WO2021109561A1

WO2021109561A1 - Charging circuit, charging device, and display screen

Info

Publication number: WO2021109561A1
Application number: PCT/CN2020/100020
Authority: WO
Inventors: 贺云飞
Original assignee: 深圳市洲明科技股份有限公司
Priority date: 2019-12-05
Filing date: 2020-07-03
Publication date: 2021-06-10
Also published as: CN110957795A; CN110957795B

Abstract

The present application relates to a charging circuit, comprising a resonant circuit, a rectification filtering circuit, and a constant-power control module. An input terminal of the resonant circuit is used to connect to an external power supply. An output terminal of the resonant circuit is connected to an input terminal of the rectification filtering circuit. An output terminal of the rectification filtering circuit is connected to an input terminal of the constant-power control module. An output terminal of the constant-power control module is used to connect to an energy storage capacitor. The output terminal of the constant-power control module is further used to adjust a charging power parameter according to a voltage of energy storage capacitor, such that the constant-power control module outputs a constant power to the energy storage capacitor. After an electrical signal input by the external power supply passes through the resonant circuit and the rectification filtering circuit, a desired direct current electrical signal is acquired and used to charge the energy storage capacitor via the constant-power control module. The constant-power control module adjusts a power input into the energy storage capacitor, thereby outputting a stable charging power.

Description

Charging circuit, charging device and display screen

Related application

This application claims the priority of the Chinese patent application filed on December 05, 2019, with the application number 201911233007.7, titled "Charging Circuit, Charging Device, and Display Screen", which is hereby incorporated by reference in its entirety.

Technical field

This application relates to the technical field of display screens, in particular to a charging circuit, a charging device and a display screen.

Background technique

With the development of display technology, more and more displays are used in various scenarios. In daily life, the use of various display screens continues to increase. When the display screen is working, it needs to be powered to ensure normal operation. The traditional display screen can be powered by the power distribution cabinet. The power distribution cabinet converts 380V industrial electricity into 220V municipal electricity, and then into the working voltage used by the display screen. During the power supply process, the energy storage capacitor of the display screen can be charged. The energy storage capacitor continuously supplies power to the display, which can improve the endurance of the display.

However, in the process of charging the energy storage capacitor, the voltage across the energy storage capacitor changes with it. The change of the voltage across the energy storage capacitor causes the charging power of the energy storage capacitor to fluctuate sharply. The charging power of the energy storage capacitor fluctuates drastically and the input power of the display screen fluctuates drastically, thereby reducing the operating stability of the display screen.

Summary of the invention

Based on this, it is necessary to provide a charging circuit, a charging device and a display screen with stable charging power output.

A charging circuit includes: a resonance circuit, a rectification filter circuit, and a constant power control module. The input end of the resonance circuit is used to connect to an external power source, and the output end of the resonance circuit is connected to the input end of the rectification filter circuit. , The output end of the rectification filter circuit is connected to the input end of the constant power control module, the output end of the rectification filter circuit is used to output a direct current signal, and the output end of the constant power control module is used to connect to an energy storage capacitor Connected, the output terminal of the constant power control module is also used to adjust the charging power parameter according to the voltage of the energy storage capacitor, so that the constant power control module outputs constant power for the energy storage capacitor.

In one of the embodiments, the constant power control module includes a feedforward control unit, the output end of the rectification filter circuit is connected to the input end of the feedforward control unit, and the output end of the feedforward control unit is used for Connected to the energy storage capacitor, the feedforward control unit is used to adjust the charging power.

In one of the embodiments, the constant power control module includes a feedback control unit, the output end of the rectification filter circuit is connected to the input end of the feedback control unit, and the comparison end of the feedback control unit is also connected to the feedback control unit respectively. The output terminal of the feedback control unit is connected to the power preset terminal, the output terminal of the feedback control unit is used to connect with the energy storage capacitor, and the feedback control unit is used to connect the output terminal of the feedback control unit to the power The power of the power preset terminal adjusts the charging power.

