Dimming circuit, lighting module and clothes airing machine

Abstract

The utility model discloses a dimming circuit, a lighting module and a clothes airing machine, the voltage output to a light source is adjusted by a voltage adjusting module, so that the output voltage meets the power demand of the light source, a PWM signal is converted into a stable direct-current voltage signal which is not easy to interfere by a PWM signal conversion module, and the power demand of the light source is satisfied. The controller controls the switching circuit to adjust the current output to the light source according to a feedback signal of the feedback module, so that the brightness of the light source is adjusted, the problem that the light source flickers in the dimming process due to unstable voltage or PWM interference can be avoided, and the stability of light source display is improved through the PWM signal conversion module.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of dimming, especially to a dimming circuit, a lighting module and a clothes airing machine. BACKGROUND

[0002] PWM (Pulse Width Modulation) dimming is a technology for controlling the brightness of LED lamps or other light sources. PWM dimming adjusts the on-off time ratio of the light source to achieve brightness adjustment, which can accurately control the brightness and save energy.

[0003] However, when the power voltage fluctuates or the PWM signal is disturbed externally, the light source is prone to flickering, affecting the normal display of the light source. SUMMARY

[0004] The utility model aims at overcoming the defects and deficiencies of prior art, and provides a dimming circuit, a lighting module and a clothes airing machine, which can improve the stability of light source display.

[0005] In a first aspect, the utility model provides a dimming circuit, which comprises a controller, a PWM signal conversion module, a switching module, a voltage adjustment module and a feedback module; the PWM signal conversion module is used for converting a PWM signal into a direct current voltage signal;

[0006] The first signal end of the controller is connected with the control signal input end of the switching module, the first end of the switching module is connected with the output end of the voltage adjustment module and the first input end of the light source respectively, the input end of the voltage adjustment module is connected with a power supply, the second end of the switching module is grounded, the first end of the feedback module is connected with the output end of the PWM signal conversion module, the second end of the feedback module is connected with the second input end of the light source, and the third end of the feedback module is connected with the second signal end of the controller.

[0007] Optionally, the switching module comprises a MOS tube and a first resistor; and the voltage adjustment module comprises an inductor.

[0008] The first signal end of the controller is connected with the gate of the MOS tube, the source of the MOS tube is grounded through the first resistor, the drain of the MOS tube is connected with the second end of the inductor and the first input end of the light source respectively, and the first end of the inductor is connected with a power supply.

[0009] In the embodiment of the application, the controller controls the switching frequency or the duty cycle of the MOS tube Q1, and then adjusts the current output to the light source. Meanwhile, the controller controls the conduction and turn-off of the MOS tube, and then controls the energy storage or release of the inductor, so as to adjust the voltage output to the light source, so that the voltage meets the voltage use requirement of the light source.

[0010] Optionally, the feedback module comprises a second resistor, a third resistor and a fourth resistor;

[0011] The second input end of the light source is connected with the first end of the second resistor and the second end of the fourth resistor respectively, the second signal end of the controller is connected with the second end of the third resistor and the first end of the fourth resistor respectively, the output end of the PWM signal conversion module is connected with the first end of the third resistor, and the second end of the second resistor is grounded.

[0012] In the embodiment of the application, the third resistor and the fourth resistor are used to divide the direct current voltage signal output by the PWM signal conversion module, so as to reduce the voltage output to the second resistor, and the controller adjusts the output current of the circuit according to the voltage between the two ends of the second resistor.

[0013] Optionally, the PWM signal conversion module comprises a fifth resistor, a sixth resistor, a first capacitor and a second capacitor;

[0014] The second end of the fifth resistor is connected with the first end of the sixth resistor and the first end of the first capacitor respectively, the second end of the sixth resistor is connected with the first end of the third resistor and the first end of the second capacitor respectively, and the second end of the first capacitor and the second end of the second capacitor are grounded.

[0015] In the embodiment of the application, the fifth resistor, the sixth resistor, the first capacitor and the second capacitor are used to form a two-stage RC filter circuit, compared with a single-stage RC filter circuit, the two-stage RC filter circuit can more effectively suppress high-frequency noise, further reduce the ripple in the output direct current voltage, improve the filtering effect, and obtain a more smooth direct current voltage output.

