A multi-mode dimming and color adjustment power supply based on PWM

Abstract

The present invention provides a PWM-based multi-mode dimming and color-adjusting power supply, comprising an EMI and rectifier filter circuit for rectifying a power supply into a pulsating DC voltage output to a tangential signal input circuit; a tangential signal input circuit for converting the pulsating DC voltage signal into a first PWM signal output to a signal processing circuit; a signal processing circuit for converting the first PWM signal into a DC voltage signal and outputting a second PWM signal to a main control circuit; and a main control circuit for determining the current access signal. If it is a phase-cut dimming signal, the main control circuit outputs a corresponding first PWM dimming signal to the dimming circuit based on the magnitude of the DC voltage signal; if it is a phase-cut carrier color temperature adjustment signal, the main control circuit performs signal processing and outputs a corresponding second PWM dimming signal to the dimming circuit based on the color temperature data signal. The present invention implements a multi-mode dimming and color-adjusting power supply through phase-cut signal input or dual analog signal input, thereby improving dimming and color adjustment accuracy, enhancing adaptability and compatibility, and enabling intelligent control.

Description

Technical Field

[0001] The present invention relates to the technical field of power supplies, 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 drivers for brightness adjustment. However, these existing dimming drivers still have the following disadvantages:

[0003] 1. Dimming drivers generally have only a single fixed dimming frequency or a single dimming curve, and the dimming accuracy of linear dimmers is relatively low;

[0004] 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;

[0005] 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 their usage costs.

[0006] 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

[0007] 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 invention realizes a multi-mode dimming and color adjustment power supply by inputting a phase-cut signal or a dual analog signal and adding a human-computer interaction module, thereby achieving the effect of improving the dimming and color adjustment accuracy, improving adaptability and compatibility, and enabling intelligent control.

[0008] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0009] 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 voltage into an operating power voltage of a load, and further includes:

[0010] An EMI and rectification and filtering circuit, a phase-cut signal input circuit, a signal processing circuit, a main control circuit, and a dimming circuit. The EMI and rectification and filtering circuit inputs a power supply, is used to filter out high-frequency interference signals in the power supply, and rectifies the power supply into a pulsating DC voltage, which is output 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, which is output to the signal processing circuit. The signal processing circuit is used to convert the first PWM signal into a DC voltage signal, which is output to a first input terminal of the main control circuit, and output a second PWM signal after filtering to a second input terminal of the main control circuit. The main control circuit is used to determine, based on the state of the second PWM signal, whether the current input signal is a phase-cut dimming signal or a phase-cut carrier color temperature adjustment signal. If the current input signal is a phase-cut dimming signal, the main control circuit outputs a corresponding first PWM dimming signal to the dimming circuit based on the magnitude of the DC voltage signal to implement a dimming function for the load. If the current input signal is a phase-cut carrier color temperature adjustment signal, the main control circuit performs signal processing and outputs a corresponding second PWM dimming signal to the dimming circuit based on a color temperature data signal to implement a color temperature adjustment function for the load.

[0011] The third input terminal and the fourth input terminal of the main control circuit respectively input a first analog signal and a second analog signal. The main control circuit is configured to output a corresponding first PWM dimming signal to the dimming circuit according to the magnitude of the first analog signal, so as to implement a dimming function for the load; or obtain a color temperature span value according to the second analog signal, and output the second PWM dimming signals with corresponding duty cycles in different color temperature channels according to the color temperature span value, so as to implement a color temperature adjustment function for the load.

[0012] 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 equal to the DC voltage value.

[0013] 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 divider circuit, a second-order low-pass filter circuit, and an RC filter circuit. The first PWM signal is divided by the third voltage divider circuit and then output to the second-order low-pass filter circuit. The second-order low-pass filter circuit is used to output the DC voltage signal; the RC filter circuit is used to filter the first PWM signal to output the second PWM signal.

[0014] According to a PWM-based multi-mode dimming and color adjustment 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.

[0015] 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 adjustment signal; wherein the second PWM signal includes a carrier color temperature adjustment code element signal issued by a phase-cut carrier controller.

