LED dimming and color modulation control circuit and method

Abstract

The invention discloses an LED dimming and color modulation control circuit and method, relates to the technical field of driving, and aims to solve the problems of inconsistent multi-lamp switch and poor dimming compatibility, and the circuit comprises an input module which receives an AC input signal, carries out rectification and dimming, and outputs a dimming signal; the pre-stage driving module is used for receiving the dimming signal and carrying out constant-voltage processing and chopping modulation on the dimming signal to obtain a constant-voltage chopping signal; and the post-stage driving module receives and processes the constant-voltage chopping signal so as to control an output signal to realize dimming, receives different voltage signals generated by dial-up, and outputs two paths of complementary PWM signals to realize color modulation. According to the LED dimming and color modulation control circuit and method, traditional constant current driving is replaced with constant voltage driving, multiple lamp loads are controlled through the same power source driving, the problem that multiple lamps are turned on and turned off inconsistently is solved, meanwhile, the dimming and color modulation functions can be achieved, and the LED dimming and color modulation control circuit and method can be compatible with multiple dimming modes.

Description

Technical Field

[0001] The present invention relates to the field of driving technology, and particularly to an LED dimming and color temperature adjustment control circuit and method. Background Art

[0002] Currently, with the development of LED and driving technologies, there are higher requirements for the diversity and functionality of driving. Lamps with functions such as dimming and color temperature adjustment have gradually replaced conventional non-dimming lamps. Currently, the driving of lamps is generally divided into built-in and external types, and single lamps sold generally come with independent drivers. For lighting in indoor and home places, generally 5 - 10 lamps are required to meet the whole-house lighting. In this way, a wall switch or dimmer is needed to control multiple lamps. This control method has the drawback of inconsistent startup or shutdown of multiple lamps, and it is difficult to meet the needs of large-scale lighting. In addition, existing lamps use a single dimming method, which not only has a high cost but also poor compatibility.

[0003] For example, there is a Chinese patent with the publication number CN204482081U, which relates to an LED lamp switch dimming and color temperature adjustment circuit, including a key switch, a thyristor dimmer, a power supply circuit, a dimming circuit, and a color temperature adjustment circuit. The key switch is connected to the input end of the power supply circuit through the thyristor dimmer. The power supply circuit is electrically connected to the dimming circuit and the color temperature adjustment circuit respectively. The key switch is connected to the input ends of the dimming circuit and the color temperature adjustment circuit through the power supply circuit. The thyristor dimmer is connected to the input end of the dimming circuit through the power supply circuit. Through a common switch and a thyristor dimmer, various requirements of users for light can be achieved, which is convenient and has a high cost performance. However, the Chinese patent with the publication number CN204482081U requires an independent dimmer for each lamp load. When using a single switch to control multiple lamps within the whole house, due to the inherent accuracy differences of different drivers, there will be a problem of asynchronous response. Summary of the Invention

[0004] In order to solve the problems of inconsistent multi-lamp switching and poor dimming compatibility, the present invention proposes an LED dimming and color temperature adjustment control circuit and method, which uses constant voltage driving to replace traditional constant current driving, realizes the control of multiple lamp loads by the same power supply, solves the problem of inconsistent startup and shutdown of multiple lamps, and at the same time can realize the functions of dimming and color temperature adjustment, and can be compatible with various dimming modes.

[0005] To achieve the above object, the present invention adopts the following technical solutions: An LED dimming and color temperature adjustment control circuit, comprising: An input module, which receives an AC input signal, rectifies and dims it, and outputs a dimming signal; A pre-stage driving module, which receives the dimming signal, performs constant voltage processing and chopping modulation on the dimming signal, and obtains a constant voltage chopping signal; The post-stage driving module receives and processes the constant-voltage chopping signal to control the output signal for dimming, receives different voltage signals generated by the DIP switches, and outputs two complementary PWM signals to achieve color temperature adjustment.

[0006] In this technical solution, an LED dimming and color temperature adjustment control circuit includes an input module, a pre-stage driving module, and a post-stage driving module. It adopts a driving framework with a pre-stage and a post-stage. The pre-stage driving module outputs the chopping voltage in different dimming states, and the DC-DC unit of the post-stage driving module processes the voltage after chopping. By adopting such a circuit architecture, no matter how severe the interference of the dimming waveform input to the pre-stage driving module is, as long as the output voltage is constant, it can be optimized by the post-stage driving module, achieving the compatibility of different dimming modules.

