Dimming control circuit and dimming glass

Abstract

The utility model relates to the technical field of car window dimming, and discloses a dimming control circuit and dimming glass, and the dimming control circuit comprises a power supply conversion unit, an isolation unit, a processor, a driving unit and a switch unit, the first output end and the second output end of the power conversion unit are correspondingly connected with the first end of the isolation unit and the power supply end of the processor respectively; the input end of the processor inputs an external dimming signal, and the output end of the processor is connected with the second end of the isolation unit; the third end of the isolation unit is connected with the power supply end of the switch unit, and the fourth end of the isolation unit is connected with the input end of the driving unit; the output end of the driving unit is connected with the control end of the switch unit; and the output end of the switch unit is connected with the control end of the dimming glass. The high-voltage side is isolated from the low-voltage side, so that the reliability and the safety of the circuit are improved.

Description

Technical Field

[0001] This utility model relates to the field of vehicle window dimming technology, specifically to a dimming control circuit and dimming glass. Background Technology

[0002] With the development of new energy vehicles, more and more new energy vehicles are using dimming sunroofs, also known as smart glass. Their control principle involves controlling the voltage of the glass to control its color and light transmittance. Vehicle-mounted products have very strict requirements on the voltage inside and between the controllers. While the power supply for most vehicle-mounted electrical equipment is 12V or 24V, the drive interface voltage for smart glass can reach 36 to 50V, or even higher, depending on the product. If the wiring harness of the interface is shorted to the low-voltage 12V part inside the controller, or to other low-voltage controllers, it may burn out the low-voltage components. Furthermore, high voltage can generally permanently damage components, easily causing partial malfunctions of the vehicle's electrical equipment and endangering personal and equipment safety. Utility Model Content

[0003] Therefore, the technical problem to be solved by this utility model is to solve the problem of low reliability of the control circuit due to the lack of isolation between the high and low voltage circuits of the dimming glass control terminal in the prior art, thereby providing a dimming control circuit and dimming glass.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] In a first aspect, this utility model provides a dimming control circuit, comprising: a power conversion unit, an isolation unit, a processor, a drive unit, and a switching unit. The power conversion unit receives a power supply voltage at its input terminal, and its first and second output terminals are respectively connected to the first terminal of the isolation unit and the power supply terminal of the processor. The power conversion unit is used to convert the voltage level of the power supply voltage. The processor receives an external dimming signal at its input terminal, and its output terminal is connected to the second terminal of the isolation unit. The processor is used to output a control signal based on the dimming signal. The isolation unit's third terminal is connected to the power supply terminal of the switching unit, and its fourth terminal is connected to the input terminal of the drive unit. The isolation unit is used to isolate and protect the drive unit and the switching unit. The drive unit's output terminal is connected to the control terminal of the switching unit. The drive unit is used to generate a switching sequence based on the control signal. The switching unit's output terminal is connected to the control terminal of the dimming glass. The switching unit is used to switch the switching state based on the switching sequence and then output a PWM signal.

[0006] The dimming control circuit provided by this utility model has a power conversion unit and processor as the high-voltage part, and a drive unit and switch unit as the low-voltage part. The low-voltage part and the high-voltage part of the dimming control circuit are isolated by the isolation unit to avoid the formation of a loop when the high-voltage circuit and the low-voltage circuit are short-circuited, to avoid damage to other low-voltage devices, and to prevent the high voltage from permanently breaking down the low-voltage devices.

[0007] In one optional embodiment, the power conversion unit includes a boost circuit and a linear regulator circuit, wherein the input terminal of the boost circuit receives the supply voltage, the output terminal of the boost circuit is connected to the first terminal of the isolation unit and the input terminal of the linear regulator circuit, and the first output terminal of the linear regulator circuit is connected to the power supply terminal of the processor.

[0008] The dimming control circuit provided by this utility model improves the accuracy of dimming control by stabilizing the power supply voltage.

[0009] In one optional embodiment, the isolation unit includes: an isolation transformer and an isolation chip, wherein the primary side of the isolation transformer is connected to the output terminal of the boost circuit, the secondary side of the isolation transformer is connected to the power supply terminal of the switching unit, and the isolation transformer is used to provide electromagnetic isolation between the boost circuit and the switching unit; the input terminal of the isolation chip is connected to the output terminal of the processor, the power supply terminal of the isolation chip is connected to the second output terminal of the linear voltage regulator circuit, and the output terminal of the isolation chip is connected to the input terminal of the drive unit, and the isolation chip is used to provide capacitive isolation between the processor and the drive unit.