In one of the embodiments, the feedback control unit includes a comparator, a regulator, and a power control circuit, the output terminal of the rectification filter circuit is connected to the input terminal of the power control circuit, and the comparison terminal of the comparator is also The output terminal and the power preset terminal of the power control circuit are respectively connected, the output terminal of the comparator is connected to the input terminal of the power control circuit through the regulator, and the output terminal of the power control circuit is used to connect with The energy storage capacitor is connected.

In one of the embodiments, the power control circuit includes a control chip and a power output circuit, the output terminal of the regulator is connected to the input terminal of the control chip, and the output terminal of the control chip is connected to the power output circuit. The input terminal of the power output circuit is connected, and the output terminal of the power output circuit is used to connect to the energy storage capacitor.

In one of the embodiments, the feedback control unit further includes a power detector, the output terminal of the power control circuit is connected to the input terminal of the comparator through the power detector, and the power detector is used to obtain charging power.

In one of the embodiments, the resonant circuit includes a second inductor and a third capacitor, and an external power source is connected to the input terminal of the rectification filter circuit through the second inductor and the third capacitor in sequence.

In one of the embodiments, the charging circuit further includes a charging power detection circuit, the charging power detection circuit includes a voltage detection circuit and a current detection circuit, the output terminal of the constant power control module and the input of the voltage detection circuit Terminal connection, the output terminal of the constant power control module is also connected to the input terminal of the current detection circuit, the output terminal of the voltage detection circuit and the output terminal of the current detection circuit are connected to the monitoring system and used to detect the input To the charging voltage and charging current of the energy storage capacitor.

A charging device includes the charging circuit as described in any of the above embodiments.

A display screen includes a display module and the charging device as described in the above embodiment. The display module has a display surface, and the charging device is arranged on a side of the display module that faces away from the display surface.

In the above charging circuit, charging device and display screen, the electrical signal input from the external power source passes through the resonant circuit and the rectifier filter circuit to obtain the required direct current signal, and then the direct current signal is charged through the constant power control module to charge the energy storage capacitor. The control module adjusts the power input to the energy storage capacitor so as to output a stable charging power, reduces the probability of fluctuations in the charging power caused by the change of the energy storage capacitor, and improves the operating stability of the display screen.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained from the disclosed drawings without creative work.

Fig. 1 is a circuit diagram of a charging circuit according to an embodiment.

Detailed ways

In order to facilitate the understanding of the application, the application will be described in a more comprehensive manner with reference to the relevant drawings. The preferred embodiments of the application are shown in the accompanying drawings. However, this application can be implemented in many different forms and is not limited to the implementation described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of this application more thorough and comprehensive.

It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or a central element may also exist. When an element is considered to be "connected" to another element, it can be directly connected to the other element or an intermediate element may be present at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only, and are not meant to be the only embodiments.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of this application. The terms used in the specification of this application are only for the purpose of describing specific implementations, and are not intended to limit the application. The term "and/or" as used herein includes any and all combinations of one or more related listed items.

This application relates to a charging circuit. In one of the embodiments, the charging circuit includes a resonance circuit, a rectifier filter circuit, and a constant power control module. The input terminal of the resonant circuit is used to connect with an external power source. The output terminal of the resonance circuit is connected to the input terminal of the rectification filter circuit. The output terminal of the rectifier filter circuit is connected to the input terminal of the constant power control module. The output terminal of the rectifier filter circuit is used to output a direct current signal. The output terminal of the constant power control module is used to connect with an energy storage capacitor. The output terminal of the constant power control module is also used to adjust the charging power parameter according to the voltage of the energy storage capacitor, so that the constant power control module outputs constant power for the energy storage capacitor. After the electric signal input by the external power source passes through the resonant circuit and the rectifier filter circuit, the required DC electric signal is obtained. The direct current signal charges the energy storage capacitor through the constant power control module. The constant power control module adjusts the power input to the energy storage capacitor to output a stable charging power, reduces the probability of fluctuations in the charging power caused by the change of the energy storage capacitor, and improves the operating stability of the display screen.

