CN105517245A - A LED constant current dimming power supply - Google Patents

Abstract

The invention belongs to the technical field of power supplies, and particularly relates to an LED constant-current dimming power supply, which comprises: the DALI signal decoding module is used for decoding the DALI control signal; the signal conversion module is used for receiving the signal of the DALI signal decoding module and converting the signal; the square wave pulse signal conversion module is used for converting the signals converted by the signal conversion module into a group of square wave pulse signals which change according to the control signals; the LED driving control module is used for receiving the square wave pulse signal of the square wave pulse signal conversion module; and the external LED lighting module receives the signal of the LED driving control module to realize dimming. Compared with the prior art, the invention can realize time-interval dimming and can simultaneously dim a plurality of LED lamps, thereby realizing energy conservation and emission reduction, and the output signal is correspondingly changed along with the DALI control signal requirement, thereby improving the dimming accuracy and flexibility.

Description

A LED constant current dimming power supply

technical field

The invention belongs to the technical field of power supplies, in particular to an LED constant current dimming power supply.

Background technique

In recent years, the current situation of energy shortage has made people increasingly aware of the importance of energy conservation and emission reduction. As a new type of high-efficiency solid-state light source, LED has the characteristics of energy saving, environmental protection, long life and small size, and is widely used in high-power lighting occasions such as road lighting and tunnel lighting.

Currently, there are two modes of driving LED panel lamps: constant current and constant voltage. Generally speaking, the constant current mode is beneficial to prolong the service life of LED light sources. Because in the constant voltage mode, once the current through the LED changes, the temperature of the PN junction of the LED will change, which is related to the life of the LED, and the constant current drive will ensure that the current through the LED will not change, that is, There will be no temperature variation of the PN junction of the LED.

However, the constant-current LED power supply in the prior art cannot realize intelligent dimming, dimming by time intervals, and simultaneous dimming of multiple lamps. With the continuous diversification of lighting requirements, LED lamps are required to be The scene has different brightness, so the existing constant power output driving method can no longer meet the market demand.

In view of this, it is indeed necessary to provide a LED constant-current dimming power supply, which can realize time-division dimming, and can dim multiple LED lights at the same time, so as to achieve energy saving and emission reduction. DALI control signal requirements are changed accordingly, thereby improving dimming accuracy and flexibility.

Contents of the invention

The purpose of the present invention is to provide a LED constant-current dimming power supply for the deficiencies of the prior art, which can realize time-division dimming, and can simultaneously dim multiple LED lamps, so as to realize energy saving and emission reduction , Moreover, the output signal changes accordingly with the DALI control signal requirements, thereby improving the dimming accuracy and flexibility.

In order to achieve the above object, the present invention adopts the following technical solutions:

An LED constant current dimming power supply, comprising:

DALI (Digital Addressable Lighting Interface Digital Addressable Lighting Interface) signal decoding module, used to decode DALI control signals;

The signal conversion module receives the signal of the DALI signal decoding module and converts it;

The square wave pulse signal conversion module is used to convert the signal converted by the signal conversion module into a group of square wave pulse signals changed according to the control signal;

The LED drive control module is used to receive the square wave pulse signal of the square wave pulse signal conversion module;

and an external LED lighting module to receive signals from the LED drive control module to realize dimming.

As an improvement of the LED constant current dimming power supply of the present invention, the square wave pulse signal conversion module includes a square wave signal duty cycle control module, a signal frequency control module and a signal amplification output module, and the square wave signal duty cycle The input end and the output end of the control module are respectively connected with the output end of the signal conversion module and the input end of the signal frequency control module, and the output end of the signal frequency control module is connected with the input end of the signal amplification output module , the output end of the signal amplification output module is connected to the input end of the LED drive control module.

As an improvement of the LED constant-current dimming power supply of the present invention, the power supply also includes a rectification and filtering module for converting AC mains power into high-voltage DC power;

And DC/DC conversion module, used to convert high voltage direct current into several groups of low voltage.