[0007] The present invention is further configured as: the pre-stage driving module includes a constant-voltage driving unit connected to the input module, and the constant-voltage driving unit is further connected to a PWM chopping modulation unit. The constant-voltage driving unit and the PWM chopping modulation unit output a constant-voltage chopping signal and transmit it to the post-stage driving module.

[0008] In this technical solution, the constant-voltage driving unit performs constant-voltage processing on the incoming alternating current and outputs a constant direct current voltage; the PWM chopping modulation unit controls the magnitude of the output voltage by chopping and modulating the input signal. The pre-stage driving module realizes the conversion from alternating current to constant-voltage direct current through the constant-voltage driving unit and the PWM chopping modulation unit, and outputs a constant-voltage chopping signal.

[0009] The present invention is further configured as: the post-stage driving module includes: a color temperature switching unit, including at least one DIP switch and several resistors, for controlling the switching between different color temperatures; a micro-control unit, which outputs two complementary PWM signals; a DC-DC unit, connected to the output end of the micro-control unit, processes the chopped voltage, and outputs a constant direct current voltage to the load; a voltage monitoring unit, which monitors the voltage input to the DC-DC unit and transmits it to the micro-control unit.

[0010] In this technical solution, the voltage monitoring unit can monitor the voltage input to the DC-DC unit and transmit it to the microcontroller; the color temperature switching module includes a DIP switch and several resistors, which can realize the selection and switching of different color temperatures. The DC-DC unit includes two parallel DC-DC circuits. There is a DC-DC chip inside the DC-DC circuit. The output ends of the two DC-DC circuits are respectively connected to a high-color-temperature load and a low-color-temperature load. The DC-DC unit of the post-stage driving module can process the voltage after chopping.

[0011] The present invention is further configured as: the micro-control unit is provided with input detection pins and color temperature detection pins, and the input end of the micro-control unit is connected to the voltage monitoring unit and the color temperature switching unit.

[0012] In this technical solution, the microcontroller unit receives the constant-voltage chopping signal output by the pre-stage driving module, calculates the percentage of the total output current according to the voltage output by the voltage monitoring unit, so as to achieve the dimming function.

[0013] The present invention is further configured as: the input module includes a rectification unit and at least one dimmer, and the rectification unit is connected to the pre-stage driving module.

[0014] In this technical solution, the input module includes a rectification unit and at least one dimmer. An LED dimming control circuit of the present invention can be compatible with Triac dimming, 0-10V dimming, and Triac&0-10V dimming, and can support different dimming modes only by replacing the dimmer in the input module and simply adjusting the circuit connection, and supports the user to select according to actual needs.

[0015] The present invention is further configured as: the input module includes a Triac dimmer, the AC input signal is input to the Triac dimmer, and the input end of the constant-voltage driving unit of the pre-stage driving module is connected to the Triac dimmer.

[0016] In this technical solution, when using Triac dimming, the input module includes a rectification unit and a Triac dimmer, the alternating current is input to the rectification unit through the Triac dimmer, and then the rectified dimming signal is input to the pre-stage driving module.

[0017] The present invention is further configured as: the input module includes a 0-10V dimmer, and the input end of the PWM chopping modulation unit of the pre-stage driving module is connected to the 0-10V dimmer.

[0018] In this technical solution, when using 0-10V dimming, the input module includes a rectification unit and a 0-10V dimmer, the alternating current is directly input to the rectification unit, and then the rectified signal is input to the pre-stage driving module, and the 0-10V dimmer outputs an analog voltage signal of 0 to 10V to the pre-stage driving module.

[0019] The present invention is further configured as: the output voltage of the pre-stage driving module is less than 60V.

[0020] In this technical solution, the output voltage of the constant-voltage driving unit of the pre-stage driving module is a low voltage below 60V, which provides a low-voltage environment for lamp assembly and improves the safety of assembly.

[0021] The present invention also adopts the following technical solution: an LED dimming and color mixing control method, using the above-mentioned LED dimming and color mixing control circuit, includes the following steps: S1, rectify and dim the AC signal, and output a dimming signal; S2, perform constant voltage processing and PWM chopper modulation on the dimming signal, and output a constant voltage chopped signal; S3, calculate and output the percentage of the total current according to the voltage of the constant voltage chopped signal; S4, obtain color temperature information, and allocate different PWM duty cycles according to the color temperature information.

