Silicon controlled rectifier dimming control circuit

Abstract

The utility model discloses a silicon controlled rectifier dimming control circuit, which relates to the technical field of illumination and comprises an AC (alternating current) input module, a power supply circuit module, a zero-cross detection module, a control signal input module, a digital signal processing module and a power switch filtering module. The input end of the AC input module is connected with an AC power supply, and the output end is connected with the power supply circuit module, the zero-cross detection module and the power switch filtering module. The power supply circuit module is used for supplying power to the digital signal processing module; the control signal input module is used for inputting a control signal into the digital signal processing module; the zero-crossing detection module is used for inputting a zero-crossing signal into the digital signal processing module; and the power switch filtering module is used for filtering the dimming signal output by the digital signal processing module. According to the utility model, double-control dimming can be realized.

Description

Technical Field

[0001] The utility model relates to the technical field of lighting, in particular to a thyristor dimming control circuit. Background Art

[0002] Phase-cut dimming is a common dimming method, which is widely used in many homes, offices, hotels and other occasions. Its principle is: by turning on or off a power switch in series in the line at a certain phase value of the line AC power to adjust the effective value of the voltage at the output end of the line, thereby achieving power and brightness adjustment of the load lamp.

[0003] like Figure 1 As shown, the traditional dimmer mainly uses resistor voltage division and capacitor charging delay as the control signal of the phase-cutting value, and changes the capacitor charging time by adjusting the resistance value of the adjustable resistor to achieve the delayed opening or closing time of the power switch, so as to adjust the size of the phase-cutting angle; however, the dimming value of the above adjustment method is not quantifiable and is easily affected by voltage fluctuations, and dual control is not easy to achieve dimming. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a thyristor dimming control circuit which can realize dual-control dimming.

[0005] In order to solve the above technical problems, the utility model provides a thyristor dimming control circuit, including: an AC input module, a power supply circuit module, a zero-crossing detection module, a control signal input module, a digital signal processing module and a power switch filter module; the input end of the AC input module is connected to an AC power supply, and the output end is respectively connected to the power supply circuit module, the zero-crossing detection module and the power switch filter module; the power supply circuit module is connected to the digital signal processing module for supplying power to the digital signal processing module; the control signal input module is connected to the digital signal processing module for inputting a control signal into the digital signal processing module; the zero-crossing detection module is connected to the digital signal processing module for inputting a zero-crossing signal into the digital signal processing module; the power switch filter module is connected to the digital signal processing module for filtering the dimming signal output by the digital signal processing module.

[0006] As an improvement of the above scheme, the power supply circuit module includes a thermal relay, a fuse, a varistor, a first diode, a first polarity capacitor, a second polarity capacitor, a twenty-seventh resistor, a second inductor, a power supply chip, an iron core inductor, a bias resistor, a third polarity capacitor, a third capacitor, a fifth resistor and a fourth capacitor; one end of the varistor is connected to the positive electrode of the first diode and connected to the neutral line through the thermal relay, and the other end is grounded and connected to the live line through the fuse; the negative electrode of the first diode is respectively connected to one end of the second inductor and the positive electrode of the first polarity capacitor, the other end of the second inductor is connected to the positive electrode of the second polarity capacitor, the negative electrode of the first polarity capacitor and the negative electrode of the second polarity capacitor are grounded, and the second inductor is connected in parallel with the twenty-seventh resistor; the high-voltage power supply end of the power supply chip is connected to the positive electrode of the second polarity capacitor, the high-voltage grounding end is connected to the detection end through the iron core inductor, the output end is connected to the positive electrode of the third polarity capacitor, and the detection end is connected to the positive electrode of the third polarity capacitor through the bias resistor; the third polarity capacitor, the third capacitor, the fifth resistor and the fourth capacitor are connected in parallel.

[0007] As an improvement of the above scheme, the zero-crossing detection module includes a second triode, a fourth diode, a first resistor, a second resistor, a third resistor, a fourth resistor and a sixth capacitor; the base of the second triode is connected to the cathode of the fourth diode through the second resistor and the first resistor in sequence, and is grounded through the third resistor; the emitter of the second triode is grounded; the collector of the second triode is connected to the output end of the power supply circuit module through the fourth resistor, and is grounded through the sixth capacitor, and the collector of the second triode is connected to the digital signal processing module; the anode of the fourth diode is connected to the anode of the first diode.

[0008] As an improvement of the above solution, the zero-crossing detection module further includes a first zener diode, the base of the second transistor is connected to the cathode of the first zener diode, and the anode of the first zener diode is grounded.

