An adaptive lighting control circuit for a smart fan light

Abstract

The application discloses a kind of adaptive lighting control circuit for intelligent fan lamp, including temperature detection early warning circuit, AC-DC power conversion circuit, voltage stabilizing circuit, PWM dimming drive circuit and temperature compensation circuit, the present application, through temperature detection early warning circuit can monitor overheating risk in real time and trigger sound light alarm, solve the safety hazard of traditional fan lamp without overheating early warning, AC-DC power conversion circuit uses isolated DC-DC module and multistage filtering, realize input and output electrical isolation, and the ripple suppression ability is stronger, solve the problem of no isolation, large ripple of traditional power supply.

Description

Technical Field

[0001] This invention relates to the field of fan light control technology, and in particular to an adaptive lighting control circuit for intelligent fan lights. Background Technology

[0002] Existing smart fan lights lack temperature monitoring and early warning mechanisms during use. Fan lights are prone to overheating under prolonged high-load operation or enclosed installation scenarios, which not only shortens the lifespan of components but may also pose safety hazards. At the same time, the power conversion circuits often use non-isolated topologies, with no electrical isolation between input and output, and insufficient ripple suppression capabilities, making them susceptible to fluctuations in mains power and reducing circuit stability. In addition, the voltage regulator circuit only uses a single capacitor filter, which cannot effectively filter out high and low frequency ripples, resulting in unstable power supply to the subsequent control chip and affecting signal processing accuracy. Furthermore, the PWM dimming drive circuit is not optimized for signal matching, and the pins are prone to floating when there is no signal, causing dimming flicker or false triggering. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies, such as the tendency of smart fan lights to overheat under prolonged high-load operation or enclosed installation scenarios, which not only shortens the lifespan of components but may also pose safety hazards. Furthermore, the power conversion circuits often employ non-isolated topologies with no electrical isolation between input and output, and insufficient ripple suppression capabilities, making them susceptible to mains power fluctuations and reducing circuit stability. Additionally, the voltage regulator circuits use only a single capacitor filter, which cannot effectively filter out high and low frequency ripple, leading to unstable power supply to the subsequent control chip and affecting signal processing accuracy. Moreover, the PWM dimming drive circuit is not optimized for signal matching, and pins are prone to floating when there is no signal, causing dimming flicker or false triggering. Therefore, this invention proposes an adaptive lighting control circuit for smart fan lights.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] An adaptive lighting control circuit for a smart fan light includes: a temperature detection and early warning circuit, an AC-DC power conversion circuit, a voltage regulator circuit, a PWM dimming drive circuit, and a temperature compensation circuit.

[0006] The temperature detection and early warning circuit includes a negative temperature coefficient thermistor RT1, an adjustable resistor R21, a resistor R22, a transistor Q4, a light-emitting diode D1, a resistor R23, and a buzzer. The thermistor RT1 is connected in series with the adjustable resistor R21, and their connection point is connected to the base of the transistor Q4 through the resistor R22. The collector of the transistor Q4 is connected to the cathode of the light-emitting diode D1, and the anode of the light-emitting diode D1 is connected to the positive terminal of the power supply through the resistor R23. The buzzer is connected in parallel with the series branch of the light-emitting diode D1 and the resistor R23.

[0007] As a preferred embodiment of the adaptive lighting control circuit for intelligent fan lights described in this invention, the AC-DC power conversion circuit includes a resistor R31, a rectifier bridge D2, a capacitor C31, a DC-DC converter module, and output filter capacitors C32 and C33; wherein, the resistor R31 is connected in series between the AC input and the input terminal of the rectifier bridge D2, the output terminal of the rectifier bridge D2 is connected to the input terminal of the DC-DC converter module through the capacitor C31, and the output terminal of the DC-DC converter module is connected to the output filter capacitors C32 and C33 to output a 12V DC voltage.