As an improvement of the LED constant current dimming power supply of the present invention, the rectification and filtering module includes a fuse F1, a varistor TVR, an inductor Lw, a capacitor C1, a capacitor CY1, a capacitor CY2, an inductor L1, a bridge rectifier filter BR, Inductor L2, resistor R3 and capacitor C3, the fuse F1 is connected to the live wire, the two ends of the varistor TVR are connected to the fuse F1 and the neutral line respectively, the two ends of the inductance Lw are connected to the two ends of the varistor TVR, the other end of the inductance Lw The two ends are respectively connected to the two ends of the capacitor C1. One end of the capacitor C1 is connected to the capacitor CY2 and then connected to the casing. The other two ends of the inductor L1 are connected to the two AC terminals of the bridge rectifier filter BR; the A+ terminal of the bridge rectifier filter BR is connected to the inductor L2 and grounded through the capacitor C3, and the inductor L2 is connected to the P pole; the resistor R3 It is connected in parallel with the inductor L2, and the A-terminal of the bridge rectifier filter BR is grounded and connected to the N pole.

As an improvement of the LED constant current dimming power supply of the present invention, the DC/DC conversion module includes a chip U1, and the first pin and the second pin of the chip U1 are sequentially connected to a resistor R12, a resistor R14, a diode D5, and a diode D12 , Resistor R21 is connected to VCC, resistor R21 is also connected to capacitor C8 and then grounded, capacitor C8 is connected in parallel with capacitor C1, resistor R12 is connected in parallel with resistor R13, resistor R12 and resistor R14 are grounded through capacitor C4, resistor R21 is also connected to resistor R12 through resistor R61 Connect with resistor R10;

The third pin of the chip U1 is connected to the resistor R9 and the capacitor C10 in turn, and then grounded. The third pin of the chip U1 is also connected to the resistor R12 through the capacitor C5, the resistor R10, and the capacitor C5 and the resistor R10 are connected to the ground;

The fourth pin of the chip U1 is grounded through the resistor R25 and the resistor R26 in turn, and the resistor R26 and the resistor R29 are connected in parallel;

The fifth pin of the chip U1 is connected to the capacitor C9 and grounded, the fifth pin of the chip U1 is also connected to the diode D12 and the resistor R21 through the resistor R23, and the resistor R23 is connected to the primary coil of the transformer T1;

The sixth pin of the chip U1 is grounded and connected to the N pole of the rectification and filtering module;

The seventh pin of the chip U1 is connected to the base of the transistor Q1 through the resistor R22, the resistor R22 is connected in parallel with the diode D7, and the resistor R22 is also connected to the emitter of the transistor Q1, the resistor R26, the resistor R29 and the resistor R25 through the resistor R57, and the set of the transistor Q1 The electrodes are connected to the primary coil of the transformer T1;

The eighth pin of the chip U1 is connected to the resistor R16 and the resistor R15 in turn, and then connected to the P pole of the rectifier filter module and the primary coil of the transformer T1. The resistor R15 is also connected to the primary coil of the transformer T1 through the capacitor C3 and the diode D6 in turn, and the capacitor C3 is connected in parallel. Resistor R19 and resistor R20;

The secondary coil of the transformer T1 is connected to VOUT through the diode D10, and the diode D10 is also grounded through the capacitor C12 and the capacitor C30 respectively, the diode D10 is connected in parallel with the capacitor C99 and the resistor R242, and the capacitor C99 and the resistor R242 are connected in series;

The secondary coil of transformer T1 is also connected to VCC through diode D9, resistor R50, and resistor RL2 in sequence. Resistor RL2 is also grounded through capacitor C18. Resistor RL2 is also connected to the collector of transistor Q2. Resistor RL2 is also connected to the base of transistor Q2 through resistor R45. The resistor R45 is also grounded through the diode D20, the emitter of the transistor Q2 is connected to VDD, and the emitter of the transistor Q2 is also grounded through the capacitor C17.

As an improvement of the LED constant current dimming power supply of the present invention, the DALI signal decoding module is set as a decoding chip, the signal conversion module is set as a signal conversion chip, and the square wave signal duty cycle control module is set as a duty cycle Compared with the control chip, the signal frequency control module is set as a signal frequency control chip, and the signal amplification output module is set as a signal amplification output chip.

