阅读说明：本技术 一种智能led灯电路 (Intelligent LED lamp circuit ) 是由 徐晓清 俞贤晓 叶清峰 吴国明 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种智能LED灯电路,包括整流电路、LED发光电路、智能通信模块、稳压电路和PWM恒流电路,PWM恒流电路采用内部具有高频变压器的开关型恒流输出电路实现,具有恒压输出模式和恒流输出模式,取代现有的恒流变换电路,通过PWM信号的占空比大小控制PWM恒流电路的工作模式,稳压电路根据PWM恒流电路的工作模式进行输入电压换挡,在恒流输出模式和恒压输出模式的输入电压相差较大,使稳压电路在亮灯状态时具有较高效率；优点是能够采用更为简单的稳压电路替换掉结构替换当前采用开关降压的辅助电源,从PWM恒流电路处获得电压、输出恒压或者恒流,减小了智能LED灯电路的整体尺寸,降低了智能LED灯电路的成本。(The invention discloses an intelligent LED lamp circuit, which comprises a rectifying circuit, an LED light-emitting circuit, an intelligent communication module, a voltage stabilizing circuit and a PWM constant current circuit, wherein the PWM constant current circuit is realized by adopting a switch type constant current output circuit with a high-frequency transformer inside, has a constant voltage output mode and a constant current output mode, replaces the existing constant current conversion circuit, controls the working mode of the PWM constant current circuit through the duty ratio of a PWM signal, and shifts the input voltage according to the working mode of the PWM constant current circuit; the intelligent LED lamp circuit has the advantages that the auxiliary power supply which adopts a switch to reduce voltage can be replaced by a simpler voltage stabilizing circuit instead of a structure, voltage and output constant voltage or constant current are obtained from the PWM constant current circuit, the overall size of the intelligent LED lamp circuit is reduced, and the cost of the intelligent LED lamp circuit is reduced.)

1. An intelligent LED lamp circuit comprises a rectifying circuit, an LED light-emitting circuit, an intelligent communication module and a voltage stabilizing circuit, wherein the rectifying circuit is provided with a first alternating current end, a second alternating current end, a positive output end and a negative output end, the rectifying circuit is used for converting alternating current voltage connected between the first alternating current end and the second alternating current end into direct current voltage to be output between the positive output end and the negative output end of the rectifying circuit, the LED light-emitting circuit is provided with a positive electrode and a negative electrode, a light-emitting voltage threshold value is arranged between the positive electrode and the negative electrode of the LED light-emitting circuit, when the voltage connected between the positive electrode and the negative electrode of the LED light-emitting circuit is smaller than the light-emitting voltage threshold value, the LED light-emitting circuit can not emit light and no current flows through, when the current flows between the positive electrode and the negative electrode of the LED light-emitting circuit and emits light, the voltage between the positive electrode and the negative electrode of the LED light-emitting circuit is larger than or equal to the light-emitting threshold value voltage, the intelligent communication module is characterized in that the intelligent module circuit is provided with a positive electrode, a negative electrode, a PWM (pulse width modulation) end and an output end, the voltage stabilizing circuit is provided with a first input end, a second input end, a control end, an output end and a negative electrode, the first input end and the second input end of the voltage stabilizing circuit are respectively used for accessing external voltage, when the control end of the voltage stabilizing circuit is accessed to 1 level, the voltage stabilizing circuit converts the voltage accessed by the first input end into direct current voltage and outputs the direct current voltage at the output end, when the control end of the voltage stabilizing circuit is accessed to 0 level, the voltage stabilizing circuit converts the voltage accessed by the second input end into the direct current voltage and outputs the direct current voltage at the output end, the power input by the second input end of the voltage stabilizing circuit is kept unchanged and is not changed along with the fluctuation of the current or the power output by the output end of the voltage stabilizing circuit, and the intelligent communication module can be controlled by external control signals or according to rules preset in the intelligent communication module, the intelligent LED lamp circuit comprises a PWM end and an intelligent LED lamp circuit, wherein the PWM end outputs a corresponding PWM signal, and the output end outputs a level signal (1 level or 0 level) corresponding to the PWM signal, the intelligent LED lamp circuit further comprises a PWM constant current circuit, the PWM constant current circuit is realized by adopting a switch type constant current output circuit internally provided with a high-frequency transformer, the PWM constant current circuit is provided with a positive electrode, a negative electrode, a positive output end, a negative output end, a PWM control end, a first voltage end and a second voltage end, and the PWM constant current circuit has two working modes: the intelligent communication module comprises a constant current output mode and a constant voltage output mode, wherein the PWM constant current circuit is provided with a PWM signal threshold interval, a PWM control end of the PWM constant current circuit is used for accessing a PWM signal output by a PWM end of the intelligent communication module, when the duty ratio of the PWM signal accessed by the PWM control end of the PWM constant current circuit is greater than the upper limit of the PWM signal threshold interval, the PWM constant current circuit is in the constant current output mode, the PWM constant current circuit converts a direct current voltage accessed between an anode and a cathode of the PWM constant current circuit into a constant current and outputs the constant current between a positive output end and a negative output end of the PWM constant current circuit, the magnitude of the constant current is in direct proportion to the PWM signal accessed by the PWM control end of the PWM constant current, the voltage output between the positive output end and the negative output end of the PWM constant current circuit is determined by the voltage of an external connecting circuit, and meanwhile, the output end of the intelligent communication module outputs 0 level, when the duty ratio of a PWM signal accessed by a PWM control end of the PWM constant current circuit is smaller than the lower limit of a PWM signal threshold interval, the PWM constant current circuit is in a constant voltage output mode, when in the constant voltage output mode, the PWM constant current circuit converts a direct current voltage accessed between a positive electrode and a negative electrode of the PWM constant current circuit into a constant voltage and outputs the constant voltage between a positive output end and a negative output end of the PWM constant current circuit, the magnitude of the constant voltage is preset and is smaller than a light-emitting voltage threshold, and meanwhile, the output end of the intelligent communication module outputs 1 level; the voltage of the first voltage end and the voltage of the second voltage end of the PWM constant current circuit are induced voltages generated by a high-frequency transformer in the PWM constant current circuit, the voltage of the first voltage end of the PWM constant current circuit is greater than the voltage of the second voltage end of the PWM constant current circuit, and the proportion of the voltage of the first voltage end, the voltage of the second voltage end and the voltage between the positive output end and the negative output end of the PWM constant current circuit is kept unchanged; the positive electrode of the PWM constant current circuit is connected with the positive output end of the rectifying circuit, the positive output end of the PWM constant current circuit is connected with the positive electrode of the LED light-emitting circuit, the negative output end of the PWM constant current circuit is connected with the negative electrode of the LED light-emitting circuit, the PWM end of the intelligent communication module is connected with the PWM control end of the PWM constant current circuit, the output end of the intelligent communication module is connected with the control end of the voltage stabilizing circuit, the first input end of the voltage stabilizing circuit is connected with the first voltage end of the PWM constant current circuit, the second input end of the voltage stabilizing circuit is connected with the second voltage end of the PWM constant current circuit, the output end of the voltage stabilizing circuit is connected with the positive electrode of the intelligent communication module, and the negative electrode of the intelligent communication module, the negative electrode of the voltage stabilizing circuit and the negative electrode of the PWM constant current circuit are connected with the negative output end of the rectifying circuit;

