Low-harmonic high-power-factor silicon-controlled dimming and color-adjusting circuit

Abstract

The utility model discloses a low-harmonic high-power-factor silicon controlled rectifier dimming and toning circuit, and relates to the technical field of circuits. Comprising a silicon controlled rectifier dimmer, the silicon controlled rectifier dimmer is connected with the L end of a power supply, the silicon controlled rectifier dimmer is also connected with an input anti-surge circuit through a protection circuit, the N end of the power supply is also connected with the input anti-surge circuit, the input anti-surge circuit is connected with a bridge rectifier circuit in parallel, and the positive electrode of the bridge rectifier circuit is connected with a constant current control circuit. The constant current control circuit is connected with the constant current reference sampling circuit, and the constant current reference sampling circuit is respectively connected with the first full balance circuit, the second control step-down power supply circuit, the second warm light LED lamp bead, the second cold light LED lamp bead, the second filter circuit and the second bleeder circuit. The dimming and color temperature adjusting device can be used for dimming and color temperature adjusting occasions of an alternating-current or direct-current silicon controlled rectifier dimmer and can also be used for dimming and color temperature adjusting occasions by adjusting input voltage through direct current.

Description

Technical Field

[0001] The utility model relates to the field of circuit technology, and particularly relates to a thyristor dimming and color mixing circuit with low harmonic and high power factor. Background Art

[0002] The light emitting diode is abbreviated as led (light emitting diode). The light emitting diode is a commonly used light emitting device that emits light by the recombination of electrons and holes. The light emitting diode can efficiently convert electrical energy into light energy and has a wide range of uses in modern society, such as lighting, flat panel display, medical devices, etc., bringing great energy-saving contributions to society.

[0003] Compared with traditional lighting, led lighting can achieve more colors. At present, to achieve color change, it mainly depends on the mixing of four or three light sources of (red), (green), (blue), (white) or (red), (green), (blue) inside the lamp.

[0004] At present, there are many existing dimming and color mixing circuits, and the main ones are represented by the following two. One is made of two or more circuits, which requires a variety of components, has a complex circuit, and has a poor dimming and color mixing effect; the other is to use an MCU unit to control the pulse width of the PWM signal through a program for dimming and color mixing, and requires multiple MOSs and feedback to achieve dimming and color mixing, with a complex circuit and difficult debugging.

[0005] 1. The multi-channel MOS dimming and color mixing circuit scheme is as Figure 1 shown. This scheme requires multiple MOSs and multiple reference voltage sampling feedbacks for dimming and color mixing.

[0006] 2. The dimming and color mixing scheme controlled by MCU is as Figure 2 shown. After the MCU writes a predetermined program, the MCU processes according to the program for dimming and color mixing, and the power supply of this scheme also needs to be specially processed.

[0007] 3. As Figure 3 shown, the existing scheme cannot meet the stroboscopic requirements of the new ErP regulation EU2019 / 2020 for lighting products announced by the European Union on December 5, 2019 and the current harmonic requirements in the current harmonic standard IEC 61000-3-2:2019, that is, the THD requirement.

[0008] In summary, the existing technical solutions mainly have the following disadvantages:

[0009] 1. The disadvantages of the multi-channel MOS dimming and color mixing circuit scheme are as follows;

[0010] a. The cost of electronic components is relatively high, and the implementation price is relatively expensive;

[0011] b. Difficult to debug the control loop and feedback circuit;

[0012] c. There are many components, making it difficult to route on the circuit board;

[0013] 2. MCU solution

[0014] a. Difficult to write and debug the program. It is difficult to debug the program and the dimming effect, which takes a long time;

[0015] b. The MCU is expensive. Currently, the prices of MCUs on the market range from 1 to several yuan;

[0016] c. The performance of the MCU is not strong. It is difficult to find an exactly the same MCU on the market. Currently, the MCUs on the market are almost irreplaceable and difficult to replace;

[0017] d. There are many peripheral circuits and a separate power supply unit is required; the power supply requirements are relatively high;

[0018] e. Difficult to pass the certification. Since the MCU control uses PWM to switch MOS, there are problems with the switching frequency. During the certification, it is difficult to adjust the conducted interference and radiation interference, and additional safety regulations components are required to pass the certification;

[0019] 3. The disadvantages of the existing single - channel solutions are as follows:

[0020] a. Unable to perform dimming and color adjustment simultaneously;

[0021] b. High harmonics and unable to pass the EU ERP certification;

[0022] c. The stroboscopic coefficient index cannot meet the EU's ERP certification.