[0022] In this technical solution, the dimming signal is first subjected to constant voltage processing to output a constant voltage chopped signal, and then the constant voltage chopped signal is processed to complete dimming and color adjustment. During the process of processing the constant voltage chopped signal, the interference of the dimming waveform can be optimized, realizing the compatibility of different dimming modules.

[0023] The present invention is further set as follows: Step S4 includes: S41, receive different voltage signals generated by the DIP switch; S42, output two complementary PWM waveforms; S43, allocate duty cycles to the two PWM waveforms according to the voltage signal.

[0024] In this technical solution, the selection and switching of different color temperatures are realized through the DIP switch, and then the color temperature information obtained from the DIP switch is detected, and different PWM duty cycles are allocated to two DC-DC circuits according to the color temperature information to realize the color adjustment function.

[0025] The beneficial effects of the present invention are: (1) The front-stage drive module uses constant voltage drive instead of a constant current circuit, realizing that the same drive can drive multiple loads, effectively avoiding the problem of inconsistent dimming of multiple lamps; (2) The dimmer acts on the constant voltage circuit, controls the output through the PWM chopping of the front-stage drive module, and the rear-stage drive module receives the same modulated chopped voltage for conversion, realizing the compatibility of different dimming modules; (3) The output of the constant voltage drive unit is a low voltage below 60V, realizing a low voltage environment during lamp assembly, which can greatly improve the safety of assembly. Brief Description of the Drawings

[0026] Figure 1 is the circuit logic diagram of the Triac dimming mode of an LED dimming and color adjustment control circuit of the present invention.

[0027] Figure 2 is the circuit logic diagram of the 0-10V dimming mode of an LED dimming and color adjustment control circuit of the present invention.

[0028] Figure 3 is the circuit logic diagram of the Triac&0-10V dimming mode of an LED dimming and color adjustment control circuit of the present invention.

[0029] Figure 4It is the schematic diagram of the post-stage driving module of an LED dimming and color temperature control circuit of the present invention. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific implementation manners described herein are only the best embodiments of the present invention, which are only used to explain the present invention and do not limit the protection scope of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0031] Embodiment 1 This embodiment provides an LED dimming and color temperature control circuit, which can use the same driver to control multiple load lamps simultaneously, prevent the inconsistency of the on or off times of multiple lamps caused by each lamp equipped with an independent driver, and can be compatible with multiple dimming modes.

[0032] As Figure 1 shown, an LED dimming and color temperature control circuit of this embodiment includes three modules: an input module, a pre-stage driving module and a post-stage driving module. The following will describe these three modules in detail.

[0033] The input module is the most front-stage module of the LED dimming and color temperature control circuit of this embodiment, which can be directly connected to the mains power network. The input module can support alternating current with a full voltage range of 100V to 347V as the voltage input, and perform the most preliminary processing on the alternating voltage to provide an input signal for the next-stage module.

[0034] The input module includes a rectification unit and at least one dimmer. Since the LED dimming and color temperature control circuit of this embodiment can be compatible with multiple dimming modes, it can be compatible with Triac dimming, 0-10V dimming and Triac&0-10V dimming respectively. It can support different dimming modes by simply replacing the dimmer in the input module and adjusting the circuit connection, and supports users to select according to actual needs.

[0035] The LED dimming and color temperature control circuit of this embodiment adopts the Triac dimming mode. The circuit logic schematic diagram is referred to Figure 1 .

[0036] In this embodiment, the input module includes a rectification unit and a Triac dimmer. The alternating current is input to the rectification unit through the Triac dimmer, and then the rectified dimming signal is input to the pre-stage driving module.

[0037] The pre-stage drive module performs constant voltage and modulation processing on the dimming signal. The pre-stage drive module includes a constant voltage drive unit and a PWM chopper modulation unit, and the constant voltage drive unit and the PWM chopper modulation unit are connected in parallel.

[0038] In this embodiment, the dimming signal is directly input to the constant voltage drive unit in the first branch, and is input to the PWM chopper modulation unit via a diode in the second branch. The constant voltage drive unit and the PWM chopper modulation unit are respectively grounded. The pre-stage drive module also has a field effect transistor. The output terminal of the constant voltage drive unit is connected to the drain of the field effect transistor, the output terminal of the PWM chopper modulation unit is connected to the gate of the field effect transistor, and the source of the field effect transistor is connected to the post-stage drive module.

