LED light source breathing effect adjustment circuit and LED light source driving circuit

Abstract

LED light source breathing effect regulating circuit and LED light source driving circuit. The present invention relates to an LED light source breathing effect regulating circuit, characterized in that it includes a voltage ramp-up module, the voltage ramp-up module including: a first resistor including a first end and a second end relative to each other, the first end of the first resistor receiving a pulse width modulation signal to be processed; a first capacitor, the positive plate of the first capacitor being connected to the second end of the first resistor, and the negative plate of the first capacitor being grounded; an operational amplifier, the positive input end of the operational amplifier being connected to the second end of the first resistor and the positive plate of the first capacitor, and the output end of the operational amplifier being short-circuited with the negative input end of the operational amplifier. The present application increases the proportion of the low brightness segment of the LED light source in the entire breathing effect time period by setting a voltage ramp-up module, solves the problem of uneven overall brightness change process caused by the low proportion of the low brightness segment of the LED light source, and improves the overall perception of the breathing effect.

Description

Technical Field

[0001] The present invention relates to the field of vehicle electronic control, and in particular to an LED light source breathing effect regulating circuit and an LED light source driving circuit. Background Art

[0002] With the rapid development of LED technology, more and more LED light sources are replacing traditional ones. As we all know, LEDs offer many advantages as light sources, one of the greatest being their easily adjustable light tone. The so-called breathing effect refers to the ability of an LED light source to gradually change from bright to dim or dim to bright, under control of the device. This process has a distinct rhythm of on and off, similar to breathing. Currently, this breathing effect has been widely used in automotive LED light sources, not only providing lighting and decoration, but also enhancing the ambient atmosphere.

[0003] Currently, many low-power automotive LED lights have relatively simple functions. Due to significant cost pressures, most automotive LED light sources are driven using a linear control method. This method uses a body control module (BCM) to output a series of PWM signals whose duty cycle increases or decreases over time, creating a breathing effect for the LED light source. However, since car manufacturers rarely modify the PWM signals output by the BCM, and LED light sources are available in a wide variety of types and models, lamp manufacturers are forced to adjust and adapt the signals themselves to achieve the desired breathing effect, which is quite inconvenient. Summary of the Invention

[0004] Based on this, it is necessary to address the problems in the above background technology and provide an LED light source breathing effect adjustment circuit and an LED light source driving circuit that can be applicable to different types and models of LED light sources.

[0005] A first aspect of the present application provides an LED light source breathing effect adjustment circuit, including a voltage ramp-up module, the voltage ramp-up module including:

[0006] a first resistor comprising a first end and a second end opposite to each other, wherein the first end of the first resistor receives a pulse width modulation signal to be processed;

[0007] a first capacitor, wherein a positive plate of the first capacitor is connected to the second end of the first resistor, and a negative plate of the first capacitor is grounded;

[0008] an operational amplifier, wherein a positive input terminal of the operational amplifier is connected to the second end of the first resistor and the positive plate of the first capacitor, and an output terminal of the operational amplifier is short-circuited with a negative input terminal of the operational amplifier.

[0009] In the LED light source breathing effect adjustment circuit in the above embodiment, since the pulse width modulation signal to be processed is usually a square wave signal, there will be a sudden change at the rising edge, causing the breathing effect of the LED light source to appear bright or dim; in addition, since the luminous characteristics of the LED light source itself are not linear, under the drive of the pulse width modulation signal to be processed, it cannot show the ideal gradual brightening or dimming effect, but will quickly pass through the low brightness segment in the breathing effect and directly come to the high brightness segment. The low brightness segment of the breathing effect accounts for too low a proportion in the entire time period, resulting in an abrupt and uneven overall breathing effect. By allowing the pulse width modulation signal to be processed to pass through the first resistor to charge the first capacitor, the first resistor and the first capacitor form an RC charging circuit to achieve the purpose of slowly rising the voltage, so that the pulse width modulation signal to be processed is changed from a square wave signal to a ramp signal, thereby increasing the time proportion of the low brightness segment of the LED light source in the entire breathing effect time period, solving the problem of uneven overall brightness change process caused by the low time proportion of the low brightness segment of the LED light source, and improving the overall perception of the breathing effect. At the same time, the output voltage of the operational amplifier is fed back to the negative input terminal of the operational amplifier to form a follower, so that the waveform after the voltage rises slowly passes through the follower output of the operational amplifier, increasing the driving capability of the voltage rise module and enabling the voltage rise module to drive the linear drive circuit at the back end.

