CN219779991U - Charging and discharging circuit of sky curtain glass and electric equipment - Google Patents

Abstract

The utility model discloses a charging and discharging circuit of sky screen glass and electric equipment. The charging and discharging circuit of the backdrop glass comprises a constant current branch, a first bridge arm branch, a second bridge arm branch and a controller. The first bridge arm branch comprises a first upper bridge arm and a first lower bridge arm, the second bridge arm branch comprises a second upper bridge arm and a second lower bridge arm, and the controller is configured to output square wave signals, first control signals and second control signals. The constant current branch is configured to output a first current in response to the square wave signal, the magnitude of the first current having a correspondence with the duty cycle of the square wave signal. The first upper leg and the second lower leg are each configured to conduct in response to a first control signal to charge the backdrop glass based on the first current. The first lower leg and the second upper leg are each configured to conduct in response to a first control signal to discharge the sheet glass at a first current. By the mode, the charge and discharge current of the sky curtain glass can be improved, so that the adjusting speed of the sky curtain glass is improved.

Description

Charging and discharging circuit of sky curtain glass and electric equipment

Technical Field

The utility model relates to the technical field of electronic circuits, in particular to a charging and discharging circuit of awning glass and electric equipment.

Background

The color-changing awning glass is a special glass material capable of automatically adjusting color according to external light. The color-changing awning glass can automatically adjust the color and the transparency thereof so as to filter ultraviolet rays and dissipate heat. The color-changing awning glass needs to calculate the charge and discharge electric quantity to determine the current gear. The color and the transparency of the color-changing awning glass corresponding to different gear positions are in different states, namely, any gear position has the color and the transparency of the color-changing awning glass corresponding to the color-changing awning glass.

At present, an LDO voltage stabilizer is generally adopted as a constant voltage source, and the charging and discharging of the color-changing awning glass are controlled so as to control the color and the transparency of the color-changing awning glass. In addition, for the control mode adopting the LDO, the output voltage of the LDO is dynamically changed in the process of changing the color and the transparency of the color-changing sky shade glass.

However, the larger voltage range of the output of the LDO results in larger power consumption generated by dynamic change of the output voltage of the LDO, and may cause serious heat generation of the LDO. In order to reduce the risk of damage of the LDO due to serious heating, the current output by the LDO is limited, so that the charge and discharge speed of the color-changing awning glass is limited, and the adjustment speed of the color-changing awning glass is slower.

Disclosure of Invention

The utility model aims to provide a charging and discharging circuit of a sky curtain glass and electric equipment.

In order to achieve the above object, in a first aspect, the present utility model provides a charging and discharging circuit for a sky screen glass, comprising:

the constant current branch, the first bridge arm branch, the second bridge arm branch and the controller; the first bridge arm branch comprises a first upper bridge arm and a first lower bridge arm, and the second bridge arm branch comprises a second upper bridge arm and a second lower bridge arm;

the first end of the constant current branch, the first end of the first upper bridge arm, the first end of the first lower bridge arm, the first end of the second upper bridge arm and the first end of the second lower bridge arm are all connected with a controller, the second end of the constant current branch is respectively connected with the second end of the first upper bridge arm and the second end of the second upper bridge arm, the third end of the first upper bridge arm and the second end of the first lower bridge arm are both connected with the first end of the backdrop glass, and the third end of the second upper bridge arm and the second end of the second lower bridge arm are connected with the second end of the backdrop glass;

the controller is configured to output a square wave signal, a first control signal and a second control signal;

the constant current branch is configured to output a first current in response to the square wave signal, wherein the magnitude of the first current has a corresponding relationship with the duty cycle of the square wave signal;

the first upper leg and the second lower leg are each configured to be turned on in response to the first control signal to charge the backdrop glass based on the first current, wherein when the first upper leg and the second lower leg are turned on, the first lower leg and the second upper leg are each turned off in response to the second control signal;

the first lower leg and the second upper leg are each configured to be turned on in response to the first control signal to discharge the backdrop glass at the first current, wherein when the first lower leg and the second upper leg are turned on, the first upper leg and the second lower leg are each turned off in response to the second control signal.