[0008] As a preferred embodiment of the adaptive lighting control circuit for intelligent fan lights described in this invention, the voltage regulator circuit includes a fixed output voltage regulator chip Q5 and filter capacitors C41, C42, and C43; wherein the input terminal of the voltage regulator chip Q5 is connected to a +5V power supply, and the output terminal outputs a VCC3V3 voltage; capacitors C41, C42, and C43 are connected in parallel between the +5V power supply and ground, and between the VCC3V3 output and ground, respectively, to achieve power supply filtering.

[0009] As a preferred embodiment of the adaptive lighting control circuit for intelligent fan lights described in this invention, the PWM dimming drive circuit includes a PWM signal input terminal, a resistor R41, a pull-down resistor R42, and a BP2838G chip; wherein the PWM signal input terminal is connected to the Dim dimming pin of the BP2838G chip through the resistor R41, and the pull-down resistor R42 is connected between the PWM signal input terminal and ground.

[0010] As a preferred embodiment of the adaptive lighting control circuit for intelligent fan lights described in this invention, the temperature compensation circuit includes a mirror current source, operational amplifiers AMP1-AMP3, transistors Q1-Q3, and a voltage divider resistor network, which can generate a reference voltage V_REF with temperature compensation characteristics and temperature-related voltage signals V_CTAT, V_PTAT1, and V_PTAT2.

[0011] As a preferred embodiment of the adaptive lighting control circuit for intelligent fan lights described in this invention, wherein: in the temperature detection and early warning circuit, transistor Q4 is an NPN transistor, resistor R22 is a base current limiting resistor, resistor R23 is a current limiting resistor for the light-emitting diode, and thermistor RT1 is a negative temperature coefficient thermistor, used to sense changes in ambient temperature and trigger subsequent circuit actions.

[0012] As a preferred embodiment of the adaptive lighting control circuit for intelligent fan lights described in this invention, wherein: in the AC-DC power conversion circuit, capacitor C31 is a high-voltage filter capacitor used to filter out voltage ripple after rectification, and the DC-DC converter module is an isolated power conversion module to achieve electrical isolation between input and output.

[0013] As a preferred embodiment of the adaptive lighting control circuit for intelligent fan lights described in this invention, wherein: in the PWM dimming drive circuit, resistor R41 is a current-limiting matching resistor for the PWM signal, used to match the electrical characteristics of the PWM signal output terminal and the dimming chip pin, and pull-down resistor R42 is used to ensure that the PWM signal input terminal is in a stable low-level state when there is no signal.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] The temperature detection and early warning circuit can monitor overheating risks in real time and trigger audible and visual alarms, solving the safety hazard of traditional fan lights without overheat warning. The AC-DC power conversion circuit adopts an isolated DC-DC module and multi-stage filtering to achieve electrical isolation between input and output, and has stronger ripple suppression capability, solving the problems of traditional power supplies having no isolation and large ripple.

[0016] The voltage regulator circuit uses multi-capacitor high and low frequency filtering to effectively reduce power supply ripple and solve the problem of power instability caused by insufficient filtering in traditional voltage regulator circuits. The PWM dimming drive circuit avoids signal floating and overshoot through current limiting matching and pull-down resistor design, and achieves flicker-free smooth dimming, solving the problems of flicker and signal instability in traditional dimming. The temperature compensation circuit suppresses the temperature drift of the reference voltage through the compensation effect of PTAT and CTAT signals, solving the problem of accuracy reduction caused by the lack of temperature compensation in traditional circuits. Attached Figure Description

[0017] Figure 1 This invention presents a temperature detection and early warning circuit diagram for an adaptive lighting control circuit for an intelligent fan light.

[0018] Figure 2 This is an AC-DC power conversion circuit diagram of an adaptive lighting control circuit for an intelligent fan light proposed in this invention.

[0019] Figure 3 This is a voltage regulator circuit diagram of an adaptive lighting control circuit for an intelligent fan light proposed in this invention;

[0020] Figure 4 This is a PWM dimming drive circuit diagram for an adaptive lighting control circuit for an intelligent fan light proposed in this invention.