Please refer to FIG. 1, which provides a circuit diagram of a charging circuit 10 according to an embodiment of the present application. The charging circuit 10 includes a resonance circuit 100, a rectification filter circuit 200 and a constant power control module 300. The input terminal of the resonance circuit 100 can be used to connect to an external power source. The output terminal of the resonance circuit 100 may be connected to the input terminal of the rectification filter circuit 200. The output terminal of the rectification filter circuit 200 may be connected to the input terminal of the constant power control module 300. The output terminal of the rectification filter circuit 200 can be used to output a direct current signal. The output terminal of the constant power control module 300 can be used to connect with an energy storage capacitor. The output terminal of the constant power control module 300 can also be used to adjust the charging power parameters according to the voltage of the energy storage capacitor, so that the constant power control module 300 outputs constant power for the energy storage capacitor.

In this embodiment, after the electrical signal input by the external power source passes through the resonant circuit 100 and the rectifier filter circuit 200, the required direct current signal is obtained, and then the direct current signal is passed through the constant power control module 300 as an energy storage capacitor Recharge. The constant power control module 300 adjusts the power input to the energy storage capacitor so as to output a stable charging power, reduces the probability of fluctuations in the charging power caused by the change of the energy storage capacitor, and improves the output stability of the charging circuit. In one of the embodiments, the energy storage capacitor includes a plurality of Farad super capacitors connected in series to form a Farad super capacitor group. The capacitance value of the farad super capacitor is 0.1-1000F, and the withstand voltage value is 2-3V. In one embodiment, the Farad super capacitor group includes 5 Farad super capacitors with a capacitance of 180F and a withstand voltage of 2.7V in series. The Faraday supercapacitor group has an energy storage capacitor with a capacitance value of 36F and a withstand voltage of 13.5V, so that when the charging voltage is 10V, the energy storage capacitor stores 1800 joules of electric energy.

In one of the embodiments, referring to FIG. 1, the constant power control module 300 includes a feedforward control unit 310. The output terminal of the rectification filter circuit 200 is connected to the input terminal of the feedforward control unit 310. The output terminal of the feedforward control unit 310 is connected to the energy storage capacitor. The feedforward control unit 310 is used to adjust the charging power. In one embodiment, the feedforward control unit 310 has a feedforward control system, which is an open-loop control system. The feedforward control unit 310 is based on the charging characteristics of the energy storage capacitor. According to the characteristics that the charging voltage of the energy storage capacitor changes with time, when the number and signal of the energy storage capacitor are determined, the capacitance value of the energy storage capacitor is fixed, according to the capacitor energy storage formula:

Wherein, C is the capacitance value of the energy storage capacitor, Uc(t) is the voltage of the energy storage capacitor over time, and P is the charging power of the energy storage capacitor. According to the above, the functional relationship between the capacitance value of the energy storage capacitor and the charging power can be derived, which is specifically as follows:

In this way, according to the relationship between the capacitance value of the energy storage capacitor and the charging power, the feedforward control unit 310 correspondingly adjusts the duty ratio of the PWM (Pulse Width Modulation) signal of the charging power so as to output to The power on the energy storage capacitor is constant power. Therefore, the charging power for charging the energy storage capacitor is stabilized, the fluctuation of the charging power is reduced, and the charging stability of the energy storage capacitor by the charging circuit 10 is improved.