when commercial power alternating voltage is connected between a first alternating current end and a second alternating current end of the rectifying circuit, direct current voltage is output between a positive output end and a negative output end of the rectifying circuit, the PWM constant current circuit is in a default constant voltage output mode, the voltage output by the positive output end and the voltage output by the negative output end are smaller than the light-emitting voltage threshold value of the LED light-emitting circuit, the LED light-emitting circuit does not emit light, meanwhile, the first voltage end and the second voltage end of the PWM constant current circuit respectively output corresponding voltages, the voltage stabilizing circuit defaults to be connected with the voltage through the first input end, then the output end of the voltage stabilizing circuit outputs the corresponding direct current voltage to supply power for the intelligent communication module, at the moment, the intelligent communication module enters a normal working state, and the intelligent communication module is according to received external control signals or internally preset rules, setting a PWM signal of a PWM end and a level signal of an output end of the PWM end so as to control the state of the intelligent LED lamp circuit; when the intelligent communication module controls the intelligent LED lamp circuit to be in a light-out state, the duty ratio of a PWM signal output by a PWM end of the intelligent communication module is smaller than the lower limit of a PWM signal threshold interval, and a level signal of an output end of the intelligent communication module is 1 level, at the moment, the PWM constant current circuit is in a constant voltage output mode, a voltage smaller than a light-emitting voltage threshold value of the LED light-emitting circuit is output between a positive output end and a negative output end of the PWM constant current circuit, the LED light-emitting circuit does not emit light, at the moment, the voltage stabilizing circuit is connected to the voltage of a first voltage end of the PWM constant current circuit through a first input end of the voltage stabilizing circuit, and the working voltage required by the intelligent communication module is output at the output end of the voltage stabilizing circuit, so that the intelligent communication module can keep working normally; when the intelligent communication module controls the intelligent LED lamp circuit to be in a lighting state, the duty ratio of the PWM signal output by the PWM end is larger than the upper limit of the PWM signal threshold interval, and the level signal output by the output end is 0 level, the PWM constant current circuit is in a constant current output mode, the PWM constant current circuit outputs direct current corresponding to the PWM signal between the positive output end and the negative output end of the PWM constant current circuit to drive the LED luminous circuit to emit light, the voltage output between the positive output end and the negative output end of the PWM constant current circuit is the working voltage of the LED light-emitting circuit, at the moment, the voltage stabilizing circuit is connected with the voltage of the second voltage end of the PWM constant current circuit through the second input end of the voltage stabilizing circuit, and the working voltage required by the intelligent communication module is output at the output end of the voltage stabilizing circuit, so that the intelligent communication module keeps normal work, and the working efficiency of the voltage stabilizing circuit is improved.