[0009] As an improvement of the above scheme, the control signal input module includes a fifth diode, a sixth diode, a sixth resistor, a nineteenth capacitor and a thirty-sixth resistor; the anode of the fifth diode is connected to the anode of the sixth diode, and the cathode of the fifth diode is used to access the control signal; the cathode of the sixth diode is grounded and connected to the digital signal processing module, the anode of the sixth diode is connected to one end of the thirty-sixth resistor and is grounded through the sixth resistor, the other end of the thirty-sixth resistor is connected to the positive electrode of the second polarity capacitor, and the sixth resistor is connected in parallel with the nineteenth capacitor.

[0010] As an improvement of the above solution, the control signal input module further includes a second voltage regulator diode, the cathode of the sixth diode is connected to the cathode of the second voltage regulator diode, and the anode of the second voltage regulator diode is grounded.

[0011] As an improvement of the above scheme, the thyristor dimming control circuit also includes a signal isolation module arranged between the digital signal processing module and the power switch filter module, and the signal isolation module is used to isolate and process the dimming signal output by the digital signal processing module; the signal isolation module includes an isolation optocoupler, an eighteenth resistor, a nineteenth resistor, a third transistor, a twenty-first resistor and a seventh capacitor; the emitter of the third transistor is grounded, the base is connected to the digital signal processing module through the eighteenth resistor, and the collector is connected to the base through the nineteenth resistor and connected to the reverse input end of the isolation optocoupler; the forward input end of the isolation optocoupler is connected to the output end of the power supply circuit module through the twenty-first resistor and is grounded through the seventh capacitor, and the output end of the isolation optocoupler is connected to the power switch filter module.

[0012] As an improvement of the above scheme, the power switch filter module includes a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a twenty-eighth resistor, a tenth capacitor, a first inductor and a bidirectional thyristor; the first output end of the signal isolation module is respectively connected to one end of the twenty-eighth resistor and one end of the twenty-third resistor through the twenty-second resistor, the other end of the twenty-eighth resistor is grounded through the tenth capacitor, and the other end of the twenty-third resistor is connected to the load through the first inductor; the second output end of the signal isolation module is grounded through the twenty-sixth resistor and connected to the control electrode of the bidirectional thyristor, the first anode of the bidirectional thyristor is grounded, and the second anode is connected to the load through the first inductor; one end of the twenty-fourth resistor is grounded through the tenth capacitor, and the other end is connected to the load through the first inductor, and the twenty-fourth resistor is connected in parallel with the twenty-fifth resistor.

[0013] As an improvement of the above solution, the thyristor dimming control circuit further includes a functional module connected to the digital signal processing module, and the functional module is used to input the adjustment signal into the digital signal processing module.

[0014] As an improvement of the above solution, the thyristor dimming control circuit also includes an external circuit connected to the control signal input module, and the external circuit includes a sub-controller.

[0015] The implementation of this utility model has the following beneficial effects:

[0016] In the utility model, the AC input module, the power supply circuit module, the zero-crossing detection module, the control signal input module, the digital signal processing module and the power switch filter module cooperate with each other, wherein the power supply circuit is a non-isolated circuit and adopts half-wave rectification, the zero-crossing detection circuit is a half-wave detection circuit, the control signal circuit realizes the sub-control function, the power switch filter module realizes the chopping output, and accurately realizes the dimming control of the load;

[0017] At the same time, the utility model realizes real-time detection of phase by introducing a zero-crossing detection module into the thyristor dimming control circuit, which can effectively avoid the influence of voltage fluctuations, making the dimming more accurate and less susceptible to interference;

[0018] In addition, the control signal input circuit in the utility model can be connected to a single-key signal or a multi-key signal provided by an external switch or other button terminals, has strong flexibility, and can also accurately realize dual-control dimming. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the circuit diagram of the existing dimmer;

[0020] Figure 2 This is a schematic structural diagram of a first embodiment of a thyristor dimming control circuit of the utility model;

[0021] Figure 3 This is a schematic structural diagram of a second embodiment of the thyristor dimming control circuit of the utility model;

[0022] Figure 4 It is a circuit diagram of the power supply circuit module in the utility model;

[0023] Figure 5 It is a circuit diagram of the zero-crossing detection module in the utility model;

[0024] Figure 6 It is a circuit diagram of the control signal input module in the utility model;

[0025] Figure 7 It is a circuit diagram of an external circuit of a control signal input module in the utility model;

[0026] Figure 8 It is a circuit diagram of a signal isolation module and a power switch filter module in the utility model. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below with reference to the accompanying drawings.

