A driving circuit, a method, a device and a medium for driving a dimming glass

Abstract

The present application discloses a driving circuit, a method, a device and a medium for driving a dimming glass, which relate to the field of automobiles. It includes an MCU, a filtering circuit, and a differential amplification circuit; wherein, the differential amplification circuit includes a resistor and an operational amplifier; the input end of the filtering circuit is connected to the MCU and is used to convert the SPWM signal into a sinusoidal DC signal; the input end of the differential amplification circuit is connected to the output end of the filtering circuit and is used to convert the sinusoidal DC signal into a sinusoidal AC signal; the output end of the differential amplification circuit is connected to the dimming glass and is used to drive the dimming glass through the sinusoidal AC signal. In the driving circuit, a differential amplification circuit is adopted to convert the sinusoidal DC signal into a sinusoidal AC signal, and the differential amplification circuit is composed of a resistor and an operational amplifier, so the circuit structure is relatively simple and the cost is relatively low; in addition, an inverter bridge is not used, so there is no dead time, which can reduce the requirements for software control and improve the reliability of the driving circuit.

Description

Technical Field

[0001] The present application relates to the field of automobiles, and in particular to a driving circuit, a method, a device and a medium for driving a dimming glass. Background Art

[0002] With the development of intelligent vehicles, the application of dimming glass in vehicles is becoming more and more widespread. When adjusting the transparency of the dimming glass, it needs to be realized through a driving circuit. For example, automotive Polymer Dispersed Liquid Crystal (PDLC) type dimming glass requires a voltage drive characteristic of 0 - 50VAC / 50Hz. Currently, on the market, a method of using a boost module + an inverter bridge + an LC filter circuit is generally adopted to convert 12V lead-acid into the required AC voltage.

[0003] In the currently commonly used driving circuit for dimming glass made of PDLC material, a Micro Control Unit (MCU) generates two sets of sinusoidal pulse width modulation (SPWM) signals with the same amplitude modulation and frequency modulation, a certain dead time, and a phase difference of π, which is simply called sinusoidal pulse width modulation signals (5V - Max). After passing through a half-bridge driving chip, the signals meet the voltage (Ud - Max) and current requirements for driving a Metal Oxide Semiconductor Field Effect Transistor (MOSFET), simply called a MOS transistor. Then, two half-bridges are driven to obtain two power supplies (Up - Max) with voltage and current meeting the SPWM waveform for driving the dimming glass. After passing through an LC filter circuit to integrate and filter the SPWM waveform, a sinusoidal alternating current (Uo - Max) is finally output to the dimming glass. In this driving circuit, since the inverter bridge is usually composed of an upper bridge arm and a lower bridge arm, and each of the upper and lower bridge arms is composed of two MOS transistors, correspondingly, a dedicated half-bridge or full-bridge driving chip is arranged on the bridge arm. Therefore, the structure of the inverter bridge is complex and the cost is high. In addition, when the inverter bridge is working, the two bridges switch back and forth, and there is a dead time in the control of the two bridge arms, which also poses high requirements for software control.

[0004] Therefore, how to provide a driving circuit for dimming glass with a simple structure and improve the reliability of the driving circuit is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present application is to provide a driving circuit, a method, a device and a medium for driving a dimming glass, so as to provide a driving circuit for dimming glass with a simple structure and improve the reliability of the driving circuit.

[0006] To solve the above technical problems, the present application provides a drive circuit, including an MCU and a filter circuit, and further including: a differential amplifier circuit; wherein, the differential amplifier circuit includes a resistor and an operational amplifier;

[0007] The MCU is used to output an SPWM signal;

[0008] The input end of the filter circuit is connected to the MCU, and is used to convert the SPWM signal into a sinusoidal DC signal;

[0009] The input end of the differential amplifier circuit is connected to the output end of the filter circuit, and is used to convert the sinusoidal DC signal into a sinusoidal AC signal; wherein, the amplitude of the sinusoidal AC signal is determined according to the amplitude of the sinusoidal DC signal and the amplification factor of the differential amplifier circuit;

[0010] The output end of the differential amplifier circuit is connected to the dimming glass, and is used to drive the dimming glass through the sinusoidal AC signal.

[0011] Preferably, the filter circuit includes a first filter circuit and a second filter circuit;

[0012] The MCU is used to output a first SPWM signal and a second SPWM signal, wherein, the amplitudes of the first SPWM signal and the second SPWM signal are the same, the frequencies are the same, and the phases differ by π;

[0013] The input end of the first filter circuit is connected to the MCU, and is used to filter the first SPWM signal to obtain a first sinusoidal DC signal;

[0014] The input end of the second filter circuit is connected to the MCU, and is used to filter the second SPWM signal to obtain a second sinusoidal DC signal; wherein, the phases of the first sinusoidal DC signal and the second sinusoidal DC signal differ by π;

[0015] The first input end of the differential amplifier circuit is connected to the output end of the first filter circuit, and is used to input the first sinusoidal DC signal to the non-inverting input end of the differential amplifier circuit;

[0016] The second input end of the differential amplifier circuit is connected to the output end of the second filter circuit, and is used to input the second sinusoidal DC signal to the inverting input end of the differential amplifier circuit;

[0017] The differential amplifier circuit is used to perform differential amplification on the first sinusoidal DC signal and the second sinusoidal DC signal to obtain a sinusoidal AC signal;

[0018] The output terminal of the differential amplifier circuit is connected to the dimming glass and is used to drive the dimming glass through the sine AC signal.