2. An intelligent LED lamp circuit according to claim 1, wherein the voltage regulator circuit comprises a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first diode, a second diode, a third diode, a fourth diode, a first MOS transistor, a second MOS transistor and an LDO integrated circuit, the first capacitor, the second capacitor and the fourth capacitor are electrolytic capacitors, the first diode and the second diode are rectifier diodes, the third diode and the fourth diode are zener diodes, the first MOS transistor is a PMOS transistor, the second MOS transistor is an NMOS transistor, the LDO integrated circuit has an input pin, an output pin and a ground pin, an anode of the first diode is a first input terminal of the voltage regulator circuit, the anode of the second diode is the second input end of the voltage stabilizing circuit, the cathode of the first diode, the cathode of the third diode and the source of the first MOS tube are connected, the drain of the first MOS tube is connected with one end of the second resistor, the gate of the first MOS light, the anode of the third diode and one end of the first resistor are connected, the other end of the first resistor is connected with the drain of the second MOS tube, the gate of the second MOS tube is the control end of the voltage stabilizing circuit, the cathode of the second diode, the anode of the first capacitor and one end of the third resistor are connected, the other end of the third resistor, the other end of the second resistor, the cathode of the fourth diode, the anode of the second capacitor and the input pin of the LDO integrated circuit are connected, the output pin of the LDO integrated circuit, one end of the third capacitor and the anode of the fourth capacitor are connected, and the connecting end of the third capacitor and the anode of the fourth capacitor is the output end of the voltage stabilizing circuit, the cathode of the first capacitor, the cathode of the second capacitor, the other end of the third capacitor, the cathode of the fourth capacitor, the anode of the fourth diode, the source electrode of the second MOS tube and the ground pin of the LDO integrated circuit are connected, and the connecting end of the fourth capacitor and the cathode of the fourth diode are connected, and the connecting end of the fourth diode and the source electrode of the second MOS tube and the ground pin of the LDO integrated circuit are connected.

3. An intelligent LED lamp circuit according to claim 1, wherein the PWM constant current circuit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a fifth diode, a sixth diode, a seventh diode, an eighth diode, a ninth diode, a transistor, a third MOS transistor, a dimming integrated circuit with model number SY5882, and a high frequency transformer, the twelfth capacitor is an electrolytic capacitor, the sixth diode is a voltage stabilizing diode, the fifth diode, the seventh diode, the eighth diode, and the ninth diode are rectifier diodes, the third MOS transistor is an NMOS transistor, the high-frequency transformer includes a primary coil, a secondary coil, an auxiliary coil, a first coil and a second coil, one end of the auxiliary coil, an anode of the fifth diode and one end of the seventh resistor are connected, a cathode of the fifth diode and one end of the fourth resistor are connected, the other end of the fourth resistor, one end of the fifth resistor and one end of the fifth capacitor are connected with a collector of the transistor, the other end of the fifth resistor and a cathode of the sixth diode are connected with a base of the transistor, an emitter of the transistor is connected with an anode of the seventh diode, a cathode of the seventh diode, one end of the sixth capacitor and one end of the sixth resistor are connected with a pin 6 of the dimming integrated circuit, the other end of the seventh resistor, one end of the eighth resistor and one end of the dimming integrated circuit are connected with pin 2 of the dimming integrated circuit, pin 7 of the dimming integrated circuit and one end of the ninth capacitor are connected, pin 1 of the dimming integrated circuit, one end of the tenth capacitor and one end of the eleventh capacitor are connected, the other end of the eleventh capacitor and one end of the eleventh resistor are connected, pin 5 of the dimming integrated circuit and one end of the tenth resistor are connected, the other end of the tenth resistor and the gate of the third MOS transistor are connected, the source of the third MOS transistor, one end of the twelfth resistor and pin 3 of the dimming integrated circuit are connected, the drain of the third MOS transistor, the anode of the eighth diode and one end of the primary coil of the high-frequency transformer are connected, a negative electrode of the eighth diode, one end of the eighth capacitor and one end of the ninth resistor are connected, the other end of the primary coil of the high-frequency transformer, the other end of the ninth resistor, the other end of the eighth capacitor, the other end of the sixth resistor and one end of the seventh capacitor are connected, a connection end of the high-frequency transformer is a positive electrode of the PWM constant current circuit, the other end of the fifth capacitor, the other end of the sixth capacitor, the other end of the seventh capacitor, a positive electrode of the sixth diode, the other end of the auxiliary coil of the high-frequency transformer, one end of the first coil of the high-frequency transformer, the other end of the eighth resistor, the other end of the eleventh resistor, the other end of the twelfth resistor, the other end of the ninth capacitor, the other end of the tenth capacitor and the 4 th pin of the dimming integrated circuit are connected, and a connection end of the high-frequency transformer and the connection end of the dimming integrated circuit is the pin 4 th pin The other end of the first coil of the high-frequency transformer is connected with one end of the second coil of the high-frequency transformer, and the connecting end of the negative pole of the PWM constant-current circuit is the second voltage end of the PWM constant-current circuit, the other end of the second coil of the high-frequency transformer is a first voltage end of the PWM constant-current circuit, the 8 th pin of the dimming integrated circuit is the PWM control end of the PWM constant current circuit, one end of the secondary coil of the high-frequency transformer is connected with the anode of the ninth diode, the cathode of the ninth diode, the anode of the twelfth capacitor and one end of the thirteenth resistor are connected, and the connecting end of the ninth diode, the anode of the twelfth capacitor and one end of the thirteenth resistor are the positive output end of the PWM constant current circuit, the other end of the secondary coil of the high-frequency transformer, the negative electrode of the twelfth capacitor and the other end of the thirteenth resistor are connected, and the connecting end of the twelfth capacitor and the thirteenth resistor is the negative output end of the PWM constant-current circuit.