[0023] Therefore, the present utility model designs a thyristor dimming and color - adjustment circuit with low harmonics and high power factor. Content of the utility model

[0024] Aiming at the deficiencies in the existing technology, the purpose of the present utility model is to provide a thyristor dimming and color - adjustment circuit with low harmonics and high power factor. The circuit is simple and can perform dimming of color temperature without a PWM signal. This circuit can be used in occasions where AC or DC thyristor dimmers are used for dimming and color - temperature adjustment, and can also be used in occasions where the input voltage is adjusted by DC for dimming and color - temperature adjustment.

[0025] To achieve the above object, the utility model is realized by the following technical solutions: A low-harmonic and high-power-factor thyristor dimming and color mixing circuit, including a thyristor dimmer, the thyristor dimmer is connected to the L terminal of the power supply, and the thyristor dimmer is also connected to the input surge protection circuit through a protection circuit. The N terminal of the power supply is also connected to the input surge protection circuit. The input surge protection circuit is connected in parallel with a bridge rectifier circuit. The positive pole of the bridge rectifier circuit is connected to a constant current control circuit. The constant current control circuit is connected through a constant current reference sampling circuit. The constant current reference sampling circuit is respectively connected to a first full balance circuit, a second control buck power supply circuit, a second warm white LED lamp bead, a second cold white LED lamp bead, a second filter circuit, and a second discharge circuit. The second control buck power supply circuit is also connected to a filter circuit B, a second power supply voltage stabilizing circuit, a second control reference circuit, and the G pole of a second warm white controller. The D pole of the second warm white controller is connected to a second warm white dimming adjustment circuit. The S pole of the second warm white controller is connected to the second control reference circuit. The second warm white dimming adjustment circuit is connected to the second warm white LED lamp bead. The second cold white LED lamp bead is connected to the second control reference circuit. The second filter circuit, the second discharge circuit, the filter circuit B, the second power supply voltage stabilizing circuit, and the second control reference circuit are all connected to a second full balance circuit. The first full balance circuit is connected to the second full balance circuit through an isolation circuit. The first full balance circuit is also connected to a first control buck power supply circuit, a first warm white LED lamp bead, a first cold white LED lamp bead, a first filter circuit, and a first discharge circuit. The first full balance circuit is also connected to a reference potential circuit A. The first control buck power supply circuit is connected to a filter circuit A, a first power supply voltage stabilizing circuit, a first control reference circuit, and the G pole of a first warm white controller. The first control reference circuit is also connected to the S pole of the first warm white controller. The D pole of the first warm white controller is connected to the first warm white LED lamp bead through a first warm white dimming adjustment circuit. The filter circuit A, the first power supply voltage stabilizing circuit, the first control reference circuit, the first filter circuit, and the first discharge circuit are all connected to a reference potential circuit B. The reference potential circuit B is also connected to the negative pole of the second full balance circuit and the bridge rectifier circuit.

[0026] Preferably, the reference potential circuit A and the reference potential circuit B provide conduction potentials for the first full balance circuit and the second full balance circuit respectively.

[0027] Preferably, the first control buck power supply circuit and the second control buck power supply circuit provide base voltage and current for the first warm white controller and the second warm white controller to control the brightness of the warm white LED lamp.

[0028] Preferably, the first warm white LED lamp bead and the second warm white LED lamp bead are any one of the K-K color temperature lamp beads.

[0029] Preferably, the first cold light LED lamp beads and the second cold light LED lamp beads are any color temperature lamp beads in the range of K-K.

[0030] The utility model has the following beneficial effects:

[0031] 1. The circuit is simple. It uses a simple single-way MOS circuit and a reference voltage source such as TL431. By detecting the voltage at the control terminal of the reference voltage source, the on / off state of the MOS is determined, and the brightness and color temperature are adjusted by adjusting the voltage at the G pole of the MOS tube to control the conduction magnitude of the MOS. At the same time, using common components makes the PCB wiring more concise.

[0032] 2. There is no need to write a specific program. This solution uses a single-way MOS in combination with a common dimmer on the market to adjust the brightness and color temperature, eliminating the trouble of debugging the program, making the debugging easier and shortening the entire product development cycle.

[0033] 3. The electronic components have strong replaceability. All products in this circuit use common electronic components on the market, and multiple suppliers can be found for all electronic components. As long as the parameter performance is the same, the electronic components can be selected, avoiding problems such as out-of-stock and long delivery times from a single supplier, and providing more diverse options for component selection.