[0019] Preferably, the first filter circuit includes a first inductor and a first capacitor; the second filter circuit includes a second inductor and a second capacitor;

[0020] The first end of the first inductor is connected to the MCU;

[0021] The second end of the first inductor and the first input terminal of the differential amplifier circuit are both connected to the first end of the first capacitor;

[0022] The second end of the first capacitor is grounded;

[0023] The first end of the second inductor is connected to the MCU;

[0024] The second end of the second inductor and the second input terminal of the differential amplifier circuit are both connected to the first end of the second capacitor;

[0025] The second end of the second capacitor is grounded.

[0026] Preferably, the differential amplifier circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, and the operational amplifier;

[0027] The first end of the first resistor is connected to the second end of the first inductor and the first end of the first capacitor;

[0028] The second end of the first resistor is connected to the first end of the second resistor and the non-inverting input terminal of the operational amplifier;

[0029] The second end of the second resistor is grounded;

[0030] The first end of the third resistor is connected to the second end of the second inductor and the first end of the second capacitor;

[0031] The second end of the third resistor is connected to the first end of the fourth resistor and the inverting input terminal of the operational amplifier;

[0032] The second end of the fourth resistor is connected to the output terminal of the operational amplifier.

[0033] Preferably, the amplification factor of the differential amplifier circuit depends on the resistance values of the first resistor, the second resistor, the third resistor, and the fourth resistor; when the resistance value of the first resistor is equal to the resistance value of the third resistor, and the resistance value of the second resistor is equal to the resistance value of the fourth resistor, the amplification factor of the differential amplifier circuit is the ratio of the resistance value of the fourth resistor to the resistance value of the third resistor.

[0034] To solve the above technical problems, the present application also provides a method for driving a dimming glass, which is applied to a driving circuit including an MCU, a filtering circuit, and a differential amplification circuit. Wherein, the differential amplification circuit includes a resistor and an operational amplifier. The input end of the filtering circuit is connected to the MCU, the input end of the differential amplification circuit is connected to the output end of the filtering circuit, and the output end of the differential amplification circuit is connected to the dimming glass; the method includes:

[0035] Output an SPWM signal;

[0036] Convert the SPWM signal into a sinusoidal DC signal through the filtering circuit;

[0037] Convert the sinusoidal DC signal into a sinusoidal AC signal through the differential amplification circuit; wherein, the amplitude of the sinusoidal AC signal is determined according to the amplitude of the sinusoidal DC signal and the amplification factor of the differential amplification circuit;

[0038] Drive the dimming glass with the sinusoidal AC signal.

[0039] Preferably, after driving the dimming glass with the sinusoidal AC signal, the method further includes:

[0040] Adjust the amplitude of the sinusoidal AC signal and obtain the adjusted sinusoidal AC signal;

[0041] Adjust the light transmittance of the dimming glass according to the adjusted sinusoidal AC signal.

[0042] To solve the above technical problems, the present application also provides a device for driving a dimming glass, which is applied to a driving circuit including an MCU, a filtering circuit, and a differential amplification circuit. Wherein, the differential amplification circuit includes a resistor and an operational amplifier. The input end of the filtering circuit is connected to the MCU, the input end of the differential amplification circuit is connected to the output end of the filtering circuit, and the output end of the differential amplification circuit is connected to the dimming glass; the device includes:

[0043] An output module, configured to output an SPWM signal;

[0044] A first conversion module, configured to convert the SPWM signal into a sinusoidal DC signal through the filtering circuit;

[0045] A second conversion module, configured to convert the sinusoidal DC signal into a sinusoidal AC signal through the differential amplification circuit; wherein, the amplitude of the sinusoidal AC signal is determined according to the amplitude of the sinusoidal DC signal and the amplification factor of the differential amplification circuit;

[0046] A driving module, configured to drive the dimming glass through the sine alternating current signal.

[0047] To solve the above technical problems, the present application further provides a device for driving a dimming glass, including:

[0048] A memory, configured to store a computer program;

[0049] A processor, configured to implement the steps of the above method for driving a dimming glass when executing the computer program.

[0050] To solve the above technical problems, the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method for driving a dimming glass are implemented.