[0016] 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 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:

[0017] 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.

[0018] 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.

[0019] When the DC voltage signal is between the maximum value and the minimum value of the dimming signal, the duty cycle of the output first PWM dimming signal is:

[0020]

[0021] 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.

[0022] 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 achieve dimming according to the first PWM dimming signal.

[0023] 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.

[0024] 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:

[0025]

[0026] in, is the target color temperature value, is the lowest color temperature value, is the maximum color temperature value.

[0027] The duty cycle of the second PWM dimming signal output by the main control circuit to the warm light channel is:

[0028]

[0029] 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.

[0030] According to a PWM-based multi-mode dimming and color adjustment power supply provided by the present invention, the main control circuit reads the carrier color temperature adjustment code element signal emitted by the phase-cut carrier controller, identifies and decodes the corresponding code element signal, 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.

[0031] 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 based on the voltage range of the second analog signal and the color temperature range of the load lamp. The total color temperature span value is obtained by multiplying the color temperature span value by the input second analog signal value. The duty cycle of the second PWM dimming signal input to the two dimming circuits is adjusted according to the total color temperature span value to achieve the color temperature adjustment function of the load.

[0032] According to the present invention, a PWM-based multi-mode dimming and color-adjusting power supply further 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.

[0033] It can be seen that compared with the prior art, the present invention has the following beneficial effects:

[0034] 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 determine whether the current access signal is a phase-cut dimming signal or a phase-cut carrier color temperature adjustment 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 functions of dimming and color adjustment of lamps 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.

[0035] 2. The present invention uses a single-chip microcomputer to process the input PWM signal TFS and DC voltage signal TD, and achieves smooth adjustment of different brightness levels by setting maximum and minimum dimming values and outputting a PWM dimming signal with a corresponding duty cycle based on the ratio of the DC voltage signal TD to them. The present invention also achieves precise color adjustment by analyzing and processing the carrier color temperature code element signal. Compared with traditional dimming methods, this method can achieve precise dimming and color adjustment, high adjustment efficiency and intelligent control.

[0036] 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 on 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.

[0037] 4. The present invention achieves flexible adjustment of the power supply's output voltage by adding a voltage fine-tuning circuit to adapt to dimming needs in different usage scenarios. For example, it can be applied when the power supply output wiring is too long, causing an excessive voltage drop at the end of the lamp or light strip, resulting in insufficient brightness or inconsistent brightness. When the power supply is installed outdoors or in a place where it is inconvenient to connect an external dimmer, the voltage fine-tuning circuit can also be used to adjust the power supply's output voltage to achieve different brightness settings for the lamp. Compared to traditional solutions that rely solely on dimmers for dimming, the dimming power supply of the present invention can be used with 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.

[0038] 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.

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] 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.

[0041] Figure 2 This is a circuit diagram of an embodiment of a PWM-based multi-mode dimming and color adjustment power supply of the present invention.

[0042] Figure 3 This 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.

[0043] Figure 4 This is a schematic diagram of the main control circuit in an embodiment of a PWM-based multi-mode dimming and color adjustment power supply of the present invention.

[0044] Figure 5 The figure is a schematic diagram of the PWM signal waveform of the phase-cut chopping signal dimming in the embodiment of the PWM-based multi-mode dimming and color adjustment power supply of the present invention.

[0045] Figure 6 This 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

[0046] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0047] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0048] 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 voltage into a working power voltage of a load, and further includes:

[0049] EMI and rectification and filtering circuit 20, phase-cut 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, for filtering out high-frequency interference signals in the power supply, and rectifying the power supply into a pulsating DC voltage output to the phase-cut signal input circuit 30; the phase-cut signal input circuit 30 is used to convert the pulsating DC voltage signal 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 input of the main control circuit 50. The main control circuit 50 is configured to output a second PWM signal TFS to a second input terminal of the main control circuit 50 after filtering. The main control circuit 50 is configured to determine, based on the state of the second PWM signal TFS, whether the current access signal is a phase-cut dimming signal or a phase-cut carrier color temperature adjustment signal. 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 based on the magnitude of the DC voltage signal TD, thereby implementing a dimming function for 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 based on the color temperature data signal, thereby implementing a color temperature adjustment function for the load.