[0010] In one embodiment, the LED light source breathing effect adjustment circuit also includes a delay module, which is connected to the voltage ramp-up module and is used to adjust the duty cycle of the received first pulse width modulation signal to obtain a second pulse width modulation signal that is delayed by a preset time compared to the first pulse width modulation signal.

[0011] In the LED light source breathing effect adjustment circuit in the above embodiment, since the car manufacturer's BCM will emit a pulse width modulation signal with a fixed frequency and an increasing or decreasing duty cycle (depending on the gradually brightening effect or the gradually dimming effect), the duty cycle of the next gear larger than 0% is not necessarily 1%. Some OEMs use 6%. In other words, the duty cycle will suddenly change from 0% to 6%, and then gradually increase to 100%, or decrease from 100% to 6%, and then suddenly change to 0%. That is, there will be a sudden change process between the gears with different duty cycles, causing the breathing effect of the LED light source to appear bright or dim. By setting a delay module, the problem of the duty cycle of the first pulse width modulation signal jumping is avoided, so that its duty cycle can be slowly stepped, for example, from 0% to 1%, thereby avoiding the sudden brightening or dimming during the breathing effect, making the entire breathing effect smoother and more fluent.

[0012] In one embodiment, the LED light source breathing effect adjustment circuit further includes a constant voltage circuit, which is connected to the delay module and is used to convert the power supply voltage into the first pulse width modulation signal after constant voltage processing.

[0013] In the LED light source breathing effect adjustment circuit in the above embodiment, a constant voltage circuit is provided to reduce the high level voltage of the pulse width modulation signal waveform output by the BCM to a first pulse width modulation signal.

[0014] In one embodiment, the delay module includes:

[0015] a second resistor comprising a first end and a second end opposite to each other, wherein the first end of the second resistor receives the first pulse width modulation signal;

[0016] a second capacitor, wherein a positive plate of the second capacitor is connected to the second end of the second resistor;

[0017] a comparator, wherein a negative input terminal of the comparator is connected to the second end of the second resistor and the positive plate of the second capacitor;

[0018] a transistor, wherein the base of the transistor is connected to the output end of the comparator, the collector of the transistor is connected to the first pulse width modulation signal, and the emitter of the transistor is connected to the first resistor, and is configured to output the second pulse width modulation signal to the first resistor as the pulse width modulation signal to be processed;

[0019] a third resistor, comprising a first end and a second end opposite to each other, the first end of the third resistor being connected to the positive input terminal of the comparator, and the second end of the third resistor being grounded;

[0020] The fourth resistor includes a first end and a second end opposite to each other, the first end of the fourth resistor is connected to the positive input end of the comparator, and the second end of the fourth resistor is connected to the first pulse width modulation signal.

[0021] In the above embodiment, a second resistor and a second capacitor form an RC charging circuit. The third and fourth resistors are used to set a detection threshold. When the second capacitor is charged to the detection threshold, the comparator is activated, and the transistor is turned on, allowing the delay module to complete the delay function. Specifically, the values of the second resistor, the second capacitor, the third resistor, and the fourth resistor can be set according to actual needs to set a specific delay duration.

[0022] In one embodiment, the transistor includes an NPN transistor.

[0023] In one embodiment, the LED light source breathing effect adjustment circuit further includes:

[0024] The discharge module is connected to the delay module and the voltage ramp module, and is used to release the electric energy stored in the delay module and the voltage ramp module to reset the delay and integration.