In one of the embodiments, referring to FIG. 1, the constant power control module 300 includes a feedback control unit 320. The output terminal of the rectification filter circuit 200 is connected to the input terminal of the feedback control unit 320. The comparison terminal of the feedback control unit 320 is also connected to the output terminal and the power preset terminal of the feedback control unit 320 respectively. The output terminal of the feedback control unit 320 is used to connect with an energy storage capacitor. The feedback control unit 320 is configured to adjust the charging power according to the power of the output terminal of the feedback control unit 320 and the power of the power preset terminal. In this embodiment, the feedback control unit 320 has a feedback control system, which is a closed-loop control system. The output terminal of the feedback control unit 320 is connected to the energy storage capacitor. The feedback control unit 320 obtains the real-time charging power of the energy storage capacitor. The charging power output by the rectification filter circuit 200 is processed by the feedback control unit 320. The charging power output from the output terminal of the rectifying filter circuit 200 is compared with the feedback of the feedback control unit 320 to adjust the output of the feedback control unit 320. The feedback control unit 320 compares the real-time output power of the feedback control unit 320 with the preset power of the power preset terminal, and feeds back the comparison result to the feedback control unit 320, so that the feedback The output power of the control unit 320 is adjusted.

Specifically, the feedback control unit 320 transmits the real-time charging power output from the output terminal of the feedback control unit 320 to the input terminal of the feedback control unit 320. The charging power of the feedback control unit 320 and the preset power of the power preset terminal perform a difference calculation to generate a power deviation signal. The feedback control unit 320 obtains the duty cycle of the PWM signal of the charging power according to the power deviation signal, so as to adjust the charging power output by the rectification filter circuit 200, so that the output terminal of the feedback control unit 320 is charged The power is adjusted to the same power as the preset power, so that the charging power of the energy storage capacitor is stabilized.

In one of the embodiments, please refer to FIG. 1, the feedback control unit 320 includes a comparator 322, a regulator 324 and a power control circuit 326. The output terminal of the rectification filter circuit 200 is connected to the input terminal of the power control circuit 326. The comparison terminal of the comparator 322 is also connected to the output terminal of the power control circuit 326 and the power preset terminal, respectively. The output terminal of the comparator 322 is connected to the input terminal of the power control circuit 326 through the regulator 324. The output terminal of the power control circuit 326 is used to connect with an energy storage capacitor. In this embodiment, the power control circuit 326 obtains the power output by the rectification filter circuit 200. The comparator 322 feeds back the real-time charging power output by the power control circuit 326 to the comparator 322. That is, the power output by the rectifying and filtering circuit 200 is fed back to the comparator 322 through the control circuit. The comparator 322 compares the feedback real-time charging power output by the power control circuit 326 with the preset power output from the power preset terminal. The comparator 322 outputs a power deviation signal according to the above comparison result. The output terminal of the comparator 322 outputs a power deviation signal. The power deviation signal is sent to the regulator 324. The regulator 324 calculates the duty cycle of the PWM signal of the charging power from the power deviation signal through algorithm calculation. The power control circuit 326 controls the final output charging power according to the duty ratio of the PWM signal. Thus, the charging power output by the feedback control unit 320 can be adjusted. The charging power actually output by the feedback control unit 320 remains equal, so that the charging power output by the feedback control unit 320 is stable. In one of the embodiments, the regulator includes a PI (Proportional Integral) regulator. The PI regulator uses a PI control algorithm to calculate the duty cycle of the corresponding PWM signal. In one of the embodiments, the final charging power output by the feedback control unit 320 is equal to the preset power.

In one of the embodiments, please refer to FIG. 1, the power control circuit 326 includes a control chip U1 and a power output circuit. The output terminal of the regulator 324 is connected to the input terminal of the control chip U1. The output terminal of the control chip U1 is connected to the input terminal of the power output circuit. The output terminal of the power output circuit is used to connect with an energy storage capacitor. In this embodiment, the input terminal of the control chip U1 is connected to the output terminal of the regulator 324. The control chip U1 obtains the duty ratio parameter of the processed PWM signal. The control chip U1 controls the power output by the power output circuit according to the duty ratio of the PWM signal, so that the charging power output by the power output circuit is equal to the preset power. The charging circuit 10 provides a fixed value of charging power for the energy storage capacitor, thereby making the output power of the charging circuit 10 stable.