[0010] The dimming control circuit provided by this utility model uses an isolation transformer and an isolation chip to achieve electromagnetic and capacitive dual isolation, thereby improving the isolation effect.

[0011] In one alternative implementation, the boost circuit is a BOOST circuit, which drives the isolation transformer via a flyback.

[0012] In one alternative implementation, the switching unit is an H-bridge circuit.

[0013] In one optional implementation, the power conversion unit and the processor are both connected to the first ground terminal, and the drive unit and the switch unit are both connected to the second ground terminal; the first ground terminal and the second ground terminal are not grounded together.

[0014] The dimming control circuit provided by this utility model has different grounding on the high-voltage side and the low-voltage side. When the high-voltage wiring harness of the dimming control circuit is shorted to the low-voltage part or other low-voltage controllers, a circuit cannot be formed. Therefore, it will not damage other low-voltage devices and prevents the high voltage from permanently breaking down the devices.

[0015] In one optional embodiment, the system further includes a voltage regulator unit, wherein the input terminal of the voltage regulator unit is connected to the third terminal of the isolation unit, and the output terminal of the voltage regulator unit is connected to the power supply terminal of the switching unit, which is used to stabilize the voltage of the power supply terminal of the switching unit.

[0016] In one optional embodiment, the dimming control circuit further includes an anti-reverse unit, wherein the input terminal of the anti-reverse unit receives the power supply voltage, the output terminal of the anti-reverse unit is connected to the input terminal of the power conversion unit, and the anti-reverse unit is used to prevent the power supply voltage from being reversed.

[0017] In one optional embodiment, the dimming control circuit further includes a communication unit, wherein a first end of the communication unit is connected to the input end of the processor, a second end of the communication unit is connected to the output end of the switching unit, and a third end of the communication unit is connected to the terminal, which is used to send the dimming signal of the terminal to the processor and send the electrical signal of the output end of the switching unit to the terminal.

[0018] Secondly, this utility model provides a dimming glass, comprising: a dimming glass body and a dimming control circuit as described in the first aspect.

[0019] The dimming glass provided by this utility model has a power conversion unit and processor in the dimming control circuit that is a high-voltage part, and a drive unit and switch unit that are low-voltage parts. The low-voltage part and the high-voltage part of the dimming control circuit are isolated by an isolation unit to prevent the formation of a loop when the high-voltage circuit and the low-voltage circuit are short-circuited, to avoid damage to other low-voltage devices, and to prevent the high voltage from permanently breaking down the low-voltage devices. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a specific example of the composition of the dimming control circuit according to an embodiment of the present utility model;

[0022] Figure 2 This is another specific example of the composition of the dimming control circuit according to an embodiment of the present utility model;

[0023] Figure 3 This is a specific circuit structure diagram of the dimming control circuit according to an embodiment of the present invention. Detailed Implementation

[0024] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0025] In the description of this utility model, it should be noted that the terms "first", "second" and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0028] With the development of new energy vehicles, more and more new energy vehicles are using dimming sunroofs, also known as dimming glass. Their control principle involves controlling the voltage of the glass to control its color and light transmittance. The system consists of three parts: a battery, a control circuit system, and the dimming glass itself. The control circuit system typically receives adjustment commands from communication nodes or switching nodes. The drive circuit controls the output of the H-bridge by adjusting the PWM output, thereby adjusting the voltage and waveform of the drive glass interface. Under different circuit waveforms, the dimming glass will produce different changes. While automotive products generally use 12V or 24V power supplies, the drive interface voltage of dimming glass can reach 36 to 50V or even higher, depending on the product. If the interface wiring harness is shorted to the low-voltage 12V section inside the controller, or to other low-voltage controllers, it may burn out low-voltage components. Therefore, when designing the dimming control circuit, it is necessary to avoid damage to other equipment from the high-voltage interface.

[0029] This embodiment provides a dimming control circuit, such as Figure 1 As shown, it includes: a power conversion unit 1, an isolation unit 2, a processor 3, a drive unit 4, and a switching unit 5.