[0051] The driving circuit provided by the present application includes an MCU, a filtering circuit, and further includes: a differential amplification circuit; wherein, the differential amplification circuit includes a resistor and an operational amplifier; the MCU is configured to output an SPWM signal; the input end of the filtering circuit is connected to the MCU and is configured to convert the SPWM signal into a sine direct current signal; the input end of the differential amplification circuit is connected to the output end of the filtering circuit and is configured to convert the sine direct current signal into a sine alternating current signal; wherein, the amplitude of the sine alternating current signal is determined according to the amplitude of the sine direct current signal and the amplification factor of the differential amplification circuit; the output end of the differential amplification circuit is connected to the dimming glass and is configured to drive the dimming glass through the sine alternating current signal. Previously, when driving the dimming glass, an inverter bridge was included in the driving circuit. Since the inverter bridge is usually composed of an upper arm and a lower arm, and each of the upper and lower arms is composed of two MOS transistors, correspondingly, a dedicated half-bridge or full-bridge driving chip is provided on the arm. Therefore, the driving circuit structure composed of the inverter bridge previously was relatively complex and the cost was also high. In the present application, a differential amplification circuit is used in the driving circuit to convert the sine direct current signal into a sine alternating current signal, and the differential amplification circuit is composed of a resistor and an operational amplifier. Therefore, the circuit structure is relatively simple and the cost is relatively low; in addition, there is a dead time in the control of the two arms in the previous method using the inverter bridge, while the inverter bridge is not used in the present application, so there is no dead time. Therefore, using the device of the present application can reduce the requirements for software control and improve the reliability of the driving circuit.

[0052] In addition, the present application further provides a method, a device, and a computer-readable storage medium for driving a dimming glass, which have the same or corresponding technical features as those of the above-mentioned driving circuit, and the effects are the same. Description of the Drawings

[0053] To more clearly illustrate the embodiments of the present application, the accompanying drawings required for use in the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0054] Figure 1 Schematic diagram of a driving circuit provided by an embodiment of the present application;

[0055] Figure 2 Schematic diagram of the waveform conversion process of a driving circuit provided by an embodiment of the present application;

[0056] Figure 3 Structural diagram of a driving circuit provided by an embodiment of the present application;

[0057] Figure 4 Flowchart of a method for driving a dimming glass provided by an embodiment of the present application;

[0058] Figure 5 Structural diagram of a device for driving a dimming glass provided by an embodiment of the present application;

[0059] Figure 6 Structural diagram of a device for driving a dimming glass provided by another embodiment of the present application;

[0060] Figure 7 Basic modulation principle diagram provided by an embodiment of the present application;

[0061] Figure 8 Basic filtering principle diagram provided by an embodiment of the present application;

[0062] Figure 9 Waveform conversion schematic diagram provided by an embodiment of the present application. Detailed implementation manners

[0063] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present application.

[0064] The core of the present application is to provide a driving circuit, a method, a device, and a medium for driving a dimming glass, which are used to provide a driving circuit for a dimming glass with a simple structure and improve the reliability of the driving circuit.

[0065] To enable those skilled in the art to better understand the solution of this application, the following provides a further detailed description of this application in conjunction with the accompanying drawings and specific embodiments. Figure 1 The following is a schematic diagram of a driving circuit provided by an embodiment of this application. As Figure 1 shown, the circuit diagram includes an MCU 1 and a filtering circuit 2, and also includes: a differential amplifier circuit 3; among them, the differential amplifier circuit 3 includes resistors and operational amplifiers.

[0066] The MCU 1 is used to output an SPWM signal.

[0067] The input end of the filtering circuit 2 is connected to the MCU 1 and is used to convert the SPWM signal into a sinusoidal DC signal.

[0068] The input end of the differential amplifier circuit 3 is connected to the output end of the filtering circuit 2 and is used to convert the sinusoidal DC signal into a sinusoidal AC signal; among them, the amplitude of the sinusoidal AC signal is determined according to the amplitude of the sinusoidal DC signal and the amplification factor of the differential amplifier circuit.

[0069] The output end of the differential amplifier circuit 3 is connected to the dimming glass 4 and is used to drive the dimming glass 4 through the sinusoidal AC signal.

[0070] Using the pulse width modulation (PWM) function of the MCU and adopting a sinusoidal modulation method, the MCU outputs an SPWM signal. The SPWM signals output by the MCU can be multiple. The filtering circuit filters out the high-frequency carrier from the SPWM signal to obtain the fundamental wave sinusoidal signal, that is, the sinusoidal DC signal. The amplitude of the fundamental wave sinusoidal signal is modulated by the SPWM modulation of the MCU and can be modulated between 0 and 5V (based on a 5V MCU) according to requirements; since the operating frequency of automotive PDLC dimming glass is generally 50Hz, the frequency is thus fixed at 50Hz; the working current of PDLC dimming glass is small, generally within 300mA. Therefore, it is feasible to use the driving circuit of this application. The sinusoidal DC signal is converted into the sinusoidal alternating current required to drive the dimming glass after passing through the differential amplifier circuit. The differential amplifier circuit is composed of resistors and operational amplifiers. Compared with the previous driving circuit using an inverter bridge to drive the dimming glass, the structure of the driving circuit in this embodiment is relatively simple and the cost is lower.