In an alternative mode, the charge-discharge circuit further comprises a current detection branch and a signal amplification branch;

the first end of the current detection branch is respectively connected with the second end of the constant current branch and the first end of the signal amplification branch, the second end of the current detection branch is respectively connected with the second end of the signal amplification branch, the second end of the first upper bridge arm and the second end of the second upper bridge arm, and the third end of the signal amplification branch is connected with the controller;

the current detection branch is configured to generate a first voltage based on the first current;

the signal amplification branch is configured to amplify the first voltage and output a second voltage to the controller, such that the controller determines a magnitude of the first current based on the second voltage.

In an alternative way, the constant current branch comprises a constant current source chip;

the power input end of the constant current source chip is connected with the power supply, the enabling end of the constant current source chip is connected with the controller to input square wave signals, and the current output end of the constant current source chip is connected with the second end of the first upper bridge arm and the second end of the second upper bridge arm respectively.

In an alternative manner, the first upper bridge arm includes a first switching tube, and the first lower bridge arm includes a second switching tube;

the first end of the first switching tube and the first end of the second switching tube are connected with the controller, the third end of the first switching tube is connected with the second end of the constant current branch and the second end of the second upper bridge arm respectively, the second end of the first switching tube is connected with the third end of the second switching tube and the first end of the awning glass respectively, and the second end of the second switching tube is grounded.

In an alternative manner, the second upper bridge arm includes a third switching tube, and the second lower bridge arm includes a fourth switching tube;

the first end of the third switching tube and the first end of the fourth switching tube are connected with the controller, the third end of the third switching tube is connected with the second end of the constant current branch and the second end of the first upper bridge arm respectively, the second end of the third switching tube is connected with the third end of the fourth switching tube and the second end of the sky curtain glass respectively, and the second end of the fourth switching tube is grounded.

In an alternative mode, the first switching tube is an NMOS tube, the first end of the first switching tube is a grid electrode of the NMOS tube, the second end of the first switching tube is a source electrode of the NMOS tube, and the third end of the first switching tube is a drain electrode of the NMOS tube;

and/or the second switching tube is an NMOS tube, the first end of the second switching tube is the grid electrode of the NMOS tube, the second end of the second switching tube is the source electrode of the NMOS tube, and the third end of the second switching tube is the drain electrode of the NMOS tube;

and/or the third switching tube is an NMOS tube, the first end of the third switching tube is the grid electrode of the NMOS tube, the second end of the third switching tube is the source electrode of the NMOS tube, and the third end of the third switching tube is the drain electrode of the NMOS tube;

and/or the fourth switching tube is an NMOS tube, the first end of the fourth switching tube is a grid electrode of the NMOS tube, the second end of the fourth switching tube is a source electrode of the NMOS tube, and the third end of the fourth switching tube is a drain electrode of the NMOS tube.

In an alternative way, the current detection branch comprises a first resistor;

the first end of the first resistor is respectively connected with the second end of the constant current branch and the first end of the signal amplifying branch, and the second end of the first resistor is respectively connected with the second end of the signal amplifying branch, the second end of the first upper bridge arm and the second end of the second upper bridge arm.

In an alternative way, the amplifying branch comprises an operational amplifier and an analog-to-digital converter;

the first input end of the operational amplifier is connected with the first end of the current detection branch, the second input end of the operational amplifier is connected with the second end of the current detection branch, the output end of the operational amplifier is connected with the input end of the analog-to-digital converter, and the output end of the analog-to-digital converter is connected with the controller.

In a second aspect, the utility model provides electric equipment, which comprises a sky curtain glass and a charging and discharging circuit of the sky curtain glass.