[0039] The constant voltage drive unit performs constant voltage processing on the incoming alternating current and outputs a constant direct current voltage; the PWM chopper modulation unit controls the magnitude of the output voltage by chopping and modulating the input signal. The pre-stage drive module realizes the conversion of alternating current to constant voltage direct current.

[0040] The post-stage drive module includes a voltage monitoring unit, a color temperature switching unit, a micro control unit and a DC-DC unit. The circuit schematic diagram of the post-stage drive module is referenced Figure 4 .

[0041] The voltage monitoring unit can monitor the voltage input to the DC-DC unit and transmit it to the microcontroller.

[0042] As Figure 4 shown, the color temperature switching module includes a DIP switch and several resistors, and can realize the selection and switching of different color temperatures.

[0043] The micro control unit includes a microcontroller with a color temperature detection pin and an input detection pin. It can be understood that the microcontroller can be a single-chip microcomputer (MCU) of various models. The microcontroller includes at least two input pins, namely the color temperature detection pin and the input detection pin, and two output pins.

[0044] The DC-DC unit includes two parallel DC-DC circuits. There is a DC-DC chip in the DC-DC circuit. The output terminals of the two DC-DC circuits are respectively connected to a high color temperature load and a low color temperature load.

[0045] It should be noted that the load can be multiple LED lamps connected electrically. In this embodiment, the load is 10 series-connected LED lamps.

[0046] The micro control unit receives the constant voltage chopping signal output by the pre-stage drive module, calculates the percentage of the total output current according to the voltage output by the voltage monitoring unit, and thus realizes the dimming function.

[0047] The microcontroller unit can detect the color temperature information output by the color temperature switching unit to the color temperature detection pin, and allocate different PWM duty cycles to two DC-DC circuits according to the color temperature information to achieve the color mixing function.

[0048] Due to the poor compatibility of different dimmers, different dimmers require different drive circuits to process different dimming signals differently. It is very difficult to integrate different dimming methods together, which results in the need to purchase different dimming devices that match different drives, causing great inconvenience to users.

[0049] Existing technologies generally use independent drives to control lamps. For lamps with independent drives, each lamp is controlled by an independent drive. Since there are accuracy differences in different drives themselves, for example, when using lamps throughout a house, if there are 6 lamps in the whole house and the dimming is between 5 - 10%, there may be differences in startup times, and these differences in startup times can be clearly detected by the naked eye. In contrast, the drive solution of the present invention controls multiple lamp loads through a single total constant voltage drive. Since there is only one drive, there is no problem of inconsistent startup.

[0050] For existing independent drives on the market, dimming compatibility is a difficult problem to solve. The advantage of the present invention in dimming compatibility lies in adopting a drive framework with a pre-stage and a post-stage. The pre-stage constant voltage circuit only outputs chopped voltages in different dimming states, and the post-stage DC-DC circuit processes the chopped voltages. With such a circuit architecture, even if the dimming waveform interference in the pre-stage is severe, as long as the output voltage is constant, it can be optimized by the post-stage circuit, enabling the circuit to have good dimming compatibility.

[0051] The drive solution of the present invention has three dimming methods: Triac dimming, 0 - 10V dimming, and Triac&0 - 10V dimming, which cover all dimming methods in the market. Users can select these three dimming methods according to their needs. The Triac&0 - 10V dimming solution can be compatible with both Triac dimming and 0 - 10V dimming solutions at the same time. The present invention adopts a drive framework with a pre-stage and a post-stage to overcome the difficult problem of poor compatibility of different dimmers.

[0052] An LED dimming and color mixing control circuit in this embodiment adopts a drive framework with a pre-stage and a post-stage. The pre-stage drive module outputs chopped voltages in different dimming states, and the DC-DC unit of the post-stage drive module processes the chopped voltages. With such a circuit architecture, no matter how severe the interference of the dimming waveform input to the pre-stage drive module is, as long as the output voltage is constant, it can be optimized by the post-stage drive module, achieving the compatibility of different dimming modules.

[0053] Embodiment 2 This embodiment provides an LED dimming and color - temperature control circuit, which can use the same driver to control multiple load lamps simultaneously, preventing the inconsistency of the on - or off - time of multiple lamps caused by each lamp equipped with an independent driver, and can be compatible with multiple dimming modes.

