Low-power-consumption wireless charging circuit

Abstract

The utility model relates to the technical field of charging circuits, in particular to a low-power-consumption wireless charging circuit, which comprises a charging management circuit, a transmitting circuit, a voltage conversion circuit and a receiving circuit. The charging management circuit comprises a single chip microcomputer U2, a key K1, resistors R1 and R2, capacitors C4, C5 and C7 and a crystal oscillator Y1; the transmitting circuit comprises an oscillation signal generator U4, a switch tube Q1, an oscillation coil, an MOS tube Q2, a triode Q3, resistors R3 to R10, capacitors C10 to C18, a voltage-regulator tube Z3 and diodes D1 to D6. According to the wireless energy transmission charger, the ultra-low power consumption single-chip microcomputer is used as a monitoring control core chip of the wireless energy transmission charger, the low power consumption effect can be preliminarily achieved, the two diodes, the two current-limiting resistors and the switch are arranged to form the detection circuit, and the detection circuit is matched with the single-chip microcomputer to intelligently detect the charging state; and the chip enters a low-power-consumption mode when the low charging speed is controlled to be selected.

Description

Technical Field

[0001] This utility model relates to the field of charging circuit technology, and in particular to a low-power wireless charging circuit. Background Technology

[0002] During the charging process, electrical equipment is generally equipped with an intelligent charging control circuit to intelligently monitor the charging status, ensuring automatic disconnection when fully charged and automatic charging when the power is depleted. However, existing intelligent charging control circuits generally only have intelligent selection between fully charged and depleted states. This selection method is still relatively mechanical, resulting in significant energy loss and failing to achieve good low-power charging control. Therefore, we propose a low-power wireless charging circuit. Utility Model Content

[0003] The main objective of this invention is to provide a low-power wireless charging circuit, including a charging management circuit, a transmitting circuit, a voltage conversion circuit, and a receiving circuit.

[0004] The charging management circuit includes a microcontroller U2, a button K1, resistors R1 and R2, capacitors C4, C5 and C7, and a crystal oscillator Y1;

[0005] The transmitting circuit includes an oscillation signal generator U4, a switching transistor Q1, an oscillation coil, a MOSFET Q2, a transistor Q3, resistors R3 to R10, capacitors C10 to C18, a Zener diode Z3, and diodes D1 to D6.

[0006] The receiving circuit includes voltage regulators U1 and U3, Zener diodes Z1 and Z2, capacitors C1, C2, C3, C6, C8, and C9, and switch SW1.

[0007] Preferably, capacitors C4 and C5 are connected in parallel between pins 5 and 6 of the microcontroller U2, and the other end of the parallel connection is grounded. Crystal oscillator Y1 is connected between capacitors C4 and C5.

[0008] Preferably, resistor R1, R2, capacitor C7 and button K1 are connected in series and then connected to pin 7 of microcontroller U2, and pin 15 of microcontroller U2 is grounded.

[0009] Preferably, resistors R4, R7, and capacitor C17 are connected in series between pins 1 and 8 of the oscillation signal generator U4, resistor R5 is connected to pin 3 of the oscillation signal generator U4, capacitor C16 is connected between pins 5 and 1 of the oscillation signal generator U4, pin 1 of the oscillation signal generator U4 is grounded, and pin 3 of the oscillation signal generator U4 is connected to the switching transistor Q1.

[0010] Preferably, the oscillation coil includes inductors L1 and L2, and inductor L1, capacitors C12 and C15 are connected in parallel and then connected to pin 3 of the switching transistor Q1.

[0011] Preferably, diodes D1 to D4 are connected end to end to form a full-wave rectifier diode. Capacitors C10 and C11 and Zener diode Z3 are connected in parallel and then connected to the full-wave rectifier diode. Resistor R3 is connected between capacitor C10 and Zener diode Z3. The other end of the full-wave rectifier diode is connected to the parallel circuit of inductor L2, capacitors C13 and C14.

[0012] Preferably, resistor R8 is connected between pin 1 and pin 3 of MOSFET Q2, and resistors R9 and R10 are connected in parallel and then connected in series with switch SW1, transistor Q3, diodes D5 and D6, resistor R6 and capacitor C18. The two ends of this series circuit are connected to pin 2 and pin 3 of MOSFET Q2, respectively.

[0013] Preferably, capacitors C1 and C3 are connected in parallel between pins 1 and 2 of voltage regulator U1, capacitor C2 is connected to pin 3 of voltage regulator U3, Zener diodes Z1 and Z2 are connected in series between pins 3 of voltage regulator U3, capacitors C6 and C9 are connected in parallel between pins 1 and 2 of voltage regulator U3, and capacitor C8 is connected to pin 3 of voltage regulator U3.