As an improvement of the LED constant current dimming power supply of the present invention, the LED drive control module includes a chip U2;

The first pin of the chip U2 is connected to the current detection chip and grounded, and the first pin of the chip U2 is connected to the primary coil of the transformer T2;

The third pin of the chip U2 is connected to VOUT, and the third pin of the chip U2 is also grounded through the diode D14, the resistor R47 and the resistor R51;

The fifth pin of the chip U2 is grounded through the diode D11, the fifth pin of the chip U2 is also connected to the secondary coil of the transformer T2 through the inductor L3, and the inductor L3 is connected to the first pin of the chip U2 through the capacitor C26;

The sixth pin of the chip U2 is connected to the signal amplification output chip through the resistor R55, the sixth pin of the chip U2 is also grounded through the capacitor C25, the capacitor C25 is connected in parallel with the resistor R34, the resistor R55 is grounded through the capacitor C22, and the resistor R55 is also connected through the resistor R41 Connect with the seventh pin of chip U2;

The seventh pin of the chip U2 is grounded through the capacitor C24, and the capacitor C24 is also connected to the resistor R51;

The primary coil of the transformer T2 is also connected to the V- terminal, the secondary coil of the transformer T2 is also connected to the V+ terminal, and a resistor R38 is also connected between the V- terminal and the V+ terminal.

As an improvement of the LED constant current dimming power supply of the present invention, the external LED lighting module includes LED lamp beads, and the LED lamp beads are respectively connected to the V- terminal and the V+ terminal.

As an improvement to the LED constant-current dimming power supply of the present invention, several LED lamp beads are provided, and the several LED lamp beads are connected in series.

As an improvement of the LED constant current dimming power supply of the present invention, the model of the decoding chip is CTT-DLPWM-8, the model of the signal conversion chip is AD0809, and the model of the duty cycle control chip is 8253, so The model of the signal frequency control chip is AD9832, and the model of the signal amplification output chip is A7700.

Working principle of the present invention is:

The AC mains output 310V DC voltage after being filtered by the rectification and filtering module--DC--filtering; through the DC/DC voltage conversion module, the DC 310V high voltage is converted into 3 groups of low voltages: the first circuit supplies power to the chip U1 (VCC); The second output powers the dimming control module DL01 (VDD); the third output supplies power to the chip U2 (VOUT), and supplies power to the LED lights after filtering and signal control.

Among them, the dimming control module DL01 includes signal decoding, conversion, dimming control modules and the like. After the DALI control signal input from the DA/DC and DA/GD terminals is decoded by the MCU signal, the coded signal is converted into a digital square wave signal whose duty cycle varies with the control signal as required, and the square wave is set according to the dimming characteristics. The frequency of the signal is amplified and output by the signal amplification circuit, and then the output current and voltage of the chip U2 are controlled, and finally the brightness of the light is intelligently controlled, thereby playing the role of energy saving, environmental protection and emission reduction.

Compared with the prior art, the present invention converts the DALI control signal into a group of square wave pulse signals that vary according to the control signal, and realizes the control of the current and voltage of the LED drive controller, and the output signal is changed accordingly according to the requirements of the DALI control signal , so as to improve the accuracy and flexibility of dimming, it can realize dimming in different periods, and can dim multiple LED lights at the same time to realize intelligent control of lighting, realize energy saving and emission reduction, and promote environmental protection.

Description of drawings

The present invention and its beneficial technical effects will be described in detail below in conjunction with the accompanying drawings and specific implementation methods, wherein:

Fig. 1 is a structural block diagram of the present invention.

Fig. 2 is a circuit diagram of the rectification and filtering module in the present invention.

Fig. 3 is a circuit diagram of a DC/DC conversion module in the present invention.

FIG. 4 is a schematic diagram of the circuit structure of the main part of the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the examples and the accompanying drawings , but the implementation of the present invention is not limited thereto.

As shown in Figures 1 to 4 , an LED constant current dimming power supply provided by the present invention is characterized in that it includes:

DALI signal decoding module 1, used to decode DALI control signals;

The signal conversion module 2 receives and converts the signal of the DALI signal decoding module 1;

The square wave pulse signal conversion module 3 is used to convert the signal converted by the signal conversion module 2 into a group of square wave pulse signals that vary according to the control signal;

The LED drive control module 4 is used to receive the square wave pulse signal of the square wave pulse signal conversion module 3;

and the external LED lighting module 5 to receive the signal from the LED driving control module 4 to realize dimming.