[0030] Figure 1In the process, the input terminal of the power conversion unit 1 receives the power supply voltage, and the first output terminal and the second output terminal of the power conversion unit 1 are respectively connected to the first terminal of the isolation unit 2 and the power supply terminal of the processor 3. The power conversion unit 1 is used to convert the voltage level of the power supply voltage.

[0031] Optionally, Figure 1 In this circuit, power conversion unit 1 can be a DC-DC converter or an A-DC converter, with the specific selection depending on the power supply voltage type.

[0032] Figure 1 In the process, the input terminal of the processor 3 receives an external dimming signal, and the output terminal of the processor 3 is connected to the second terminal of the isolation unit 2. The processor 3 is used to output a control signal based on the dimming signal.

[0033] Figure 1 In the middle, the third end of the isolation unit 2 is connected to the power supply end of the switch unit 5, and the fourth end of the isolation unit 2 is connected to the input end of the drive unit 4. The isolation unit 2 is used to isolate and protect the drive unit 4 and the switch unit 5.

[0034] Specifically, Figure 1 In the circuit, the power conversion unit 1 and the processor 3 are the high-voltage part, and the drive unit 4 and the switch unit 5 are the low-voltage part. In order to prevent the high supply voltage from shorting to the low-voltage part of the circuit and damaging the components in the circuit, the isolation unit 2 is used to completely isolate the high-voltage side from the low-voltage side.

[0035] Optionally, the isolation unit can be a circuit with opto-isolation, electromagnetic isolation, or capacitive isolation.

[0036] Figure 1 In this process, the output terminal of the drive unit 4 is connected to the control terminal of the switch unit 5, and the drive unit 4 is used to generate a corresponding switch sequence based on the control signal.

[0037] Figure 1 In the middle, the output terminal of the switching unit 5 is connected to the control terminal of the dimming glass. The switching unit 5 is used to switch the switching state based on the switching sequence and then output a PWM signal.

[0038] Optionally, the switching unit 5 can be an H-bridge circuit. The driving unit 4 drives the switches in the switching unit 5 to switch states through the output switching sequence, thereby adjusting the duty cycle of the output pulse signal and thus adjusting the transparency of the glass.

[0039] It should be noted that the methods of generating dimming control signals based on dimming signals by the processor, generating corresponding switching sequences based on dimming control signals by the drive unit, and adjusting the transparency of dimming glass based on PWM signals are all mature adjustment methods in the prior art and will not be described in detail here. That is, this embodiment only protects the structure of the dimming control circuit and does not protect the dimming logic and dimming method inside the circuit.

[0040] The dimming control circuit provided in this embodiment has a power conversion unit and processor as the high-voltage part, and a drive unit and switching unit as the low-voltage part. The low-voltage part and the high-voltage part of the dimming control circuit are isolated by the isolation unit to avoid the formation of a loop when the high-voltage circuit and the low-voltage circuit are short-circuited, to avoid damage to other low-voltage devices, and to prevent the high voltage from permanently breaking down the low-voltage devices.

[0041] In some alternative implementations, such as Figure 2 As shown, the power conversion unit 1 includes a boost circuit 11 and a linear regulator circuit 12. The input terminal of the boost circuit 11 receives the power supply voltage, and the output terminal of the boost circuit 11 is connected to the first terminal of the isolation unit 2 and the input terminal of the linear regulator circuit 12. The first output terminal of the linear regulator circuit 12 is connected to the power supply terminal of the processor 3.

[0042] Specifically, Figure 2 In this circuit, the driving voltage of the dimming glass is typically above 24V. After obtaining the external power supply voltage, the boost circuit 11 converts the input DC power into a higher voltage DC power. Since the processor's power supply voltage is typically below 24V, the linear regulator circuit 12 is used to suppress noise interference in the DC power and to convert the higher voltage DC power into a lower voltage to power the processor 3.

[0043] It should be noted that when the power supply voltage is AC, the boost circuit is used to convert AC to DC and boost the voltage. The specific structure of the boost circuit can be set according to actual needs.

[0044] In some alternative implementations, such as Figure 2 As shown, the isolation unit 2 includes an isolation transformer 21 and an isolation chip 22. The primary side of the isolation transformer 21 is connected to the output terminal of the boost circuit 11, and the secondary side of the isolation transformer 21 is connected to the power supply terminal of the switching unit 5. The input terminal of the isolation chip 22 is connected to the output terminal of the processor 3, the power supply terminal of the isolation chip 22 is connected to the second output terminal of the linear voltage regulator circuit 12, and the output terminal of the isolation chip 22 is connected to the input terminal of the drive unit 4.