[0050] 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. The main control circuit 50 is used to output the corresponding first PWM dimming signal to the dimming circuit 60 according to the magnitude 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 signals with corresponding duty cycles in different color temperature channels according to the color temperature span value, so as to realize the color temperature adjustment function of the load.

[0051] 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 from the power supply, protecting sensitive components within the power supply from the effects of high-frequency interference signals. For example, when a switching device operates in a high-frequency on-off state, the high-frequency rapid transient process generates an electromagnetic disturbance (EMD) source. The EMI filtering circuit, composed of capacitors and inductors, can filter out this interference and prevent the power supply from becoming a source of external interference, ensuring the normal operation of the device. The rectification and filtering circuit uses diode rectification to rectify AC power into pulsating DC power.

[0052] 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 ensure the efficient and stable operation of the circuit by precisely controlling the key parameters in the circuit, thereby improving the signal quality.

[0053] 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 operating state of the circuit by detecting the phase and waveform of the input pulsating DC voltage and its current to reduce the phase difference between the two, thereby improving the power factor of the power supply, reducing harmonic generation, and improving energy utilization. At the same time, the pulsating DC voltage is subjected to secondary rectification and filtering 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, and is used to convert the secondary rectified DC voltage into the operating power supply voltage required by the connected load lamp according to the preset parameters of the internal voltage feedback control loop.

[0054] See also Figure 3 Specifically, this embodiment further includes a voltage fine-tuning circuit 13, which is connected to the output terminal of the DC / DC converter 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. The feedback parameter is changed by adjusting the potentiometer RP1.

[0055] 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 having an amplitude equal to the DC voltage.

[0056] Specifically, in this embodiment, the first voltage divider circuit includes resistors R1 and R2. The EMI and rectifier filter circuit 20 rectifies the AC power supply via diodes D1 and D2 to output the pulsating DC voltage. The voltage is connected to the base of the first transistor Q1 via resistor R1, and resistor R2 is connected in parallel between the base and emitter of the first transistor Q1. Resistors R1 and R2 are used to divide the pulsating DC voltage. When the voltage drop across resistor R2 is greater than the base-emitter voltage of the first transistor Q1, the first transistor Q1 is in a saturated conduction state. When the voltage drop across resistor R2 is less than the base-emitter voltage of the first transistor Q1, the first transistor Q1 is in a cutoff state, and its collector outputs a PWM signal.

[0057] Specifically, the optocoupler U1 of this embodiment is used for photoelectric isolation. 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.

[0058] Specifically, the second voltage divider circuit in this embodiment includes resistors R4 and R5. The collector of the second transistor Q2 is connected to a 3.3V DC voltage through the resistor R5, the base of the second transistor Q2 is connected to a 3.3V DC voltage through the resistor R4, and the emitter of the second transistor Q2 is grounded.

[0059] When the first transistor Q1 is in the on state, the power supply VDD flows sequentially through the resistor R3, the light-emitting diode of the optocoupler U1, and the first transistor Q1 to the ground GND. At this 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. At the same time, it flows through the phototransistor of the optocoupler U1 to the ground GNS. At this 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 through the current-limiting resistor R5 to the collector of the second transistor Q2, and the collector of the second transistor Q2 outputs a high level.

[0060] When the first transistor Q1 is in the off state, the phototransistor of the optocoupler U1 is not conducting, and the 3.3V DC voltage flows through the bias resistor R4 to the base of the second transistor Q2. 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 through the current-limiting resistor R5 to the collector of the second transistor Q2, 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 of 3.3V.

[0061] 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 divided by the third voltage-dividing circuit and then output to the second-order low-pass filtering 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.

[0062] Specifically, the third voltage divider circuit in this embodiment is formed by a resistor R8 connected in parallel between the collector and emitter of the second transistor Q2. The second-order low-pass filter circuit is formed by 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. Its cutoff frequency is:

[0063]

[0064] in, is the resistance value of resistor R9, is the value of capacitor C2.