[0016] Optionally, a diode is further included, the positive electrode of the diode is connected with the output end of the voltage adjustment module, and the negative electrode of the diode is connected with the first input end of the light source.

[0017] In the embodiment of the application, the diode is arranged between the output end of the voltage adjustment module and the first input end of the light source, the unidirectional conduction characteristic of the diode is used to prevent the inductive current from flowing reversely, the normal work of the circuit is ensured, and the stable operation of the circuit is ensured.

[0018] Optionally, a first filter capacitor and a second filter capacitor are further included;

[0019] The first end of the first filter capacitor is connected with a power supply, and the second end of the first filter capacitor is grounded; the first end of the second filter capacitor is connected with the first input end of the light source, and the second end of the second filter capacitor is grounded.

[0020] In the embodiment of the application, the quality of the input and output power signals is improved by connecting filter capacitors in parallel at the input and output ends of the power supply, and the stability of the power supply of the light source is improved.

[0021] Optionally, the light modulation circuit further comprises a seventh resistor and an eighth resistor; a first end of the seventh resistor is connected with a second signal end of the controller, a second end of the seventh resistor is connected with a first end of the eighth resistor and a control signal input end of the switch module respectively, and a second end of the eighth resistor is connected with a third signal end of the controller and a first end of the first resistor respectively.

[0022] In the embodiment of the application, the controller adjusts the duty cycle of the driving signal according to the signal of the third signal end, so as to control the output current and prevent the element from being damaged due to the excessively large output current.

[0023] Optionally, the light modulation circuit further comprises a ninth resistor and a tenth resistor.

[0024] A first end of the ninth resistor is connected with a first input end of the light source, a second end of the ninth resistor is connected with a fourth signal end of the controller and a first end of the tenth resistor respectively, and a second end of the tenth resistor is grounded.

[0025] In the embodiment of the application, the controller triggers the self-locking mode of the controller when the voltage detected by the fourth signal end exceeds the target voltage, so as to realize the safety protection of the controller and improve the service life of the controller.

[0026] In a second aspect, the utility model provides a kind of lighting module, including light source and the dimming circuit as any of the above.

[0027] In a third aspect, the utility model provides a kind of clothes airing machine, including light source and the dimming circuit as any of the above.

[0028] In the embodiment of the application, the voltage adjustment module is used to adjust the voltage output to the light source, so that the output voltage meets the power demand of the light source, the PWM signal conversion module is used to convert the PWM signal into a stable direct current voltage signal which is not easily disturbed, and the controller controls the adjustment circuit to adjust the current output to the light source according to the feedback signal of the feedback module, so as to realize the adjustment of the brightness of the light source.

[0029] For better understanding and implementation, the utility model is described in detail below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is the circuit diagram of a kind of existing dimming circuit;

[0031] Figure 2 is a circuit diagram of the dimming circuit in one embodiment of the present application;

[0032] Figure 3 is a circuit diagram of the dimming circuit in another embodiment of the present application;

[0033] Figure 4 is a structural schematic diagram of the lighting module in one embodiment of the present application;

[0034] Figure 5 is a structural schematic diagram of the clothes airing machine in one embodiment of the present application. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings.

[0036] It should be clear that the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0037] The terms used in the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein means and includes any or all possible combinations of one or more associated listed items.

[0038] The following description refers to the accompanying drawings. Unless otherwise indicated, same numbers in different drawings indicate same or similar elements. The implementation described in the following example embodiments is not meant to represent all implementations consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as detailed in the appended claims. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are used only to distinguish similar objects, and do not necessarily have to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] In addition, in the description of the present application, unless otherwise specified, "several" refers to two or more. The association relationship of the associated objects described by "and / or" indicates that there can be three relationships, for example, A and / or B can represent the three cases of A existing alone, A and B existing together, and B existing alone. The character " / " generally represents an "or" relationship between the associated objects before and after it.

[0040] PWM (Pulse Width Modulation, Pulse Width Modulation) dimming is a technology for controlling the brightness of LED lights or other light sources. PWM dimming adjusts the on-off time ratio of the light source to adjust the brightness, which can accurately control the brightness and save energy.