Wherein, the square wave pulse signal conversion module 3 comprises a square wave signal duty cycle control module 31, a signal frequency control module 32 and a signal amplification output module 33, and the input and output terminals of the square wave signal duty cycle control module 31 are respectively connected to the signal The output end of the conversion module 2 is connected to the input end of the signal frequency control module 32, the output end of the signal frequency control module 32 is connected to the input end of the signal amplification output module 33, and the output end of the signal amplification output module 33 is connected to the LED drive control module 4 input connection. Wherein, the square wave signal duty cycle control module 31 can generate a square wave signal to make the duty cycle variable according to the requirements of the DALI control signal, and then output the signal to control the light. In this way, it is possible to perform dimming in different periods of time.

The power supply also includes a rectification and filtering module 6, which is used to convert AC mains power into high-voltage direct current;

And a DC/DC conversion module 7, used to convert the high-voltage direct current into several groups of low voltages.

The rectification and filtering module 6 includes a fuse F1, a varistor TVR, an inductor Lw, a capacitor C1, a capacitor CY1, a capacitor CY2, an inductor L1, a bridge rectifier filter BR, an inductor L2, a resistor R3, and a capacitor C3. The fuse F1 is connected to the fire wire, The two ends of the varistor TVR are respectively connected to the fuse F1 and the neutral line, the two ends of the inductance Lw are connected to the two ends of the varistor TVR, the other two ends of the inductance Lw are respectively connected to the two ends of the capacitor C1, and one end of the capacitor C1 is connected to Capacitor CY2 is connected to the casing, one of the other ends of the inductor Lw is connected to the capacitor CY1 and connected to the casing, the two ends of the inductor L1 are respectively connected to the two ends of the capacitor C1, and the other two ends of the inductor L1 are connected to the bridge rectifier filter BR The two AC terminals of the bridge rectifier filter BR are connected to the inductor L2 and grounded through the capacitor C3, and the inductor L2 is connected to the P pole; the resistor R3 is connected in parallel with the inductor L2, and the A- of the bridge rectifier filter BR The terminal is grounded and connected to the N pole.

The DC/DC conversion module 7 includes a chip U1, the first pin and the second pin of the chip U1 are sequentially connected to a resistor R12, a resistor R14, a diode D5, a diode D12, a resistor R21 and then connected to VCC, and the resistor R21 is also connected to a capacitor C8 and then grounded , capacitor C8 is connected in parallel with capacitor C1, resistor R12 is connected in parallel with resistor R13, resistor R12 and resistor R14 are grounded through capacitor C4, resistor R21 is also connected with resistor R12 and resistor R10 through resistor R61;

The third pin of the chip U1 is connected to the resistor R9 and the capacitor C10 in turn, and then grounded. The third pin of the chip U1 is also connected to the resistor R12 through the capacitor C5, the resistor R10, and the capacitor C5 and the resistor R10 are connected to the ground;

The fourth pin of the chip U1 is grounded through the resistor R25 and the resistor R26 in turn, and the resistor R26 and the resistor R29 are connected in parallel;

The fifth pin of the chip U1 is connected to the capacitor C9 and grounded, the fifth pin of the chip U1 is also connected to the diode D12 and the resistor R21 through the resistor R23, and the resistor R23 is connected to the primary coil of the transformer T1;

The sixth pin of the chip U1 is grounded and connected to the N pole of the rectification and filtering module;

The seventh pin of the chip U1 is connected to the base of the transistor Q1 through the resistor R22, the resistor R22 is connected in parallel with the diode D7, and the resistor R22 is also connected to the emitter of the transistor Q1, the resistor R26, the resistor R29 and the resistor R25 through the resistor R57, and the set of the transistor Q1 The electrodes are connected to the primary coil of the transformer T1;