[0054] As Figure 1 shown, an LED dimming and color - temperature control circuit of this embodiment includes three modules: an input module, a pre - stage driver module, and a post - stage driver module. The following will elaborate on these three modules.

[0055] The input module is the most front - end module of the LED dimming and color - temperature control circuit of this embodiment. It can be directly connected to the mains power network. The input module can support alternating current with a full - voltage range of 100V to 347V as the voltage input, and perform the most preliminary processing on the AC voltage to provide an input signal for the next - stage module.

[0056] The input module includes a rectification unit and at least one dimmer. Since the LED dimming and color - temperature control circuit of this embodiment can be compatible with multiple dimming modes, it can be compatible with Triac dimming, 0 - 10V dimming, and Triac&0 - 10V dimming respectively. It can support different dimming modes by simply replacing the dimmer in the input module and adjusting the circuit connection, and supports users to select according to actual needs.

[0057] The LED dimming and color - temperature control circuit of this embodiment adopts the 0 - 10V dimming mode. The circuit logic schematic diagram is referred to Figure 2 .

[0058] In this embodiment, the input module includes a rectification unit and a 0 - 10V dimmer. The alternating current is directly input to the rectification unit, and then the rectified signal is input to the pre - stage driver module. The 0 - 10V dimmer outputs an analog voltage signal of 0 to 10V to the pre - stage driver module.

[0059] The pre - stage driver module performs constant - voltage and modulation processing on the dimming signal. The pre - stage driver module includes a constant - voltage driving unit and a PWM chopper modulation unit.

[0060] In this embodiment, the rectified signal is directly input to the constant - voltage driving unit. The 0 - 10V dimmer outputs an analog voltage signal of 0 to 10V to the PWM chopper modulation unit. The constant - voltage driving unit and the PWM chopper modulation unit are respectively grounded. The pre - stage driver module also has a field - effect transistor. The output end of the constant - voltage driving unit is connected to the drain of the field - effect transistor, the output end of the PWM chopper modulation unit is connected to the gate of the field - effect transistor, and the source of the field - effect transistor is connected to the post - stage driver module.

[0061] The constant-voltage drive unit performs constant-voltage processing on the incoming alternating current and outputs a constant direct current voltage; the PWM chopper modulation unit controls the magnitude of the output voltage by chopper modulation of the input signal, and the front-stage drive module realizes the conversion of alternating current to constant-voltage direct current.

[0062] The rear-stage drive module includes a voltage monitoring unit, a color temperature switching unit, a micro-control unit, and a DC-DC unit. The circuit schematic diagram of the rear-stage drive module is referenced Figure 4 .

[0063] The voltage monitoring unit can monitor the voltage input to the DC-DC unit and transmit it to the microcontroller.

[0064] As Figure 4 shown, the color temperature switching module includes a DIP switch and several resistors, which can realize the selection and switching of different color temperatures.

[0065] The micro-control unit includes a microcontroller with a color temperature detection pin and an input detection pin. It can be understood that the microcontroller can be a single-chip microcomputer (MCU) of various models. The microcontroller includes at least two input pins, namely the color temperature detection pin and the input detection pin, and two output pins.

[0066] The DC-DC unit includes two parallel DC-DC circuits. There is a DC-DC chip inside the DC-DC circuit. The output terminals of the two DC-DC circuits are respectively connected to a high-color-temperature load and a low-color-temperature load.

[0067] It should be noted that the load can be multiple LED lamps connected electrically. In this embodiment, the load is 10 LED lamps connected in series.

[0068] The micro-control unit receives the constant-voltage chopping signal output by the front-stage drive module, calculates the percentage of the total output current according to the voltage output by the voltage monitoring unit, and thus realizes the dimming function.

[0069] The micro-control unit can detect the color temperature information output by the color temperature switching unit to the color temperature detection pin, and assigns different PWM duty cycles to the two DC-DC circuits according to the color temperature information to realize the color mixing function.

[0070] Due to the poor compatibility of different dimmers, different dimmers require different drive circuits to process different dimming signals differently, and it is very difficult to integrate different dimming methods together. This results in the need to purchase different dimming devices that match different drives, causing great inconvenience to users.