[0071] The driving circuit provided in this embodiment includes an MCU, a filtering circuit, and further includes: a differential amplification circuit; wherein, the differential amplification circuit includes a resistor and an operational amplifier; the MCU is used to output an SPWM signal; the input end of the filtering circuit is connected to the MCU and is used to convert the SPWM signal into a sinusoidal DC signal; the input end of the differential amplification circuit is connected to the output end of the filtering circuit and is used to convert the sinusoidal DC signal into a sinusoidal AC signal; the output end of the differential amplification circuit is connected to the dimming glass and is used to drive the dimming glass through the sinusoidal AC signal. Previously, when driving the dimming glass, the driving circuit included an inverter bridge. Since the inverter bridge is usually composed of an upper arm and a lower arm, and each of the upper and lower arms is composed of two MOS transistors, correspondingly, a dedicated half-bridge or full-bridge driving chip is provided on the arm. Therefore, the driving circuit structure composed of the inverter bridge previously was relatively complex and the cost was also high. In this application, a differential amplification circuit is used in the driving circuit to convert the sinusoidal DC signal into a sinusoidal AC signal, and the differential amplification circuit is composed of a resistor and an operational amplifier. Therefore, the circuit structure is relatively simple and the cost is relatively low; in addition, there is a dead time in the control of the two arms in the previous method using the inverter bridge, while the inverter bridge is not used in this application, so there is no dead time. Therefore, using the device of this application can reduce the requirements for software control and improve the reliability of the driving circuit.

[0072] For driving the dimming glass, in a preferred embodiment, the filtering circuit includes a first filtering circuit and a second filtering circuit;

[0073] The MCU is used to output a first SPWM signal and a second SPWM signal, wherein, the amplitudes of the first SPWM signal and the second SPWM signal are the same, the frequencies are the same, and the phases differ by π;

[0074] The input end of the first filtering circuit is connected to the MCU and is used to filter the first SPWM signal to obtain a first sinusoidal DC signal;

[0075] The input end of the second filtering circuit is connected to the MCU and is used to filter the second SPWM signal to obtain a second sinusoidal DC signal; wherein, the phases of the first sinusoidal DC signal and the second sinusoidal DC signal differ by π;

[0076] The first input end of the differential amplification circuit is connected to the output end of the first filtering circuit and is used to input the first sinusoidal DC signal to the non-inverting input end of the differential amplification circuit;

[0077] The second input end of the differential amplification circuit is connected to the output end of the second filtering circuit and is used to input the second sinusoidal DC signal to the inverting input end of the differential amplification circuit;

[0078] The differential amplification circuit is used to perform differential amplification on the first sinusoidal DC signal and the second sinusoidal DC signal to obtain a sinusoidal AC signal;

[0079] The output terminal of the differential amplifier circuit is connected to the dimming glass, and is used to drive the dimming glass through a sinusoidal AC signal.

[0080] Figure 2 It is a schematic diagram of the waveform conversion process of a driving circuit provided by an embodiment of the present application. As Figure 2 shown,

[0081] ① Use the PWM function of the MCU, adopt the sinusoidal modulation method, and output two groups of SPWM signals SPWM1 and SPWM2 with a phase difference of π;

[0082] ② The two groups of SPWM signals pass through the filter circuit to filter out the high-frequency carrier, and obtain the fundamental wave sine signals Sin1 and Sin2. The two signals have the same amplitude, the same frequency, and a phase difference of π. The amplitudes of the two signals are modulated by the SPWM of the MCU and can be modulated between 0 and 5V (based on a 5V MCU) according to requirements; the frequency is fixed at 50Hz;

[0083] ③ The two groups of sine signals are differentially amplified by the operational amplifier to obtain the sinusoidal alternating current Uout required to drive the dimming glass; Uout is obtained by differential amplification based on Sin1 and Sin2, so the amplitude of Uout is also modulated by the SPWM signal of the MCU, and the output voltage amplitude can be arbitrarily set according to requirements, thereby adjusting the light transmittance of the dimming glass, changing the interior light intensity of the vehicle, improving the driving and riding experience, and protecting the privacy of members.

[0084] The present embodiment provides two groups of SPWM signals with a phase difference of π, filters them through a filter circuit to obtain two groups of sine DC signals with a phase difference of π, and then converts the two groups of sine DC signals into sinusoidal AC signals through a differential amplifier circuit, so as to be able to drive the dimming glass.