Technical Field

The invention relates to an LED lamp circuit, in particular to an intelligent LED lamp circuit.

Background

As shown in fig. 1, a conventional intelligent LED lamp circuit generally includes a rectifying circuit, a constant current converting circuit, an LED light emitting circuit, an intelligent communication module, and an auxiliary power supply. The constant current conversion circuit is connected with the rectification circuit and the LED light-emitting circuit, when the rectification circuit is connected with mains supply voltage, the rectification circuit converts the mains supply alternating current voltage into direct current voltage, and the constant current conversion circuit converts the direct current voltage output by the rectification circuit into direct current with constant magnitude to drive the LED light-emitting circuit to emit light. The LED light-emitting circuit has a light-emitting voltage threshold, and when the voltage connected to the LED light-emitting circuit is smaller than the light-emitting voltage threshold, the LED light-emitting circuit does not emit light and no current flows through the LED light-emitting circuit. When the LED light-emitting circuit has current flowing through and emits light, the connected voltage is greater than the light-emitting threshold voltage, and the light-emitting intensity is in direct proportion to the magnitude of direct current for driving the LED light-emitting circuit to emit light. The constant current conversion circuit is further connected with the intelligent communication module, when the intelligent communication module outputs different control signals, the size of the direct current output by the constant current conversion circuit corresponds to the control signals output by the intelligent communication module, and the intelligent communication module controls the size of the direct current output by the constant current conversion circuit by outputting different control signals, so that the luminous intensity of the LED luminous circuit can be adjusted, and the LED luminous circuit can be in a non-luminous state. The auxiliary power supply is generally connected to mains voltage or direct-current voltage output by the rectifying circuit, and the connected voltage is converted into working voltage required by the intelligent communication module to supply power to the intelligent communication module. However, the auxiliary power supply of the existing intelligent LED lamp circuit is realized by switching, which not only occupies a large space, but also has high cost, so that the whole size of the intelligent LED lamp circuit is large and the cost is high.

Disclosure of Invention

The invention aims to solve the technical problem of providing an intelligent LED lamp circuit with smaller overall size and lower cost.

