, the positive electrode of the diode D1, and the drain of the field effect transistor Q1, and the other end of the resistor R1 and the other end of the capacitor C1 are grounded.
[0009] The utility model is further improved, the filtering and noise reduction circuit is also provided with a resistor R7 and a resistor R7, wherein one end of the resistor R7 is connected to one end of the resistor R1, one end of the capacitor C1, the drain of the field effect transistor Q1, the DC power socket of the tablet computer, the positive electrode of the diode D1, and the drain of the field effect transistor Q1, and the other end is connected to one end of the resistor R12, and the other end of the resistor R12 is grounded.
[0010] The utility model is further improved in that the field effect tube Q1 is a P-type MOS tube.
[0011] The utility model is further improved, the USB interface charging circuit is provided with a field effect tube Q3, a resistor R14 and a diode D3, wherein the gate of the field effect tube Q3 is connected to one end of the resistor R14, the other end of the resistor R14 is connected to the cathode of the diode D3, the drain of the field effect tube Q1 is connected to the USB charging interface of the tablet computer and the anode of the diode D3, and the source of the field effect tube Q3 is connected to the source of the field effect tube Q1, the other end of the resistor R3, and the main control circuit board of the tablet computer.
[0012] Compared with the prior art, the beneficial effects of the utility model are as follows: a low-loss dual charging circuit for a tablet computer is provided, by arranging a filtering noise reduction circuit and a unidirectional conduction circuit that cooperate with each other in the low-loss dual charging circuit for a tablet computer, the unidirectional conduction circuit can separate the USB interface charging circuit from the DC power socket charging circuit, and make the DC power socket charging circuit have a higher priority than the USB interface charging circuit, the unidirectional conduction circuit as a whole can replace a single diode to prevent reverse voltage input, and the overall resistance of the unidirectional conduction circuit is much lower than that of the diode, which can reduce the voltage difference between the two ends of the unidirectional conduction circuit and reduce the heat generated by the unidirectional conduction circuit, thereby solving the problem in the prior art that the dual charging circuit for tablet computers uses diodes with a large voltage difference and generates a high amount of additional heat. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to more clearly illustrate the solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0014] Figure 1 The utility model is a circuit diagram of a low-loss dual charging circuit for a tablet computer. DETAILED DESCRIPTION
[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present utility model; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present utility model; the terms "including" and "having" and any variations thereof in the specification and claims of the present utility model and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present utility model or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order.
[0016] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0017] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the accompanying drawings.
[0018] like Figure 1As shown, the utility model provides a low-loss dual charging circuit for a tablet computer, including a USB interface charging circuit and a DC power socket charging circuit, the input end of the USB interface charging circuit is connected to the USB charging interface of the tablet computer, the input end of the DC power socket charging circuit is connected to the DC power socket of the tablet computer, the output end of the USB interface charging circuit and the output end of the DC power socket charging circuit are connected to the main control circuit board of the tablet computer for charging, the DC power socket charging circuit includes a filtering noise reduction circuit and a unidirectional conduction circuit, the input end of the filtering noise reduction circuit is connected to the DC power socket of the tablet computer, the output end of the filtering noise reduction circuit is connected to the input end of the unidirectional conduction circuit, and the output end of the unidirectional conduction circuit is connected to the main control circuit board of the tablet computer; the unidirectional conduction circuit is provided with a field effect transistor Q1, a resistor R2, a resistor R3 and a diode D1, the gate of the field effect transistor Q1 is connected to one end of the resistor R2 and one end of the resistor R3, the drain of the field effect transistor Q1 is connected to the DC power socket of the tablet computer, the filtering noise reduction circuit, and the output end of the unidirectional conduction circuit. The output end of the noise reduction circuit is connected to the positive electrode of the diode D1, the source of the field effect tube Q1 is connected to the other end of the resistor R3 and the main control circuit board of the tablet computer, and the other end of the resistor R2 is connected to the negative electrode of the diode D1; the unidirectional conduction circuit is also provided with a transistor Q2, a resistor R4, a resistor R5 and a resistor R6, the base of the transistor Q2 is connected to one end of the resistor R4 and one end of the resistor R6, the other end of the resistor R4 is connected to the DC power socket of the tablet computer, the output end of the filtering and noise reduction circuit, the positive electrode of the diode D1, and the drain of the field effect tube Q1, the collector of the transistor Q2 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to the gate of the field effect tube Q1, one end of the resistor R2, and one end of the resistor R3, and the other end of the resistor R6 and the emitter of the transistor Q2 are grounded; wherein the field effect tube Q1 is a P-type MOS tube, which plays the role of a switch, and the diode D1 has a unidirectional conduction function to prevent the main control circuit board of the tablet computer, that is, the VBUS power supply from leaking to the drain of the field effect tube Q1. In this embodiment, the unidirectional conducting circuit as a whole can replace a single diode to prevent reverse voltage input, and the overall resistance of the unidirectional conducting circuit is much lower than that of the diode, which can reduce the voltage difference across the unidirectional conducting circuit and reduce the heat generated by the unidirectional conducting circuit.