[0028] See also Figure 2 , Figure 2The first embodiment of the thyristor dimming control circuit of the utility model is shown, which includes an AC input module 1, a power supply circuit module 2, a zero-crossing detection module 3, a control signal input module 4, a digital signal processing module 6 and a power switch filter module 8. Specifically:

[0029] The input end of the AC input module 1 is connected to the AC power supply, and the output end is respectively connected to the power supply circuit module 2, the zero-crossing detection module 3 and the power switch filter module 8;

[0030] The power supply circuit module 2 is connected to the digital signal processing module 6 and is used to supply power to the digital signal processing module 6;

[0031] The control signal input module 4 is connected to the digital signal processing module 6 and is used to input the control signal into the digital signal processing module 6;

[0032] The zero-crossing detection module 3 is connected to the digital signal processing module 6 and is used to input the zero-crossing signal into the digital signal processing module 6;

[0033] The digital signal processing module 6 is used to shield and filter the phase interference signal according to the zero-crossing signal, and convert the control signal into a dimming signal. It should be noted that the processing function of the digital signal processing module 6 is a prior art, and as long as it can realize simple signal filtering and conversion functions, it will not be further described in the present utility model.

[0034] The power switch filter module 8 is connected to the digital signal processing module 6 and is used to filter the dimming signal output by the digital signal processing module 6 .

[0035] Therefore, the utility model can perform phase detection through the zero-crossing detection module 3, and obtain the control signal through the control signal input module 4, and then convert the control signal into a dimming signal through the digital signal processing module 6, and finally the dimming signal is filtered through the power switch filter module 8 and output to the load to achieve dimming control.

[0036] It should be noted that the control signal input module 4 can input a control signal (which can be a digital signal or an analog signal) provided by an external switch or other button terminal to achieve dual control, and its dual control functions include controlling the switch and brightness.

[0037] During operation, the user can input a key signal (i.e., a control signal) through an external switch or other button terminal. After receiving the key signal, the digital signal processing module 6 triggers a control interrupt and converts the key signal into a dimming signal. The specific conversion logic can refer to the prior art, including:

[0038] (1) Threshold control: When connected to a multi-key controller, threshold a corresponds to the on / off command, threshold b corresponds to the dimming + command, and threshold c corresponds to the dimming - command;

[0039] (2) Key duration control: Single-key control can identify key values ​​by detecting the key duration; for example, if the key duration is less than d and greater than e, it corresponds to an on / off command, and if the key duration is greater than d, it corresponds to continuous dimming + / continuous dimming -.

[0040] In summary, the utility model realizes real-time detection of phase by introducing the zero-crossing detection module 3 into the thyristor dimming control circuit, which can effectively avoid the influence of voltage fluctuations, making the dimming more accurate and less susceptible to interference; at the same time, combined with the key signal, dual-control dimming can be accurately achieved.

[0041] See also Figure 3 , Figure 3 The second embodiment of the thyristor dimming control circuit of the utility model is shown. Figure 1 The difference from the first embodiment shown is that this embodiment further includes a functional module 5 and a signal isolation module 7, specifically:

[0042] The functional module 5 is connected to the digital signal processing module 6 and is used to input the adjustment signal into the digital signal processing module 6 .

[0043] The signal isolation module 7 is provided between the digital signal processing module 6 and the power switch filter module 8, and is used to isolate and process the dimming signal output by the digital signal processing module 6;

[0044] Furthermore, the thyristor dimming control circuit of the utility model also includes an external circuit connected to the control signal input module, and the external circuit includes a sub-controller.

[0045] In conjunction with the specific circuit diagram, the AC input module 1, the power supply circuit module 2, the zero-crossing detection module 3, the control signal input module 4, the external circuit, the functional module 5, the signal isolation module 7, the power switch filter module 8 and the digital signal processing module 6 are described in detail below:

[0046] 1. AC input module

[0047] The AC input module 1 can be connected to an AC power source by connecting a neutral line N and a live line L.