[0085] On the basis of the above embodiment, in order to make the structure of the driving circuit simple and highly reliable, the preferred implementation is that the filter circuit adopts two groups of LC filter circuits, and the differential amplifier circuit is composed of four resistors and an operational amplifier. Figure 3 It is a structural diagram of a driving circuit provided by an embodiment of the present application. As Figure 3 shown: The first filter circuit includes a first inductor L1 and a first capacitor C1; the second filter circuit includes a second inductor L2 and a second capacitor C2;

[0086] The first end of the first inductor L1 is connected to the MCU;

[0087] The second end of the first inductor L1 and the first input terminal of the differential amplifier circuit are both connected to the first end of the first capacitor C1;

[0088] The second terminal of the first capacitor C1 is grounded;

[0089] The first terminal of the second inductor L2 is connected to the MCU;

[0090] The second terminal of the second inductor L2 and the second input terminal of the differential amplifier circuit are both connected to the first terminal of the second capacitor C2;

[0091] The second terminal of the second capacitor C2 is grounded.

[0092] In addition, the differential amplifier circuit includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and an operational amplifier U1;

[0093] The first terminal of the first resistor R1 is connected to the second terminal of the first inductor L1 and the first terminal of the first capacitor C1;

[0094] The second terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the non-inverting input terminal of the operational amplifier U1;

[0095] The second terminal of the second resistor R2 is grounded;

[0096] The first terminal of the third resistor R3 is connected to the second terminal of the second inductor L2 and the first terminal of the second capacitor C2;

[0097] The second terminal of the third resistor R3 is connected to the first terminal of the fourth resistor R4 and the inverting input terminal of the operational amplifier U1;

[0098] The second terminal of the fourth resistor R4 is connected to the output terminal of the operational amplifier U1.

[0099] Figure 3 The driving principle of the shown driving circuit is as follows:

[0100] ① The MCU modulates and outputs two groups of SPWM signals with the same amplitude, the same frequency, and a phase difference of π through the PWM port: SPWM1 and SPWM2;

[0101] ② SPWM1 and SPWM2 respectively pass through the LC filter circuits composed of L1 + C1 and L2 + C2 to filter out the high-frequency carrier signals, and obtain two groups of low-frequency sine DC signals Sin1 and Sin2 with the same amplitude and frequency and a phase difference of π;

[0102] ③ The differential amplifier circuit composed of R1, R2, R3, R4, and U1 amplifies Sin1 and Sin2 to obtain the sinusoidal alternating current Uout required to drive the dimming glass;

[0103] ④ The MCU controls the amplitude of the input signal of the operational amplifier circuit through amplitude modulation, changes the amplitude of the output Uout voltage to adjust the light transmittance of the dimming glass, changes the indoor light intensity, improves the driving and riding experience, and can also protect the privacy of the members;

[0104] ⑤Up and -Up are obtained by boosting the 12V vehicle-mounted lead-acid battery through a boost circuit.

[0105] In implementation, the amplitude of the sinusoidal AC signal is determined according to the amplitude of the sinusoidal DC signal and the amplification factor of the differential amplification circuit. Among them, the amplification factor of the differential amplification circuit depends on the resistance value of the first resistor R1, the resistance value of the second resistor R2, the resistance value of the third resistor R3, and the resistance value of the fourth resistor R4; when the resistance value of the first resistor R1 is equal to the resistance value of the third resistor R3, and the resistance value of the second resistor R2 is equal to the resistance value of the fourth resistor R4, the amplification factor of the differential amplification circuit is the ratio of the resistance value of the fourth resistor R4 to the resistance value of the third resistor R3. For example, if the amplitude of the sinusoidal AC signal is from -25V to 25V, the amplitudes of the two groups of sinusoidal DC signals are between 0V and 5V, and the differential amplitude of the two groups of sinusoidal DC signals is between -5V and 5V. In order to make the amplitude of the sinusoidal AC signal between -25V and 25V, the amplification factor of the differential amplification circuit is 5.

[0106] In the drive circuit provided in this embodiment, the filter circuit adopts two groups of LC filter circuits, and the differential amplification circuit is composed of four resistors and an operational amplifier. Since the LC filter circuit has the advantages of simple structure and high reliability, therefore, using the LC filter circuit in the drive circuit makes the drive circuit have a simple structure and high reliability; in addition, the differential amplification circuit composed of resistors and an operational amplifier in the drive circuit can simplify the circuit structure and has no control dead time compared with the method of using an inverter bridge in the drive circuit. Therefore, it can improve the reliability of the drive circuit.

[0107] A drive circuit is described above. Corresponding to the above embodiment, this embodiment provides a method for driving a dimming glass, which is applied to a drive circuit including an MCU, a filter circuit, and a differential amplification circuit. Among them, the differential amplification circuit includes a resistor and an operational amplifier. The input end of the filter circuit is connected to the MCU, the input end of the differential amplification circuit is connected to the output end of the filter circuit, and the output end of the differential amplification circuit is connected to the dimming glass; Figure 4 It is a flowchart of a method for driving a dimming glass provided by an embodiment of the present application, as Figure 4 shown, this method includes:

[0108] S10: Output an SPWM signal;

[0109] S11: Convert the SPWM signal into a sinusoidal DC signal through the filter circuit;

[0110] S12: Convert the sinusoidal DC signal into a sinusoidal AC signal through the differential amplification circuit;

[0111] Among them, the amplitude of the sinusoidal AC signal is determined according to the amplitude of the sinusoidal DC signal and the amplification factor of the differential amplification circuit;

[0112] S13: Drive the dimming glass with the sinusoidal AC signal.