In one of the embodiments, the power output circuit includes a first resistor R1, a second resistor R2, a first capacitor C1, a second capacitor C2, a first diode D1, a first inductor L1, and a first electronic switch tube Q1 and the second electronic switch tube Q2.

The power supply terminal of the control chip U1 is used to connect with a power supply. The anode of the first diode D1 is used to connect to the power supply. The cathode of the first diode D1 is connected to the output terminal of the control chip U1 through the first capacitor C1. The first control terminal of the control chip U1 is connected to the control terminal of the first electronic switch tube Q1 through the first resistor R1. The output terminal of the rectifying and filtering circuit 200 is connected to the first terminal of the first electronic switch tube Q1. The second end of the first electronic switch tube Q1 is connected to the first end of the second electronic switch tube Q2. The second control terminal of the control chip U1 is connected to the control terminal of the second electronic switch tube Q2 through the second resistor R2. The second end of the second electronic switch tube Q2 is grounded. The first terminal of the second electronic switch tube Q2 is also connected to the first terminal of the second capacitor C2 through the first inductor L1. The first terminal of the second capacitor C2 is connected to the input terminal of the comparator 322. The first end of the second capacitor C2 is also used to connect with an energy storage capacitor. The second terminal of the second capacitor C2 is grounded.

In this embodiment, the control chip U1 obtains the duty cycle parameter of the PWM signal output by the regulator 324, and correspondingly controls the on-off state of the first control terminal and the second control terminal of the control chip U1, thereby adjusting Charging power. For example, when charging is required, the control chip U1 turns on the first electronic switch tube Q1 through the first control terminal. In addition, the control chip U1 also turns off the second electronic switch tube Q2 through the second control terminal. That is, the control chip U1 sends a conduction signal to the control terminal of the first electronic switch tube Q1 through the first control terminal. The control chip U1 sends a blocking signal to the control terminal of the second electronic switch Q2 through the second control terminal. The voltage output from the output terminal of the rectifying and filtering circuit 200 charges the first inductor L1 and the second capacitor C2 through the first electronic switch tube Q1. After charging for a predetermined time, the second electronic switch tube Q2 is turned off, and the second electronic switch tube Q2 is turned on. The second electronic switch tube Q2 forms an output loop with the first inductor L1 and the second capacitor C2, that is, the second capacitor C2 outputs the required power, that is, the second capacitor C2 outputs the corresponding The charging power. The on-off time of the on-off signal sent by the first control terminal and the second control terminal of the control chip U1 is determined according to the duty ratio of the PWM signal. In this way, by controlling the on-time of the first electronic switch tube Q1, the charging power output by the power control circuit 326 is adjusted so that the charging power output by the power control circuit 326 is the same as the preset power, thereby This makes the charging power output by the power control circuit 326 stable.

In one of the embodiments, referring to FIG. 1, the power output circuit may further include a second diode D2. The first terminal of the second capacitor C2 is connected to the anode of the second diode D2. The cathode of the second diode D2 is connected to the input terminal of the comparator 322. The cathode of the second diode D2 is also used to connect with an energy storage capacitor. The power output by the power output circuit is half of the total power, realizing half-bridge power output. Half of the power output by the power output circuit is used as the charging power, so that the power output by the power output circuit remains consistent, and the stability of the charging power is further improved.

In one of the embodiments, the feedback control unit further includes a power detector. The output terminal of the power control circuit is connected to the input terminal of the comparator through the power detector. The power detector is used to obtain charging power. In this embodiment, the electrical signals that are easily detected in the circuit are mainly voltage signals and current signals. To obtain the real-time power output by the power control circuit, the power detector converts the detected output voltage and output current of the power control circuit into corresponding values, that is, the output power of the power control circuit. It is convenient to compare the real-time output power of the power control circuit with the preset power of the power preset terminal, thereby facilitating the acquisition of the corresponding duty cycle parameters of the PWM signal, thereby facilitating adjustment of the charging power output by the power control circuit, The stability of the charging power output by the power control circuit is improved.