[0045] Specifically, Figure 2In this circuit, the isolation transformer 21 is used for electromagnetic isolation between the boost circuit 11 and the switching unit 5, and the isolation chip is used for capacitive isolation between the processor 3 and the drive unit 4. The power conversion unit 1 and the processor 3 are also connected to the first ground terminal GND, and the drive unit 4 and the switching unit 5 are also connected to the second ground terminal ISO_GND. Since the first ground terminal GND and the second ground terminal ISO_GND are not common ground, a loop will not be formed between the low-voltage circuit and the high-voltage circuit. When the supply voltage is shorted to the low-voltage part of the circuit, the supply voltage will not damage the components in the circuit.

[0046] Optionally, the boost circuit is a BOOST circuit, which drives the isolation transformer 21 via a flyback.

[0047] In some alternative implementations, such as Figure 3 As shown, the dimming control circuit also includes: a voltage regulator unit 6, an anti-reverse unit 7, and a communication unit 8. The input terminal of the voltage regulator unit 6 is connected to the third terminal of the isolation unit 2, and the output terminal of the voltage regulator unit 6 is connected to the power supply terminal of the switching unit 5. The input terminal of the anti-reverse unit 7 receives the power supply voltage, and the output terminal of the anti-reverse unit 7 is connected to the input terminal of the power conversion unit 1. The first terminal of the communication unit 8 is connected to the input terminal of the processor 3, the second terminal of the communication unit 8 is connected to the output terminal of the switching unit 5, and the third terminal of the communication unit 8 is connected to the terminal.

[0048] Specifically, Figure 3 In this circuit, voltage regulator unit 6 stabilizes the voltage at the power supply terminal of switch unit 5 to prevent malfunction due to voltage fluctuations; anti-reverse unit 7 prevents reverse voltage supply. Communication unit 8 sends the dimming signal from the terminal to processor 3 and the electrical signal from the output terminal of switch unit 5 to the terminal, allowing users to view the output status of the dimming control circuit, fault status, and other information through the terminal.

[0049] Specifically, Figure 3 In this circuit, battery BT1 supplies DC power to the dimming control circuit. C4 is a filter capacitor after the input of battery BT1, used to filter out noise and ensure power quality. Q5 is an NMOS anti-reverse circuit to prevent reverse connection of the input power. Boost circuit 11 is a BOOST chip that drives isolation transformer 21 in flyback mode to achieve the boost function, boosting the battery power to the high voltage required by the dimming glass load circuit Rd. Isolation transformer 21 transmits the boosted voltage to voltage regulator unit 6. C2 is the output capacitor of voltage regulator unit 6, used to reduce output power fluctuations. Q1, Q2, Q3, and Q4 are MOS switches of switching unit 5, which convert DC power to AC power by switching the switching state to provide drive power to the load.

[0050] Specifically, Figure 3In this circuit, C5 is the filter capacitor after the input of battery BT1, and the anti-reverse unit 7 may include the anti-reverse diode D1 of the logic control circuit. The linear voltage regulator circuit 12 is an LDO chip, and C8 is the output capacitor of the linear voltage regulator circuit 12, used to convert the DC battery voltage into a low voltage to stably power the subsequent circuits. The processor 3 receives external dimming signals through the communication unit and outputs control signals based on the dimming signals. The isolation chip 22 is used to achieve electrical isolation of the processor 3, preventing damage to the low-voltage side circuit from some high-voltage side circuits. The drive unit 4 outputs a drive signal based on the isolated control signal, driving the switch unit 5 to switch its on / off state, so that the switch unit 5 outputs a sinusoidal or PWM AC signal to drive the dimming glass load circuit Rd, thereby realizing the on / off and dimming functions of the dimming ratio of the dimming glass load circuit Rd.

[0051] This embodiment provides a dimming glass, including: a dimming glass body and a dimming control circuit of the above embodiments and any optional embodiments thereof.

[0052] It should be noted that the control method corresponding to the dimming glass in this embodiment is the same as that in the above embodiments and any of their optional embodiments, and will not be repeated here. That is, this embodiment only protects the structure of the dimming glass, and does not protect the dimming method corresponding to the dimming glass.