[0048] 2. Power supply circuit module

[0049] like Figure 4As shown, the power supply circuit module 2 includes a thermal relay FR1, a fuse FU1, a varistor VR1, a first diode D1, a first polarity capacitor CE1, a second polarity capacitor CE2, a twenty-seventh resistor R27, a second inductor L2, a power supply chip U1, an iron core inductor T1, a bias resistor RS1, a third polarity capacitor CE3, a third capacitor C3, a fifth resistor R5 and a fourth capacitor C4;

[0050] One end of the varistor VR1 is connected to the positive electrode of the first diode D1 and to the neutral line N through the thermal relay FR1, and the other end is grounded and connected to the live line L through the fuse FU1; the negative electrode of the first diode D1 is respectively connected to one end of the second inductor L2 and the positive electrode of the first polarity capacitor CE1, the other end of the second inductor L2 is connected to the positive electrode of the second polarity capacitor CE2, the negative electrode of the first polarity capacitor CE1 and the negative electrode of the second polarity capacitor CE2 are grounded, and the second inductor L2 is connected in parallel with the twenty-seventh resistor R27; the high-voltage power supply terminal HV of the power supply chip U1 is connected to the positive electrode of the second polarity capacitor CE2, the high-voltage grounding terminal VS is connected to the detection terminal CSP through the iron core inductor T1, the output terminal Vout is connected to the positive electrode of the third polarity capacitor CE3, and the detection terminal CSP is connected to the positive electrode of the third polarity capacitor CE3 through the bias resistor RS1; the third polarity capacitor CE3, the third capacitor C3, the fifth resistor R5 and the fourth capacitor C4 are connected in parallel.

[0051] It should be noted that the power supply circuit module 2 is a non-isolated circuit, which adopts half-wave rectification, takes the live wire L as the common wire, and two insurance devices (thermal relay FR1 and fuse FU1) are respectively connected to the live wire L and the neutral wire N to ensure the normal operation of the power supply circuit module 2.

[0052] 3. Zero Crossing Detection Module

[0053] like Figure 5 As shown, the zero-crossing detection module 3 includes a second transistor Q2, a fourth diode D4, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a sixth capacitor C6;

[0054] The base of the second triode Q2 is connected to the cathode of the fourth diode D4 through the second resistor R2 and the first resistor R1 in sequence, and is grounded through the third resistor R3; the emitter of the second triode Q2 is grounded; the collector of the second triode Q2 is connected to the output end of the power supply circuit module 2 through the fourth resistor R4, and is grounded through the sixth capacitor C6, and the collector of the second triode Q2 is connected to the digital signal processing module 6; the anode of the fourth diode D4 is connected to the anode of the first diode D1.

[0055] It should be noted that the zero-crossing detection module 3 is a half-wave detection circuit, and the zero-crossing detection input is before the power supply circuit module 2. After the zero-crossing detection module 3 amplifies the input waveform, it is convenient to detect the zero-crossing position.

[0056] Furthermore, the zero-crossing detection module 3 further includes a first voltage-stabilizing diode DZ1, the base of the second transistor Q2 is connected to the cathode of the first voltage-stabilizing diode DZ1, and the anode of the first voltage-stabilizing diode DZ1 is grounded. The first voltage-stabilizing diode DZ1 is used as a signal protection device and can be set or cancelled according to actual needs.

[0057] 4. Control signal input module

[0058] like Figure 6 As shown, the control signal input module 4 includes a fifth diode D5, a sixth diode D6, a sixth resistor R6, a nineteenth capacitor C19 and a thirty-sixth resistor R36;

[0059] The anode of the fifth diode D5 is connected to the anode of the sixth diode D6, and the cathode of the fifth diode D5 is used to access the control signal; the cathode of the sixth diode D6 is grounded and connected to the digital signal processing module 6, the anode of the sixth diode D6 is connected to one end of the thirty-sixth resistor R36 and is grounded through the sixth resistor R6, the other end of the thirty-sixth resistor R36 is connected to the anode of the second polarity capacitor CE2, and the sixth resistor R6 is connected in parallel with the nineteenth capacitor C19.

[0060] The control signal input module 4 is used to realize the sub-control function. After voltage division by the thirty-sixth resistor R36 and the sixth resistor R6R6, combined with two unidirectional switches of the fifth diode D5 and the sixth diode D6, the detection of the sub-controller access level signal can be realized.

[0061] Furthermore, the control signal input module 4 further includes a second voltage stabilizing diode DZ2, the cathode of the sixth diode D6 is connected to the cathode of the second voltage stabilizing diode DZ2, and the anode of the second voltage stabilizing diode DZ2 is grounded. The second voltage stabilizing diode DZ2 is used as a signal protection device and can be set or cancelled according to actual needs.