In one of the embodiments, please refer to FIG. 1, the resonant circuit 100 includes a second inductor L2 and a third capacitor C3. The external power source is connected to the input terminal of the rectifying and filtering circuit 200 through the second inductor L2 and the third capacitor C3 in sequence. In this implementation, the second inductor L2 and the third capacitor C3 are connected in a series connection to form an LC oscillating circuit and generate magnetic resonance. According to the characteristics of the LC oscillating circuit, the frequency of the electrical signal input to the resonant circuit 100 is selected, that is, the frequency corresponding to the required charging power is selected, which reduces the volatility of the electrical signal input to the charging circuit and improves The stability of the charging power output by the charging circuit is improved. In one of the embodiments, the second inductor and the third capacitor are connected in parallel.

In one of the embodiments, the charging circuit 10 further includes a third resistor R3. The resonant circuit 100 is connected to the rectifying and filtering circuit 200 through the third resistor R3. The third resistor R3 is used to limit the current of the output of the resonant circuit 100 to prevent the current input to the rectifier filter circuit 200 and the constant power control module 300 from being too large. In one of the embodiments, the charging circuit and the external power supply transmit electric energy in a wireless manner, and the external power supply realizes electromagnetic conversion through an inductor and the second inductor L2, thereby generating an induced voltage and an induced current on the enemy inductance To provide the charging circuit with power for charging the energy storage capacitor, so that the second inductor L2 and the inductance in the external power supply circuit form a transformer to realize wireless transmission of electric energy. In one of the embodiments, because the voltage provided by the external power source is relatively large, the induced voltage on the second inductor L2 is relatively large, and the third capacitor C3 adopts a capacitor group with a relatively large withstand voltage, for example, the The third capacitor C3 includes an electrolytic capacitor bank with a withstand voltage of 100-300V.

In one of the embodiments, please refer to FIG. 1, the charging circuit 10 further includes a charging power detection circuit 400. The charging power detection circuit 400 includes a voltage detection circuit 410 and a current detection circuit 420. The output terminal of the constant power control module 300 is connected to the input terminal of the voltage detection circuit 410. The output terminal of the constant power control module 300 is also connected to the input terminal of the current detection circuit 420. The output terminal of the voltage detection circuit 410 and the output terminal of the current detection circuit 420 are connected to a monitoring system, and are used to detect the charging voltage and charging current input to the energy storage capacitor.

In this embodiment, the voltage detection circuit 410 obtains the charging voltage for charging the energy storage capacitor. The current detection circuit 420 obtains the charging current for charging the energy storage capacitor. The monitoring system determines whether the charging power for charging the energy storage capacitor is within the working power range according to the charging voltage and the charging current. When the charging power is greater than the maximum working power, the monitoring system sends a stop output signal to the constant power control module 300, and continues to stop charging for a corresponding time, avoiding excessive charging power of the energy storage capacitor and ensuring the charging Circuit 10 operates normally.

In one of the embodiments, please refer to FIG. 1, the voltage detection circuit 410 further includes a fourth resistor R4 and a fifth resistor R5. The output terminal of the constant power control module 300 is connected to the first terminal of the fifth resistor R5 through the fourth resistor R4. The second end of the fifth resistor R5 is grounded, and the first end of the fifth resistor R5 is used to connect to the monitoring system.

In this embodiment, the output terminal of the constant power control module 300 outputs charging power, that is, the output terminal of the constant power control module 300 outputs charging voltage and charging current. The first terminal of the fifth resistor R5 serves as a detection terminal of the charging voltage. The fourth resistor R4 and the fifth resistor R5 are connected in series to perform voltage division processing on the charging voltage. The first end of the fifth resistor R5 transmits part of the charging voltage to the monitoring system. The voltage transmitted to the monitoring system is the charging voltage distributed in a certain proportion. That is, the voltage transmitted to the monitoring system is the divided voltage of the charging voltage. By detecting the partial pressure of the charging voltage, according to the ratio of the fourth resistor R4 and the fifth resistor R5, the magnitude of the charging voltage can be directly obtained, which facilitates the detection of the charging voltage.

