Multi-mode dimming and toning power supply based on PWM (Pulse Width Modulation)

Abstract

The invention provides a multi-mode dimming and toning power supply based on PWM. The multi-mode dimming and toning power supply comprises an EMI and rectification filter circuit used for rectifying a power supply into pulsating direct-current voltage and outputting the pulsating direct-current voltage to a tangential signal input circuit; the tangential signal input circuit is used for converting a pulsating DC voltage signal into a first PWM signal and outputting the first PWM signal to the signal processing circuit; the signal processing circuit is used for converting the first PWM signal into a direct-current voltage signal and outputting a second PWM signal to the main control circuit; the main control circuit is used for judging a current access signal, and if the current access signal is a phase-cut dimming signal, outputting a corresponding first PWM dimming signal to the dimming circuit according to the size of the direct-current voltage signal; and if the color temperature data signal is a phase-cut carrier color temperature adjusting signal, performing signal processing and outputting a corresponding second PWM dimming signal to the dimming circuit according to the color temperature data signal. According to the invention, a multi-mode dimming and color-adjusting power supply is realized through phase-cut signal input or dual-analog signal input, and the effects of improving dimming and color-adjusting precision, improving adaptability and compatibility and realizing intelligent control are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply, and in particular to a PWM-based multi-mode dimming and color adjustment power supply. Background Art

[0002] With the development of intelligent lighting, PWM dimming has become a more convenient, efficient and safer dimming method compared to traditional linear dimming and thyristor dimming power supplies for brightness adjustment. However, these existing dimming power supplies still have the following disadvantages: 1. Dimming power supplies generally have only a single fixed dimming frequency or a single dimming curve, and the dimming accuracy of linear dimmers is relatively low; 2. The dimming function is also relatively simple, and most methods such as thyristor dimming and 0-10V analog signal can only perform ordinary dimming, which cannot meet the user's needs for brightness adjustment and color temperature adjustment at the same time; 3. Due to the wide variety of functions of existing dimming power supplies, the adaptability and compatibility of dimming power supplies are low. Dimmers of different brands and models may not be fully compatible, resulting in unsatisfactory dimming effects. This will bring many inconveniences to users' actual use or increase the user's use costs.

[0003] Therefore, there is an urgent need for a PWM dimming power supply that can realize dimming and color adjustment functions and has high flexibility and compatibility. Summary of the invention

[0004] In order to solve the common problems in the prior art, the purpose of the present invention is to provide a multi-mode dimming and color adjustment power supply based on PWM. The present invention realizes a multi-mode dimming and color adjustment power supply by phase-cutting signal input or dual analog signal input and adding a human-computer interaction module, thereby achieving the effect of improving dimming and color adjustment accuracy, improving adaptability and compatibility and enabling intelligent control.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions: A PWM-based multi-mode dimming and color adjustment power supply includes a power conversion circuit, wherein the power conversion circuit is used to convert an input power supply voltage into a working power supply voltage of a load, and further includes: EMI and rectification and filtering circuit, phase-cut signal input circuit, signal processing circuit, main control circuit, dimming circuit, the EMI and rectification and filtering circuit input power supply, used to filter out high-frequency interference signals in the power supply, and rectify the power supply into a pulsating DC voltage and output it to the phase-cut signal input circuit; the phase-cut signal input circuit is used to convert the pulsating DC voltage signal into a first PWM signal and output it to the signal processing circuit; the signal processing circuit is used to convert the first PWM signal into a DC voltage signal and output it to the first input end of the main control circuit, and output a second PWM signal to the second input end of the main control circuit after filtering; the main control circuit is used to determine whether the current access signal is a phase-cut dimming signal or a phase-cut carrier color temperature adjustment signal according to the state of the second PWM signal, and if it is a phase-cut dimming signal, output the corresponding first PWM dimming signal to the dimming circuit according to the size of the DC voltage signal, so as to realize the dimming function of the load; if it is a phase-cut carrier color temperature adjustment signal, perform signal processing and output the corresponding second PWM dimming signal to the dimming circuit according to the color temperature data signal, so as to realize the color temperature adjustment function of the load.

[0006] Among them, the third input terminal and the fourth input terminal of the main control circuit respectively input the first analog signal and the second analog signal, and the main control circuit is used to output the corresponding first PWM dimming signal to the dimming circuit according to the size of the first analog signal, so as to realize the dimming function of the load; or obtain the color temperature span value according to the second analog signal, and output the second PWM dimming signal with the corresponding duty cycle in different color temperature channels according to the color temperature span value, so as to realize the color temperature adjustment function of the load.