The technical scheme adopted by the invention for solving the technical problems is as follows: an intelligent LED lamp circuit comprises a rectifying circuit, an LED light-emitting circuit, an intelligent communication module and a voltage stabilizing circuit, wherein the rectifying circuit is provided with a first alternating current end, a second alternating current end, a positive output end and a negative output end, the rectifying circuit is used for converting alternating current voltage connected between the first alternating current end and the second alternating current end into direct current voltage to be output between the positive output end and the negative output end of the rectifying circuit, the LED light-emitting circuit is provided with a positive electrode and a negative electrode, a light-emitting voltage threshold value is arranged between the positive electrode and the negative electrode of the LED light-emitting circuit, when the voltage connected between the positive electrode and the negative electrode of the LED light-emitting circuit is smaller than the light-emitting voltage threshold value, the LED light-emitting circuit can not emit light and no current flows through, when the current flows between the positive electrode and the negative electrode of the LED light-emitting circuit and emits light, the voltage between the positive electrode and the negative electrode of the LED light-emitting circuit is larger than or equal to the light-emitting threshold value voltage, the intelligent communication module is provided with a positive electrode, a negative electrode, a PWM end and an output end, the voltage stabilizing circuit is provided with a first input end, a second input end, a control end, an output end and a negative electrode, the first input end and the second input end of the voltage stabilizing circuit are respectively used for accessing external voltage, when the control end of the voltage stabilizing circuit is accessed to 1 level, the voltage stabilizing circuit converts the voltage accessed by the first input end into direct current voltage and outputs the direct current voltage at the output end, when the control end of the voltage stabilizing circuit is accessed to 0 level, the voltage stabilizing circuit converts the voltage accessed by the second input end into the direct current voltage and outputs the direct current voltage at the output end, the power input by the second input end of the voltage stabilizing circuit is kept unchanged and does not change along with the fluctuation of the current or the power output by the output end of the voltage stabilizing circuit, and the intelligent communication module can be controlled by external control signals or according to the preset rules inside the intelligent communication module, the intelligent LED lamp circuit comprises a PWM end and an intelligent LED lamp circuit, wherein the PWM end outputs a corresponding PWM signal, and the output end outputs a level signal (1 level or 0 level) corresponding to the PWM signal, the intelligent LED lamp circuit further comprises a PWM constant current circuit, the PWM constant current circuit is realized by adopting a switch type constant current output circuit internally provided with a high-frequency transformer, the PWM constant current circuit is provided with a positive electrode, a negative electrode, a positive output end, a negative output end, a PWM control end, a first voltage end and a second voltage end, and the PWM constant current circuit has two working modes: the intelligent communication module comprises a constant current output mode and a constant voltage output mode, wherein the PWM constant current circuit is provided with a PWM signal threshold interval, a PWM control end of the PWM constant current circuit is used for accessing a PWM signal output by a PWM end of the intelligent communication module, when the duty ratio of the PWM signal accessed by the PWM control end of the PWM constant current circuit is greater than the upper limit of the PWM signal threshold interval, the PWM constant current circuit is in the constant current output mode, the PWM constant current circuit converts a direct current voltage accessed between an anode and a cathode of the PWM constant current circuit into a constant current and outputs the constant current between a positive output end and a negative output end of the PWM constant current circuit, the magnitude of the constant current is in direct proportion to the PWM signal accessed by the PWM control end of the PWM constant current, the voltage output between the positive output end and the negative output end of the PWM constant current circuit is determined by the voltage of an external connecting circuit, and meanwhile, the output end of the intelligent communication module outputs 0 level, when the duty ratio of a PWM signal accessed by a PWM control end of the PWM constant current circuit is smaller than the lower limit of a PWM signal threshold interval, the PWM constant current circuit is in a constant voltage output mode, when in the constant voltage output mode, the PWM constant current circuit converts a direct current voltage accessed between a positive electrode and a negative electrode of the PWM constant current circuit into a constant voltage and outputs the constant voltage between a positive output end and a negative output end of the PWM constant current circuit, the magnitude of the constant voltage is preset and is smaller than a light-emitting voltage threshold, and meanwhile, the output end of the intelligent communication module outputs 1 level; the voltage of the first voltage end and the voltage of the second voltage end of the PWM constant current circuit are induced voltages generated by a high-frequency transformer in the PWM constant current circuit, the voltage of the first voltage end of the PWM constant current circuit is greater than the voltage of the second voltage end of the PWM constant current circuit, and the proportion of the voltage of the first voltage end, the voltage of the second voltage end and the voltage between the positive output end and the negative output end of the PWM constant current circuit is kept unchanged; the positive electrode of the PWM constant current circuit is connected with the positive output end of the rectifying circuit, the positive output end of the PWM constant current circuit is connected with the positive electrode of the LED light-emitting circuit, the negative output end of the PWM constant current circuit is connected with the negative electrode of the LED light-emitting circuit, the PWM end of the intelligent communication module is connected with the PWM control end of the PWM constant current circuit, the output end of the intelligent communication module is connected with the control end of the voltage stabilizing circuit, the first input end of the voltage stabilizing circuit is connected with the first voltage end of the PWM constant current circuit, the second input end of the voltage stabilizing circuit is connected with the second voltage end of the PWM constant current circuit, the output end of the voltage stabilizing circuit is connected with the positive electrode of the intelligent communication module, and the negative electrode of the intelligent communication module, the negative electrode of the voltage stabilizing circuit and the negative electrode of the PWM constant current circuit are connected with the negative output end of the rectifying circuit;