[0025] In one embodiment, the discharge module includes:

[0026] a first diode, wherein an anode of the first diode is connected to the second end of the first resistor;

[0027] a fifth resistor, comprising a first end and a second end opposite to each other, the first end of the fifth resistor being connected to the cathode of the first diode and the power supply voltage, and the second end of the fifth resistor being grounded;

[0028] A second diode, wherein an anode of the second diode is connected to the second end of the second resistor, and a cathode of the second diode is connected to the power supply voltage and the first end of the fifth resistor.

[0029] In the LED light source breathing effect adjustment circuit in the above embodiment, when the pulse width modulation signal output by the BCM is a low-level signal, the first diode and the second diode in the discharge module are turned on to release the electrical energy stored in the first capacitor and the second capacitor, thereby resetting the delay and integration.

[0030] In one embodiment, the LED light source breathing effect adjustment circuit also includes a processing module, which is connected to the voltage ramp-up module, and is used to adjust the duty cycle of the received first pulse width modulation signal to obtain a second pulse width modulation signal delayed by a preset time compared to the first pulse width modulation signal, and transmit the second pulse width modulation signal to the voltage ramp-up module as the pulse width modulation signal to be processed.

[0031] In the LED light source breathing effect adjustment circuit in the above embodiment, the output of the DAC (digital-to-analog converter) is realized by using a processing module plus a simple RC filter, thereby saving costs.

[0032] In one embodiment, the processing module is further configured to reset when the first pulse width modulation signal is at a low level.

[0033] In the LED light source breathing effect adjustment circuit in the above embodiment, when the first pulse width modulation signal is at a low level, the processing module will be reset, so there is no need for the discharge module to perform delayed reset processing.

[0034] A second aspect of the present application provides an LED light source driving circuit, comprising the LED light source breathing effect adjustment circuit according to any one of the embodiments of the present application;

[0035] A linear drive circuit, wherein an input end of the linear drive circuit is connected to an output end of the operational amplifier.

[0036] In one embodiment, the linear drive circuit includes:

[0037] A linear output module, comprising a first input terminal and a second input terminal, wherein the first input terminal of the linear output module is connected to the output terminal of the operational amplifier;

[0038] An LED load, wherein an input end of the LED load is connected to an output end of the linear output module;

[0039] A load current feedback unit, wherein an input end of the load current feedback unit is connected to the LED load;

[0040] A load voltage feedback unit, wherein the input end of the load voltage feedback unit is connected to the output end of the load current feedback unit, and the output end of the load voltage feedback unit is connected to the linear output module.

[0041] In one embodiment, the linear output module further includes a third input terminal; the LED light source driving circuit further includes a power supply input module, and the power supply input terminal is connected to the third input terminal of the linear output module.

[0042] The above-mentioned LED light source breathing effect adjustment circuit and LED light source driving circuit can make the breathing effect process of the LED light source smooth and fluent, avoid the problem of flickering light or dark, and improve the overall appearance of the LED light source breathing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0044] Figures 1 to 4 This is a structural schematic diagram of the LED light source breathing effect adjustment circuit provided in some embodiments of the present application.

[0045] Figure 5 This is a schematic diagram of the structure of an LED light source driving circuit provided in one embodiment of the present application.

[0046] Figures 6 and 7 This is a circuit diagram of an LED light source breathing effect adjustment circuit provided in some embodiments of the present application.

[0047] Figure 8 This is a flowchart of the LED light source breathing effect adjustment circuit provided in one embodiment of the present application.

[0048] Description of reference numerals:

[0049] 1-LED light source breathing effect adjustment circuit, 10-voltage ramp-up module, 11-delay module, 12-constant voltage circuit, 13-discharge module, 2-LED light source drive circuit, 20-linear output module, 21-LED load, 22-load feedback current unit, 23-load feedback voltage unit, 24-power supply input module, 25-processing module. DETAILED DESCRIPTION

[0050] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0052] It will be understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor without departing from the scope of this application. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0053] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if there is transmission of electrical signals or data between the connected circuits, modules, units, etc.

[0054] As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include," "comprising," "having," and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Furthermore, the term "and / or" as used in this specification includes any and all combinations of the relevant listed items.