[0014] Preferably, pin 2 of microcontroller U2 is connected to capacitor C11, pin 16 of microcontroller U2 is connected to diode D5, pin 9 of microcontroller U2 is connected to transistor Q3, and pin 27 of microcontroller U2 is connected to voltage regulator U3.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This invention uses an ultra-low power microcontroller as the core monitoring and control chip for the wireless power charger, which can initially achieve a low power consumption effect. By setting up a detection circuit consisting of two diodes, two current-limiting resistors, and a switch, the microcontroller can intelligently detect the charging status. When no charging is being performed, it will control the selection of a low charging speed and the chip will enter a low power consumption mode. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall circuit of this utility model. Detailed Implementation

[0018] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0019] Please see Figure 1 This embodiment provides a low-power wireless charging circuit, including a charging management circuit, a transmitting circuit, a voltage conversion circuit, and a receiving circuit;

[0020] The charging management circuit includes a microcontroller U2, a button K1, resistors R1 and R2, capacitors C4, C5 and C7, and a crystal oscillator Y1;

[0021] The transmitting circuit includes an oscillation signal generator U4, a switching transistor Q1, an oscillation coil, a MOSFET Q2, a transistor Q3, resistors R3 to R10, capacitors C10 to C18, a Zener diode Z3, and diodes D1 to D6.

[0022] The receiving circuit includes voltage regulators U1 and U3, Zener diodes Z1 and Z2, capacitors C1, C2, C3, C6, C8, and C9, and switch SW1.

[0023] Preferably, capacitors C4 and C5 are connected in parallel between pins 5 and 6 of the microcontroller U2, and the other end of the parallel connection is grounded. Crystal oscillator Y1 is connected between capacitors C4 and C5.

[0024] Preferably, resistor R1, R2, capacitor C7 and button K1 are connected in series and then connected to pin 7 of microcontroller U2, and pin 15 of microcontroller U2 is grounded.

[0025] Preferably, resistors R4, R7, and capacitor C17 are connected in series between pins 1 and 8 of the oscillation signal generator U4, resistor R5 is connected to pin 3 of the oscillation signal generator U4, capacitor C16 is connected between pins 5 and 1 of the oscillation signal generator U4, pin 1 of the oscillation signal generator U4 is grounded, and pin 3 of the oscillation signal generator U4 is connected to the switching transistor Q1.

[0026] Preferably, the oscillation coil includes inductors L1 and L2, and inductor L1, capacitors C12 and C15 are connected in parallel and then connected to pin 3 of the switching transistor Q1.

[0027] Preferably, diodes D1 to D4 are connected end to end to form a full-wave rectifier diode. Capacitors C10 and C11 and Zener diode Z3 are connected in parallel and then connected to the full-wave rectifier diode. Resistor R3 is connected between capacitor C10 and Zener diode Z3. The other end of the full-wave rectifier diode is connected to the parallel circuit of inductor L2, capacitors C13 and C14.

[0028] Preferably, resistor R8 is connected between pin 1 and pin 3 of MOSFET Q2, and resistors R9 and R10 are connected in parallel and then connected in series with switch SW1, transistor Q3, diodes D5 and D6, resistor R6 and capacitor C18. The two ends of this series circuit are connected to pin 2 and pin 3 of MOSFET Q2, respectively.

[0029] Preferably, capacitors C1 and C3 are connected in parallel between pins 1 and 2 of voltage regulator U1, capacitor C2 is connected to pin 3 of voltage regulator U3, Zener diodes Z1 and Z2 are connected in series between pins 3 of voltage regulator U3, capacitors C6 and C9 are connected in parallel between pins 1 and 2 of voltage regulator U3, and capacitor C8 is connected to pin 3 of voltage regulator U3.

[0030] Preferably, pin 2 of microcontroller U2 is connected to capacitor C11, pin 16 of microcontroller U2 is connected to diode D5, pin 9 of microcontroller U2 is connected to transistor Q3, and pin 27 of microcontroller U2 is connected to voltage regulator U3.

[0031] The wireless charging system is designed to transfer energy using coil coupling, ensuring that the receiving unit receives sufficient power to guarantee the power supply for subsequent circuits. Multiple power-saving modes are selected for the components. The microcontroller used is the MSP430 series ultra-low-power microcontroller with strong anti-interference capabilities, specifically the MSP430F2274, which serves as the core monitoring and control chip for the wireless power charger.

[0032] R1 is a pull-up resistor, and R2 is a pull-down resistor. When the microcontroller U2 is working normally, the pin is pulled up. When the program fails and a manual reset is required, press button K1, the pin is pulled down, and the microcontroller U2 restarts. Capacitors C4 and C5 and crystal oscillator Y1 form a clock circuit to provide timing for the microcontroller U2.

[0033] The oscillation frequency of the oscillation signal generator U4 is about 510KHZ, which provides the excitation signal for the power amplifier circuit. The switching transistor Q1, the oscillation coil, resistors R3 to R8, capacitors C10 to C17, Zener diode Z3, and diodes D1 to D4 together constitute the power amplifier circuit.