[0007] According to a PWM-based multi-mode dimming and color adjustment power supply provided by the present invention, the phase-cutting signal input circuit includes a first voltage-dividing circuit, a first transistor, an optocoupler, a second voltage-dividing circuit and a second transistor. The first voltage-dividing circuit is used to divide the pulsating DC voltage and output it to the first transistor. The collector of the first transistor is connected to the input end of the optocoupler, and the output end of the optocoupler is connected to the base of the second transistor. The second transistor is connected to a DC voltage through the second voltage-dividing circuit, and its collector outputs the first PWM signal with an amplitude value equal to the DC voltage value.

[0008] According to a PWM-based multi-mode dimming and color adjustment power supply provided by the present invention, the signal processing circuit includes a third voltage-dividing circuit, a second-order low-pass filtering circuit and an RC filtering circuit. The first PWM signal is output to the second-order low-pass filtering circuit after being divided by the third voltage-dividing circuit. The second-order low-pass filtering circuit is used to output the DC voltage signal; the RC filtering circuit is used to filter the first PWM signal to output the second PWM signal.

[0009] According to a PWM-based multi-mode dimming and color adjusting power supply provided by the present invention, when the main control circuit detects that the second PWM signal contains only one PWM waveform in each cycle, and the PWM waveform consists of only a high level and a low level, it is determined that the second PWM signal is the phase-cut dimming signal.

[0010] When the main control circuit detects that the second PWM signal includes two PWM waveforms of different sizes in each cycle, it determines that the second PWM signal is the phase-cut carrier color temperature modulation signal; wherein the second PWM signal includes a carrier color temperature modulation symbol signal issued by a phase-cut carrier controller.

[0011] According to a PWM-based multi-mode dimming and color adjustment power supply provided by the present invention, the main control circuit is preset with a maximum value and a minimum value of a dimming signal, and the first PWM dimming signal with a corresponding duty cycle is output by comparing the DC voltage signal with the preset value, including: When the DC voltage signal is greater than or equal to the maximum value of the dimming signal, the first PWM dimming signal with a duty cycle of 100% is output.

[0012] When the DC voltage signal is less than or equal to the minimum value of the dimming signal, the first PWM dimming signal with a duty cycle of 0% is output.

[0013] When the DC voltage signal is between the maximum value and the minimum value of the dimming signal, the duty cycle of the first PWM dimming signal is:

[0014] Wherein, TD is the DC voltage signal value, MAX is the maximum value of the dimming signal, and MIN is the minimum value of the dimming signal.

[0015] According to a PWM-based multi-mode dimming and color adjustment power supply provided by the present invention, the dimming circuit includes a driving circuit and a MOS tube, and the driving circuit is used to drive the MOS tube to operate according to the first PWM dimming signal to achieve dimming.

[0016] At least two dimming circuits are included. When in the color temperature adjustment mode, one of the dimming circuits is defined as a cold light channel and the other dimming circuit is defined as a warm light channel. At this time, the PWM values ​​of the two channels are complementary.

[0017] According to a PWM-based multi-mode dimming and color adjustment power supply provided by the present invention, the duty cycle of the second PWM dimming signal output by the main control circuit to the cold light channel is:

[0018] in, is the target color temperature value, is the minimum color temperature value, is the maximum color temperature value.

[0019] The duty cycle of the second PWM dimming signal output by the main control circuit to the warm light channel is:

[0020] The color temperature adjustment function of the load is achieved by adjusting the duty cycle of the PWM dimming signal input to the two dimming circuits.

[0021] According to a PWM-based multi-mode dimming and color-adjusting power supply provided by the present invention, the main control circuit reads the carrier color temperature code element signal emitted by the phase-cut carrier controller, identifies the corresponding code element signal and decodes it, and adjusts the value of the second PWM dimming signal output to the two dimming circuits according to the color temperature data carried in the code element signal.

[0022] According to a PWM-based multi-mode dimming and color adjustment power supply provided by the present invention, the color temperature span value of the minimum unit signal is obtained according to the voltage range of the second analog signal and the color temperature range of the load lamp, and the total color temperature span value is obtained by multiplying the color temperature span value and the input second analog signal value, so that the duty cycle of the second PWM dimming signal input to the two dimming circuits is adjusted respectively according to the total color temperature span value to achieve the color temperature adjustment function of the load.

[0023] A PWM-based multi-mode dimming and color-adjusting power supply provided according to the present invention also includes a human-computer interaction module, which is connected to the main control circuit and is used to perform parameterized adjustment on the dimming and color-adjusting power supply to achieve customized parameter settings for dimming frequency, color temperature, dimming curve and power output function.