[0053] The dimming glass provided in this embodiment has a high-voltage section in the power conversion unit and processor of the dimming control circuit, and a low-voltage section in the drive unit and switch unit. The low-voltage section and the high-voltage section of the dimming control circuit are isolated by the isolation unit to prevent the formation of a loop when the high-voltage circuit and the low-voltage circuit are short-circuited, to avoid damage to other low-voltage devices, and to prevent the high voltage from permanently breaking down the low-voltage devices.

[0054] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A dimming control circuit, characterized by, The application relates to a dimming control circuit, which comprises a power conversion unit, an isolation unit, a processor, a driving unit and a switching unit, wherein, an input end of the power conversion unit inputs a power supply voltage, a first output end and a second output end of the power conversion unit are respectively connected with a first end of the isolation unit and a power supply end of the processor, and the power conversion unit is used for converting the voltage level of the power supply voltage; an input end of the processor inputs an external dimming signal, an output end of the processor is connected with a second end of the isolation unit, and the processor is used for outputting a control signal based on the dimming signal; a third end of the isolation unit is connected with a power supply end of the switching unit, a fourth end of the isolation unit is connected with an input end of the driving unit, and the isolation unit is used for isolating and protecting the driving unit and the switching unit; an output end of the driving unit is connected with a control end of the switching unit, and the driving unit is used for generating a switching sequence based on the control signal; an output end of the switching unit is connected with a control end of dimming glass, and the switching unit is used for outputting a PWM signal after switching a switching state based on the switching sequence. The power conversion unit comprises a boost circuit and a linear voltage stabilizing circuit, wherein, 2. The dimming control circuit of claim 1, wherein, an input end of the boost circuit inputs a power supply voltage, an output end of the boost circuit is connected with a first end of the isolation unit and an input end of the linear voltage stabilizing circuit; a first output end of the linear voltage stabilizing circuit is connected with a power supply end of the processor. The isolation unit comprises an isolation transformer and an isolation chip, wherein, 3. The dimming control circuit of claim 2, wherein, a primary side of the isolation transformer is connected with an output end of the boost circuit, a secondary side of the isolation transformer is connected with a power supply end of the switching unit, and the isolation transformer is used for performing electromagnetic isolation between the boost circuit and the switching unit; an input end of the isolation chip is connected with an output end of the processor, a power supply end of the isolation chip is connected with a second output end of the linear voltage stabilizing circuit, and an output end of the isolation chip is connected with an input end of the driving unit, and the isolation chip is used for performing capacitive isolation between the processor and the driving unit.

4. The dimming control circuit according to claim 3, wherein, the boost circuit is a BOOST circuit, and the BOOST circuit drives the isolation transformer in flyback mode.

5. The dimming control circuit according to claim 1, wherein, the switching unit is an H-bridge circuit.

6. The dimming control circuit according to claim 1, wherein, the power conversion unit and the processor are both connected with a first ground end, and the driving unit and the switching unit are both connected with a second ground end; the first ground end and the second ground end are not common grounds. The application further comprises a voltage stabilizing unit, wherein, 7. The dimming control circuit of any one of claims 1 to 6, wherein, an input end of the voltage stabilizing unit is connected with a third end of the isolation unit, and an output end of the voltage stabilizing unit is connected with a power supply end of the switching unit, and the voltage stabilizing unit is used for stabilizing the voltage of the power supply end of the switching unit. The application further comprises an anti-reverse unit, wherein, ​ 8. The dimming control circuit of any one of claims 1 to 6, wherein, ​ ​ The input end of the anti-reverse unit inputs the power supply voltage, and the output end of the anti-reverse unit is connected with the input end of the power conversion unit, and the anti-reverse unit is used for preventing the power supply voltage from being reversed.

9. The dimming control circuit of any one of claims 1 to 6, wherein, Also comprising: A communication unit, wherein, The first end of the communication unit is connected with the input end of the processor, the second end of the communication unit is connected with the output end of the switch unit, and the third end of the communication unit is connected with the terminal, which is used for sending the dimming signal of the terminal to the processor and sending the electrical signal of the output end of the switch unit to the terminal.

10. A light-adjustable glass, characterized by, Comprising: The dimming glass body and the dimming control circuit of any one of claims 1 to 9. The dimming glass body and the dimming control circuit of any one of claims 1 to 9.

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