[0065] 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 cutoff frequency is:

[0066]

[0067] 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.

[0068] From the above, it can be seen that the total cutoff rate of the second-order low-pass filter circuit is:

[0069]

[0070] 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.

[0071] 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 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.

[0072] 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.

[0073] 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, then 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.

[0074] See also Figure 6 When the main control circuit 50 detects that the second PWM signal TFS contains two PWM waveforms of different magnitudes within each cycle, it determines that the second PWM signal is the phase-cut carrier color temperature modulation signal. The second PWM signal TFS includes the carrier color temperature modulation symbol signal emitted by the phase-cut carrier controller. As shown in the figure, within a cycle T, the second PWM signal TFS includes a large PWM square wave consisting of a high level T3 and a low level T4, and a small PWM square wave consisting of a high level T5 and a low level T6. T5 is the carrier color temperature modulation symbol signal emitted by the phase-cut carrier controller.

[0075] 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 values, including:

[0076] 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.

[0077] 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.

[0078] When the DC voltage signal TD is between the maximum value and the minimum value of the dimming signal, the duty cycle of the output first PWM dimming signal is:

[0079]

[0080] Wherein, TD is the DC voltage signal TD value, MAX is the maximum value of the dimming signal, and MIN is the minimum value of the dimming signal.

[0081] In this embodiment, the dimming circuit 60 includes a driving circuit and a MOS transistor. The driving circuit is configured to drive the MOS transistor to operate according to the first PWM dimming signal to implement dimming.

[0082] 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.

[0083] Specifically, the circuit structures of the two dimming circuits 60 in this embodiment are consistent, including a MOS transistor driving circuit 1, a MOS transistor driving circuit 2, a first MOS transistor Q3, and a second MOS transistor Q4, respectively. The sum of the duty cycles of the PWM dimming signals of the two channels is 100%.

[0084] Specifically, in this embodiment, when the first PWM dimming signal with a duty cycle of 100% is input, the MOS transistor driving circuit 1 and the MOS transistor driving circuit 2 respectively drive the first MOS transistor Q3 and the second MOS transistor 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 transistor driving circuit 1 and the MOS transistor driving circuit 2 respectively drive the first MOS transistor Q3 and the second MOS transistor Q4 to be fully turned off, the dimming power supply has no output, and the load lamp does not light up; as the duty cycle of the first PWM dimming signal increases, the brightness of the load lamp increases, and vice versa.

[0085] 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:

[0086]

[0087] in, is the target color temperature value, is the lowest color temperature value, is the maximum color temperature value.

[0088] The duty cycle of the second PWM dimming signal output by the main control circuit 50 to the warm light channel is:

[0089]

[0090] 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 .

[0091] 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.

[0092] Specifically, each data frame of the carrier color temperature modulation symbol signal described 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 state, it is counted as 0. The microcontroller 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 to 6500K as an example, when the microcontroller U3 receives the target color temperature frame data of 3000K, the duty cycle of the second PWM dimming signal output to the cold light channel is:

[0093]

[0094] The duty cycle of the second PWM dimming signal output to the warm light channel is:

[0095]

[0096] The above embodiment is 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.

[0097] Specifically, in addition to controlling the dimming or color adjustment mode via the phase-cut input signal described above, this embodiment also includes controlling the dimming or color adjustment mode via dual analog signals. The first and second analog signals are input to the detection pin of microcontroller U3. Microcontroller U3 compares the magnitude of the first analog signal with its preset maximum and minimum dimming signal values, and outputs the first PWM dimming signal with the corresponding duty cycle. This process is similar to the aforementioned phase-cut input signal control dimming mode and is not further described here.

[0098] In this embodiment, the color temperature span value of the minimum unit signal is obtained based on 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 by 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.

[0099] Specifically, the color temperature span value of the minimum unit signal in this embodiment is:

[0100]

[0101] in, is the maximum input value of the second analog signal, is the minimum input value of the second analog signal.