[0055] In one embodiment of the present application, Figure 1 As shown, a LED light source breathing effect regulating circuit 1 is provided, including a voltage ramp-up module 10, see Figure 6 The voltage ramp-up module 10 includes a first resistor R1, a first capacitor C1, and an operational amplifier U1A. The first resistor R1 includes a first end and a second end opposite to each other, and the first end of the first resistor R1 receives the pulse width modulation signal to be processed; the positive plate of the first capacitor C1 is connected to the second end of the first resistor R1, and the negative plate of the first capacitor C1 is grounded; the positive input terminal of the operational amplifier U1A is connected to the second end of the first resistor R1 and the positive plate of the first capacitor C1, and the output terminal of the operational amplifier U1A is short-circuited with the negative input terminal of the operational amplifier U1A.

[0056] Optionally, the output terminal of the operational amplifier U1A and the negative input terminal of the operational amplifier U1A may be directly short-circuited, or may be fed back to the negative input terminal through a resistor, which is not limited in the present application.

[0057] Specifically, in the LED light source breathing effect adjustment circuit 1 in the above embodiment, since the pulse width modulation signal to be processed is usually a square wave signal, there will be a sudden change at the rising edge, causing the breathing effect of the LED light source to appear bright or dim. In addition, since the luminous characteristics of the LED light source itself are not linear, under the drive of the pulse width modulation signal to be processed, it cannot show the ideal gradually brightening or dimming effect, but will quickly pass through the low brightness section of the breathing effect and directly enter the high brightness section. The low brightness section of the breathing effect accounts for too low a proportion of the entire time period, resulting in an abrupt and uneven overall breathing effect. By allowing the pulse width modulation signal to be processed to pass through the first resistor R1 to charge the first capacitor C1, the first resistor R1 and the first capacitor C1 form an RC charging circuit to achieve the purpose of slowly rising the voltage, so that the pulse width modulation signal to be processed is changed from a square wave signal to a ramp signal, thereby increasing the time proportion of the low brightness section of the LED light source in the entire breathing effect time period, solving the problem of uneven overall brightness change process caused by the low time proportion of the low brightness section of the LED light source, and improving the overall perception of the breathing effect. At the same time, the output voltage of the operational amplifier U1A is fed back to the negative input terminal of the operational amplifier U1A to form a follower, so that the waveform after the voltage rises slowly passes through the follower output of the operational amplifier U1A, increasing the driving capability of the voltage rise module 10, so that the voltage rise module 10 can drive the linear driving circuit at the back end.

[0058] Furthermore, in the LED light source breathing effect adjustment circuit 1 provided in one embodiment of the present application, as Figure 2As shown, it also includes a delay module 11, which is connected to the voltage ramp-up module 10 and is used to adjust the duty cycle of the received first pulse width modulation signal to obtain a second pulse width modulation signal that is delayed by a preset time compared to the first pulse width modulation signal.

[0059] For details, please refer to Figure 6 In one embodiment of the present application, the delay module 11 includes a second resistor R2, a second capacitor C2, a comparator U1B, a transistor Q1, a third resistor R3, and a fourth resistor R4. The second resistor R2 includes a first end and a second end opposite to each other, the first end of the second resistor R2 receiving the first pulse width modulated signal; the positive plate of the second capacitor C2 is connected to the second end of the second resistor; the negative input end of the comparator U1B is connected to the second end of the second resistor R2 and the positive plate of the second capacitor C1; the base of the transistor Q1 is connected to the output end of the comparator U1B, the collector of the transistor Q1 is connected to the first pulse width modulated signal, and the emitter of the transistor Q1 is connected to the first resistor R1, for outputting the second pulse width modulated signal to the first resistor R1 as the to-be-processed pulse width modulated signal; the third resistor R3 includes a first end and a second end opposite to each other, the first end of the third resistor R3 is connected to the positive input end of the comparator U1B, and the second end of the third resistor R3 is grounded; the fourth resistor R4 includes a first end and a second end opposite to each other, the first end of the fourth resistor R4 is connected to the positive input end of the comparator U1B, and the second end of the fourth resistor R4 is connected to the first pulse width modulated signal.