[0113] The method for driving the dimming glass provided in this embodiment has the same or corresponding technical features as the driving circuit described above. The driving circuit has been described in detail above, so the method for driving the dimming glass will not be elaborated here, and the method for driving the dimming glass has the same beneficial effects as the driving circuit mentioned above.

[0114] In practice, users may require different glass transmittances. The preferred implementation is that after driving the dimming glass with the sinusoidal AC signal, the method for driving the dimming glass further includes:

[0115] Adjust the amplitude of the sinusoidal AC signal and obtain the adjusted sinusoidal AC signal;

[0116] Adjust the transmittance of the dimming glass according to the adjusted sinusoidal AC signal.

[0117] The MCU controls the amplitude of the input signal of the differential amplification circuit through amplitude modulation, and changes the amplitude of the output Uout voltage to adjust the transmittance of the dimming glass.

[0118] The adjustment of the transmittance of the glass provided in this embodiment can change the light intensity inside the vehicle, improve the driving and riding experience, and also protect the privacy of the members.

[0119] In the above embodiment, the method for driving the dimming glass has been described in detail. The present application also provides an embodiment corresponding to the device for driving the dimming glass. It should be noted that the present application describes the embodiments of the device part from two perspectives, one is from the perspective of functional modules, and the other is from the perspective of hardware.

[0120] This embodiment provides a device for driving a dimming glass, which is applied to a driving circuit including an MCU, a filtering circuit, and a differential amplification circuit. Among them, the differential amplification circuit includes a resistor and an operational amplifier. The input end of the filtering circuit is connected to the MCU, the input end of the differential amplification circuit is connected to the output end of the filtering circuit, and the output end of the differential amplification circuit is connected to the dimming glass. Figure 5 This is a structural diagram of a device for driving a dimming glass provided in an embodiment of the present application. Based on the perspective of functional modules, this embodiment includes:

[0121] Output module 10, used to output SPWM signals;

[0122] First conversion module 11, used to convert the SPWM signal into a sinusoidal DC signal through a filtering circuit;

[0123] A second conversion module 12, configured to convert a sinusoidal DC signal into a sinusoidal AC signal through a differential amplifier circuit; wherein, the amplitude of the sinusoidal AC signal is determined according to the amplitude of the sinusoidal DC signal and the amplification factor of the differential amplifier circuit;

[0124] A driving module 13, configured to drive the dimming glass through the sinusoidal AC signal.

[0125] Since the embodiments in the device part correspond to the embodiments in the method part, for the descriptions of the embodiments in the device part, please refer to the descriptions of the embodiments in the method part, which will not be elaborated here for the time being.

[0126] The device for driving the dimming glass provided in this embodiment outputs an SPWM signal through an output module; uses a first conversion module to convert the SPWM signal into a sinusoidal DC signal through a filter circuit; uses a second conversion module to convert the sinusoidal DC signal into a sinusoidal AC signal through a differential amplifier circuit, wherein the amplitude of the sinusoidal AC signal is determined according to the amplitude of the sinusoidal DC signal and the amplification factor of the differential amplifier circuit; and uses a driving module to drive the dimming glass through the sinusoidal AC signal. This device uses a differential amplifier circuit in the driving circuit to convert the sinusoidal DC signal into a sinusoidal AC signal, and the differential amplifier circuit is composed of resistors and operational amplifiers, so the circuit structure is relatively simple and the cost is relatively low; in addition, there is a dead time in the control of the two bridge arms in the previous inverter bridge method, while the inverter bridge is not used in the device of this embodiment, so there is no dead time. Therefore, the requirements for software control can be reduced and the reliability of the driving circuit can be improved.

[0127] Figure 6 It is a structural diagram of a device for driving a dimming glass provided in another embodiment of the present application. This embodiment is from a hardware perspective, as Figure 6 shown, the device for driving the dimming glass includes:

[0128] A memory 20, configured to store a computer program;

[0129] A processor 21, configured to implement the steps of the method for driving the dimming glass as mentioned in the above embodiments when executing the computer program.

[0130] The device for driving the dimming glass provided in this embodiment may include but is not limited to a smart phone, a tablet computer, a laptop computer, or a desktop computer, etc.

[0131] Among them, the processor 21 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 may be implemented in at least one hardware form of a Digital Signal Processor (DSP), a Field-Programmable Gate Array (FPGA), or a Programmable Logic Array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the wake state, also known as the Central Processing Unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 21 may be integrated with a Graphics Processing Unit (GPU), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 21 may further include an Artificial Intelligence (AI) processor, and the AI processor is used to process computational operations related to machine learning.