[0034] 4. It is easy to pass the certification. The circuit uses a reference power supply, i.e., a voltage type, for switching, eliminating the switching frequency problem. No interference is generated when the MOS is turned on and off, and no conducted interference or radiation interference is produced, so there is no need to add any safety regulations components, saving costs.

[0035] 5. The brightness and color temperature curves are smooth, and the dimming process experience is excellent. There is no flickering during the dimming process. The dimming curve is shown in the following figure.

[0036] 6. Low harmonics and low frequency flicker meet the requirements of the new EU regulation ERP.

[0037] 7. High cost performance. Compared with the bulky dimming power supply lamps, this solution integrates the driven LEDs on the same lamp board, reducing component costs and processing costs, and greatly improving the cost performance and market share of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The following will describe the present utility model in detail with reference to the drawings and specific embodiments.

[0039] Figure 1 It is a schematic diagram of the prior art one;

[0040] Figure 2 It is a schematic diagram of the prior art two;

[0041] Figure 3 It is a schematic diagram of the prior art three;

[0042] Figure 4 This is the structural schematic diagram of the present utility model. Specific embodiments

[0043] In order to make the technical means, creative features, achieved purposes and effects of the present utility model easy to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0044] Refer to Figure 4 , the following technical solutions are adopted in this specific embodiment: A low-harmonic high-power-factor thyristor dimming and color-tuning circuit, including a thyristor dimmer 1, the thyristor dimmer 1 is connected to the L terminal of the power supply, the thyristor dimmer 1 is also connected to the input surge protection circuit 3 through the protection circuit 2, the N terminal of the power supply is also connected to the input surge protection circuit 3, the input surge protection circuit 3 is connected in parallel with the bridge rectifier circuit 4, the positive pole of the bridge rectifier circuit 4 is connected to the constant current control circuit 5, the constant current control circuit 5 is connected through the constant current reference sampling circuit 6, and the constant current reference sampling circuit 6 is respectively connected to the first full balance circuit 7, the second control buck power supply circuit 8, the second warm white LED lamp bead 9, the second cold white LED lamp bead 10, the second filter circuit 11, the second discharge circuit 12, the second control buck power supply circuit 8 is also connected to the filter circuit B13, the second power supply voltage stabilizing circuit 14, the second control reference circuit 15 and the G pole of the second warm white controller 16, the D pole of the second warm white controller 16 is connected to the second warm white dimming adjustment circuit 17, the S pole of the second warm white controller 16 is connected to the second control reference circuit 15, the second warm white dimming adjustment circuit 17 is connected to the second warm white LED lamp bead 9, the second cold white LED lamp bead 10 is connected to the second control reference circuit 15, the second filter circuit 11, the second discharge circuit 12, the filter circuit B13, the second power supply voltage stabilizing circuit 14, the second control reference circuit 15 are all connected to the second full balance circuit 19, the first full balance circuit 7 is connected to the second full balance circuit 19 through the isolation circuit 20, the first full balance circuit 7 is also connected to the first control buck power supply circuit 21, the first warm white LED lamp bead 22, the first cold white LED lamp bead 23, the first filter circuit 24, the first discharge circuit 25, the first full balance circuit 7 is also connected to the reference potential circuit A26, the first control buck power supply circuit 21 is connected to the filter circuit A27, the first power supply voltage stabilizing circuit 28, the first control reference circuit 29, the G pole of the first warm white controller 30, the first control reference circuit 29 is also connected to the S pole of the first warm white controller 30, the D pole of the first warm white controller 30 is connected to the first warm white LED lamp bead 22 through the first warm white dimming adjustment circuit 31, the filter circuit A27, the first power supply voltage stabilizing circuit 28, the first control reference circuit 29, the first filter circuit 24, the first discharge circuit 25 are all connected to the reference potential circuit B32, and the reference potential circuit B32 is also connected to the negative pole of the second full balance circuit 19 and the bridge rectifier circuit 4.