[0060] Optionally, the transistor Q1 includes an NPN transistor.

[0061] Specifically, in the LED light source breathing effect adjustment circuit 1 in the above embodiment, an RC charging circuit is formed by the second resistor R2 and the second capacitor C2, and the third resistor R3 and the fourth resistor R4 are used to set the detection threshold. When the second capacitor C2 is charged to the detection threshold, the comparator is activated, and the transistor is turned on at this time, so that the delay module completes the delay function.

[0062] Optionally, the preset time can be adaptively adjusted artificially according to the duty cycle of the pulse width modulation signal itself emitted by the BCM and the ideal duty cycle step speed. Specifically, the sizes of the second resistor R2, the second capacitor C2, the third resistor R3 and the fourth resistor R4 can be set according to actual needs to set a specific delay duration, that is, the delay duration can be set according to the sizes of the second resistor R2, the second capacitor C2, the third resistor R3 and the fourth resistor R4.

[0063] Specifically, in the LED light source breathing effect adjustment circuit 1 in the above embodiment, since the car manufacturer's BCM will send a pulse width modulation signal with a fixed frequency and an increasing or decreasing duty cycle (depending on the gradually brightening effect or the gradually dimming effect), the duty cycle of the next gear larger than 0% is not necessarily 1%. Some main manufacturers use 6%. In other words, the duty cycle will suddenly change from 0% to 6%, and then gradually increase to 100%, or decrease from 100% to 6%, and then suddenly change to 0%. That is, there will be a sudden change process between gears with different duty cycles, causing the breathing effect of the LED light source to appear bright or dim. By setting a delay module, the problem of the duty cycle of the first pulse width modulation signal jumping is avoided, so that its duty cycle can be slowly stepped, for example, from 0% to 1%, thereby avoiding the sudden brightening or dimming during the breathing effect, making the entire breathing effect smoother and more fluent.

[0064] Furthermore, in the LED light source breathing effect adjustment circuit 1 provided in one embodiment of the present application, as Figure 3 As shown, a constant voltage circuit 12 is further included. The constant voltage circuit 12 is connected to the delay module 11 and is used to convert the power supply voltage into the first pulse width modulation signal after constant voltage processing.

[0065] Specifically, in the LED light source breathing effect adjustment circuit 1 in the above embodiment, a constant voltage circuit 13 is provided to reduce the high level voltage of the pulse width modulation signal waveform output by the BCM to a first pulse width modulation signal.

[0066] Optionally, when the delay module 11 is not set in the LED light source breathing effect adjustment circuit 1, the constant voltage circuit 12 can be directly connected to the voltage ramp-up module 10. This application does not limit the connection method between the constant voltage circuit and the voltage ramp-up module or the delay module.

[0067] Furthermore, in the LED light source breathing effect adjustment circuit 1 provided in one embodiment of the present application, as Figure 4 As shown, it also includes a discharge module 13, which is connected to the delay module 11 and the voltage ramp-up module 10, and is used to release the electric energy stored in the delay module 11 and the voltage ramp-up module 10 to achieve the reset of the delay and integration.

[0068] Specifically, in the discharge module 13 provided in one embodiment of the present application, please continue to refer to Figure 6, including a first diode D1, a fifth resistor R5, and a second diode D2. The anode of the first diode D1 is connected to the second end of the second resistor R2; the fifth resistor R5 includes a first end and a second end opposite to each other, the first end of the fifth resistor R5 being connected to the cathode of the first diode D1 and a power supply voltage, and the second end of the fifth resistor R5 being grounded; the anode of the second diode D2 is connected to the second end of the second resistor R2, and the cathode of the second diode D2 is connected to the power supply voltage and the first end of the fifth resistor R5.

[0069] Specifically, in the LED light source breathing effect adjustment circuit 1 in the above embodiment, when the pulse width modulation signal output by the BCM is a low-level signal, the first diode D1 and the second diode D2 in the discharge module 13 are turned on to release the electric energy stored in the first capacitor C1 and the second capacitor C2, thereby achieving the reset of the delay and integration.