[0102] Specifically, in this embodiment, taking the second analog signal with an input range of 0-10V as an example, when the color temperature is adjusted to a range of 3000K-7000K, the color temperature span value of the minimum unit signal is:

[0103]

[0104] When the input second analog signal value is 2.3V, the total color temperature span that needs to be adjusted is:

[0105]

[0106] 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 above, the duty cycle of the second PWM dimming signal output by the microcontroller U3 to the cold light channel can be obtained as:

[0107]

[0108] The duty cycle of the second PWM dimming signal output to the warm light channel is:

[0109]

[0110] 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.

[0111] Specifically, the human-computer interaction module 70 of this embodiment can utilize, for example, an NFC circuit, a position switch, a key control circuit, a touchpad, etc., to connect to the single-chip computer U3 for human-computer interaction, thereby enabling parameter setting. For example, when utilizing a position switch, to set the dimming curve output by the dimming power supply, simply shifting the position switch to a position with preset output curve parameters can change the dimming curve currently output by the dimming power supply. For example, a key control circuit or a touchpad can be used to customize the dimming curve output by the dimming power supply; similarly, parameter adjustment for dimming frequency, color temperature, or color can also be achieved through the human-computer interaction interface.

[0112] The technical features of the above embodiments can 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.

[0113] The above 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 replacements made by technicians in this field on the basis of the present invention 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 voltage into a working power voltage of a load, characterized in that: Also includes: An EMI and rectification and filtering circuit, a phase-cut signal input circuit, a signal processing circuit, a main control circuit, and a dimming circuit. The EMI and rectification and filtering circuit inputs a power supply, is used to filter out high-frequency interference signals in the power supply, and rectify the power supply into a pulsating DC voltage, which is output 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, which is output to the signal processing circuit. The signal processing circuit is used to convert the first PWM signal into a DC voltage signal, which is output to the first input terminal of the main control circuit, and output a second PWM signal after filtering to the second input terminal of the main control circuit. The main control circuit is used to determine, based on the state of the second PWM signal, whether the current access signal is a phase-cut dimming signal or a phase-cut carrier color temperature adjustment signal. If it is a phase-cut dimming signal, the main control circuit outputs a corresponding first PWM dimming signal to the dimming circuit based on the magnitude of the DC voltage signal, thereby implementing a dimming function for the load. If it is a phase-cut carrier color temperature adjustment signal, the main control circuit performs signal processing and outputs a corresponding second PWM dimming signal to the dimming circuit based on the color temperature data signal, thereby implementing a color temperature adjustment function for the load. The third and fourth input terminals of the main control circuit are respectively input with a first analog signal and a second analog signal. The main control circuit is configured to output the first PWM dimming signal having a corresponding duty cycle to the dimming circuit according to the magnitude of the first analog signal, thereby implementing a dimming function for the load; or to obtain a color temperature span value according to the second analog signal, and output the second PWM dimming signals having corresponding duty cycles in different color temperature channels according to the color temperature span value, thereby implementing a color temperature adjustment function for the load; The color temperature span value of the minimum unit signal is obtained based on 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 by the input second analog signal value. The duty cycle of the second PWM dimming signal input to the two dimming circuits is adjusted according to the total color temperature span value to achieve the color temperature adjustment function of the load; In which, the power conversion circuit includes a power factor correction circuit and a DC / DC conversion circuit. The power factor correction circuit is connected to the output end of the EMI and rectification and filtering circuit, and is used to perform secondary rectification and filtering on the pulsating DC voltage to ensure that a smooth DC voltage is provided to the subsequent DC / DC conversion circuit; the DC / DC conversion circuit adopts a feedback control mode, and 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.

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 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 divided by the third voltage-dividing circuit and then output to the second-order low-pass filtering 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 determines 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 adjustment signal; wherein the second PWM signal includes a carrier color temperature adjustment code element 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 values, 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 output 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 includes a driving circuit and a MOS transistor, wherein the driving circuit is used to drive the MOS transistor 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 lowest 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 any one of claims 1 to 8, 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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