[0041] Please refer to Figure 1 , which is a circuit diagram of an existing dimming circuit; as Figure 1 shown, the dimming circuit receives a PWM signal through a controller, and the controller adjusts the electrical signal output to the light source according to the PWM signal, thereby realizing the adjustment of the brightness of the light source. When the PWM signal duty cycle is larger, the light source brightness is larger, and when the PWM signal duty cycle is smaller, the light source brightness is smaller.

[0042] However, in the above-mentioned dimming circuit, when the power supply voltage fluctuates, such as when the power supply of the dimming circuit is shared with the motor, the motor starting process will quickly consume a large amount of current, which may cause a momentary drop in the power supply voltage, causing the current of the light source to drop or change momentarily, thereby causing flickering; or when the PWM signal is disturbed by external interference, such as when the motor needs a large current, and the momentary fluctuation of such current (for example, the starting momentary current peak of the motor) may affect the stability of the entire circuit, so that the PWM signal is disturbed, affecting the adjustment of the dimming circuit, causing the current of the light source to be unstable, thereby causing problems such as flickering of the light source, affecting the normal display of the light source.

[0043] Therefore, in view of the above problems, the embodiments of the present application provide a dimming circuit, which converts the PWM signal into a direct current voltage signal by using a PWM signal conversion module, and adjusts the output current by controlling the conduction and turn-off of the switch module through the controller by reading the feedback signal of the feedback module, thereby realizing the adjustment of the brightness of the light source. Compared with the existing dimming circuit, the present application can avoid the problem of flickering of the light source during dimming caused by unstable voltage or interference of PWM, and improve the stability of the display of the light source.

[0044] As Figure 2 shown, the embodiments of the present application provide a dimming circuit, which includes a controller 110, a PWM signal conversion module 120, a switch module 130, a voltage adjustment circuit 140, and a feedback module 150.

[0045] The first signal end of the controller 110 is connected with the control signal input end of the switch module 130, the first end of the switch module 130 is connected with the output end of the voltage adjustment module 140 and the first input end of the light source respectively, the input end of the voltage adjustment module 140 is connected with the power supply, the second end of the switch module 130 is grounded, the first end of the feedback module 150 is connected with the output end of the PWM signal conversion module, the second end of the feedback module 150 is connected with the second input end of the light source, and the third end of the feedback module 150 is connected with the second signal end of the controller 110.

[0046] The controller 110 can be a light source driving chip corresponding to the light source, for example, when the light source is an LED, the controller 110 can be an LED driving chip OB3350. It should be noted that the light source of the embodiment of the present application can also be other light emitting devices with lighting function, which is not limited here.

[0047] The filter circuit, the RC filter circuit or other circuits with the same function.

[0048] The switch module 130 is turned on or turned off according to the control signal of the controller 110, so as to realize the control of the power supply output of the light source. The switch module 130 can use switch elements such as switches and MOS tubes to control the power supply output of the light source.

[0049] The controller 110 can control the size of the current output to the light source through the switching frequency or duty cycle of the switch module 130.

[0050] The voltage adjustment circuit 140 is used to adjust the voltage output to the light source, so as to meet the voltage use requirement of the light source. The voltage adjustment circuit 140 can use voltage conversion chips or other commonly used voltage adjustment circuits to realize the adjustment of voltage.

[0051] The feedback module 150 is used to collect the output signal of the PWM signal conversion module and the output signal output to the light source, and generate a feedback signal to the controller 110, so that the controller 110 adjusts the electrical signal output to the light source through the current adjustment circuit according to the feedback signal.

[0052] The PWM signal conversion module 120 converts the PWM signal into a direct current voltage signal after receiving the PWM signal, and outputs different direct current voltage signals when the PWM signal is different. The feedback module 150 outputs a feedback signal to the controller 110 according to the direct current voltage signal output by the PWM signal conversion module 120 and the voltage signal of the light source, and the controller 110 adjusts the current output to the light source through the switch module 130 according to the feedback signal, so as to realize the adjustment of the brightness of the light source.