The eighth pin of the chip U1 is connected to the resistor R16 and the resistor R15 in turn, and then connected to the P pole of the rectifier filter module and the primary coil of the transformer T1. The resistor R15 is also connected to the primary coil of the transformer T1 through the capacitor C3 and the diode D6 in turn, and the capacitor C3 is connected in parallel. Resistor R19 and resistor R20;

The secondary coil of the transformer T1 is connected to VOUT through the diode D10, and the diode D10 is also grounded through the capacitor C12 and the capacitor C30 respectively, the diode D10 is connected in parallel with the capacitor C99 and the resistor R242, and the capacitor C99 and the resistor R242 are connected in series;

The secondary coil of transformer T1 is also connected to VCC through diode D9, resistor R50, and resistor RL2 in sequence. Resistor RL2 is also grounded through capacitor C18. Resistor RL2 is also connected to the collector of transistor Q2. Resistor RL2 is also connected to the base of transistor Q2 through resistor R45. The resistor R45 is also grounded through the diode D20, the emitter of the transistor Q2 is connected to VDD, and the emitter of the transistor Q2 is also grounded through the capacitor C17.

The DALI signal decoding module 1 is set as a decoding chip, the signal conversion module 2 is set as a signal conversion chip, the square wave signal duty cycle control module 31 is set as a duty cycle control chip, and the signal frequency control module 32 is set as a signal frequency control chip. The amplification output module 33 is configured as a signal amplification output chip. In this embodiment, these chips are integrated in the same MCU (DL01), as shown in the block diagram of FIG . 4 .

The LED drive control module 4 includes a chip U2;

The first pin of the chip U2 is connected to the current detection chip and grounded, and the first pin of the chip U2 is connected to the primary coil of the transformer T2;

The third pin of the chip U2 is connected to VOUT, and the third pin of the chip U2 is also grounded through the diode D14, the resistor R47 and the resistor R51;

The fifth pin of the chip U2 is grounded through the diode D11, the fifth pin of the chip U2 is also connected to the secondary coil of the transformer T2 through the inductor L3, and the inductor L3 is connected to the first pin of the chip U2 through the capacitor C26;

The sixth pin of the chip U2 is connected to the signal amplification output chip through the resistor R55, the sixth pin of the chip U2 is also grounded through the capacitor C25, the capacitor C25 is connected in parallel with the resistor R34, the resistor R55 is grounded through the capacitor C22, and the resistor R55 is also connected through the resistor R41 Connect with the seventh pin of chip U2;

The seventh pin of the chip U2 is grounded through the capacitor C24, and the capacitor C24 is also connected to the resistor R51;

The primary coil of the transformer T2 is also connected to the V- terminal, the secondary coil of the transformer T2 is also connected to the V+ terminal, and a resistor R38 is also connected between the V- terminal and the V+ terminal. The LED lights are controlled by controlling the power conversion of U2.

The external LED lighting module 5 includes LED lamp beads, and the LED lamp beads are respectively connected to the V- terminal and the V+ terminal.

There are several LED lamp beads, and several LED lamp beads are connected in series, so that the brightness of multiple LED lamp beads can be controlled at the same time.

The model of the decoding chip is CTT-DLPWM-8, the model of the signal conversion chip is AD0809, the model of the duty ratio control chip is 8253, the model of the signal frequency control chip is AD9832, and the model of the signal amplification output chip is A7700.

Working principle of the present invention is:

The AC mains output 310V DC voltage after being filtered by the rectification and filtering module 6--DC--filtering; through the DC/DC voltage conversion module 7, the DC 310V high voltage is converted into 3 groups of low voltages: the first channel is for the chip U1 (VCC) Power supply; the second output powers the dimming control module DL01 (VDD); the third output supplies power to the chip U2 (VOUT), and then supplies power to the LED lights after filtering and signal control.

Among them, the dimming control module (MCU) DL01 includes signal decoding, conversion, dimming control modules, etc. After the DALI control signal input from the DA/DC and DA/GD terminals is decoded by the MCU signal, the coded signal is converted into a digital square wave signal whose duty cycle varies with the control signal as required, and the square wave is set according to the dimming characteristics. The frequency of the signal is amplified and output by the signal amplification circuit, and then the output current and voltage of the chip U2 are controlled, and finally the brightness of the light is intelligently controlled, thereby playing the role of energy saving, environmental protection and emission reduction.