[0045] The thyristor dimmer in this specific embodiment uses a commercially available AC or DC thyristor dimmer. The protection circuit includes safety protection devices such as a fuse tube, a fuse resistor, and a thermistor. When a fault or open circuit occurs in the circuit, this circuit protects and disconnects the power supply to protect the subsequent circuit. The input surge protection circuit protects the entire circuit system from damage by external grid surge voltage. The rectification circuit rectifies the alternating current into a direct current circuit. The linear constant current circuit is a commercially available linear constant current IC. The constant current reference sampling circuit sets the output current of the entire circuit, and the total output current can be adjusted by adjusting the reference voltage on this circuit. The first full balance circuit 7 and the second full balance circuit 19 perform series-parallel operations according to the magnitude of the input voltage. The reference potential circuit A26 and the reference potential circuit B32 respectively provide conduction potentials for the first full balance circuit 7 and the second full balance circuit 19. The first control buck power supply circuit 21 and the second control buck power supply circuit 8 provide base voltage and current for the first warm light controller 30 and the second warm light controller 16, thereby controlling the brightness of the warm light LED lamp. The first warm light LED lamp beads 22 and the second warm light LED lamp beads 9 are common LED lamp beads for warm light color temperature, and the color temperature can be any color temperature lamp beads in the range of 1000K - 5000K. The first warm light LED lamp beads 23 and the second cold light LED lamp beads 10 are common LED lamp beads for cold light color temperature, and the color temperature can be any color temperature lamp beads in the range of 1800K - 10000K. The first filter circuit 24 and the second filter circuit 11 filter out the AC ripple of the lamp strings of the first warm light LED lamp beads 22, the second warm light LED lamp beads 9, the first warm light LED lamp beads 23, and the second cold light LED lamp beads 10. The first discharge circuit 25 discharges the stored energy in the first filter circuit 24 through this circuit when the lamp is turned off. The second discharge circuit 12 discharges the stored energy in the second filter circuit 11 through this circuit when the lamp is turned off.

[0046] The first warm light dimming adjustment circuit 31 of this specific embodiment adjusts the magnitude of the current of the first warm light LED lamp beads 22. By adjusting the magnitude of the current of the first warm light LED lamp beads 22 and coordinating with the current of the white light LED, a smoother curve is obtained. The second warm light dimming adjustment circuit 17 adjusts the magnitude of the current of the second warm light LED lamp beads 9. By adjusting the magnitude of the current of the second warm light LED lamp beads 9 and coordinating with the current of the white light LED, a smoother curve is obtained. The isolation circuit conducts when the input voltage is higher than about twice the voltage of the lamp string of the second cold light LED lamp beads 10, connecting the cold light lamp beads 2 in series with the first warm light LED lamp beads 23, so that the efficiency of the entire circuit is higher. When the input voltage is lower than about twice the voltage of the cold light LED lamp string, it plays a reverse isolation role at this time, and the first full balance circuit 7 and the second full balance circuit 19 work independently to prevent interference between the controllers during series-parallel operation.

[0047] The first warm light controller 30 and the second warm light controller 16 of this specific embodiment control the on / off and conduction magnitude of the first warm light LED beads 22 and the second warm light LED beads 9. The first control reference circuit 29 and the second control reference circuit 15 feedback the reference potential to the G poles of the first warm light controller 30 and the second warm light controller 16, thereby controlling the conduction and turn-off of the first warm light controller 30 and the second warm light controller 16. The filter circuit A 27 and the filter circuit B 13 filter out high-frequency noise, enabling the first warm light controller 30 and the second warm light controller 16 to obtain a more stable voltage; the first power supply voltage regulator 28 and the second power supply voltage regulator 14 provide a stable conduction voltage for the first warm light controller 30 and the second warm light controller 16.

[0048] The so-called alternating current can be the alternating current on the US standard mains electricity and the alternating current of the domestic or European standard mains electricity. The voltage is not limited. This circuit can make corresponding parameter adjustments according to the input voltage to achieve the same power parameters. At the same time, this circuit can also be used for a DC power supply. The voltage is not limited. This circuit can make corresponding parameter adjustments according to the input voltage to achieve the same power parameters.