[0024] It can be seen that compared with the prior art, the present invention has the following beneficial effects: 1. The present invention outputs a PWM signal through the phase-cut signal input circuit, and the signal is a phase-cut chopping signal or a phase-cut carrier signal. The signal processing circuit is used to further process the signal into a DC voltage signal TD and another more stable PWM signal TFS, so that the main control circuit can judge whether the current access signal is a phase-cut dimming signal or a phase-cut carrier color temperature signal through the state of the PWM signal TFS, thereby adjusting the duty cycle of the output PWM dimming signal to achieve dimming or color adjustment through the phase-cut input signal; at the same time, the main control circuit also realizes dual analog signal control dimming or color adjustment by inputting two analog signals. Compared with the traditional single dimming mode, the multi-mode dimming and color adjustment power supply of the present invention can have the dimming and color adjustment functions of the lamp in different modes, and can adopt different modes according to different usage requirements, with a wider range of applications and more flexible dimming and color adjustment.

[0025] 2. The present invention uses a single-chip microcomputer to process the input PWM signal TFS and the DC voltage signal TD, and realizes smooth adjustment of different brightness levels by setting the maximum and minimum dimming values ​​and outputting the PWM dimming signal with the corresponding duty cycle according to the ratio of the DC voltage signal TD and the DC voltage signal TD; the precise color adjustment effect is achieved by analyzing and processing the carrier color temperature code element signal. Compared with the traditional dimming method, it can realize precise dimming and color adjustment, high adjustment efficiency and intelligent control.

[0026] 3. The present invention can significantly reduce the impact of input electromagnetic interference on the dimming and color-adjusting power supply through EMI, rectification and filtering circuits and power factor correction circuits, and can also prevent the dimming and color-adjusting power supply itself from becoming an electromagnetic interference source and emitting interference signals to the outside; at the same time, it can improve the power factor of the power supply, thereby reducing the generation of power supply harmonic components, further reducing the interference of the power supply to the input network, making the dimming and color-adjusting power supply more adaptable to more diversified input environments, and improving the market competitiveness of the product.

[0027] 4. The present invention realizes flexible adjustment of the output voltage of the power supply by adding a voltage fine-tuning circuit to adapt to the dimming needs in different usage scenarios. For example, it can be applied to the situation where the voltage drop obtained at the tail end of the lamp or light strip is too large due to the long output wiring of the power supply, resulting in insufficient brightness and inconsistent brightness; when the power supply is installed outdoors or in a place where it is inconvenient to connect an external dimmer, the output voltage of the power supply can also be adjusted through the voltage fine-tuning circuit to achieve the adjustment of different brightness of the lamp. Compared with the traditional solution of dimming only by a dimmer, the dimming power supply of the present invention can be applied to lamps of various voltage levels without the need for a dimmer, thereby improving the adaptability and compatibility of the dimming and color-adjusting power supply.

[0028] 5. The present invention can realize parameterized adjustment of dimming and color-adjusting power supply through the human-computer interaction module. The traditional single fixed dimming can realize customized parameter setting of dimming frequency, color temperature, dimming curve and power output function, which is convenient for users to adjust the power supply to the corresponding functional mode according to the actual use demand environment, with high flexibility and compatibility; at the same time, it can greatly reduce the user's use cost.

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of an embodiment of a PWM-based multi-mode dimming and color adjustment power supply of the present invention.

[0031] Figure 2 The present invention is a circuit diagram of a PWM-based multi-mode dimming and color adjustment power supply embodiment.

[0032] Figure 3 It is a schematic diagram of a voltage fine-tuning circuit in an embodiment of a PWM-based multi-mode dimming and color-adjusting power supply of the present invention.

[0033] Figure 4 It is a schematic diagram of a main control circuit in an embodiment of a PWM-based multi-mode dimming and color adjustment power supply of the present invention.

[0034] Figure 5 It is a schematic diagram of a PWM signal waveform of phase-cut chopping signal dimming in an embodiment of a PWM-based multi-mode dimming and color-adjusting power supply of the present invention.

[0035] Figure 6 It is a schematic diagram of a PWM signal waveform for phase-cut carrier color adjustment in an embodiment of a PWM-based multi-mode dimming and color adjustment power supply of the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] See also Figure 1 The present invention provides a PWM-based multi-mode dimming and color adjustment power supply, including a power conversion circuit, wherein the power conversion circuit is used to convert an input power supply voltage into a working power supply voltage of a load, and further includes: EMI and rectification and filtering circuit 20, phase-cutting signal input circuit 30, signal processing circuit 40, main control circuit 50, dimming circuit 60, EMI and rectification and filtering circuit 20 input power supply, used to filter out high-frequency interference signals in the power supply, and rectify the power supply into a pulsating DC voltage output to the phase-cutting signal input circuit 30; the phase-cutting signal input circuit 30 is used to convert the pulsating DC voltage signal TD into a first PWM signal and output it to the signal processing circuit 40; the signal processing circuit 40 is used to convert the first PWM signal into a DC voltage signal TD and output it to the first The main control circuit 50 is used to determine whether the current access signal is a phase-cut dimming signal or a phase-cut carrier color temperature adjustment signal according to the state of the second PWM signal TFS. If it is a phase-cut dimming signal, the main control circuit 50 outputs a corresponding first PWM dimming signal to the dimming circuit 60 according to the size of the DC voltage signal TD, so as to realize the dimming function of the load; if it is a phase-cut carrier color temperature adjustment signal, the main control circuit 50 performs signal processing and outputs a corresponding second PWM dimming signal to the dimming circuit 60 according to the color temperature data signal, so as to realize the color temperature adjustment function of the load.