The beneficial effects of the utility model are as follows: the charge-discharge circuit of the backdrop glass provided by the utility model comprises a constant current branch, a first bridge arm branch, a second bridge arm branch and a controller. The controller can output square wave signals, first control signals and second control signals. The square wave signal is input to the constant current branch circuit, so that the constant current branch circuit outputs a first current based on the square wave signal. And, as the duty cycle of the square wave signal changes, the first current also changes. When a first control signal is input to the first upper bridge arm and the second lower bridge arm so that the first upper bridge arm and the second lower bridge arm are both conducted, and a second control signal is input to the first lower bridge arm and the second upper bridge arm so that the first lower bridge arm and the second upper bridge arm are both disconnected, the first current charges the sky curtain glass through the first upper bridge arm and the second lower bridge arm. When the second control signal is input to the first lower bridge arm and the second upper bridge arm so as to enable the first lower bridge arm and the second upper bridge arm to be conducted, and the first control signal is input to the first upper bridge arm and the second lower bridge arm respectively so as to enable the first upper bridge arm and the second lower bridge arm to be disconnected, the sky curtain glass can be discharged through the first lower bridge arm and the second upper bridge arm through a first current. Through the process, the charge and discharge process of the sky curtain glass is realized, so that the color and transparency control process of the sky curtain glass is realized. Meanwhile, the charging and discharging process of the sky screen glass is not influenced by voltage any more, but is influenced by the first current only. Thus, the first larger current can be used to charge and discharge the backdrop glass. Compared with the technical scheme that the current output by the LDO is required to be limited in the related art, the utility model can improve the charge and discharge current of the sky curtain glass so as to improve the adjusting speed of the sky curtain glass.

Drawings

One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which the figures of the drawings are not to be taken in a limiting sense, unless otherwise indicated.

FIG. 1 is a schematic diagram of a charge/discharge circuit of a glass backdrop according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of a charge/discharge circuit of a glass backdrop according to an embodiment of the present utility model;

fig. 3 is a schematic circuit diagram of a charge-discharge circuit of a glass awning according to an embodiment of the utility model.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a charge-discharge circuit of a glass curtain according to an embodiment of the utility model. As shown in fig. 1, the charge-discharge circuit 100 of the backdrop glass includes a constant current branch 10, a first bridge arm branch 20, a second bridge arm branch 30, and a controller 40.

The first end of the constant current branch 10, the first end of the first upper arm 21, the first end of the first lower arm 22, the first end of the second upper arm 31, and the first end of the second lower arm 32 are all connected to the controller 40, the second end of the constant current branch 10 is connected to the second end of the first upper arm 21 and the second end of the second upper arm 31 (connected to the first connection point N1), the third end of the first upper arm 21 and the second end of the first lower arm 22 are all connected to the first end of the backdrop glass 200, that is, the connection point between the first upper arm 21 and the first lower arm 22 (that is, the second connection point N2) is connected to the first end of the backdrop glass 200, and the third end of the second upper arm 31 and the second end of the second lower arm 32 are all connected to the second end of the backdrop glass 200, that is, the connection point between the second upper arm 31 and the second lower arm 32 (that is, the third connection point N3) is connected to the second end of the backdrop glass 200.

Specifically, the controller 40 is configured to output a square wave signal, a first control signal, and a second control signal. The constant current branch 10 is configured to output a first current in response to a square wave signal. The magnitude of the first current has a corresponding relation with the duty ratio of the square wave signal. The corresponding relation between the magnitude of the first current and the duty ratio of the square wave signal comprises a positive correlation relation or a negative correlation relation. Taking the positive correlation between the magnitude of the first current and the duty cycle of the square wave signal as an example, the first current increases with increasing duty cycle of the square wave signal and the first current decreases with decreasing duty cycle of the square wave signal. The first upper leg 21 and the second lower leg 32 are each configured to conduct in response to a first control signal to charge the backdrop glass 200 based on a first current. When the first upper arm 21 and the second lower arm 32 are turned on, the first lower arm 22 and the second upper arm 31 are both turned off in response to the second control signal. The first lower leg 22 and the second upper leg 31 are each configured to conduct in response to a first control signal to discharge the sheet of glass 200 at a first current. When the first lower arm 22 and the second upper arm 31 are turned on, the first upper arm 21 and the second lower arm 32 are both turned off in response to the second control signal.

Wherein the square wave signal is also referred to as pulse width modulated (Pulse Width Modulation, PWM) signal.

The controller 40 may employ a micro control unit (Microcontroller Unit, MCU) or a digital signal processing (Digital Signal Processing, DSP) controller, etc.

The backdrop glass 200 is a color-changing backdrop glass.

In practical application, first, the controller 40 outputs a square wave signal to the constant current branch 10. The constant current branch 10 outputs a first current. Meanwhile, the controller 40 also outputs a first control signal and a second control signal. When the first control signal is input to the first upper arm 21 and the second lower arm 32, the first upper arm 21 and the second lower arm 32 are both turned on, and at the same time, the second control signal is input to the first lower arm 22 and the second upper arm 31, and the first lower arm 22 and the second upper arm 31 are both turned off in response to the second control signal. At this time, the first current charges the glass sheet 200 through the first upper arm 21 and the second lower arm 32.