The present invention converts the DALI control signal into a group of square wave pulse signals according to the change of the control signal to realize the control of the current and voltage of the LED drive controller, and the output signal is changed correspondingly according to the requirements of the DALI control signal, thereby improving the dimming efficiency. Accuracy and flexibility can realize time-segmented dimming, and can dim multiple LED lights at the same time to realize intelligent control of lighting, realize energy saving and emission reduction, and promote environmental protection.

According to the disclosure and teaching of the above-mentioned specification, those skilled in the art to which the present invention belongs can also make changes and modifications to the above-mentioned embodiment. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims (10)

1. A LED constant current dimming power supply, characterized in that it comprises: DALI signal decoding module, used to decode DALI control signals; The signal conversion module receives the signal of the DALI signal decoding module and converts it; The square wave pulse signal conversion module is used to convert the signal converted by the signal conversion module into a group of square wave pulse signals changed according to the control signal; The LED drive control module is used to receive the square wave pulse signal of the square wave pulse signal conversion module; and an external LED lighting module to receive signals from the LED drive control module to realize dimming. 2. The LED constant current dimming power supply according to claim 1, characterized in that: the square wave pulse signal conversion module includes a square wave signal duty cycle control module, a signal frequency control module and a signal amplification output module, the The input end and the output end of the square wave signal duty ratio control module are respectively connected with the output end of the signal conversion module and the input end of the signal frequency control module, and the output end of the signal frequency control module is connected with the signal amplification The input end of the output module is connected, and the output end of the signal amplification output module is connected with the input end of the LED drive control module. 3. The LED constant-current dimming power supply according to claim 1, characterized in that: the power supply also includes a rectification and filtering module for converting AC mains power into high-voltage direct current; And DC/DC conversion module, used to convert high voltage direct current into several groups of low voltage. 4. The LED constant current dimming power supply according to claim 3, characterized in that: the rectification and filtering module includes a fuse F1, a varistor TVR, an inductor Lw, a capacitor C1, a capacitor CY1, a capacitor CY2, an inductor L1, a bridge Type rectifier filter BR, inductor L2, resistor R3 and capacitor C3, fuse F1 is connected to the live wire, the two ends of the varistor TVR are connected to the fuse F1 and the neutral line respectively, and the two ends of the inductance Lw are connected to the two ends of the varistor TVR Connection, the other two ends of the inductor Lw are respectively connected to the two ends of the capacitor C1, one end of the capacitor C1 is connected to the capacitor CY2 and then connected to the casing, one of the other two ends of the inductor Lw is connected to the capacitor CY1 and then connected to the casing, and the two ends of the inductor L1 The two ends of the capacitor C1 are respectively connected, and the other two ends of the inductor L1 are connected to the two AC terminals of the bridge rectifier filter BR; the A+ terminal of the bridge rectifier filter BR is connected to the inductor L2 and grounded through the capacitor C3, and the inductor L2 and The P pole is connected; the resistor R3 is connected in parallel with the inductor L2, and the A-end of the bridge rectifier filter BR is grounded and connected to the N pole. 5. The LED constant current dimming power supply according to claim 4, characterized in that: the DC/DC conversion module includes a chip U1, the first pin and the second pin of the chip U1 are sequentially connected to a resistor R12 and a resistor R14 , Diode D5, diode D12, resistor R21 are connected to VCC, resistor R21 is also connected to capacitor C8 and then grounded, capacitor C8 is connected in parallel with capacitor C1, resistor R12 is connected in parallel with resistor R13, resistor R12 and resistor R14 are connected to ground through capacitor C4, and resistor R21 is connected to the ground. Connect with resistor R12 and resistor R10 through resistor R61; The third pin of the chip U1 is connected to the resistor R9 and the capacitor C10 in turn, and then grounded. The third pin of the chip U1 is also connected to the resistor R12 through the capacitor C5, the resistor R10, and the capacitor C5 and the resistor R10 are connected to the ground; The