[0039] Among them, the third input terminal and the fourth input terminal of the main control circuit 50 respectively input the first analog signal and the second analog signal, and the main control circuit 50 is used to output the corresponding first PWM dimming signal to the dimming circuit 60 according to the size of the first analog signal, so as to realize the dimming function of the load; or obtain the color temperature span value according to the second analog signal, and output the second PWM dimming signal of the corresponding duty cycle in different color temperature channels according to the color temperature span value, so as to realize the color temperature adjustment function of the load.

[0040] Specifically, the EMI and rectification and filtering circuit 20 of this embodiment includes an EMI filtering circuit and a rectification and filtering circuit. The EMI filtering circuit is used to filter out high-frequency interference signals in the power supply, so that sensitive devices inside the power supply are protected from the influence of high-frequency interference signals. For example, when the switch device works in a high-frequency on-off state, the high-frequency rapid transient process will generate an electromagnetic disturbance (EMD) source, which can be filtered out by an EMI filtering circuit composed of capacitors, inductors, etc., while also preventing the power supply from becoming an external interference source to ensure the normal operation of the equipment. The rectification and filtering circuit uses a diode rectification method to rectify the AC into a pulsating DC.

[0041] Specifically, the above-mentioned EMI and rectification and filtering circuit 20 in this embodiment is only exemplary and not the only way. For example, the EMI and rectification and filtering circuit 20 can adopt an integrated control circuit to filter the interference electromagnetic waves generated in the equipment, while also being able to accurately control the key parameters in the circuit to ensure efficient and stable operation of the circuit, thereby improving signal quality.

[0042] Specifically, the power conversion circuit of this embodiment includes a power factor correction circuit 11 and a DC / DC conversion circuit 12. The power factor correction circuit 11 is connected to the output end of the EMI and rectification and filtering circuit 20, and is used to adjust the working state of the circuit by detecting the phase and waveform of the input pulsating DC voltage and its current, so as to reduce the phase difference between the two, thereby improving the power factor of the power supply, achieving the effect of reducing harmonic generation and improving energy utilization; at the same time, the pulsating DC voltage is rectified and filtered twice to ensure that a more stable and smooth DC voltage is provided to the subsequent DC / DC conversion circuit 12, thereby further optimizing the efficiency and performance of the power supply. The DC / DC conversion circuit 12 adopts a feedback control mode, which is used to convert the DC voltage after secondary rectification into the working power supply voltage required by the connected load lamp according to the preset parameters of the internal voltage feedback control loop.

[0043] See also Figure 3 Specifically, the present embodiment further includes a voltage fine-tuning circuit 13, which is connected to the output end of the DC / DC conversion circuit 12 and is used to set the feedback parameter of the voltage feedback control loop. The voltage fine-tuning circuit 13 uses an adjustable device to adjust the feedback parameter, such as a potentiometer RP1, which is connected to the voltage feedback control loop, and the feedback parameter is changed by adjusting the potentiometer RP1.

[0044] See also Figure 2In this embodiment, the phase-cutting signal input circuit 30 includes a first voltage-dividing circuit, a first transistor Q1, an optocoupler U1, a second voltage-dividing circuit and a second transistor Q2. The first voltage-dividing circuit is used to divide the pulsating DC voltage and output it to the first transistor Q1. The collector of the first transistor Q1 is connected to the input end of the optocoupler U1, and the output end of the optocoupler U1 is connected to the base of the second transistor Q2. The second transistor Q2 is connected to a DC voltage through the second voltage-dividing circuit, and its collector outputs the first PWM signal with an amplitude value equal to the DC voltage value.