[0070] In another embodiment, Figure 7 As shown, the LED light source breathing effect adjustment circuit 1 also includes a processing module 25, which is connected to the voltage ramp-up module 10 and is used to adjust the duty cycle of the received first pulse width modulation signal to obtain a second pulse width modulation signal delayed by a preset time compared to the first pulse width modulation signal, and transmit the second pulse width modulation signal to the voltage ramp-up module 10 as the pulse width modulation signal to be processed.

[0071] Specifically, in the LED light source breathing effect adjustment circuit 1 in the above embodiment, the output of the DAC (digital-to-analog conversion circuit) is realized by using a processing module plus a simple RC filter, thereby saving costs.

[0072] Optionally, the processing module 1 may be an MCU (single-chip microcomputer). The present application does not limit the type of the processing module 1 and may include any existing MCU that can implement the above functions.

[0073] Furthermore, the processing module 25 provided in an embodiment of the present application is further configured to perform a reset when the first pulse width modulation signal is at a low level.

[0074] Specifically, in the LED light source breathing effect adjustment circuit 1 in the above embodiment, when the first pulse width modulation signal is at a low level, the processing module 25 will be reset, so there is no need for the discharge module to perform delayed reset processing.

[0075] Optionally, the processing module 25 includes an input end, a first output end, a second output end and a third output end, and the third output end is an ADC (analog-to-digital converter) output end; the input end of the processing module 25 is connected to the output end of the constant voltage circuit, the first output end of the processing module 25 is connected to the first end of the first resistor R1, the second output end of the processing module 25 is connected to the positive plate of the first capacitor C1, and the third output end of the processing module 25 is connected to the negative input end of the operational amplifier U1A; the processing module 25 is also used to perform feedback monitoring on the voltage ramp module 10, control the slope of the voltage ramp, and prevent voltage overshoot.

[0076] For details, please refer to Figure 8 The working process of the LED light source breathing effect adjustment circuit 1 provided in one embodiment of the present application is as follows:

[0077] S1: When the first pulse width modulation signal changes from a low level to a high level, the processing module 25 starts;

[0078] S2: Discharge the first capacitor C1 and start delay timing;

[0079] S3: The delay is completed and the discharge of the first capacitor C1 stops;

[0080] S4: The processing module 25 outputs a second pulse width modulation signal;

[0081] S5: Feedback monitoring of Vout is performed through the ADC, and the processing module 25 is adjusted;

[0082] S6: The voltage is gradually increased, the output of the constant processing module 25 is constant, and the output voltage is stabilized.

[0083] Specifically, in the LED light source breathing effect adjustment circuit 1 in the above embodiment, by setting an ADC to perform feedback monitoring on Vout, the processing module 25 is prevented from outputting an excessively high voltage, and at the same time, the control accuracy is improved.

[0084] In another embodiment of the present application, an LED light source driving circuit is provided, comprising an LED light source breathing effect adjustment circuit 1 according to any embodiment of the present application; and a linear driving circuit 2, wherein the input end of the linear driving circuit 2 is connected to the output end of the operational amplifier U1A.

[0085] Specifically, in one embodiment of the present application, in the LED light source driving circuit provided, as Figure 5As shown, it includes a linear output module 20, an LED load 21, a load current feedback unit 22, and a load voltage feedback unit 23. The linear output module 20 includes a first input terminal and a second input terminal. The first input terminal of the linear output module 20 is connected to the output terminal of the operational amplifier U1A; the input terminal of the LED load 21 is connected to the output terminal of the linear output module 20; the input terminal of the load current feedback unit 22 is connected to the LED load 21; the input terminal of the load voltage feedback unit 23 is connected to the output terminal of the load current feedback unit 22, and the output terminal of the load voltage feedback unit 23 is connected to the linear output module 20.

[0086] Specifically, in one of the embodiments of the present application, the LED light source driving circuit is provided. Figure 5 , the linear output module 20 also includes a third input terminal; the LED light source driving circuit also includes a power supply input module 24, the power supply input terminal 24 is connected to the third input terminal of the linear output module 20.