fourth pin of the chip U1 is grounded through the resistor R25 and the resistor R26 in turn, and the resistor R26 and the resistor R29 are connected in parallel; The fifth pin of the chip U1 is connected to the capacitor C9 and grounded, the fifth pin of the chip U1 is also connected to the diode D12 and the resistor R21 through the resistor R23, and the resistor R23 is connected to the primary coil of the transformer T1; The sixth pin of the chip U1 is grounded and connected to the N pole of the rectification and filtering module; The seventh pin of the chip U1 is connected to the base of the transistor Q1 through the resistor R22, the resistor R22 is connected in parallel with the diode D7, and the resistor R22 is also connected to the emitter of the transistor Q1, the resistor R26, the resistor R29 and the resistor R25 through the resistor R57, and the set of the transistor Q1 The electrodes are connected to the primary coil of the transformer T1; The eighth pin of the chip U1 is connected to the resistor R16 and the resistor R15 in turn, and then connected to the P pole of the rectifier filter module and the primary coil of the transformer T1. The resistor R15 is also connected to the primary coil of the transformer T1 through the capacitor C3 and the diode D6 in turn, and the capacitor C3 is connected in parallel. Resistor R19 and resistor R20; The secondary coil of the transformer T1 is connected to VOUT through the diode D10, and the diode D10 is also grounded through the capacitor C12 and the capacitor C30 respectively, the diode D10 is connected in parallel with the capacitor C99 and the resistor R242, and the capacitor C99 and the resistor R242 are connected in series; The secondary coil of transformer T1 is also connected to VCC through diode D9, resistor R50, and resistor RL2 in sequence. Resistor RL2 is also grounded through capacitor C18. Resistor RL2 is also connected to the collector of transistor Q2. Resistor RL2 is also connected to the base of transistor Q2 through resistor R45. The resistor R45 is also grounded through the diode D20, the emitter of the transistor Q2 is connected to VDD, and the emitter of the transistor Q2 is also grounded through the capacitor C17. 6. The LED constant current dimming power supply according to claim 2, characterized in that: the DALI signal decoding module is set as a decoding chip, the signal conversion module is set as a signal conversion chip, and the square wave signal duty cycle The control module is configured as a duty cycle control chip, the signal frequency control module is configured as a signal frequency control chip, and the signal amplification output module is configured as a signal amplification output chip. 7. The LED constant current dimming power supply according to claim 6, characterized in that: the LED drive control module includes a chip U2; The first pin of the chip U2 is connected to the current detection chip and grounded, and the first pin of the chip U2 is connected to the primary coil of the transformer T2; The third pin of the chip U2 is connected to VOUT, and the third pin of the chip U2 is also grounded through the diode D14, the resistor R47 and the resistor R51; The fifth pin of the chip U2 is grounded through the diode D11, the fifth pin of the chip U2 is also connected to the secondary coil of the transformer T2 through the inductor L3, and the inductor L3 is connected to the first pin of the chip U2 through the capacitor C26; The sixth pin of the chip U2 is connected to the signal amplification output chip through the resistor R55, the sixth pin of the chip U2 is also grounded through the capacitor C25, the capacitor C25 is connected in parallel with the resistor R34, the resistor R55 is grounded through the capacitor C22, and the resistor R55 is also connected through the resistor R41 Connect with the seventh pin of chip U2; The seventh pin of the chip U2 is grounded through the capacitor C24, and the capacitor C24 is also connected to the resistor R51; The primary coil of the transformer T2 is also connected to the V- terminal, the secondary coil of the transformer T2 is also connected to the V+ terminal, and a resistor R38 is also connected between the V- terminal and the V+ terminal. 8 . The LED constant current dimming power supply according to claim 7 , wherein the external LED lighting module includes LED lamp beads, and the LED lamp beads are respectively connected to the V- terminal and the V+ terminal. 9. The LED constant current dimming power supply according to claim 8, characterized in that: there are several LED lamp beads, and the several LED lamp beads are connected in series. 10. The LED constant current dimming power supply according to claim 6, characterized in that: the model of the decoding chip is CTT-DLPWM-8, the model of the signal conversion chip is AD0809, and the duty cycle control chip The model of the signal frequency control chip is 8253, the model of the signal frequency control chip is AD9832, and the model of the signal amplification output chip is A7700.