In one of the embodiments, the voltage detection circuit 410 further includes a fourth capacitor C4. The first end of the fifth resistor R5 is grounded through the fourth capacitor C4. The voltage of the fourth capacitor C4 is the voltage of the fifth resistor R5. The voltage of the fourth capacitor C4 is a divided voltage of the charging voltage input to the monitoring system. The voltage on the fourth capacitor C4 reduces the rate of voltage change on the fifth resistor R5 and reduces the sudden change in voltage on the fifth resistor R5, thereby reducing the voltage overshoot on the voltage input of the monitoring system The odds.

In one of the embodiments, please refer to FIG. 1, the current detection circuit 420 further includes a current acquisition chip U2 and a sixth resistor R6, the output terminal of the constant power control module 300 and the first current acquisition chip U2 The detection terminal is connected, the output terminal of the constant power control module 300 is also connected to the second detection terminal of the current acquisition chip U2 through the sixth resistor R6, and the output terminal of the current acquisition chip U2 is connected to the monitoring system connection. In this embodiment, the first detection terminal and the second detection terminal of the current acquisition chip U2 are used to obtain the voltage on the sixth resistor R6. According to the voltage and resistance of the sixth resistor R6, the The charging current of the output terminal of the current collecting chip U2 is convenient for the monitoring system to obtain the charging current for charging the energy storage capacitor.

In one of the embodiments, please refer to FIG. 1, the rectifier filter circuit 200 includes a rectifier bridge BD1 and a filter circuit 210. The filter circuit 210 includes a third inductor L3, a fifth capacitor C5, and a sixth capacitor C6. The output terminal of the resonance circuit 100 is connected to the input terminal of the rectifier bridge BD1. The first output terminal of the rectifier bridge BD1 is connected to the first terminal of the fifth capacitor C5. The second end of the fifth capacitor C5 is grounded. The first output terminal of the rectifier bridge BD1 is connected to the first terminal of the sixth capacitor C6 through the third inductor L3. The second end of the sixth capacitor C6 is grounded, and the second end of the sixth capacitor C6 is connected to the input end of the constant power control module 300. In this way, the electrical signal output by the resonance circuit 100 outputs a DC signal after passing through the rectifier bridge BD1. The filter circuit 210 performs filtering by using the fifth capacitor C5 and the sixth capacitor C6. The filter circuit formed with the third inductor L3 enables the filter circuit 210 to have strong filtering characteristics, which facilitates filtering of high-frequency signals, and further facilitates obtaining a stable DC signal with little interference.

In one of the embodiments, a charging device is provided, which includes the charging circuit 10 as in any of the above embodiments. After the electrical signal input by the external power source passes through the resonant circuit and the rectifier filter circuit, the required direct current signal is obtained, and then the direct current signal is charged through the constant power control module to charge the energy storage capacitor. The constant power control module adjusts the power input to the energy storage capacitor to output a stable charging power, reduces the probability of fluctuations in the charging power caused by the change of the energy storage capacitor, and improves the operating stability of the charging device.

In one of the embodiments, a display screen is provided, which includes a display module and the charging device described in the above embodiments. The display module has a display surface. The charging device is arranged on a side of the display module away from the display surface. In the above display, the electrical signal input from the external power supply passes through the resonance circuit and the rectifier filter circuit to obtain the required DC signal, and then the DC signal is charged through the constant power control module to charge the energy storage capacitor, and the constant power control module will be input to The power of the energy storage capacitor is adjusted so that a stable charging power is output, the probability of fluctuations in the charging power caused by the change of the energy storage capacitor is reduced, and the operation stability of the display screen is improved.