When the first control signal is input to the first lower arm 22 and the second upper arm 31, the first lower arm 22 and the second upper arm 31 are both turned on, and at the same time, the second control signal is input to the first upper arm 21 and the second lower arm 32, and the first upper arm 21 and the second lower arm 32 are both turned off in response to the second control signal. At this time, the glass sheet 200 is discharged with a first current through the first lower leg 22 and the second upper leg 31.

Through the above-described process, the charge and discharge process of the backdrop glass 200 is realized to realize the control process of the color and transparency of the backdrop glass 200. Meanwhile, the charge and discharge process of the backdrop glass 200 is not affected by the voltage but is affected by the first current only. Thus, the backdrop glass 200 can be charged and discharged with a larger first current. Compared with the technical scheme that the current output by the LDO needs to be limited in the related art, the utility model can achieve the purpose of improving the charge and discharge current of the sky curtain glass 200, thereby improving the adjusting speed of the sky curtain glass 200.

The LDO (Low Dropout Regulator, low dropout linear regulator) is capable of generating a regulated output voltage by subtracting an excess voltage from an input voltage using a transistor or Field Effect Transistor (FET) operating in its saturation region.

In one embodiment, as shown in fig. 2, the charge-discharge circuit 100 of the backdrop glass 200 further includes a current detection branch 50 and a signal amplification branch 60.

The first end of the current detection branch 50 is connected to the second end of the constant current branch 10 and the first end of the signal amplification branch 60, the second end of the current detection branch 50 is connected to the second end of the signal amplification branch 60, the second end of the first upper bridge arm 21 and the second end of the second upper bridge arm 31, and the third end of the signal amplification branch 60 is connected to the controller 40.

Specifically, the current detection branch 50 is configured to generate a first voltage based on the first current. The signal amplification branch 60 is configured to amplify the first voltage and output a second voltage to the controller 40, such that the controller 40 determines the magnitude of the first current based on the second voltage.

In this embodiment, the current detection branch 50 and the signal amplification branch 60 are configured to detect the actual first current, and feed back to the controller 40, so that the controller 40 determines whether the output of the constant current branch 10 is normal. Therefore, a negative feedback process is realized to improve the reliability of the first current.

Referring to fig. 3, fig. 3 is a schematic circuit diagram illustrating a charge-discharge circuit of the awning glass.

In one embodiment, as shown in fig. 3, the constant current branch 10 includes a constant current source chip U1.

The power input end of the constant current source chip U1 (i.e., the 1 st pin of the constant current source chip U1) is connected to the power V1, the enable end of the constant current source chip U1 (i.e., the 2 nd pin of the constant current source chip U1) is connected to the controller 40, the enable end of the constant current source chip U1 inputs a square wave signal, and the current output end of the constant current source chip U1 (i.e., the 3 rd pin of the constant current source chip U1) is connected to the second end of the first upper bridge arm 21 and the second end of the second upper bridge arm 31, respectively.

Specifically, the controller 40 outputs a square wave signal to the enable terminal of the constant current source chip U1. When the square wave signal is at a high level, the current output end of the constant current source chip U1 outputs current; when the square wave signal is at a low level, the current output terminal of the constant current source chip U1 stops outputting current. The first current is the average current output by the current output end of the constant current source chip U1.

When the duty ratio of the square wave signal is increased, the time length of the square wave signal at a high level is increased, the average current output by the current output end of the constant current source chip U1 is increased, and the first current is increased; when the duty ratio of the square wave signal is reduced, the duration that the square wave signal is at a high level is reduced, the average current output by the current output end of the constant current source chip U1 is reduced, and the first current is reduced. In this embodiment, a positive correlation is exemplified between the duty cycle of the square wave signal and the magnitude of the first current.

In this embodiment, the constant current source chip U1 may be a constant current source chip of model LN33X 61. In other embodiments, the specific pin definition may be different when using other types of constant current source chips, but the function and signal definition are the same, as the constant current source chips are of different types. If other types of constant current source chips are used, the configuration may be performed in a similar manner to the above embodiments, which are within the scope of those skilled in the art, and will not be repeated here.