[0053] In the embodiment of the present application, the voltage adjustment module is used to adjust the voltage output to the light source, so that the output voltage meets the power demand of the light source; the PWM signal conversion module is used to convert the PWM signal into a stable direct current voltage signal which is not easily disturbed; the controller controls the switching circuit to adjust the current output to the light source according to the feedback signal of the feedback module, so as to realize the adjustment of the brightness of the light source. The present application can avoid the problem of light source flickering in the dimming process caused by unstable voltage or disturbed PWM, and improve the stability of light source display.

[0054] As shown in Figure 3 the embodiment, the light source is an LED, the controller 110 is an LED driving chip U1, the switching module 130 includes a MOS tube Q1 and a first resistor R7, and the voltage adjustment module 140 includes an inductor L.

[0055] The first signal end GATE of the controller U1 is connected with the gate of the MOS tube Q1, the source of the MOS tube Q1 is grounded through the first resistor R7, the drain of the MOS tube Q1 is connected with the second end of the inductor L and the first input end of the light source respectively, and the first end of the inductor L is connected with the power supply.

[0056] The power input end VIN of the controller U1 is connected with the power supply, the controller U1 is used to control the conduction and turn-off of the MOS tube Q1, so as to control the energy storage or release of the inductor L1, thereby adjusting the output voltage.

[0057] In the embodiment of the present application, the MOS tube Q1 is a PMOS tube.

[0058] The carrier of the PMOS tube is a hole, when the voltage of the gate relative to the source is negative and less than the threshold voltage, a P-type conductive channel will be formed between the source and the drain, so as to be turned on. The PMOS tube can be turned on at low level of the gate, and be turned off at high level, which can be used to realize the control of power on-off.

[0059] Specifically, when the controller U1 controls the MOS tube Q1 to be turned on, the inductor L1 in the loop stores energy, and when the controller U1 controls the MOS tube Q1 to be turned off, the inductor L1 in the loop releases the stored energy, so as to increase the voltage output to the light source, so that the voltage output to the light source can be higher than the input voltage VIN, thereby meeting the voltage use demand of the light source. The size of the voltage output to the light source can be determined according to the working voltage of the light source.

[0060] In the embodiment of the present application, the controller adjusts the current output to the light source by controlling the switching frequency or duty cycle of the MOS tube Q1, and at the same time, the controller controls the energy storage or release of the inductor by controlling the conduction and turn-off of the MOS tube, so as to adjust the voltage output to the light source, so that it meets the voltage use demand of the light source.

[0061] As Figure 3 shown, in one embodiment, the feedback module includes a second resistor R9, a third resistor R14 and a fourth resistor R5;

[0062] The second input end of the light source is connected with the first end of the second resistor R9 and the second end of the fourth resistor R5 respectively, the second signal end FB of the controller U1 is connected with the second end of the third resistor R14 and the first end of the fourth resistor R5 respectively, the output end of the PWM signal conversion module 120 is connected with the first end of the third resistor R14, and the second end of the second resistor R9 is grounded.

[0063] The second signal end FB can be a feedback signal input end of the controller U1, and the second signal end FB has a fixed reference voltage. The controller U1 compares the voltage of the second signal end FB with the reference voltage to adjust the output current of the current adjustment circuit.

[0064] In the embodiment of the application, the controller U1 can adjust the switching frequency or duty cycle of the MOS tube Q1 according to the voltage across the second resistor R9, thereby adjusting the output current.

[0065] The third resistor R14 and the fourth resistor R5 are used to divide the direct current voltage signal output by the PWM signal conversion module 120, thereby reducing the voltage output to the second resistor R9. The controller U1 can adjust the switching frequency or duty cycle of the MOS tube Q1 according to the voltage across the second resistor R9, thereby reducing the output current of the circuit.

[0066] In the embodiment of the application, the PWM signal conversion module 120 converts the PWM signal into a direct current voltage signal after receiving the PWM signal. When the PWM signal is different, the PWM signal conversion module 120 outputs different direct current voltage signals, and the voltage across the second resistor R9 is different. When the duty cycle of the PWM signal is greater, the voltage across the second resistor R9 is smaller, and the output current is smaller.