In one of the embodiments, the charging device is a wireless charging device. The resonant circuit of the charging device serves as a wireless receiving end. The wireless transmitting end of the external power supply sends energy to the resonant circuit. The resonant circuit includes a second inductor and a third capacitor. The wireless transmitting end of the external power supply is wirelessly connected to the input end of the rectifying and filtering circuit through the second inductor and the third capacitor in sequence. The wireless transmitting end of the external power supply has an inductance. The inductance and the second inductance form a transformer, so that the electric energy of the external power supply can be transferred to the second inductance through magnetic induction.

The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered as the scope of this specification.

The above-mentioned embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can be made, and these all fall within the protection scope of this application. Therefore, the scope of protection of the patent of this application shall be subject to the appended claims.

Claims

A charging circuit, characterized in that it comprises:

A resonance circuit, a rectification filter circuit and a constant power control module. The input terminal of the resonance circuit is used to connect to an external power source. The output terminal of the resonance circuit is connected to the input terminal of the rectification filter circuit. The output terminal is connected to the input terminal of the constant power control module, the output terminal of the rectification filter circuit is used to output a direct current signal, the output terminal of the constant power control module is used to connect to an energy storage capacitor, and the constant power control The output terminal of the module is also used to adjust the charging power parameter according to the voltage of the energy storage capacitor, so that the constant power control module outputs constant power for the energy storage capacitor.
The charging circuit according to claim 1, wherein the constant power control module comprises a feedforward control unit, an output terminal of the rectification filter circuit is connected to an input terminal of the feedforward control unit, and the feedforward control unit The output terminal of the control unit is used to connect with the energy storage capacitor, and the feedforward control unit is used to adjust the charging power.
The charging circuit according to claim 1, wherein the constant power control module comprises a feedback control unit, the output end of the rectification filter circuit is connected to the input end of the feedback control unit, and the feedback control unit The comparison terminal is also connected to the output terminal of the feedback control unit and the power preset terminal respectively. The output terminal of the feedback control unit is used to connect to the energy storage capacitor. The power at the output end and the power at the power preset end adjust the charging power.
The charging circuit according to claim 3, wherein the feedback control unit includes a comparator, a regulator, and a power control circuit, and the output terminal of the rectification filter circuit is connected to the input terminal of the power control circuit, so The comparison terminal of the comparator is also connected to the output terminal of the power control circuit and the power preset terminal, and the output terminal of the comparator is connected to the input terminal of the power control circuit through the regulator. The output terminal of the power control circuit is used to connect with the energy storage capacitor.
The charging circuit according to claim 4, wherein the power control circuit comprises a control chip and a power output circuit, the output of the regulator is connected to the input of the control chip, and the output of the control chip The terminal is connected to the input terminal of the power output circuit, and the output terminal of the power output circuit is used to connect to the energy storage capacitor.
The charging circuit according to claim 4, wherein the feedback control unit further comprises a power detector, and the output terminal of the power control circuit is connected to the input terminal of the comparator through the power detector, so The power detector is used to obtain charging power.
The charging circuit according to claim 1, wherein the resonant circuit includes a second inductor and a third capacitor, and an external power source sequentially passes through the second inductor and the third capacitor and the input of the rectifier filter circuit.端连接。 End connection.
The charging circuit according to claim 1, further comprising a charging power detection circuit, the charging power detection circuit comprising a voltage detection circuit and a current detection circuit, the output terminal of the constant power control module and the voltage detection circuit The input end of the circuit is connected, the output end of the constant power control module is also connected to the input end of the current detection circuit, the output end of the voltage detection circuit and the output end of the current detection circuit are connected to the monitoring system, and used To detect the charging voltage and charging current input to the energy storage capacitor.
A charging device, characterized by comprising the charging circuit as claimed in any one of claims 1 to 8.
A display screen, characterized by comprising a display module and the charging device as claimed in claim 9, the display module having a display surface, and the charging device is arranged on the display module away from the display surface The side.