[0132] The memory 20 may include one or more computer-readable storage media, and the computer-readable storage media may be non-transitory. The memory 20 may further include high-speed random access memory and non-volatile memory, such as one or more disk storage devices and flash storage devices. In this embodiment, the memory 20 is at least used to store the following computer program 201. After the computer program is loaded and executed by the processor 21, it can implement the relevant steps of the method for driving the dimming glass disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may further include an operating system 202 and data 203, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system 202 may include Windows, Unix, Linux, etc. The data 203 may include, but is not limited to, the data involved in the method for driving the dimming glass mentioned above.

[0133] In some embodiments, the device for driving the dimming glass may further include a display screen 22, an input / output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.

[0134] Those skilled in the art can understand that Figure 6 the structure shown in

[0135] The device for driving a dimming glass provided by an embodiment of the present application includes a memory and a processor. When the processor executes the program stored in the memory, the following method can be implemented: the method for driving a dimming glass, with the same effect as above.

[0136] The present application also provides an embodiment corresponding to a computer-readable storage medium. A computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the steps recorded in the above method embodiment are implemented.

[0137] It can be understood that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: various media such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc that can store program codes.

[0138] The computer-readable storage medium provided by the present application includes the method for driving a dimming glass mentioned above, with the same effect as above.

[0139] To enable those skilled in the art to better understand the solution of the present application, the following will further combine the attached Figure 7 、the attached Figure 8 、the attached Figure 9 and the above-mentioned Figure 3 and the specific implementation manners to make a further detailed description of the present application.

[0140] Suppose Figure 3 the first inductor L1 and the second inductor L2 in are 470 uH, the first resistor R1 and the third resistor R3 are 10 kΩ, and the second resistor R2 and the fourth resistor R4 are 51 kΩ. The detailed process of driving the dimming glass is as follows:

[0141] ① The MCU outputs two groups of SPWM signals, SPWM1 and SPWM2, based on the SPWM modulation method. The amplitudes of the two groups of signals are equal and can be arbitrarily adjusted between 0 and 5 V according to system requirements; the modulation frequencies are equal, the carrier frequency is 80 KHz, and the fundamental frequency is 50 Hz based on the working characteristics of the dimming glass; the phases differ by π. Figure 7 This is the basic modulation principle diagram provided by the embodiment of the present application.

[0142] ② The SPWM1 and SPWM2 signals are respectively filtered by L1+C1 and L2+C2 through LC filtering to obtain fundamental sine signals. The cut-off frequency of the LC filtering network is 7.3KHz (the calculation formula is shown in formula (1)), which can effectively filter out the high-frequency carrier signals of 80KHz and can relatively completely retain the fundamental signals of 50Hz. Figure 8 This is the basic schematic diagram of filtering provided by the embodiment of the present application.

[0143]

[0144] ③ The two groups of sine DC signals after LC filtering are differentially amplified by the differential amplification circuit composed of R1, R2, R3, R4 and U1 to obtain the voltage Uout required for the operation of the dimming glass. The amplification factor of the differential amplification circuit is 5.1. According to the amplitudes of Sin1 and Sin2 being between 0 and 5V, the amplitude of Usin1 - Usin2 is between -5 and 5V. After amplification, the amplitude of Uout will be between -25.5 and 25.5V, and the output voltage value can be adjusted according to the amplitude modulation parameter of the SPWM of the MCU. Figure 9 This is the schematic diagram of waveform conversion provided by the embodiment of the present application. The calculation formula of Uout is shown in formula (2):

[0145] Uout = 51KΩ / 10KΩ * (Usin1 - Usin2) (2)

[0146] The driving circuit provided in this embodiment is used to generate a sine AC power supply to drive the dimming glass, simplify the topology of the driving circuit, simplify the software control algorithm, improve the reliability of the circuit and software, and reduce costs.

[0147] The above has introduced in detail a driving circuit, a method, a device and a medium for driving a dimming glass provided by the present application. Each embodiment in the specification is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

[0148] It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

Claims

1. A driving circuit, including an MCU and a filtering circuit, is characterized in that, It further includes: A differential amplifier circuit; wherein, the differential amplifier circuit includes resistors and an operational amplifier; The MCU is used to output an SPWM signal; The input end of the filtering circuit is connected to the MCU and is used to convert the SPWM signal into a sinusoidal DC signal; The input end of the differential amplifier circuit is connected to the output end of the filtering circuit and is used to convert the sinusoidal DC signal into a sinusoidal AC signal; wherein, the amplitude of the sinusoidal AC signal is determined according to the amplitude of the sinusoidal DC signal and the amplification factor of the differential amplifier circuit; The output end of the differential amplifier circuit is connected to the dimming glass and is used to drive the dimming glass through the sinusoidal AC signal.