[0062] 5. External circuit

[0063] like Figure 7 As shown, the external circuit is connected to the control signal input module 4, and the external circuit includes a sub-controller, which can be an ordinary single-button switch or a multi-button function device, but is not limited to this and can be selected according to actual conditions. At the same time, the sub-controller can be connected to any line of the live wire L or the neutral wire N, which is easy to install.

[0064] 6. Functional modules

[0065] Functional module 5 includes any one or more of an interactive unit, an indication unit, and a communication unit, wherein the interactive unit can be a key input of the control panel, the indication unit can realize the indicator light function, and the communication unit can realize the wireless communication function. Users can set it according to actual needs, which is highly flexible.

[0066] 7. Signal isolation module and power switch filter module

[0067] like Figure 8 As shown, the signal isolation module 7 and the power switch filter module 8 include an isolation optical coupler U6, an eighteenth resistor R18, a nineteenth resistor R19, a third transistor Q3, a twenty-first resistor R21, a seventh capacitor C7, a twenty-second resistor R22, a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a twenty-eighth resistor R28, a tenth capacitor C10, a first inductor L1 and a bidirectional thyristor Q1;

[0068] The emitter of the third transistor Q3 is grounded, the base is connected to the digital signal processing module through the eighteenth resistor R18, and the collector is connected to the base through the nineteenth resistor R19 and connected to the reverse input end of the isolation optocoupler U6; the positive input end of the isolation optocoupler U6 is connected to the output end of the power supply circuit module 2 through the twenty-first resistor R21 and is grounded through the seventh capacitor C7; the output end of the isolation optocoupler U6 is connected to the power switch filter module 8, wherein the first output end of the isolation optocoupler U6 is respectively connected to one end of the twenty-eighth resistor R28 and the twenty-third resistor R2 through the twenty-second resistor R22 3, the other end of the twenty-eighth resistor R28 is grounded through the tenth capacitor C10, and the other end of the twenty-third resistor R23 is connected to the load through the first inductor L1; the second output end of the isolation optocoupler U6 is grounded through the twenty-sixth resistor R26, and connected to the control electrode of the bidirectional thyristor Q1, the first anode of the bidirectional thyristor Q1 is grounded, and the second anode is connected to the load through the first inductor L1; one end of the twenty-fourth resistor R24 ​​is grounded through the tenth capacitor C10, and the other end is connected to the load through the first inductor L1, and the twenty-fifth resistor R25 is connected in parallel with the twenty-fourth resistor R24.

[0069] The isolation of high / low voltage signals can be performed through the isolation optocoupler U6, wherein the third transistor Q3 is the driving switch of the optocoupler U6, and its base and collector are connected to the nineteenth resistor R19, which can accelerate the conduction speed of the third transistor Q3 when the eighteenth resistor R18 input controls a high level.

[0070] It should be noted that chopping output can be achieved through the power switch filter module 8, and the output end of the power switch filter module can be connected to a load to achieve dimming control.

[0071] 8. Digital Signal Processing Module

[0072] The digital signal processing module 6 is a conventional digital circuit with MCU as the core, which is used to receive control signals and zero-crossing signals and output dimming signals. The model of MCU can be Atmega8 or JZ1508-MCU-OTP-I C, which is not limited in this embodiment.

[0073] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the protection scope of the present invention.

Claims

1. A thyristor dimming control circuit, characterized in that: It includes an AC input module, a power supply circuit module, a zero-crossing detection module, a control signal input module, a digital signal processing module and a power switch filter module; The input end of the AC input module is connected to the AC power supply, and the output end is respectively connected to the power supply circuit module, the zero-crossing detection module and the power switch filter module; The power supply circuit module is connected to the digital signal processing module and is used to supply power to the digital signal processing module; The control signal input module is connected to the digital signal processing module and is used to input the control signal into the digital signal processing module; The zero-crossing detection module is connected to the digital signal processing module and is used to input the zero-crossing signal into the digital signal processing module; The power switch filter module is connected to the digital signal processing module and is used to filter the dimming signal output by the digital signal processing module.