[0045] Specifically, the first voltage divider circuit of the present embodiment includes resistors R1 and R2, and the EMI and rectification and filtering circuit 20 rectifies the AC power supply through diodes D1 and D2 to output the pulsating DC voltage, which is connected to the base of the first transistor Q1 through the resistor R1, and the resistor R2 is connected in parallel between the base and the emitter of the first transistor Q1. The resistors R1 and R2 are used to divide the pulsating DC voltage. When the voltage drop across the resistor R2 is greater than the conduction voltage between the base and the emitter of the first transistor Q1, the first transistor Q1 is in a saturated conduction state; when the voltage drop across the resistor R2 is less than the conduction voltage between the base and the emitter of the first transistor Q1, the first transistor Q1 is in a cut-off state, and its collector outputs a PWM signal.

[0046] Specifically, the optocoupler U1 of this embodiment is used for photoelectric isolation, and the positive electrode of the light-emitting diode at its input end is connected to the power supply VDD through the resistor R3, and its negative electrode is grounded through the first transistor Q1; the first output end of the photosensitive transistor at its output end is connected to the base of the second transistor Q2, and its second output end is grounded.

[0047] Specifically, the second voltage divider circuit of this embodiment includes resistors R4 and R5. The collector of the second transistor Q2 is connected to the 3.3V DC voltage through the resistor R5, the base thereof is connected to the 3.3V DC voltage through the resistor R4, and the emitter thereof is grounded.

[0048] Among them, when the first transistor Q1 is in the on state, the power supply VDD flows through the resistor R3, the light-emitting diode of the optocoupler U1 and the first transistor Q1 to the ground GND in sequence, at which time the phototransistor of the optocoupler U1 is turned on, and the 3.3V DC voltage flows to the base of the second transistor Q2 through the bias resistor R4, and at the same time flows through the phototransistor of the optocoupler U1 to the ground GNS, at which time the base voltage of the second transistor Q2 is pulled down to 0V, and the second transistor Q2 is in the off state. At the same time, the 3.3V DC voltage flows to the collector of the second transistor Q2 through the current limiting resistor R5, and at this time the collector of the second transistor Q2 outputs a high level.

[0049] When the first transistor Q1 is in the cut-off state, the photosensitive transistor of the optocoupler U1 is not turned on, and the 3.3V DC voltage flows to the base of the second transistor Q2 through the bias resistor R4. At this time, the base of the second transistor Q2 outputs a high level, and the second transistor Q2 is turned on. At the same time, the 3.3V DC voltage flows to the collector of the second transistor Q2 through the current limiting resistor R5 and the emitter is grounded. The collector voltage of the second transistor Q2 is pulled down to 0V, and the collector of the transistor Q2 outputs a low level. At this time, the collector of the second transistor Q2 outputs a first PWM signal with a voltage amplitude value of 3.3V.

[0050] In this embodiment, the signal processing circuit 40 includes a third voltage-dividing circuit, a second-order low-pass filtering circuit and an RC filtering circuit. The first PWM signal is output to the second-order low-pass filtering circuit after being divided by the third voltage-dividing circuit. The second-order low-pass filtering circuit is used to output a DC voltage signal TD; the RC filtering circuit is used to filter the first PWM signal to output a second PWM signal TFS.

[0051] Specifically, the third voltage divider circuit in this embodiment is composed of a resistor R8 connected in parallel between the collector and the emitter of the second transistor Q2. The second-order low-pass filter circuit is composed of two first-order RC filters in cascade, including a resistor R9, a capacitor C2, resistors R10, R11 and a capacitor C3. The resistor R9 and the capacitor C2 constitute a pre-stage filter. After the first PWM signal is divided by the resistor R8, it is connected to the capacitor C2 through the resistor R9, and its cut-off frequency is:

[0052] in, is the resistance value of resistor R9, is the value of capacitor C2.

[0053] Resistors R10, R11 and capacitor C3 form a post-stage filter. The voltage signal output by the pre-stage filter is connected to capacitor C3 through resistor R10. Resistor R11 is connected in parallel across capacitor C3. Its cut-off frequency is:

[0054] in, is the equivalent resistance value of the connection between resistors R10, R11 and capacitor C3 in the circuit, is the value of capacitor C3.

[0055] From the above, it can be seen that the total cutoff rate of the second-order low-pass filter circuit is:

[0056] It can be seen that the second-order low-pass filter circuit can significantly reduce the voltage ripple of the first PWM signal, thereby obtaining a smooth DC voltage signal TD.

[0057] Specifically, the RC filter circuit of this embodiment includes a resistor R6 and a capacitor C1. The resistor R6 and the capacitor C1 are connected in series and then in parallel between the collector and the emitter of the second transistor Q2. The second PWM signal TFS is output to the main control circuit 50 from the common connection point of the resistor R6 and the capacitor C1.

[0058] See also Figure 4 Specifically, the main control circuit 50 of this embodiment includes a single-chip microcomputer U3 and its peripheral circuits. The two detection interfaces of the single-chip microcomputer U3 are respectively connected to the DC voltage signal TD and the second PWM signal TFS, and respectively output the second PWM dimming signal to the two dimming circuits 60.