when commercial power alternating voltage is connected between a first alternating current end and a second alternating current end of the rectifying circuit, direct current voltage is output between a positive output end and a negative output end of the rectifying circuit, the PWM constant current circuit is in a default constant voltage output mode, the voltage output by the positive output end and the voltage output by the negative output end are smaller than the light-emitting voltage threshold value of the LED light-emitting circuit, the LED light-emitting circuit does not emit light, meanwhile, the first voltage end and the second voltage end of the PWM constant current circuit respectively output corresponding voltages, the voltage stabilizing circuit defaults to be connected with the voltage through the first input end, then the output end of the voltage stabilizing circuit outputs the corresponding direct current voltage to supply power for the intelligent communication module, at the moment, the intelligent communication module enters a normal working state, and the intelligent communication module is according to received external control signals or internally preset rules, setting a PWM signal of a PWM end and a level signal of an output end of the PWM end so as to control the state of the intelligent LED lamp circuit; when the intelligent communication module controls the intelligent LED lamp circuit to be in a light-out state, the duty ratio of a PWM signal output by a PWM end of the intelligent communication module is smaller than the lower limit of a PWM signal threshold interval, and a level signal of an output end of the intelligent communication module is 1 level, at the moment, the PWM constant current circuit is in a constant voltage output mode, a voltage smaller than a light-emitting voltage threshold value of the LED light-emitting circuit is output between a positive output end and a negative output end of the PWM constant current circuit, the LED light-emitting circuit does not emit light, at the moment, the voltage stabilizing circuit is connected to the voltage of a first voltage end of the PWM constant current circuit through a first input end of the voltage stabilizing circuit, and the working voltage required by the intelligent communication module is output at the output end of the voltage stabilizing circuit, so that the intelligent communication module can keep working normally; when the intelligent communication module controls the intelligent LED lamp circuit to be in a lighting state, the duty ratio of the PWM signal output by the PWM end is larger than the upper limit of the PWM signal threshold interval, and the level signal output by the output end is 0 level, the PWM constant current circuit is in a constant current output mode, the PWM constant current circuit outputs direct current corresponding to the PWM signal between the positive output end and the negative output end of the PWM constant current circuit to drive the LED luminous circuit to emit light, the voltage output between the positive output end and the negative output end of the PWM constant current circuit is the working voltage of the LED light-emitting circuit, at the moment, the voltage stabilizing circuit is connected with the voltage of the second voltage end of the PWM constant current circuit through the second input end of the voltage stabilizing circuit, and the working voltage required by the intelligent communication module is output at the output end of the voltage stabilizing circuit, so that the intelligent communication module keeps normal work, and the working efficiency of the voltage stabilizing circuit is improved.

The voltage stabilizing circuit comprises a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first diode, a second diode, a third diode, a fourth diode, a first MOS (metal oxide semiconductor) transistor, a second MOS transistor and an LDO (low dropout regulator) integrated circuit, wherein the first capacitor, the second capacitor and the fourth capacitor are electrolytic capacitors, the first diode and the second diode are rectifier diodes, the third diode and the fourth diode are voltage stabilizing diodes, the first MOS transistor is a PMOS (P-channel metal oxide semiconductor) transistor, the second MOS transistor is an NMOS (N-channel metal oxide semiconductor) transistor, the LDO integrated circuit is provided with an input pin, an output pin and a grounding pin, the anode of the first diode is a first input end of the voltage stabilizing circuit, and the anode of the second diode is a second input end of the voltage stabilizing circuit, the negative electrode of the first diode, the negative electrode of the third diode and the source electrode of the first MOS tube are connected, the drain electrode of the first MOS tube is connected with one end of the second resistor, the grid electrode of the first MOS light, the positive electrode of the third diode and one end of the first resistor are connected, the other end of the first resistor and the drain electrode of the second MOS tube are connected, the grid electrode of the second MOS tube is the control end of the voltage stabilizing circuit, the negative electrode of the second diode, the positive electrode of the first capacitor and one end of the third resistor are connected, the other end of the third resistor, the other end of the second resistor, the negative electrode of the fourth diode, the positive electrode of the second capacitor and the input pin of the LDO integrated circuit are connected, the output pin of the LDO integrated circuit, one end of the third capacitor and the positive electrode of the fourth capacitor are connected, and the connecting end of the output pin, one end of the third capacitor and the positive electrode of the fourth capacitor are connected The negative electrode of the first capacitor, the negative electrode of the second capacitor, the other end of the third capacitor, the negative electrode of the fourth capacitor, the positive electrode of the fourth diode, the source electrode of the second MOS transistor and the ground pin of the LDO integrated circuit are connected, and the connection end of the second MOS transistor and the ground pin of the LDO integrated circuit is the negative electrode of the voltage stabilizing circuit. In the voltage stabilizing circuit, other elements except the capacitor are easy to design in the same integrated circuit, so that the space is further reduced and the cost is reduced.