2. The thyristor dimming control circuit according to claim 1, characterized in that: The power supply circuit module includes a thermal relay, a fuse, a varistor, a first diode, a first polarity capacitor, a second polarity capacitor, a twenty-seventh resistor, a second inductor, a power supply chip, an iron core inductor, a bias resistor, a third polarity capacitor, a third capacitor, a fifth resistor and a fourth capacitor; One end of the varistor is connected to the positive electrode of the first diode and connected to the neutral line through the thermal relay, and the other end is grounded and connected to the live line through the fuse; The cathode of the first diode is connected to one end of the second inductor and the anode of the first polarity capacitor respectively, the other end of the second inductor is connected to the anode of the second polarity capacitor, the cathode of the first polarity capacitor and the cathode of the second polarity capacitor are grounded, and the second inductor is connected in parallel with the twenty-seventh resistor; The high-voltage power supply end of the power supply chip is connected to the positive electrode of the second polarity capacitor, the high-voltage grounding end is connected to the detection end through the iron core inductor, the output end is connected to the positive electrode of the third polarity capacitor, and the detection end is connected to the positive electrode of the third polarity capacitor through the bias resistor; The third polarity capacitor, the third capacitor, the fifth resistor and the fourth capacitor are connected in parallel.

3. The thyristor dimming control circuit according to claim 2, characterized in that: The zero-crossing detection module includes a second triode, a fourth diode, a first resistor, a second resistor, a third resistor, a fourth resistor and a sixth capacitor; The base of the second transistor is connected to the cathode of the fourth diode through the second resistor and the first resistor in sequence, and is grounded through the third resistor; The emitter of the second triode is grounded; The collector of the second transistor is connected to the output end of the power supply circuit module through the fourth resistor and is grounded through the sixth capacitor, and the collector of the second transistor is connected to the digital signal processing module; An anode of the fourth diode is connected to an anode of the first diode.

4. The thyristor dimming control circuit according to claim 3, characterized in that: The zero-crossing detection module further includes a first voltage-stabilizing diode, the base of the second transistor is connected to the cathode of the first voltage-stabilizing diode, and the anode of the first voltage-stabilizing diode is grounded.

5. The thyristor dimming control circuit according to claim 2, characterized in that: The control signal input module includes a fifth diode, a sixth diode, a sixth resistor, a nineteenth capacitor and a thirty-sixth resistor; The anode of the fifth diode is connected to the anode of the sixth diode, and the cathode of the fifth diode is used to access the control signal; The cathode of the sixth diode is grounded and connected to the digital signal processing module, the anode of the sixth diode is connected to one end of the thirty-sixth resistor and grounded through the sixth resistor, the other end of the thirty-sixth resistor is connected to the anode of the second polarity capacitor, and the sixth resistor is connected in parallel with the nineteenth capacitor.

6. The thyristor dimming control circuit according to claim 5, characterized in that: The control signal input module further includes a second voltage stabilizing diode, a cathode of the sixth diode is connected to a cathode of the second voltage stabilizing diode, and an anode of the second voltage stabilizing diode is grounded.

7. The thyristor dimming control circuit according to claim 1, characterized in that: It also includes a signal isolation module disposed between the digital signal processing module and the power switch filter module, the signal isolation module is used to isolate the dimming signal output by the digital signal processing module; The signal isolation module includes an isolation optical coupler, an eighteenth resistor, a nineteenth resistor, a third transistor, a twenty-first resistor and a seventh capacitor; The emitter of the third transistor is grounded, the base is connected to the digital signal processing module through the eighteenth resistor, and the collector is connected to the base through the nineteenth resistor and connected to the reverse input end of the isolation optocoupler; The positive input end of the isolation optocoupler is connected to the output end of the power supply circuit module through the twenty-first resistor and is grounded through the seventh capacitor, and the output end of the isolation optocoupler is connected to the power switch filter module.

8. The thyristor dimming control circuit according to claim 7, characterized in that: The power switch filter module includes a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a twenty-eighth resistor, a tenth capacitor, a first inductor and a bidirectional thyristor; The first output end of the signal isolation module is respectively connected to one end of the twenty-eighth resistor and one end of the twenty-third resistor through the twenty-second resistor, the other end of the twenty-eighth resistor is grounded through the tenth capacitor, and the other end of the twenty-third resistor is connected to the load through the first inductor; The second output end of the signal isolation module is grounded through the twenty-sixth resistor and connected to the control electrode of the bidirectional thyristor, the first anode of the bidirectional thyristor is grounded, and the second anode is connected to the load through the first inductor; One end of the twenty-fourth resistor is grounded via the tenth capacitor, and the other end is connected to a load via the first inductor. The twenty-fourth resistor is connected in parallel with the twenty-fifth resistor.

9. The thyristor dimming control circuit according to claim 1, characterized in that: It also includes a functional module connected to the digital signal processing module, and the functional module is used to input the adjustment signal into the digital signal processing module.

10. The thyristor dimming control circuit according to claim 1, characterized in that: It also includes an external circuit connected to the control signal input module, and the external circuit includes a sub-controller.

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