[0059] See also Figure 5 In this embodiment, when the main control circuit 50 detects that the second PWM signal TFS contains only one PWM waveform in each cycle, and the PWM waveform consists of only a high level and a low level, the second PWM signal is determined to be the phase-cut dimming signal. In one cycle T, it contains only a single PWM square wave consisting of a high level T1 and a low level T2.

[0060] See also Figure 6 When the main control circuit 50 detects that the second PWM signal TFS contains two PWM waveforms of different sizes in each cycle, it is determined that the second PWM signal is the phase-cut carrier color temperature modulation signal; wherein the second PWM signal TFS contains the carrier color temperature modulation symbol signal issued by the phase-cut carrier controller. Referring to the figure, in one cycle T, it contains a large PWM square wave composed of a high level T3 and a low level T4, and a small PWM square wave composed of a high level T5 and a low level T6, wherein T5 is the carrier color temperature modulation symbol signal issued by the phase-cut carrier controller.

[0061] In this embodiment, the main control circuit 50 presets a maximum value and a minimum value of the dimming signal, and outputs the first PWM dimming signal with a corresponding duty cycle by comparing the DC voltage signal TD with the preset value, including: When the DC voltage signal TD is greater than or equal to the maximum value of the dimming signal, the first PWM dimming signal with a duty cycle of 100% is output.

[0062] When the DC voltage signal TD is less than or equal to the minimum value of the dimming signal, the first PWM dimming signal with a duty cycle of 0% is output.

[0063] When the DC voltage signal TD is between the maximum value and the minimum value of the dimming signal, the duty cycle of the first PWM dimming signal is:

[0064] Wherein, TD is the TD value of the DC voltage signal, MAX is the maximum value of the dimming signal, and MIN is the minimum value of the dimming signal.

[0065] In this embodiment, the dimming circuit 60 includes a driving circuit and a MOS tube, and the driving circuit is used to drive the MOS tube to operate according to the first PWM dimming signal to achieve dimming.

[0066] At least two dimming circuits 60 are included. When in the color temperature adjustment mode, one of the dimming circuits 60 is defined as a cold light channel, and the other dimming circuit 60 is defined as a warm light channel. At this time, the PWM values ​​of the two channels are complementary.

[0067] Specifically, the circuit structures of the two dimming circuits 60 in this embodiment are consistent, and include a MOS tube driving circuit 1, a MOS tube driving circuit 2, a first MOS tube Q3, and a second MOS tube Q4, respectively, wherein the sum of the duty cycles of the PWM dimming signals of the two channels is 100%.

[0068] Specifically, in this embodiment, when the first PWM dimming signal with a duty cycle of 100% is input, the MOS tube driving circuit 1 and the MOS tube driving circuit 2 respectively drive the first MOS tube Q3 and the second MOS tube Q4 to be fully turned on, the dimming power supply reaches the maximum output, and the brightness of the load lamp reaches the brightest state; when the first PWM dimming signal with a duty cycle of 0% is input, the MOS tube driving circuit 1 and the MOS tube driving circuit 2 respectively drive the first MOS tube Q3 and the second MOS tube Q4 to be completely cut off, the dimming power supply has no output, and the load lamp is not bright; as the duty cycle of the first PWM dimming signal increases, the brightness of the load lamp increases, and vice versa.

[0069] In this embodiment, the duty cycle of the second PWM dimming signal output by the main control circuit 50 to the cold light channel is:

[0070] in, is the target color temperature value, is the minimum color temperature value, is the maximum color temperature value.

[0071] The duty cycle of the second PWM dimming signal output by the main control circuit 50 to the warm light channel is:

[0072] The color temperature adjustment function of the load is achieved by adjusting the duty cycle of the PWM dimming signal input to the two dimming circuits 60 .

[0073] In this embodiment, the main control circuit 50 reads the carrier color temperature code element signal emitted by the phase-cut carrier controller, identifies the corresponding code element signal and decodes it, and adjusts the value of the second PWM dimming signal output to the two dimming circuits 60 according to the color temperature data carried in the code element signal.

[0074] Specifically, each data frame of the carrier color temperature modulation symbol signal in this embodiment includes multiple symbol signals. When the detected symbol signal T5 is in a high level state, it is counted as 1, and when it is in a low level, it is counted as 0. The single-chip microcomputer U3 combines the multiple symbol signals to restore the frame data, and parses the color temperature data defined in the frame data. Taking the adjustment of the color temperature range of 2700K~6500K as an example, when the single-chip microcomputer U3 receives the target color temperature frame data of 3000K in the color temperature data, the duty cycle of the second PWM dimming signal output to the cold light channel is:

[0075] The duty cycle of the second PWM dimming signal output to the warm light channel is:

[0076] The above embodiments are merely exemplary, and the duty cycle of the PWM dimming signal of other color temperature values ​​may be adjusted in the above manner according to actual needs.