[0021] Figure 5This invention presents a temperature compensation circuit diagram for an adaptive lighting control circuit for an intelligent fan light. Detailed Implementation

[0022] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set up," "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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Reference Figures 1-5 An adaptive lighting control circuit for an intelligent fan light includes a temperature detection and early warning circuit, an AC-DC power conversion circuit, a voltage regulator circuit, a PWM dimming drive circuit, and a temperature compensation circuit. The temperature detection and early warning circuit includes a negative temperature coefficient thermistor RT1, an adjustable resistor R21, a resistor R22, a transistor Q4, an LED D1, a resistor R23, and a buzzer. The thermistor RT1 is connected in series with the adjustable resistor R21, and their connection point is connected to the base of the transistor Q4 through the resistor R22. The collector of the transistor Q4 is connected to the cathode of the LED D1, and the anode of the LED D1 is connected to the positive terminal of the power supply through the resistor R23. The buzzer is connected in parallel with the series branch of the LED D1 and the resistor R23. The transistor Q4 is an NPN transistor, the resistor R22 is the base current-limiting resistor, the resistor R23 is the current-limiting resistor for the LED, and the thermistor RT1 is a negative temperature coefficient thermistor used to sense changes in ambient temperature and trigger subsequent circuit actions.

[0025] Considering the fluctuations in mains voltage in different regions and the need to ensure personal safety for the fan light, an AC-DC power conversion circuit is required. This circuit includes a resistor R31, a rectifier bridge D2, a capacitor C31, a DC-DC converter module, and output filter capacitors C32 and C33. Resistor R31 is connected in series between the AC input and the input of rectifier bridge D2. The output of rectifier bridge D2 is connected to the input of the DC-DC converter module via capacitor C31. The output of the DC-DC converter module is connected to output filter capacitors C32 and C33 to output a 12V DC voltage. Capacitor C31 is a high-voltage filter capacitor used to filter out voltage ripple after rectification. The DC-DC converter module is an isolated power conversion module to achieve electrical isolation between the input and output.

[0026] Furthermore, considering that the subsequent control chip requires a stable low-voltage power supply, and that power supply ripple will affect the signal processing accuracy, a voltage regulator circuit is required, including a fixed output voltage regulator chip Q5 and filter capacitors C41, C42, and C43. The input terminal of the voltage regulator chip Q5 is connected to the +5V power supply, and the output terminal outputs VCC3V3 voltage. Capacitors C41, C42, and C43 are connected in parallel between the +5V power supply and ground, and between the VCC3V3 output and ground, respectively, to achieve power supply filtering.

[0027] Furthermore, considering the user's need for a smooth dimming experience and the susceptibility of floating interference in PWM signal transmission, a PWM dimming driver circuit is required, including a PWM signal input terminal, resistor R41, pull-down resistor R42, and a BP2838G chip. The PWM signal input terminal is connected to the Dim dimming pin of the BP2838G chip via resistor R41, and the pull-down resistor R42 is connected between the PWM signal input terminal and ground. In the PWM dimming driver circuit, resistor R41 is a current-limiting matching resistor for the PWM signal, used to match the electrical characteristics of the PWM signal output terminal and the dimming chip pin. The pull-down resistor R42 ensures that the PWM signal input terminal is in a stable low-level state when there is no signal.

[0028] Furthermore, considering that changes in ambient temperature can cause the reference voltage to drift and affect the circuit accuracy, a temperature compensation circuit is required. This circuit includes a current mirror, operational amplifiers AMP1-AMP3, transistors Q1-Q3, and a voltage divider resistor network. It can generate a reference voltage V_REF with temperature compensation characteristics and temperature-related voltage signals V_CTAT, V_PTAT1, and V_PTAT2.

[0029] It is worth noting that the entire device is controlled by a controller. Since the controller is a common device and belongs to existing mature technology, its electrical connection relationship and specific circuit structure will not be described in detail here.