The PWM constant current circuit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a fifth diode, a sixth diode, a seventh diode, an eighth diode, a ninth diode, a transistor, a third MOS (metal oxide semiconductor) transistor, a dimming integrated circuit with the model of SY5882 and a high-frequency transformer, wherein the twelfth capacitor is an electrolytic capacitor, the sixth diode is a voltage stabilizing diode, the fifth diode, the seventh diode, the eighth diode and the ninth diode are rectifier diodes, the third MOS transistor is an NMOS (N-channel metal oxide semiconductor) transistor, and the high-frequency transformer comprises a primary coil, A secondary winding, an auxiliary winding, a first winding and a second winding, wherein one end of the auxiliary winding, an anode of the fifth diode and one end of the seventh resistor are connected, a cathode of the fifth diode and one end of the fourth resistor are connected, the other end of the fourth resistor, one end of the fifth resistor and one end of the fifth capacitor are connected with a collector of the transistor, the other end of the fifth resistor and a cathode of the sixth diode are connected with a base of the transistor, an emitter of the transistor is connected with an anode of the seventh diode, a cathode of the seventh diode, one end of the sixth capacitor and one end of the sixth resistor are connected with a pin 6 of the dimming integrated circuit, and the other end of the seventh resistor, one end of the eighth resistor and a pin 2 of the dimming integrated circuit are connected, the 7 th pin of the dimming integrated circuit is connected with one end of the ninth capacitor, the 1 st pin of the dimming integrated circuit, one end of the tenth capacitor and one end of the eleventh capacitor are connected, the other end of the eleventh capacitor and one end of the eleventh resistor are connected, the 5 th pin of the dimming integrated circuit and one end of the tenth resistor are connected, the other end of the tenth resistor and the gate of the third MOS transistor are connected, the source of the third MOS transistor, one end of the twelfth resistor and the 3 rd pin of the dimming integrated circuit are connected, the drain of the third MOS transistor, the anode of the eighth diode and one end of the primary coil of the high-frequency transformer are connected, the cathode of the eighth diode, one end of the eighth capacitor and one end of the ninth resistor are connected, the other end of the primary coil of the high-frequency transformer, the other end of the ninth resistor, the other end of the eighth capacitor, the other end of the sixth resistor and one end of the seventh capacitor are connected, the connection end of the other end of the sixth resistor and one end of the seventh capacitor is the anode of the PWM constant current circuit, the other end of the fifth capacitor, the other end of the sixth capacitor, the other end of the seventh capacitor, the anode of the sixth diode, the other end of the auxiliary coil of the high-frequency transformer, one end of the first coil of the high-frequency transformer, the other end of the eighth resistor, the other end of the eleventh resistor, the other end of the twelfth resistor, the other end of the ninth capacitor, the other end of the tenth capacitor and the 4 th pin of the dimming integrated circuit are connected, and the connection end of the other end of the fifth capacitor and the other end of the sixth capacitor are the cathode of the PWM constant current circuit, the other end of the first coil of the high-frequency transformer is connected with one end of the second coil of the high-frequency transformer, the connecting end of the first coil of the high-frequency transformer is a second voltage end of the PWM constant current circuit, the other end of the second coil of the high-frequency transformer is a first voltage end of the PWM constant-current circuit, the 8 th pin of the dimming integrated circuit is the PWM control end of the PWM constant current circuit, one end of the secondary coil of the high-frequency transformer is connected with the anode of the ninth diode, the cathode of the ninth diode, the anode of the twelfth capacitor and one end of the thirteenth resistor are connected, and the connecting end of the ninth diode, the anode of the twelfth capacitor and one end of the thirteenth resistor are the positive output end of the PWM constant current circuit, the other end of the secondary coil of the high-frequency transformer, the negative electrode of the twelfth capacitor and the other end of the thirteenth resistor are connected, and the connecting end of the twelfth capacitor and the thirteenth resistor is the negative output end of the PWM constant-current circuit. In the PWM constant current circuit, according to the actual parameters of the dimming integrated circuit, the threshold interval of the PWM signal can be set to be 2.5% -5.5%, the PWM control end is in a constant current output mode when the PWM signal with the duty ratio larger than 5.5% is accessed, the PWM control end is in a constant voltage output mode when the PWM signal with the duty ratio smaller than 2.5% is accessed, and in practical application, after the working voltage of the LED light-emitting circuit in the constant current output mode is determined, the minimum voltage output between the positive output end and the negative output end of the PWM constant current circuit in the constant voltage output mode can be close to 1/3 of the working voltage of the LED light-emitting circuit and is far smaller than the light-emitting voltage threshold of the LED light-emitting circuit.