In an embodiment, the first upper bridge arm 21 includes a first switching tube Q1, and the first lower bridge arm 22 includes a second switching tube Q2.

The first end of the first switching tube Q1 and the first end of the second switching tube Q2 are connected to the controller 40, the third end of the first switching tube Q1 is connected to the second end of the constant current branch 10 and the second end of the second upper bridge arm 31, the second end of the first switching tube Q1 is connected to the third end of the second switching tube Q2 and the first end of the awning glass 200, and the second end of the second switching tube Q2 is grounded GND.

In this embodiment, the first switching tube Q1 and the second switching tube Q2 are both NMOS tubes. The grid electrode of the NMOS tube is the first end of the first switching tube Q1 (or the second switching tube Q2), the source electrode of the NMOS tube is the second end of the first switching tube Q1 (or the second switching tube Q2), and the drain electrode of the NMOS tube is the third end of the first switching tube Q1 (or the second switching tube Q2).

In addition, the first and second switching transistors Q1 and Q2 may be any controllable switch, such as an Insulated Gate Bipolar Transistor (IGBT) device, an Integrated Gate Commutated Thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a Silicon Controlled Rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS Controlled Thyristor (MCT) device, and the like.

In an embodiment, the second upper bridge arm 31 includes a third switching tube Q3, and the second lower bridge arm 32 includes a fourth switching tube Q4.

The first end of the third switching tube Q3 and the first end of the fourth switching tube Q4 are both connected to the controller 40, the third end of the third switching tube Q3 is connected to the second end of the constant current branch 10 and the second end of the first upper bridge arm 21, the second end of the third switching tube Q3 is connected to the third end of the fourth switching tube Q4 and the second end of the awning glass 200, and the second end of the fourth switching tube Q4 is grounded GND.

In this embodiment, the third switching tube Q3 and the fourth switching tube Q4 are NMOS tubes. The grid electrode of the NMOS tube is the first end of the third switching tube Q3 (or the fourth switching tube Q4), the source electrode of the NMOS tube is the second end of the third switching tube Q3 (or the fourth switching tube Q4), and the drain electrode of the NMOS tube is the third end of the third switching tube Q3 (or the fourth switching tube Q4).

In addition, the third and fourth switching transistors Q3 and Q4 may be any controllable switch, such as an Insulated Gate Bipolar Transistor (IGBT) device, an Integrated Gate Commutated Thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a Silicon Controlled Rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS Controlled Thyristor (MCT) device, and the like.

In one embodiment, the current detection branch 50 includes a first resistor R1.

The first end of the first resistor R1 is connected to the second end of the constant current branch 10 and the first end of the signal amplifying branch 60, and the second end of the first resistor R1 is connected to the second end of the signal amplifying branch 60, the second end of the first upper bridge arm 21 and the second end of the second upper bridge arm 31.

Specifically, when the first current flows through the first resistor R1, the two ends of the first resistor R1 generate a voltage, and the voltage is the first voltage.

In one embodiment, the amplifying branch 60 includes an operational amplifier U2 and an analog-to-digital converter U3.

The first input end of the operational amplifier U2 is connected to the first end of the current detection branch 50, the second input end of the operational amplifier U2 is connected to the second end of the current detection branch 50, the output end of the operational amplifier U2 is connected to the input end of the analog-to-digital converter U3, and the output end of the analog-to-digital converter U3 is connected to the controller 40.

Specifically, the operational amplifier U2 amplifies the voltage across the first resistor R1 (i.e., the first voltage), and outputs the second voltage to the analog-to-digital converter U3. The analog-to-digital converter U3 is capable of converting this analog quantity of the second voltage into a digital quantity so that the controller 40 can recognize it.

In the embodiment shown in fig. 3, the first end of the backdrop 200 is a positive electrode and the second end is a negative electrode. The first control signal is a high level signal, and the second control signal is a low level signal. When the first control signal is input to the first switching tube Q1 and the fourth switching tube Q4, the first switching tube Q1 and the fourth switching tube Q4 are turned on, meanwhile, the second control signal is input to the second switching tube Q2 and the third switching tube Q3, the second switching tube Q2 and the third switching tube Q3 are disconnected, the constant current source chip U1, the first resistor R1, the first switching tube Q1, the sky curtain glass 200 and the fourth switching tube Q4 form a loop, and the sky curtain glass 200 is charged.