[0067] Specifically, assuming that the level of the PWM signal is 5V and the reference voltage of the second signal end of the controller U1 is 0.25V, when the duty cycle of the PWM signal is 0, the PWM signal conversion module 120 outputs 0V, the voltage across the second resistor R9 is maximum, and the controller U1 controls the switching of the MOS tube Q1 according to the voltage across the second resistor R9, so that the output current output to the light source is maximum. When the duty cycle of the PWM signal is 50%, the PWM signal conversion module 120 outputs a 2.5V voltage, and the direct current voltage signal is divided by the third resistor R14 and the fourth resistor R5, so that the voltage across the second resistor R9 is reduced. The controller U1 controls the switching of the MOS tube Q1 according to the voltage across the second resistor R9, so that the output current output to the light source is reduced.

[0068] In this embodiment, the output voltage is adjusted by controlling the switching on and off of the MOSFET using a controller, thereby regulating the energy storage and release of the inductor. Simultaneously, the PWM signal conversion module converts the PWM signal into a DC voltage signal. The controller controls the switching of the MOSFET based on the voltage across the second resistor, adjusting the output current to adjust the brightness of the light source. This avoids flickering of the light source during dimming due to voltage instability or PWM interference, thus improving the stability of the light source display.

[0069] In the above embodiments, the PWM signal conversion module 120 can be a single-stage RC filter circuit.

[0070] However, a single-stage RC filter circuit may not be able to completely filter out high-frequency components, resulting in noticeable ripples in the output voltage.

[0071] Therefore, as Figure 3 As shown, in a preferred embodiment, the PWM signal conversion module includes a fifth resistor R12, a sixth resistor R13, a first capacitor C4, and a second capacitor C5;

[0072] The second end of the fifth resistor R12 is connected to the first end of the sixth resistor R13 and the first end of the first capacitor, respectively. The second end of the sixth resistor R13 is connected to the first end of the third resistor R14 and the first end of the second capacitor C5, respectively. The second ends of the first capacitor C4 and the second ends of the second capacitor C5 are grounded.

[0073] In this embodiment, a two-stage RC filter circuit is formed by the fifth resistor, the sixth resistor, the first capacitor, and the second capacitor. Compared with a single-stage RC filter circuit, the two-stage RC filter circuit can more effectively suppress high-frequency noise, further reduce ripple in the output DC voltage, improve the filtering effect, and obtain a smoother DC voltage output.

[0074] like Figure 3 As shown, in one embodiment, the circuit further includes a third capacitor C3; the first terminal of the third capacitor C3 is connected to the second signal terminal of the controller U1, and the second terminal of the third capacitor C3 is grounded.

[0075] In this embodiment, a third capacitor is added between the second signal terminal of the controller and ground to smooth the feedback signal, reduce instability caused by noise and fluctuations, and improve the stability of the output.

[0076] like Figure 3 As shown, in one embodiment, the circuit further includes a diode D1; the positive terminal of the diode D1 is connected to the output terminal of the voltage adjustment module, and the negative terminal of the diode D1 is connected to the first input terminal of the light source.

[0077] When MOSFET Q1 is turned on, diode D1 is turned off, which can be used to prevent the inductor current from flowing in reverse and affecting the normal operation of the circuit. When MOSFET Q1 is turned off, diode D1 is turned on, and the inductor releases energy to supply power to the load through the diode.

[0078] In this embodiment, a diode is placed between the drain of the MOS transistor and the first input terminal of the light source. The unidirectional conduction characteristic of the diode is used to prevent the inductor current from flowing in reverse, thereby ensuring the normal operation of the circuit and guaranteeing its stable operation.

[0079] like Figure 3 As shown, in one embodiment, it further includes a first filter capacitor CE1 and a second filter capacitor CE2;

[0080] The first terminal of the first filter capacitor CE1 is connected to the power supply, and the second terminal of the first filter capacitor CE1 is grounded; the first terminal of the second filter capacitor CE2 is connected to the first input terminal of the light source, and the second terminal of the second filter capacitor CE2 is grounded.

[0081] The first filter capacitor CE1 and the second filter capacitor CE2 can be electrolytic capacitors.