[0019] like Figure 1As shown, a field effect transistor Q3, a resistor R14 and a diode D3 are provided in the USB interface charging circuit, wherein the gate of the field effect transistor Q3 is connected to one end of the resistor R14, the other end of the resistor R14 is connected to the negative electrode of the diode D3, the drain of the field effect transistor Q1 is connected to the USB charging interface of the tablet computer and the positive electrode of the diode D3, and the source of the field effect transistor Q3 is connected to the source of the field effect transistor Q1, the other end of the resistor R3, and the main control circuit board of the tablet computer. In this embodiment, the unidirectional conduction circuit as a whole can replace a single diode to prevent reverse voltage input. When the DC power socket of the tablet computer is connected to a high level, the field effect transistor Q1 is turned on, and the DC power socket of the tablet computer and the main control circuit board of the tablet computer are connected, and charging is normal; when the DC power socket of the tablet computer and the USB charging interface of the tablet computer are connected to a high level at the same time, the DC power socket of the tablet computer and the main control circuit board of the tablet computer are connected, and the USB charging interface of the tablet computer and the main control circuit board of the tablet computer are disconnected by the field effect transistor Q3, and the DC power socket of the tablet computer gives priority to charging the main control circuit board of the tablet computer; when the DC power socket of the tablet computer is connected to a high level at the same time, the DC power socket of the tablet computer and the main control circuit board of the tablet computer are connected, and the USB charging interface of the tablet computer and the main control circuit board of the tablet computer are disconnected by the field effect transistor Q3, and the DC power socket of the tablet computer gives priority to charging the main control circuit board of the tablet computer; When the USB charging interface of the tablet computer and the DC power socket are both at low level and the main control circuit board of the tablet computer is at high level, the field effect transistor Q1 cuts off the connection between the DC power socket of the tablet computer and the main control circuit board of the tablet computer, and the field effect transistor Q3 cuts off the connection between the USB charging interface of the tablet computer and the main control circuit board of the tablet computer to prevent reverse leakage; and because the resistance of the field effect transistor Q1 is very low, the overall resistance of the unidirectional conduction circuit is much lower than that of a single diode. A single diode generally has a resistance of 0.3Ω and generates high heat. Therefore, the field effect transistor Q1 can reduce the voltage difference between the two ends of the unidirectional conduction circuit and reduce the heat generated by the DC power socket charging circuit.
[0020] like Figure 1 As shown, the filter noise reduction circuit is provided with a resistor R1 and a capacitor C1, wherein one end of the resistor R1 is connected to one end of the capacitor C1, the drain of the field effect tube Q1, the USB charging interface of the tablet computer, the positive electrode of the diode D1, and the drain of the field effect tube Q1, and the other end of the resistor R1 and the other end of the capacitor C1 are grounded; the filter noise reduction circuit is also provided with a resistor R7 and a resistor R7, wherein one end of the resistor R7 is connected to one end of the resistor R1, one end of the capacitor C1, the drain of the field effect tube Q1, the DC power socket of the tablet computer, the positive electrode of the diode D1, and the drain of the field effect tube Q1, and the other end is connected to one end of the resistor R12, and the other end of the resistor R12 is grounded. In this embodiment, the filter noise reduction circuit is used to reduce the noise interference in the low-loss dual charging circuit for the tablet computer and improve the stability of the low-loss dual charging circuit for the tablet computer.
[0021] As can be seen from the above, the utility model provides a low-loss dual charging circuit for a tablet computer. By arranging a filtering noise reduction circuit and a unidirectional conduction circuit that cooperate with each other in the low-loss dual charging circuit for a tablet computer, the unidirectional conduction circuit can separate the USB interface charging circuit from the DC power socket charging circuit, and make the DC power socket charging circuit have a higher priority than the USB interface charging circuit. The unidirectional conduction circuit as a whole can replace a single diode to prevent reverse voltage input, and the overall resistance of the unidirectional conduction circuit is much lower than that of the diode, which can reduce the voltage difference between the two ends of the unidirectional conduction circuit and reduce the heat generated by the unidirectional conduction circuit, thereby solving the problem in the prior art that the dual charging circuit for tablet computers uses diodes with a large voltage difference and generates a high amount of additional heat.