[0087] The LED light source driving circuit in the above embodiment can make the breathing effect of the LED light source smooth and fluent, avoid the problem of flickering light or dark, and improve the overall appearance of the LED light source breathing effect.

[0088] In the description of this specification, reference to the terms "one embodiment" or "another embodiment" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0089] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0090] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A LED light source breathing effect adjustment circuit, characterized in that: Including constant voltage circuit, delay module, voltage ramp-up module and discharge module, The delay module is connected to the voltage ramp module and is used to adjust the duty cycle of the received first pulse width modulation signal to obtain a second pulse width modulation signal that is delayed by a preset time compared to the first pulse width modulation signal; The constant voltage circuit is connected to the delay module and is used to convert the power supply voltage into the first pulse width modulation signal after constant voltage processing; The discharge module is connected to the delay module and the voltage ramp module, and is used to release the electric energy stored in the delay module and the voltage ramp module to reset the delay and integration; The voltage ramp-up module includes: a first resistor comprising a first end and a second end opposite to each other, wherein the first end of the first resistor receives a pulse width modulation signal to be processed; a first capacitor, wherein a positive plate of the first capacitor is connected to the second end of the first resistor, and a negative plate of the first capacitor is grounded; the pulse width modulated signal to be processed passes through the first resistor to charge the first capacitor, and the first resistor and the first capacitor form an RC charging circuit, so that the pulse width modulated signal to be processed is converted from a square wave signal to a ramp signal; an operational amplifier, wherein a positive input terminal of the operational amplifier is connected to the second end of the first resistor and the positive plate of the first capacitor, and an output terminal of the operational amplifier is short-circuited with a negative input terminal of the operational amplifier.

2. The LED light source breathing effect adjustment circuit according to claim 1, characterized in that: The delay module includes: a second resistor comprising a first end and a second end opposite to each other, wherein the first end of the second resistor receives the first pulse width modulation signal; a second capacitor, wherein a positive plate of the second capacitor is connected to the second end of the second resistor; a comparator, wherein a negative input terminal of the comparator is connected to the second end of the second resistor and the positive plate of the second capacitor; a transistor, wherein the base of the transistor is connected to the output end of the comparator, the collector of the transistor is connected to the first pulse width modulation signal, and the emitter of the transistor is connected to the first resistor, and is configured to output the second pulse width modulation signal to the first resistor as the pulse width modulation signal to be processed; a third resistor, comprising a first end and a second end opposite to each other, the first end of the third resistor being connected to the positive input terminal of the comparator, and the second end of the third resistor being grounded; The fourth resistor includes a first end and a second end opposite to each other, the first end of the fourth resistor is connected to the positive input end of the comparator, and the second end of the fourth resistor is connected to the first pulse width modulation signal.

3. The LED light source breathing effect adjustment circuit according to claim 2, characterized in that: The discharge module includes: a first diode, wherein an anode of the first diode is connected to the second end of the first resistor; a fifth resistor, comprising a first end and a second end opposite to each other, the first end of the fifth resistor being connected to the cathode of the first diode and the power supply voltage, and the second end of the fifth resistor being grounded; A second diode, wherein an anode of the second diode is connected to the second end of the second resistor, and a cathode of the second diode is connected to the power supply voltage and the first end of the fifth resistor.

4. An LED light source driving circuit, characterized in that: include: The LED light source breathing effect adjustment circuit according to any one of claims 1 to 3; A linear drive circuit, wherein the input end of the linear drive circuit is connected to the output end of the operational amplifier.

5. The LED light source driving circuit according to claim 4, characterized in that: The linear drive circuit comprises: A linear output module, comprising a first input terminal and a second input terminal, wherein the first input terminal of the linear output module is connected to the output terminal of the operational amplifier; An LED load, wherein an input end of the LED load is connected to an output end of the linear output module; A load current feedback unit, wherein an input end of the load current feedback unit is connected to the LED load; A load voltage feedback unit, wherein the input end of the load voltage feedback unit is connected to the output end of the load current feedback unit, and the output end of the load voltage feedback unit is connected to the linear output module.

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