[0030] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention. In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

Claims

1. An adaptive lighting control circuit for a smart fan light, comprising: The circuit comprises a temperature detection and early warning circuit, an AC-DC power conversion circuit, a voltage regulator circuit, a PWM dimming drive circuit, and a temperature compensation circuit, characterized in that: The temperature detection and early warning circuit includes a negative temperature coefficient thermistor RT1, an adjustable resistor R21, a resistor R22, a transistor Q4, a light-emitting diode D1, a resistor R23, and a buzzer. The thermistor RT1 is connected in series with the adjustable resistor R21, and their connection point is connected to the base of the transistor Q4 through the resistor R22. The collector of the transistor Q4 is connected to the cathode of the light-emitting diode D1, and the anode of the light-emitting diode D1 is connected to the positive terminal of the power supply through the resistor R23. The buzzer is connected in parallel with the series branch of the light-emitting diode D1 and the resistor R23.

2. The adaptive lighting control circuit for intelligent fan lights according to claim 1, characterized in that: The AC-DC power conversion circuit includes a resistor R31, a rectifier bridge D2, a capacitor C31, a DC-DC converter module, and output filter capacitors C32 and C33. The resistor R31 is connected in series between the AC input and the input terminal of the rectifier bridge D2. The output terminal of the rectifier bridge D2 is connected to the input terminal of the DC-DC converter module via capacitor C31. The output terminal of the DC-DC converter module is connected to the output filter capacitors C32 and C33 to output a 12V DC voltage.

3. The adaptive lighting control circuit for intelligent fan lights according to claim 1, characterized in that: The voltage regulator circuit includes a fixed output voltage regulator chip Q5 and filter capacitors C41, C42, and C43. The input terminal of the voltage regulator chip Q5 is connected to a +5V power supply, and the output terminal outputs a VCC3V3 voltage. Capacitors C41, C42, and C43 are connected in parallel between the +5V power supply and ground, and between the VCC3V3 output and ground, respectively, to achieve power supply filtering.

4. The adaptive lighting control circuit for an intelligent fan light according to claim 1, characterized in that: The PWM dimming drive circuit includes a PWM signal input terminal, a resistor R41, a pull-down resistor R42, and a BP2838G chip; wherein, the PWM signal input terminal is connected to the Dim dimming pin of the BP2838G chip through the resistor R41, and the pull-down resistor R42 is connected between the PWM signal input terminal and ground.

5. The adaptive lighting control circuit for an intelligent fan light according to claim 1, characterized in that: The temperature compensation circuit includes a mirror current source, operational amplifiers AMP1-AMP3, transistors Q1-Q3, and a voltage divider resistor network, which can generate a reference voltage V_REF with temperature compensation characteristics and temperature-related voltage signals V_CTAT, V_PTAT1, and V_PTAT2.

6. The adaptive lighting control circuit for an intelligent fan light according to claim 1, characterized in that: In the temperature detection and early warning circuit, transistor Q4 is an NPN transistor, resistor R22 is a base current limiting resistor, resistor R23 is a current limiting resistor for the light-emitting diode, and thermistor RT1 is a negative temperature coefficient thermistor, used to sense changes in ambient temperature and trigger subsequent circuit actions.

7. The adaptive lighting control circuit for an intelligent fan light according to claim 2, characterized in that: In the AC-DC power conversion circuit, capacitor C31 is a high-voltage filter capacitor used to filter out the voltage ripple after rectification. The DC-DC converter module is an isolated power conversion module to achieve electrical isolation between input and output.

8. The adaptive lighting control circuit for an intelligent fan light according to claim 4, characterized in that: In the PWM dimming drive circuit, resistor R41 is a current-limiting matching resistor for the PWM signal, used to match the electrical characteristics of the PWM signal output terminal and the dimming chip pin. Pull-down resistor R42 is used to ensure that the PWM signal input terminal is in a stable low-level state when there is no signal.

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