[0077] Specifically, in addition to the above-mentioned dimming or color adjustment mode controlled by the phase-cut input signal, this embodiment also includes controlling the dimming or color adjustment mode by dual analog signals. The first analog signal and the second analog signal are input to the detection pin of the single-chip microcomputer U3. The single-chip microcomputer U3 compares the first analog signal with its preset maximum and minimum values ​​of the dimming signal, thereby outputting the first PWM dimming signal of the corresponding duty cycle. The process is similar to the above-mentioned phase-cut input signal control dimming mode, and will not be repeated here.

[0078] In this embodiment, the color temperature span value of the minimum unit signal is obtained according to the voltage range of the second analog signal and the color temperature range of the load lamp, and the total color temperature span value is obtained by multiplying the color temperature span value and the input second analog signal value. The duty cycle of the second PWM dimming signal input to the two dimming circuits 60 is adjusted according to the total color temperature span value to achieve the color temperature adjustment function of the load.

[0079] Specifically, the color temperature span value of the minimum unit signal in this embodiment is:

[0080] in, is the maximum input value of the second analog signal, is the minimum input value of the second analog signal.

[0081] Specifically, this embodiment takes the second analog signal with an input range of 0-10V as an example. When the color temperature range is adjusted to 3000K-7000K, the color temperature span value of the minimum unit signal is:

[0082] When the input second analog signal value is 2.3V, the total span of color temperature to be adjusted is:

[0083] That is, the target color temperature value of the load lamp at this time is: 3000K+920K=3920K. According to the calculation formula of the duty cycle of the second PWM dimming signal, the duty cycle of the second PWM dimming signal output by the microcontroller U3 to the cold light channel can be obtained as:

[0084] Then the duty cycle of the second PWM dimming signal output to the warm light channel is:

[0085] In this embodiment, a human-computer interaction module 70 is also included. The human-computer interaction module 70 is connected to the main control circuit 50 and is used to perform parameterized adjustment on the dimming and color adjustment power supply to achieve customized parameter settings for dimming frequency, color temperature, dimming curve and power output function.

[0086] Specifically, the human-computer interaction module 70 of this embodiment can be connected to the single-chip computer U3 by means of NFC circuit, gear switch, key control circuit, touch panel, etc. to perform human-computer interaction, so as to realize parameter setting. For example, when the gear switch is used, when it is necessary to set the dimming curve output by the dimming power supply, the dimming curve currently output by the dimming power supply can be changed by simply turning the gear switch to the gear position where the output curve parameters have been preset. For example, the dimming curve output by the dimming power supply can be customized by using a key control circuit or a touch panel; similarly, the dimming frequency, color temperature or color can also be adjusted through the human-computer interaction interface.

[0087] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above 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.

[0088] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A PWM-based multi-mode dimming and color adjustment power supply, comprising a power conversion circuit, wherein the power conversion circuit is used to convert an input power supply voltage into a working power supply voltage of a load, characterized in that: Also includes: EMI and rectification and filtering circuit, phase-cut signal input circuit, signal processing circuit, main control circuit, dimming circuit, the EMI and rectification and filtering circuit input power supply, used to filter out high-frequency interference signals in the power supply, and rectify the power supply into a pulsating DC voltage and output it to the phase-cut signal input circuit; the phase-cut signal input circuit is used to convert the pulsating DC voltage signal into a first PWM signal and output it to the signal processing circuit; the signal processing circuit is used to convert the first PWM signal into a DC voltage signal and output it to the first input end of the main control circuit, and output the second PWM signal to the second input end of the main control circuit after filtering; the main control circuit is used to determine whether the current access signal is a phase-cut dimming signal or a phase-cut carrier color temperature adjustment signal according to the state of the second PWM signal, and if it is a phase-cut dimming signal, output the corresponding first PWM dimming signal to the dimming circuit according to the size of the DC voltage signal, so as to realize the dimming function of the load; if it is a phase-cut carrier color temperature adjustment signal, perform signal processing and output the corresponding second PWM dimming signal to the dimming circuit according to the color temperature data signal, so as to realize the color temperature adjustment function of the load; Among them, the third input terminal and the fourth input terminal of the main control circuit respectively input the first analog signal and the second analog signal, and the main control circuit is used to output the first PWM dimming signal with a corresponding duty cycle to the dimming circuit according to the size of the first analog signal, so as to realize the dimming function of the load; or obtain the color temperature span value according to the second analog signal, and output the second PWM dimming signal with a corresponding duty cycle in different color temperature channels according to the color temperature span value, so as to realize the color temperature adjustment function of the load.