[0082] Electrolytic capacitors typically have a larger capacitance than ordinary capacitors, allowing them to store more energy. At the same time, electrolytic capacitors can effectively filter out low-frequency ripple and noise in the power supply, making the output voltage more stable. Connecting electrolytic capacitors in parallel at the input and output terminals of the power supply can further smooth voltage fluctuations and provide a more stable power supply.

[0083] In this embodiment, by connecting a filter capacitor in parallel at the power input and output terminals, the quality of the input and output power signals is improved, thereby enhancing the stability of the power supply to the light source.

[0084] In one embodiment, the controller U1 may further include a third signal terminal CS; the third signal terminal CS is used to acquire the current signal in the circuit, and to monitor and control the output current based on the current signal.

[0085] like Figure 3 As shown, the circuit also includes a seventh resistor R2 and an eighth resistor R4; the first end of the seventh resistor R2 is connected to the second signal terminal FB of the controller U1, the second end of the seventh resistor R2 is connected to the first end of the eighth resistor R4 and the control signal input terminal of the switch module, and the second end of the eighth resistor R4 is connected to the third signal terminal CS of the controller U1 and the first end of the first resistor R7.

[0086] In the embodiment of the present application, the third signal end of the controller can adjust the duty cycle of the driving signal by detecting the voltage across the seventh resistor, thereby realizing control of the output current and preventing the output current from being too large to damage the element.

[0087] In one embodiment, the controller U1 can further include a fourth signal end OVP for protecting the controller U1 from damage when the voltage is abnormal.

[0088] As shown in Figure 3 The circuit further includes a ninth resistor R1 and a tenth resistor R11.

[0089] The first end of the ninth resistor R1 is connected to the first input end of the light source, the second end of the ninth resistor R1 is connected to the fourth signal end OVP of the controller U1 and the first end of the tenth resistor R11 respectively, and the second end of the tenth resistor R11 is grounded.

[0090] The controller U1 triggers the self-locking mode when the voltage detected by the fourth signal end OVP exceeds the target voltage.

[0091] The self-locking mode refers to a protection state of the chip under certain abnormal conditions, which can protect itself from damage to prevent further damage. The target voltage can be determined according to the specific controller U1.

[0092] In the embodiment of the present application, the controller determines whether the voltage of the light source output end exceeds the target voltage according to the signal of the fourth signal end, and triggers the self-locking mode of the controller when the voltage exceeds the target voltage, thereby realizing safety protection of the controller and improving the service life of the controller.

[0093] As shown in Figure 3 In one embodiment, the circuit further includes an eleventh resistor R6 and a third capacitor C2; the first end of the eleventh resistor R6 is connected to the loop compensation end COMP of the controller U1, the second end of the eleventh resistor R6 is connected to the first end of the third capacitor C2, and the second end of the third capacitor C2 is grounded.

[0094] The loop compensation end COMP can adjust the frequency response and phase characteristics of the boost loop by connecting a compensation network to realize compensation of the boost loop.

[0095] The eleventh resistor R6 and the third capacitor C2 can constitute a compensation network for adjusting the frequency response and phase characteristics of the loop.

[0096] The frequency response and phase characteristics of the control loop are adjusted by connecting the compensation network composed of the eleventh resistor R6 and the third capacitor C2 at the compensation end COMP in the embodiment of the application, so as to prevent the system from oscillating when the load changes or the input voltage fluctuates, and ensure the stability and fast response of the circuit.

[0097] Optionally, as shown in Figure 4 the PWM end of the controller U1 can be connected with the power supply through the resistor R3, and the circuit can further include the resistor R8 connected with the first resistor R7 in parallel and the resistor R10 connected with the second resistor R9 in parallel.

[0098] By connecting the resistor R8 with the first resistor R7 in parallel and the resistor R10 with the second resistor R9 in parallel, the circuit can withstand greater current and meet the power demand of the light source, and the reliability of the circuit can be improved, that is, even if one of the resistors fails, the circuit can still work normally and ensure the basic function of the circuit.

[0099] As shown in Figure 5 the embodiment of the application further provides a lighting module 200, which includes a light source 210 and the dimming circuit 220 as described in any of the above.

[0100] The lighting module of the embodiment of the application can be applied in a device with a motor, so that when the device starts the motor in the dimming process, the starting of the motor will not cause the flicker of the light source, and the stability of the lighting can be improved.