[0049] The working principle of this specific embodiment is as follows:

[0050] L / N is connected to the alternating current or the direct current. After being chopped by the thyristor dimmer and absorbed by the input surge protection circuit, it is rectified after passing through the protection circuit to obtain pulsating direct current. When the dimmer is adjusted from the minimum to the maximum, at this time, one path supplies the positive poles of the first warm light LED beads 22 and the first warm light LED beads 23 after being limited by the first full balance circuit 7. At the same time, the first filter circuit 24 starts to work to provide a smoother direct current for the positive poles of the first warm light LED beads 22 and the first warm light LED beads 23. At the same time, the first control step-down power supply circuit 21 starts to work. After being filtered by the filter circuit A 27 and regulated by the power supply voltage regulator circuit, the G pole of the first warm light controller 30 obtains the corresponding control voltage. At the same time, the D pole of the first warm light LED bead 22 also obtains the voltage flowing through the first warm light LED bead 22 lamp string. It flows through the control reference 1, is limited by the full balance bridge, and then returns to the - pole of the bridge rectifier circuit to form a loop. At this time, all the first warm light LED beads 22 start to light up from the set darkest brightness (because the cold light LED string is always higher than the warm light, and at this time, the cold light LED string has not reached the turn-on point, so the cold light will not light up).

[0051] Another path supplies the positive electrode of the second warm - light LED lamp bead 9 and the positive electrode of the first cold - light LED lamp bead 23. At the same time, the second filter circuit 11 starts to work to provide smoother direct current electricity for the positive electrode of the second warm - light LED lamp bead 9 and the second cold - light LED lamp bead 10. At the same time, the second control buck - power - supply circuit 8 starts to work. After being filtered by the filter circuit B13 and regulated by the power - supply voltage - regulating circuit, the G - pole of the second warm - light controller 16 obtains the corresponding control voltage. At the same time, the D - pole of the second warm - light LED lamp bead 9 also obtains the voltage flowing through the second warm - light LED lamp string. After flowing through the control reference and passing through the reference potential circuit B32, it returns to the negative pole of the bridge - type rectifier circuit to form a loop. At this time, all the second warm - light LED lamp beads 9 start to light up from the set darkest brightness (because the cold - light LED string is always brighter than the warm - light one, and at this time, the cold - light LED string has not reached the turn - on voltage, so the cold - light does not light up).

[0052] Slowly adjust the thyristor dimming. The input voltage obtained is getting higher and higher. The first warm - light LED lamp beads 22 and the second warm - light LED lamp beads 9 will become brighter and brighter. When adjusted to a certain amplitude, it reaches the turn - on voltage of the cold - light, the first warm - light LED lamp bead 23, and the second cold - light LED lamp bead 10 starts to glow slightly and starts color - mixing. Then, when adjusting the thyristor dimmer upwards, the first warm - light LED lamp beads 22 are mixed with each other, and the brightness of the first warm - light LED lamp bead 23 is getting brighter and brighter. On the other hand, the second warm - light LED lamp beads 9 are mixed with each other, and the brightness of the second cold - light LED lamp bead 10 is getting brighter and brighter. In this way, multiple color - temperature scenes can be mixed. When adjusting the thyristor dimmer upwards to a certain amplitude, at this time, the reference potential circuit A26 obtains a high voltage of about 1V, reaching the cut - off threshold of the first full - balance circuit 7. At this time, the circuit is converted to series operation of the lamp string. Most of the current passes through the second cold - light LED lamp bead 10 and the second warm - light LED lamp bead 9, passes through the corresponding control circuit, then through the isolation circuit, through the reference potential circuit A26, through the first warm - light LED lamp bead 23 and the first warm - light LED lamp bead 22, passes through the corresponding control circuit, and then returns to the negative pole of the bridge - type rectifier circuit through the reference potential circuit B32 to form a loop;

[0053] When further adjusting the thyristor dimmer upwards, at this time, the brightness and color - temperature increase simultaneously. When adjusting to the reference voltages of the first warm - light controller 30 and the second warm - light controller 16 reaching 2.5V, that is, when the reference voltages of the first warm - light controller 30 and the second warm - light controller 16 reach this value, the first warm - light controller 30 and the second warm - light controller 16 are cut off, and the first warm - light LED lamp beads 22 and the second warm - light LED lamp beads 9 go out. Only the first warm - light LED lamp bead 23 and the second cold - light LED lamp bead 10 are on. When further adjusting to the maximum range of the dimmer, at this time, the brightness is the highest, the power of the lamp is the largest, and the color - temperature is the largest.