2. The drive circuit according to claim 1, wherein The filtering circuit includes a first filtering circuit and a second filtering circuit; The MCU is used to output a first SPWM signal and a second SPWM signal, wherein, the amplitudes of the first SPWM signal and the second SPWM signal are the same, the frequencies are the same, and the phases differ by π; The input end of the first filtering circuit is connected to the MCU and is used to filter the first SPWM signal to obtain a first sinusoidal DC signal; The input end of the second filtering circuit is connected to the MCU and is used to filter the second SPWM signal to obtain a second sinusoidal DC signal; wherein, the phase of the first sinusoidal DC signal and the second sinusoidal DC signal differ by π; The first input end of the differential amplifier circuit is connected to the output end of the first filtering circuit and is used to input the first sinusoidal DC signal to the non-inverting input end of the differential amplifier circuit; The second input end of the differential amplifier circuit is connected to the output end of the second filtering circuit and is used to input the second sinusoidal DC signal to the inverting input end of the differential amplifier circuit; The differential amplifier circuit is used to perform differential amplification on the first sinusoidal DC signal and the second sinusoidal DC signal to obtain a sinusoidal AC signal; The output end of the differential amplifier circuit is connected to the dimming glass and is used to drive the dimming glass through the sinusoidal AC signal.

3. The driving circuit according to claim 2, wherein The first filtering circuit includes a first inductor and a first capacitor; the second filtering circuit includes a second inductor and a second capacitor; The first end of the first inductor is connected to the MCU; The second end of the first inductor and the first input end of the differential amplifier circuit are both connected to the first end of the first capacitor; The second end of the first capacitor is grounded; The first end of the second inductor is connected to the MCU; The second end of the second inductor and the second input end of the differential amplifier circuit are both connected to the first end of the second capacitor; The second end of the second capacitor is grounded.

4. The drive circuit according to claim 3, wherein The differential amplifier circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, and the operational amplifier; The first end of the first resistor is connected to the second end of the first inductor and the first end of the first capacitor; The second end of the first resistor is connected to the first end of the second resistor and the non-inverting input end of the operational amplifier; The second end of the second resistor is grounded; The first end of the third resistor is connected to the second end of the second inductor and the first end of the second capacitor; The second terminal of the third resistor is connected to the first terminal of the fourth resistor and the inverting input terminal of the operational amplifier; The second terminal of the fourth resistor is connected to the output terminal of the operational amplifier.

5. The drive circuit according to claim 4, wherein The amplification factor of the differential amplification circuit depends on the resistance values of the first resistor, the second resistor, the third resistor, and the fourth resistor; When the resistance value of the first resistor is equal to that of the third resistor and the resistance value of the second resistor is equal to that of the fourth resistor, the amplification factor of the differential amplification circuit is the ratio of the resistance value of the fourth resistor to that of the third resistor.

6. A method for driving a dimming glass, characterized in that, Applied to a driving circuit including an MCU, a filtering circuit, and a differential amplification circuit, wherein the differential amplification circuit includes resistors and an operational amplifier, the input terminal of the filtering circuit is connected to the MCU, the input terminal of the differential amplification circuit is connected to the output terminal of the filtering circuit, and the output terminal of the differential amplification circuit is connected to the dimming glass; the method includes: Output an SPWM signal; Convert the SPWM signal into a sinusoidal DC signal through the filtering circuit; Convert the sinusoidal DC signal into a sinusoidal AC signal through the differential amplification circuit; wherein the amplitude of the sinusoidal AC signal is determined according to the amplitude of the sinusoidal DC signal and the amplification factor of the differential amplification circuit; Drive the dimming glass through the sinusoidal AC signal.

7. The method for driving a dimming glass according to claim 6, wherein After driving the dimming glass through the sinusoidal AC signal, the method further includes: Adjust the amplitude of the sinusoidal AC signal and obtain the adjusted sinusoidal AC signal; Adjust the light transmittance of the dimming glass according to the adjusted sinusoidal AC signal.

8. A device for driving a dimming glass, characterized in that, Applied to a driving circuit including an MCU, a filtering circuit, and a differential amplification circuit, wherein the differential amplification circuit includes resistors and an operational amplifier, the input terminal of the filtering circuit is connected to the MCU, the input terminal of the differential amplification circuit is connected to the output terminal of the filtering circuit, and the output terminal of the differential amplification circuit is connected to the dimming glass; the device includes: An output module for outputting an SPWM signal; A first conversion module for converting the SPWM signal into a sinusoidal DC signal through the filtering circuit; A second conversion module for converting the sinusoidal DC signal into a sinusoidal AC signal through the differential amplification circuit; wherein the amplitude of the sinusoidal AC signal is determined according to the amplitude of the sinusoidal DC signal and the amplification factor of the differential amplification circuit; A driving module for driving the dimming glass through the sinusoidal AC signal.

9. A device for driving a dimming glass, characterized in that, Including: A memory for storing a computer program; A processor for implementing the steps of the method for driving a dimming glass as claimed in claim 6 or 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the steps of the method for driving a dimming glass as claimed in claim 6 or 7 are implemented.

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