[0034] The inductance of the oscillating coil is approximately 142uH. When the resonance is at 510kHz, the capacitors C12 and C15 connected in parallel with it are approximately 680pF. A 200pF adjustable capacitor can be connected in parallel with a 470pF fixed capacitor to easily adjust the resonant frequency.

[0035] After the electrical energy is received by the coil, it is rectified by the full-wave rectifier diode. C10 is a filter capacitor with a capacitance of 3300F. Then, the voltage is regulated by the 5.1V Zener diode Z3. The output DC power provides a relatively stable operating voltage for the charger. C11 performs secondary output filtering.

[0036] Two diodes, D5 and D6, are step-down diodes; two resistors, R9 and R10, are current-limiting resistors; the charging speed can be selected by switch SW1. Diodes D5 and D6, resistors R9 and R10, and switch SW1 constitute a detection circuit; R6 and R8 are the gate drive resistors of MOSFET Q2; C18 is an energy storage capacitor; the microcontroller U2 detects the charging status; when no charging is in progress, it controls SW1 to select a low charging speed, and the chip enters a low-power mode.

[0037] In the voltage conversion circuit, regulator U1 is a 5V LDO. The two Zener diodes Z1 and Z2 at the front end are used to reduce the input voltage of regulator U1, so that the input and output voltage difference of regulator U1 are close. Otherwise, regulator U1 will consume too much power and is easy to burn out. C2 is used as input filter, and C1 and C3 are used as output filter. Regulator U3 is a 3.3V LDO. C8 is used as input filter, and C6 and C9 are used as output filter. Regulators U1 and U3 provide voltage conversion for the mobile terminal and the microcontroller U2, respectively.

[0038] After the transmitting circuit starts working, the microcontroller U2 starts working, and P3.6 outputs a PWM control signal. The higher the duty cycle, the greater the output current. At the same time, R9 and R10 can also be used to adjust the output current.

[0039] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A low-power wireless charging circuit, characterized in that, It includes a charging management circuit, a transmitting circuit, a voltage conversion circuit, and a receiving circuit; The charging management circuit includes a microcontroller U2, a button K1, resistors R1 and R2, capacitors C4, C5 and C7, and a crystal oscillator Y1; The transmitting circuit includes an oscillation signal generator U4, a switching transistor Q1, an oscillation coil, a MOSFET Q2, a transistor Q3, resistors R3 to R10, capacitors C10 to C18, a Zener diode Z3, and diodes D1 to D6. The receiving circuit includes voltage regulators U1 and U3, Zener diodes Z1 and Z2, capacitors C1, C2, C3, C6, C8, and C9, and switch SW1; Capacitors C4 and C5 are connected in parallel between pins 5 and 6 of microcontroller U2, with the other end grounded. Crystal oscillator Y1 is connected between capacitors C4 and C5. Resistor R1, R2, capacitor C7, and button K1 are connected in series between pins 7 and 15 of microcontroller U2, which is grounded. Resistor R4, R7, and capacitor C17 are connected in series between pins 1 and 8 of oscillation generator U4, with resistor R5 connected to pin 3 of oscillation generator U4, and capacitor C16... The circuit is connected between pins 5 and 1 of the oscillation signal generator U4. Pin 1 of the oscillation signal generator U4 is grounded, and pin 3 of the oscillation signal generator U4 is connected to the switching transistor Q1. The oscillation coil includes inductors L1 and L2. Inductor L1, capacitors C12 and C15 are connected in parallel and then connected to pin 3 of the switching transistor Q1. Diodes D1 to D4 are connected end-to-end to form a full-wave rectifier diode. Capacitors C10 and C11 and Zener diode Z3 are connected in parallel and then connected to the full-wave rectifier diode. Resistor R3 is connected to capacitor C10. Between diode Z10 and Zener diode Z3, the other end of the full-wave rectifier diode is connected to a parallel circuit of inductor L2, capacitors C13 and C14; resistor R8 is connected between pins 1 and 3 of MOSFET Q2; resistors R9 and R10 are connected in parallel and then connected in series with switch SW1, transistor Q3, diodes D5 and D6, resistor R6, and capacitor C18 to form a series circuit, with the two ends of this series circuit connected to pins 2 and 3 of MOSFET Q2 respectively; capacitors C1 and C3 are connected in parallel and then connected to voltage regulator U. Between pins 1 and 2 of microcontroller U2, capacitor C2 is connected to pin 3 of voltage regulator U3; Zener diodes Z1 and Z2 are connected in series to pin 3 of voltage regulator U3; capacitors C6 and C9 are connected in parallel between pins 1 and 2 of voltage regulator U3; capacitor C8 is connected to pin 3 of voltage regulator U3; pin 2 of microcontroller U2 is connected to capacitor C11; pin 16 of microcontroller U2 is connected to diode D5; pin 9 of microcontroller U2 is connected to transistor Q3; and pin 27 of microcontroller U2 is connected to voltage regulator U3.

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