[0071] In the prior art, generally, independent drive control is adopted for lamps. For lamps with independent drive, each lamp is controlled by an independent drive. Since there are accuracy differences among different drives themselves, for example, when lamps are used throughout a house and there are 6 lamps in the whole house, when the dimming is between 5 - 10%, there may be differences in start-up time, and these differences in start-up time can be clearly detected by the naked eye. However, the drive scheme of the present invention controls multiple lamp loads through a total constant voltage drive. Since there is only one drive, there is no problem of inconsistent start-up.

[0072] For the existing independent drives in the market, dimming compatibility is a difficult problem to solve. The advantage of the present invention in dimming compatibility lies in adopting a drive framework with a pre-stage and a post-stage. The constant voltage circuit of the pre-stage only outputs chopped voltages under different dimming states, and the post-stage DC-DC circuit processes the chopped voltages. With such a circuit architecture, even if the dimming waveform interference of the pre-stage is severe, as long as the output voltage is constant, it can be optimized by the post-stage circuit, enabling the circuit to have good dimming compatibility.

[0073] The drive scheme of the present invention has three dimming methods: Triac dimming, 0 - 10V dimming, and Triac&0 - 10V dimming, which cover all the dimming methods in the market. Users can select these three dimming methods according to their needs. The dimming scheme of Triac&0 - 10V can be compatible with both Triac dimming and 0 - 10V dimming schemes at the same time. The present invention adopts a drive framework with a pre-stage and a post-stage to overcome the difficult problem of poor compatibility of different dimmers.

[0074] An LED dimming and color temperature control circuit of this embodiment adopts a drive framework with a pre-stage and a post-stage. The pre-stage drive module outputs chopped voltages under different dimming states, and the DC-DC unit of the post-stage drive module processes the chopped voltages. With such a circuit architecture, no matter how severe the dimming waveform interference input to the pre-stage drive module is, as long as the output voltage is constant, it can be optimized by the post-stage drive module, achieving the compatibility of different dimming modules.

[0075] Embodiment 3 This embodiment provides an LED dimming and color temperature control circuit, which can use the same drive to control multiple load lamps simultaneously, preventing the inconsistency of the on or off time of multiple lamps caused by each lamp being equipped with an independent drive, and can be compatible with multiple dimming modes.

[0076] As Figure 1 shown, an LED dimming and color temperature control circuit of this embodiment includes three modules: an input module, a pre-stage drive module, and a post-stage drive module. The following will explain these three modules in detail.

[0077] The input module is the front - most module of an LED dimming and color - temperature - adjusting control circuit in this embodiment. It can be directly connected to the mains power network. The input module can support alternating current with a full - voltage range from 100V to 347V as the voltage input, and perform the most preliminary processing on the alternating voltage to provide an input signal for the next - stage module.

[0078] The input module includes a rectification unit and at least one dimmer. Since an LED dimming and color - temperature - adjusting control circuit in this embodiment can be compatible with multiple dimming modes, it can be compatible with Triac dimming, 0 - 10V dimming, and Triac&0 - 10V dimming respectively. It can support different dimming modes by simply replacing the dimmer in the input module and adjusting the circuit connection, and supports users to select according to actual needs.

[0079] An LED dimming and color - temperature - adjusting control circuit in this embodiment adopts the Triac&0 - 10V dimming mode. The circuit logic schematic diagram is referred to Figure 3 .

[0080] In this embodiment, the input module includes a rectification unit, a Triac dimmer, and a 0 - 10V dimmer. The alternating current is input to the Triac dimmer, and then the rectified dimming signal is input to the pre - stage driving module. The 0 - 10V dimmer outputs an analog voltage signal from 0V to 10V to the pre - stage driving module.

[0081] The pre - stage driving module performs constant - voltage and modulation processing on the dimming signal. The pre - stage driving module includes a constant - voltage driving unit and a PWM chopper modulation unit, and the constant - voltage driving unit and the PWM chopper modulation unit are connected in parallel.

[0082] In this embodiment, the rectified dimming signal is directly input to the constant - voltage driving unit in the first branch, and is input to the PWM chopper modulation unit via a diode in the second branch. The 0 - 10V dimmer outputs an analog voltage signal from 0V to 10V to the PWM chopper modulation unit. The constant - voltage driving unit and the PWM chopper modulation unit are grounded respectively. The pre - stage driving module also has a field - effect transistor. The output end of the constant - voltage driving unit is connected to the drain of the field - effect transistor, the output end of the PWM chopper modulation unit is connected to the gate of the field - effect transistor, and the source of the field - effect transistor is connected to the post - stage driving module.