When the first control signal is input to the second switching tube Q2 and the third switching tube Q3, the second switching tube Q2 and the third switching tube Q3 are turned on, meanwhile, the second control signal is input to the first switching tube Q1 and the fourth switching tube Q4, the first switching tube Q1 and the fourth switching tube Q4 are disconnected, the constant current source chip U1, the first resistor R1, the third switching tube Q3, the backdrop glass 200 and the second switching tube Q2 form a loop, and the backdrop glass 200 discharges.

In conclusion, the charging and discharging process of the sky curtain glass is realized, so that the color and transparency control process of the sky curtain glass is realized.

Meanwhile, in this embodiment, the charge and discharge process of the roof glass 200 is not affected by the voltage any more, but is affected by only the first current. Thus, the first larger current can be used to charge and discharge the backdrop glass. Compared with the technical scheme that the current output by the LDO needs to be limited in the related art, the utility model can improve the charge and discharge current of the sky shade glass 200 so as to improve the adjusting speed of the sky shade glass 200.

Secondly, the control of the first current is realized through square wave signals, the first current is not easy to interfere, and the precision of the first current can be improved.

In addition, in the related art, it is assumed that the input voltage of the LDO is also the power V1. Then, assuming that the output voltage of the LDO is 5V and the output current is 1A, the power loss on the LDO is (5-1) ×1=4w. For the present utility model, the power loss is mainly the loss on the constant current source chip U1, assuming that the first current is 1A. Taking the constant current source chip U1 as LN33X61 as an example, the main power consumption is a MOS transistor in the constant current source chip U1, and the equivalent resistance of the MOS transistor is 0.34 Ω, and then the power loss on the constant current source chip U1 is 1×1×0.34=0.34W < 4W. Compared with the technical scheme in the related art, the technical scheme of the embodiment of the utility model can also reduce the power loss, thereby reducing the heat generated on the constant current source chip U1 and being beneficial to improving the first current. Therefore, the first current can be larger to charge and discharge the sky curtain glass 200, so as to accelerate the charge and discharge speed, and further realize the rapid adjustment of the sky curtain glass 200.

The embodiment of the utility model also provides a control device for the awning glass. The control device of the sky shade glass comprises a power supply and a charging and discharging circuit 100 of the sky shade glass according to any one of the embodiments of the present utility model.

The power supply is connected with the charge-discharge circuit to supply power to the charge-discharge circuit.

The embodiment of the utility model also provides electric equipment, which comprises the sky screen glass and the charging and discharging circuit of the sky screen glass in any embodiment of the utility model.

The electric equipment can be a vehicle, and side windows and skylights of the vehicle can be made of electrochromic glass. In other possible embodiments, the powered device may also be a terminal device configured with an electrochromic display panel, such as a cell phone, tablet computer, personal computer, or the like. In other possible embodiments, the powered device may also be electrochromic smart glasses or the like.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and are not limiting; the technical features of the above embodiments or in the different embodiments may also be combined within the idea of the utility model, the steps may be implemented in any order, and there are many other variations of the different aspects of the utility model as described above, which are not provided in detail for the sake of brevity; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model.

Claims (9)

1. A charge-discharge circuit for a sheet of glass, comprising:

the constant current branch, the first bridge arm branch, the second bridge arm branch and the controller; the first bridge arm branch comprises a first upper bridge arm and a first lower bridge arm, and the second bridge arm branch comprises a second upper bridge arm and a second lower bridge arm;

the first end of the constant current branch, the first end of the first upper bridge arm, the first end of the first lower bridge arm, the first end of the second upper bridge arm and the first end of the second lower bridge arm are all connected with a controller, the second end of the constant current branch is respectively connected with the second end of the first upper bridge arm and the second end of the second upper bridge arm, the third end of the first upper bridge arm and the second end of the first lower bridge arm are both connected with the first end of the backdrop glass, and the third end of the second upper bridge arm and the second end of the second lower bridge arm are connected with the second end of the backdrop glass;

the controller is configured to output a square wave signal, a first control signal and a second control signal;

the constant current branch is configured to output a first current in response to the square wave signal, wherein the magnitude of the first current has a corresponding relationship with the duty cycle of the square wave signal;

the first upper leg and the second lower leg are each configured to be turned on in response to the first control signal to charge the backdrop glass based on the first current, wherein when the first upper leg and the second lower leg are turned on, the first lower leg and the second upper leg are each turned off in response to the second control signal;

the first lower leg and the second upper leg are each configured to be turned on in response to the first control signal to discharge the backdrop glass at the first current, wherein when the first lower leg and the second upper leg are turned on, the first upper leg and the second lower leg are each turned off in response to the second control signal.