2. The PWM-based multi-mode dimming and color adjustment power supply according to claim 1, characterized in that: The phase-cutting signal input circuit includes a first voltage-dividing circuit, a first transistor, an optocoupler, a second voltage-dividing circuit and a second transistor. The first voltage-dividing circuit is used to divide the pulsating DC voltage and output it to the first transistor. The collector of the first transistor is connected to the input end of the optocoupler, and the output end of the optocoupler is connected to the base of the second transistor. The second transistor is connected to a DC voltage through the second voltage-dividing circuit, and its collector outputs the first PWM signal with an amplitude value equal to the DC voltage value.

3. The PWM-based multi-mode dimming and color adjustment power supply according to claim 2, characterized in that: The signal processing circuit includes a third voltage-dividing circuit, a second-order low-pass filtering circuit and an RC filtering circuit. The first PWM signal is output to the second-order low-pass filtering circuit after being divided by the third voltage-dividing circuit. The second-order low-pass filtering circuit is used to output the DC voltage signal. The RC filtering circuit is used to filter the first PWM signal and output the second PWM signal.

4. The PWM-based multi-mode dimming and color adjustment power supply according to claim 1, characterized in that: When the main control circuit detects that the second PWM signal contains only one PWM waveform in each cycle, and the PWM waveform consists of only a high level and a low level, it is determined that the second PWM signal is the phase-cut dimming signal; When the main control circuit detects that the second PWM signal includes two PWM waveforms of different sizes in each cycle, it determines that the second PWM signal is the phase-cut carrier color temperature modulation signal; wherein the second PWM signal includes a carrier color temperature modulation symbol signal issued by a phase-cut carrier controller.

5. The PWM-based multi-mode dimming and color adjustment power supply according to claim 4, characterized in that: The main control circuit is preset with a maximum value and a minimum value of the dimming signal, and outputs the first PWM dimming signal with a corresponding duty cycle by comparing the DC voltage signal with the preset value, including: When the DC voltage signal is greater than or equal to the maximum value of the dimming signal, outputting the first PWM dimming signal with a duty cycle of 100%; When the DC voltage signal is less than or equal to the minimum value of the dimming signal, outputting the first PWM dimming signal with a duty cycle of 0%; When the DC voltage signal is between the maximum value and the minimum value of the dimming signal, the duty cycle of the first PWM dimming signal is: Wherein, TD is the DC voltage signal value, MAX is the maximum value of the dimming signal, and MIN is the minimum value of the dimming signal.

6. The PWM-based multi-mode dimming and color adjustment power supply according to claim 4, characterized in that: The dimming circuit comprises a driving circuit and a MOS tube, wherein the driving circuit is used to drive the MOS tube to realize dimming according to the first PWM dimming signal; At least two dimming circuits are included. When in the color temperature adjustment mode, one of the dimming circuits is defined as a cold light channel and the other dimming circuit is defined as a warm light channel. At this time, the PWM values ​​of the two channels are complementary.

7. The PWM-based multi-mode dimming and color adjustment power supply according to claim 6, characterized in that: The duty cycle of the second PWM dimming signal output by the main control circuit to the cold light channel is: in, is the target color temperature value, is the minimum color temperature value, is the maximum color temperature value; The duty cycle of the second PWM dimming signal output by the main control circuit to the warm light channel is: The color temperature adjustment function of the load is achieved by adjusting the PWM ratio of the two dimming circuits.

8. The PWM-based multi-mode dimming and color adjustment power supply according to claim 7, characterized in that: The main control circuit reads the carrier color temperature code element signal sent by the phase-cut carrier controller, identifies the corresponding code element signal and decodes it, and adjusts the value of the second PWM dimming signal output to the two dimming circuits according to the color temperature data carried in the code element signal.

9. The PWM-based multi-mode dimming and color adjustment power supply according to claim 7, characterized in that: The color temperature span value of the minimum unit signal is obtained according to the voltage range of the second analog signal and the color temperature range of the load lamp, and the total color temperature span value is obtained by multiplying the color temperature span value and the input second analog signal value, so as to adjust the duty cycle of the second PWM dimming signal input to the two dimming circuits according to the total color temperature span value, so as to realize the color temperature adjustment function of the load.

10. The PWM-based multi-mode dimming and color adjustment power supply according to any one of claims 1 to 9, characterized in that: It also includes a human-computer interaction module, which is connected to the main control circuit and is used to perform parameterized adjustment on the dimming and color-adjusting power supply to achieve customized parameter settings for dimming frequency, color temperature, dimming curve and power output function.

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