[0022] The specific implementation modes described above are preferred implementation modes of the present utility model, and are not intended to limit the specific implementation scope of the present utility model. The scope of the present utility model includes but is not limited to the specific implementation modes, and all equivalent changes made in accordance with the present utility model are within the protection scope of the present utility model.
Claims
1. A low-loss dual charging circuit for a tablet computer, characterized in that: The invention comprises a USB interface charging circuit and a DC power socket charging circuit, wherein the input end of the USB interface charging circuit is connected to the USB charging interface of the tablet computer, the input end of the DC power socket charging circuit is connected to the DC power socket of the tablet computer, the output end of the USB interface charging circuit and the output end of the DC power socket charging circuit are connected to the main control circuit board of the tablet computer for charging, the DC power socket charging circuit comprises a filtering noise reduction circuit and a unidirectional conduction circuit, the input end of the filtering noise reduction circuit is connected to the DC power socket of the tablet computer, the output end of the filtering noise reduction circuit is connected to the input end of the unidirectional conduction circuit, the output end of the unidirectional conduction circuit is connected to the main control circuit board of the tablet computer, and the unidirectional conduction circuit as a whole can replace a single diode to prevent reverse voltage input.
2. The low-loss dual charging circuit for a tablet computer according to claim 1, characterized in that: The unidirectional conduction circuit is provided with a field effect transistor Q1, a resistor R2, a resistor R3 and a diode D1, wherein the gate of the field effect transistor Q1 is connected to one end of the resistor R2 and one end of the resistor R3, the drain of the field effect transistor Q1 is connected to the DC power socket of the tablet computer, the output end of the filtering and noise reduction circuit, and the positive electrode of the diode D1, the source of the field effect transistor Q1 is connected to the other end of the resistor R3 and the main control circuit board of the tablet computer, and the other end of the resistor R2 is connected to the negative electrode of the diode D1.
3. The low-loss dual charging circuit for a tablet computer according to claim 2, characterized in that: The unidirectional conduction circuit is further provided with a transistor Q2, a resistor R4, a resistor R5 and a resistor R6, wherein the base of the transistor Q2 is connected to one end of the resistor R4 and one end of the resistor R6, the other end of the resistor R4 is connected to the DC power socket of the tablet computer, the output end of the filtering and noise reduction circuit, the positive electrode of the diode D1, and the drain of the field effect transistor Q1, the collector of the transistor Q2 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to the gate of the field effect transistor Q1, one end of the resistor R2, and one end of the resistor R3, and the other end of the resistor R6 and the emitter of the transistor Q2 are grounded.
4. The low-loss dual charging circuit for a tablet computer according to claim 3, characterized in that: The filtering and noise reduction circuit is provided with a resistor R1 and a capacitor C1, wherein one end of the resistor R1 is connected to one end of the capacitor C1, the drain of the field effect transistor Q1, the DC power socket of the tablet computer, the positive electrode of the diode D1, and the drain of the field effect transistor Q1, and the other end of the resistor R1 and the other end of the capacitor C1 are grounded.
5. The low-loss dual charging circuit for a tablet computer according to claim 4, characterized in that: The filtering and noise reduction circuit is also provided with a resistor R7 and a resistor R7, wherein one end of the resistor R7 is connected to one end of the resistor R1, one end of the capacitor C1, the drain of the field effect transistor Q1, the DC power socket of the tablet computer, the positive electrode of the diode D1, and the drain of the field effect transistor Q1, and the other end is connected to one end of the resistor R12, and the other end of the resistor R12 is grounded.
6. The low-loss dual charging circuit for a tablet computer according to claim 5, characterized in that: The field effect transistor Q1 is a P-type MOS tube.
7. The low-loss dual charging circuit for a tablet computer according to claim 6, characterized in that: The USB interface charging circuit is provided with a field effect tube Q3, a resistor R14 and a diode D3, wherein the gate of the field effect tube Q3 is connected to one end of the resistor R14, the other end of the resistor R14 is connected to the cathode of the diode D3, the drain of the field effect tube Q1 is connected to the USB charging interface of the tablet computer and the anode of the diode D3, and the source of the field effect tube Q3 is connected to the source of the field effect tube Q1, the other end of the resistor R3 and the main control circuit board of the tablet computer.