2. The charge-discharge circuit of claim 1, further comprising a current detection branch and a signal amplification branch;

the first end of the current detection branch is respectively connected with the second end of the constant current branch and the first end of the signal amplification branch, the second end of the current detection branch is respectively connected with the second end of the signal amplification branch, the second end of the first upper bridge arm and the second end of the second upper bridge arm, and the third end of the signal amplification branch is connected with the controller;

the current detection branch is configured to generate a first voltage based on the first current;

the signal amplification branch is configured to amplify the first voltage and output a second voltage to the controller to cause the controller to determine a magnitude of the first current based on the second voltage.

3. The charge-discharge circuit of claim 1, wherein the constant current branch comprises a constant current source chip;

the power input end of the constant current source chip is connected with a power supply, the enabling end of the constant current source chip is connected with the controller to input the square wave signal, and the current output end of the constant current source chip is respectively connected with the second end of the first upper bridge arm and the second end of the second upper bridge arm.

4. The charge-discharge circuit of claim 1, wherein the first upper leg comprises a first switching tube and the first lower leg comprises a second switching tube;

the first end of the first switching tube and the first end of the second switching tube are connected with the controller, the third end of the first switching tube is connected with the second end of the constant current branch and the second end of the second upper bridge arm respectively, the second end of the first switching tube is connected with the third end of the second switching tube and the first end of the sky curtain glass respectively, and the second end of the second switching tube is grounded.

5. The charge-discharge circuit of claim 4, wherein the second upper leg comprises a third switching tube and the second lower leg comprises a fourth switching tube;

the first end of the third switching tube and the first end of the fourth switching tube are connected with the controller, the third end of the third switching tube is connected with the second end of the constant current branch and the second end of the first upper bridge arm respectively, the second end of the third switching tube is connected with the third end of the fourth switching tube and the second end of the awning glass respectively, and the second end of the fourth switching tube is grounded.

6. The charge-discharge circuit of claim 5, wherein the first switching tube is an NMOS tube, a first end of the first switching tube is a gate of the NMOS tube, a second end of the first switching tube is a source of the NMOS tube, and a third end of the first switching tube is a drain of the NMOS tube;

and/or the second switching tube is an NMOS tube, the first end of the second switching tube is a grid electrode of the NMOS tube, the second end of the second switching tube is a source electrode of the NMOS tube, and the third end of the second switching tube is a drain electrode of the NMOS tube;

and/or the third switching tube is an NMOS tube, the first end of the third switching tube is a grid electrode of the NMOS tube, the second end of the third switching tube is a source electrode of the NMOS tube, and the third end of the third switching tube is a drain electrode of the NMOS tube;

and/or the fourth switching tube is an NMOS tube, the first end of the fourth switching tube is a grid electrode of the NMOS tube, the second end of the fourth switching tube is a source electrode of the NMOS tube, and the third end of the fourth switching tube is a drain electrode of the NMOS tube.

7. The charge-discharge circuit of claim 2, wherein the current detection branch comprises a first resistor;

the first end of the first resistor is respectively connected with the second end of the constant current branch and the first end of the signal amplifying branch, and the second end of the first resistor is respectively connected with the second end of the signal amplifying branch, the second end of the first upper bridge arm and the second end of the second upper bridge arm.

8. The charge-discharge circuit of claim 2, wherein the amplifying branch comprises an operational amplifier and an analog-to-digital converter;

the first input end of the operational amplifier is connected with the first end of the current detection branch, the second input end of the operational amplifier is connected with the second end of the current detection branch, the output end of the operational amplifier is connected with the input end of the analog-to-digital converter, and the output end of the analog-to-digital converter is connected with the controller.

9. A powered device comprising a backdrop glass and a charging and discharging circuit for the backdrop glass as defined in any one of claims 1 to 8.