[0083] The constant - voltage driving unit performs constant - voltage processing on the incoming alternating current and outputs a constant DC voltage; the PWM chopper modulation unit controls the magnitude of the output voltage by chopping and modulating the input signal. The pre - stage driving module realizes the conversion of alternating current to constant - voltage direct current.

[0084] The post - stage driving module includes a voltage monitoring unit, a color - temperature switching unit, a micro - control unit, and a DC - DC unit. The circuit schematic diagram of the post - stage driving module is referred to Figure 4 .

[0085] The voltage monitoring unit can monitor the voltage of the input DC-DC unit and transmit it to the microcontroller.

[0086] As Figure 4 shown, the color temperature switching module includes a DIP switch and several resistors, and can realize the selection and switching of different color temperatures.

[0087] The microcontrol unit includes a microcontroller with a color temperature detection pin and an input detection pin. It can be understood that the microcontroller can be a single-chip microcomputer (MCU) of various models. The microcontroller includes at least two input pins, namely the color temperature detection pin and the input detection pin, and two output pins.

[0088] The DC-DC unit includes two parallel DC-DC circuits. A DC-DC chip is provided in each DC-DC circuit. The output ends of the two DC-DC circuits are respectively connected to a high-color-temperature load and a low-color-temperature load.

[0089] It should be noted that the load can be multiple LED lamps connected electrically. In this embodiment, the load is 10 series-connected LED lamps.

[0090] The microcontrol unit receives the constant voltage chopping signal output by the pre-stage driving module, calculates the percentage of the total output current according to the voltage output by the voltage monitoring unit, so as to realize the dimming function.

[0091] The microcontrol unit can detect the color temperature information output by the color temperature switching unit to the color temperature detection pin, and allocate different PWM duty cycles to the two DC-DC circuits according to the color temperature information to realize the color mixing function.

[0092] Due to the poor compatibility of different dimmers, different dimmers require different drive circuits to process different dimming signals differently. It is very difficult to integrate different dimming methods together. This results in the need to purchase different dimming devices that match different drives, causing great inconvenience to users.

[0093] The prior art generally uses independent drives to control lamps. For lamps with independent drives, each lamp is controlled by an independent drive. Since there are differences in accuracy among different drives, for example, when using lamps in a whole house, there are 6 lamps in the whole house. When the dimming is between 5-10%, there may be differences in start-up time. These differences in start-up time can be clearly detected by the naked eye. However, the drive scheme of the present invention controls multiple lamp loads through a total constant voltage drive. Since there is only one drive, there is no problem of inconsistent start-up.

[0094] For the existing stand-alone drivers on the market, dimming compatibility is a difficult problem to solve. The advantage of the present invention in dimming compatibility lies in adopting a driving framework with a pre-stage plus a post-stage. The constant-voltage circuit of the pre-stage only outputs chopped voltages under different dimming states, and the post-stage DC-DC circuit processes the chopped voltage. With such a circuit architecture, even if the dimming waveform interference of the pre-stage is severe, as long as the output voltage is constant, it can be optimized by the post-stage circuit, enabling the circuit to have good dimming compatibility.

[0095] There are three dimming methods in the driving scheme of the present invention: Triac dimming, 0-10V dimming, and Triac&0-10V dimming, which cover all the dimming methods in the market. Users can select these three dimming methods according to their needs. The dimming scheme of Triac&0-10V can be compatible with both Triac dimming and 0-10V dimming schemes at the same time. The present invention adopts a driving framework with a pre-stage plus a post-stage to overcome the difficult problem of poor compatibility of different dimmers.

[0096] Embodiment 4 This embodiment proposes an LED dimming and color temperature control method, which adopts one of the above-mentioned LED dimming and color temperature control circuits and mainly includes the following several steps.

[0097] Step S1, rectify and dim the AC signal to output a dimming signal.

[0098] In this embodiment, this step is carried out in the input module. For the detailed content of this step, refer to the introduction of the input module in the above circuit.

[0099] Step S2, perform constant-voltage processing and PWM chopping modulation on the dimming signal to output a constant-voltage chopped signal.

[0100] In this embodiment, this step is carried out in the pre-stage driving module. For the detailed content of this step, refer to the introduction of the pre-stage driving module in the above circuit.