[0101] As shown in ​ the embodiment of the application further provides a clothes drying machine 300, which includes a light source 310 and the dimming circuit 320 as described in any of the above.

[0102] The clothes drying machine 300 of the embodiment of the application can include a motor, and when the clothes drying machine 300 starts the motor in the dimming process, the starting of the motor will not cause the flicker of the light source, and the stability of the light source display can be improved.

[0103] The utility model is not limited to the above-mentioned implementation, if various changes or deformation of the utility model do not deviate from the spirit and scope of the utility model, if these changes and deformation belong to the right claim and equivalent technical scope of the utility model, the utility model also intends to include these changes and deformation.

Claims

1. A dimming circuit, characterized by: It includes a controller, a PWM signal conversion module, a switching module, a voltage adjustment module, and a feedback module; the PWM signal conversion module is used to convert the PWM signal into a DC voltage signal. The first signal terminal of the controller is connected to the control signal input terminal of the switch module. The first terminal of the switch module is connected to the output terminal of the voltage adjustment module and the first input terminal of the light source. The input terminal of the voltage adjustment module is connected to the power supply. The second terminal of the switch module is grounded. The first terminal of the feedback module is connected to the output terminal of the PWM signal conversion module. The second terminal of the feedback module is connected to the second input terminal of the light source. The third terminal of the feedback module is connected to the second signal terminal of the controller.

2. The dimming circuit according to claim 1, characterized in that, The switching module includes a MOSFET and a first resistor; the voltage adjustment module includes an inductor. The first signal terminal of the controller is connected to the gate of the MOS transistor, the source of the MOS transistor is grounded through the first resistor, the drain of the MOS transistor is connected to the second terminal of the inductor and the first input terminal of the light source, and the first terminal of the inductor is connected to the power supply.

3. The dimming circuit according to claim 1, characterized in that, The feedback module includes a second resistor, a third resistor, and a fourth resistor; The second input terminal of the light source is connected to the first terminal of the second resistor and the second terminal of the fourth resistor, respectively. The second signal terminal of the controller is connected to the second terminal of the third resistor and the first terminal of the fourth resistor, respectively. The output terminal of the PWM signal conversion module is connected to the first terminal of the third resistor, and the second terminal of the second resistor is grounded.

4. The dimming circuit according to claim 1, characterized in that: The PWM signal conversion module includes a fifth resistor, a sixth resistor, a first capacitor, and a second capacitor; The second end of the fifth resistor is connected to the first end of the sixth resistor and the first end of the first capacitor, respectively. The second end of the sixth resistor is connected to the first end of the third resistor and the first end of the second capacitor, respectively. The second ends of the first capacitor and the second ends of the second capacitor are grounded.

5. The dimming circuit according to claim 1, characterized in that: It also includes a diode; the positive terminal of the diode is connected to the output terminal of the voltage adjustment module, and the negative terminal of the diode is connected to the first input terminal of the light source.

6. The dimming circuit according to claim 1, characterized in that: It also includes a first filter capacitor and a second filter capacitor; The first terminal of the first filter capacitor is connected to the power supply, and the second terminal of the first filter capacitor is grounded; the first terminal of the second filter capacitor is connected to the first input terminal of the light source, and the second terminal of the second filter capacitor is grounded.

7. The dimming circuit according to claim 1, characterized in that: It also includes a seventh resistor and an eighth resistor; the first end of the seventh resistor is connected to the second signal terminal of the controller, the second end of the seventh resistor is connected to the first end of the eighth resistor and the control signal input terminal of the switch module, and the second end of the eighth resistor is connected to the third signal terminal of the controller and the first end of the first resistor.

8. The dimming circuit according to claim 1, characterized in that, It also includes the ninth and tenth resistors; The first end of the ninth resistor is connected to the first input end of the light source, the second end of the ninth resistor is connected to the fourth signal end of the controller and the first end of the tenth resistor, and the second end of the tenth resistor is grounded.

9. A lighting module, characterized in that, Includes a light source and a dimming circuit as described in any one of claims 1-8.

10. A clothes drying rack, characterized in that, Includes a light source and a dimming circuit as described in any one of claims 1-8.

Images