[0054] Adjust from the maximum brightness. When the reference voltages of the first warm light controller 30 and the second warm light controller 16 are lower than 2.5V, the warm light turns on, and this is the maximum brightness of the warm light at this time. Adjust the dimmer to make it darker and darker. When the potential of the reference potential circuit A26 is lower than the reference cut-off threshold of full balance, at this time, the first full balance circuit 7 starts to work, and the circuit is converted into a parallel working state of the first full balance circuit 7 and the second full balance circuit 19; then slowly adjust the thyristor dimmer. At this time, the power supply is too low to turn on the cold light lamp beads. The first warm light LED lamp beads 23 and the second cold light LED lamp beads 10 go out. At this time, only the first warm light LED lamp beads 22 and the second warm light LED lamp beads 9 are on. When adjusting further down, when the voltage is insufficient to maintain the voltage of the first warm light LED lamp beads 22 and the second warm light LED lamp beads 9, all the LEDs go out. When adjusting further down, the power supply is turned off to complete a dimming process.

[0055] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A low harmonic and high power factor thyristor dimming and color adjustment circuit, characterized in that: The invention comprises a thyristor dimmer (1), wherein the thyristor dimmer (1) is connected to the L end of a power supply, the thyristor dimmer (1) is also connected to an input surge protection circuit (3) through a protection circuit (2), the N end of the power supply is also connected to the input surge protection circuit (3), the input surge protection circuit (3) is connected in parallel with a bridge rectifier circuit (4), the positive electrode of the bridge rectifier circuit (4) is connected to a constant current control circuit (5), the constant current control circuit (5) is connected through a constant current reference sampling circuit (6), and the constant current reference sampling circuit (6) is respectively connected to a first fully balanced circuit (7), a second control step-down power supply circuit (8), a second warm light LED lamp bead (9), a second cold light LED lamp bead (10), a second filter circuit (11), and a first full balanced circuit (7), a second control step-down power supply circuit (8), a second warm light LED lamp bead (9), a second cold light LED lamp bead (10), and a second filter circuit (11). The second control step-down power supply circuit (8) is also connected to the filter circuit B (13), the second power supply stabilizing circuit (14), the second control reference circuit (15) and the G pole of the second warm light controller (16); the D pole of the second warm light controller (16) is connected to the second warm light dimming adjustment circuit (17); the S pole of the second warm light controller (16) is connected to the second control reference circuit (15); the second warm light dimming adjustment circuit (17) is connected to the second warm light LED lamp bead (9); the second cold light LED lamp bead (10) is connected to the second control reference circuit (15); the second filter circuit (11), the second discharge circuit ( The first fully balanced circuit (7) is connected to the second fully balanced circuit (19); the first fully balanced circuit (7) is connected to the second fully balanced circuit (19) through the isolation circuit (20); the first fully balanced circuit (7) is also connected to the first controlled step-down power supply circuit (21), the first warm light LED lamp bead (22), the first cold light LED lamp bead (23), the first filter circuit (24), and the first discharge circuit (25); the first fully balanced circuit (7) is also connected to the reference potential circuit A (26); the first controlled step-down power supply circuit (21) is connected to the filter circuit A (27), the first power supply voltage stabilization circuit (28), and the first discharge circuit (25). The first control reference circuit (28), the first control reference circuit (29), and the G pole of the first warm light controller (30) are connected; the first control reference circuit (29) is also connected to the S pole of the first warm light controller (30); the D pole of the first warm light controller (30) is connected to the first warm light LED lamp bead (22) through the first warm light dimming adjustment circuit (31); the filter circuit A (27), the first power supply stabilizing circuit (28), the first control reference circuit (29), the first filter circuit (24), and the first discharge circuit (25) are all connected to the reference potential circuit B (32); the reference potential circuit B (32) is also connected to the second fully balanced circuit (19) and the negative pole of the bridge rectifier circuit (4).

2. A low harmonic high power factor thyristor dimming and color adjustment circuit according to claim 1, characterized in that: The reference potential circuit A (26) and the reference potential circuit B (32) provide conduction potentials for the first fully balanced circuit (7) and the second fully balanced circuit (19) respectively.

3. The low harmonic and high power factor thyristor dimming and color adjustment circuit according to claim 1, characterized in that: The first control step-down power supply circuit (21) and the second control step-down power supply circuit (8) provide base voltage and current for the first warm light controller (30) and the second warm light controller (16).

4. The low harmonic and high power factor thyristor dimming and color adjustment circuit according to claim 1, characterized in that: The first warm light LED lamp bead (22) and the second warm light LED lamp bead (9) are lamp beads with a color temperature in any range of 1000K-5000K.

5. The low harmonic and high power factor thyristor dimming and color adjustment circuit according to claim 1, characterized in that: The first cold light LED lamp bead (23) and the second cold light LED lamp bead (10) are lamp beads with a color temperature in any range of 1800K-10000K.

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