[0101] Step S3, calculate the percentage of the total output current according to the voltage of the constant-voltage chopped signal.

[0102] In this embodiment, this step is carried out in the post-stage driving module.

[0103] In the technical solution of step S3 in this embodiment, the micro-control unit of the post-stage driving module receives the constant-voltage chopped signal output by the pre-stage driving module and calculates the percentage of the total output current according to the voltage output by the voltage monitoring unit, thereby realizing the dimming function.

[0104] Step S4, obtain the color temperature information and allocate different PWM duty cycles according to the color temperature information.

[0105] For the specific process of S4, it includes several sub-steps as follows.

[0106] Step S41: Receive different voltage signals generated by the DIP switch.

[0107] Step S42: Output two complementary PWM waveforms.

[0108] Step S43: Allocate the duty cycles of the two PWM waveforms according to the voltage signals.

[0109] In the technical solution of step S4 in this embodiment, the selection and switching of different color temperatures are realized through the DIP switch, and then the color temperature information obtained from the DIP switch is detected. The color mixing function is realized by allocating different PWM duty cycles to the two DC-DC circuits according to the color temperature information.

Claims

1. An LED dimming and color adjustment control circuit, characterized in that: include: Input module, receives AC input signal and performs rectification and dimming, and outputs dimming signal; The front-stage driver module receives the dimming signal, performs constant voltage processing and chopping modulation on the dimming signal to obtain a constant voltage chopping signal; The post-stage driver module receives and processes the constant voltage chopping signal and then controls the output signal to achieve dimming. It receives the different voltage signals generated by the dial code and outputs two complementary PWM signals to achieve color adjustment.

2. The LED dimming and color adjustment control circuit according to claim 1, characterized in that: The front-stage driving module includes a constant voltage driving unit connected to the input module, and the constant voltage driving unit is also connected to a PWM chopping modulation unit. The constant voltage driving unit and the PWM chopping modulation unit output a constant voltage chopping signal and transmit it to the rear-stage driving module.

3. The LED dimming and color adjustment control circuit according to claim 1, characterized in that: The post-stage drive module includes: a color temperature switching unit, which includes at least one dip switch and several resistors to control the switching between different color temperatures; a microcontroller unit, which outputs two complementary PWM signals; a DC-DC unit, which is connected to the output end of the microcontroller unit, processes the chopped voltage, and outputs a constant DC voltage to the load; and a voltage monitoring unit, which monitors the voltage input to the DC-DC unit and transmits it to the microcontroller unit.

4. The LED dimming and color adjustment control circuit according to claim 3, characterized in that: The micro control unit is provided with an input detection pin and a color temperature detection pin, and the input end of the micro control unit is connected with the voltage monitoring unit and the color temperature switching unit.

5. The LED dimming and color adjustment control circuit according to claim 1, characterized in that: The input module includes a rectifier unit and at least one dimmer, and the rectifier unit is connected to the front-stage driving module.

6. The LED dimming and color adjustment control circuit according to claim 1, characterized in that: The input module includes a Triac dimmer, the AC input signal is input to the Triac dimmer, and the input end of the constant voltage driving unit of the pre-stage driving module is connected to the Triac dimmer.

7. The LED dimming and color adjustment control circuit according to claim 1, characterized in that: The input module includes a 0-10V dimmer, and the input end of the PWM chopping modulation unit of the front-stage driving module is connected to the 0-10V dimmer.

8. The LED dimming and color adjustment control circuit according to any one of claims 1 to 7, characterized in that: The output voltage of the pre-stage driver module is less than 60V.

9. A method for controlling LED dimming and color adjustment, characterized in that: The LED dimming and color adjustment control circuit according to any one of claims 1 to 8 comprises the following steps: S1, rectifies and dims the AC signal and outputs a dimming signal; S2, performs constant voltage processing and PWM chopping modulation on the dimming signal, and outputs a constant voltage chopping signal; S3, calculates the percentage of the total output current according to the voltage of the constant voltage chopping signal; S4, obtaining color temperature information, and assigning different PWM duty cycles according to the color temperature information.

10. The LED dimming and color adjustment control method according to claim 9, characterized in that: The step S4 includes: S41, receiving different voltage signals generated by the dial switch; S42, outputs two complementary PWM waveforms; S43, allocating duty cycles to the two PWM waveforms according to the voltage signal.

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