Compared with the prior art, the invention has the advantages that the PWM constant current circuit is arranged, the PWM constant current circuit is realized by adopting a switch type constant current output circuit with a high-frequency transformer inside, the PWM constant current circuit is provided with a positive pole, a negative pole, a positive output end, a negative output end, a PWM control end, a first voltage end and a second voltage end, and the PWM constant current circuit has two working modes: a constant current output mode and a constant voltage output mode, wherein the PWM constant current circuit has a PWM signal threshold interval, the PWM control end of the PWM constant current circuit is used for accessing the PWM signal output by the PWM end of the intelligent communication module, when the duty ratio of the PWM signal accessed by the PWM control end of the PWM constant current circuit is larger than the upper limit of the PWM signal threshold interval, the PWM constant current circuit is in the constant current output mode, the PWM constant current circuit converts the direct current voltage accessed between the anode and the cathode into constant current and outputs the constant current between the anode output end and the cathode output end, the magnitude of the constant current is in direct proportion to the PWM signal accessed by the PWM control end, the voltage output between the anode output end and the cathode output end is determined by the voltage of the external connection circuit, meanwhile, the output end of the intelligent communication module outputs 0 level, when the duty ratio of the PWM signal accessed by the PWM control end of the PWM circuit is smaller than the lower limit of the PWM signal threshold interval, the PWM constant-current circuit is in a constant-voltage output mode, when in the constant-voltage output mode, the PWM constant-current circuit converts direct-current voltage connected between the anode and the cathode of the PWM constant-current circuit into constant voltage and outputs the constant voltage between the anode output end and the cathode output end of the PWM constant-current circuit, the magnitude of the constant voltage is preset and is smaller than a light-emitting voltage threshold value, and meanwhile, the output end of the intelligent communication module outputs 1 level; the voltage of a first voltage end and the voltage of a second voltage end of the PWM constant-current circuit are induced voltages generated by a high-frequency transformer in the PWM constant-current circuit, the voltage of the first voltage end of the PWM constant-current circuit is greater than the voltage of the second voltage end of the PWM constant-current circuit, and the voltage of the first voltage end, the voltage of the second voltage end and the voltage between a positive output end and a negative output end of the PWM constant-current circuit are constant in proportion; the positive electrode of the PWM constant current circuit is connected with the positive output end of the rectifying circuit, the positive output end of the PWM constant current circuit is connected with the positive electrode of the LED light-emitting circuit, the negative output end of the PWM constant current circuit is connected with the negative electrode of the LED light-emitting circuit, the PWM end of the intelligent communication module is connected with the PWM control end of the PWM constant current circuit, the output end of the intelligent communication module is connected with the control end of the voltage stabilizing circuit, the first input end of the voltage stabilizing circuit is connected with the first voltage end of the PWM constant current circuit, the second input end of the voltage stabilizing circuit is connected with the second voltage end of the PWM constant current circuit, the output end of the voltage stabilizing circuit is connected with the positive electrode of the intelligent communication module, and the negative electrode of the intelligent communication module, the negative electrode of the voltage stabilizing circuit, the negative electrode of the PWM constant current circuit and the negative output end of the rectifying circuit are connected; when the alternating-current voltage of the commercial power is connected between the first alternating-current end and the second alternating-current end of the rectifying circuit, the direct-current voltage is output between the positive output end and the negative output end of the rectifying circuit, the PWM constant-current circuit defaults to be in a constant-voltage output mode, the voltage output by the positive output end and the negative output end is less than the light-emitting voltage threshold value of the LED light-emitting circuit, the LED light-emitting circuit does not emit light, meanwhile, the first voltage end and the second voltage end of the PWM constant current circuit respectively output corresponding voltages, the voltage stabilizing circuit is defaulted to be connected with the voltage through the first input end, then, outputting corresponding direct current voltage at the output end of the intelligent LED lamp circuit to supply power to the intelligent communication module, enabling the intelligent communication module to enter a normal working state at the moment, and setting a PWM (pulse width modulation) signal at a PWM (pulse width modulation) end and a level signal at the output end of the intelligent LED lamp circuit by the intelligent communication module according to a received external control signal or an internal preset rule so as to control the state of the intelligent LED lamp circuit; when the intelligent communication module controls the intelligent LED lamp circuit to be in a light-off state, the duty ratio of a PWM signal output by a PWM end of the intelligent communication module is smaller than the lower limit of a PWM signal threshold interval, and a level signal of an output end of the intelligent communication module is 1 level, at the moment, the PWM constant-current circuit is in a constant-voltage output mode, a voltage smaller than a light-emitting voltage threshold of the LED light-emitting circuit is output between a positive output end and a negative output end of the PWM constant-current circuit, the LED light-emitting circuit does not emit light, at the moment, a voltage stabilizing circuit is connected to a voltage of a first voltage end of the PWM constant-current circuit through a first input end of the voltage stabilizing circuit, and a working voltage required by the intelligent communication module is output at the output end of the voltage stabilizing circuit, so that the intelligent communication module can keep working normally; when the intelligent communication module controls the intelligent LED lamp circuit to be in a lighting state, the duty ratio of a PWM signal output by a PWM end of the intelligent communication module is larger than the upper limit of a PWM signal threshold interval, a level signal output by an output end of the intelligent communication module is 0 level, the PWM constant-current circuit is in a constant-current output mode, the PWM constant-current circuit outputs direct current corresponding to the PWM signal between a positive output end and a negative output end of the PWM constant-current circuit to drive the LED light-emitting circuit to emit light, the voltage output between the positive output end and the negative output end of the PWM constant-current circuit is the working voltage of the LED light-emitting circuit, at the moment, the voltage stabilizing circuit is connected with the voltage of a second voltage end of the PWM constant-current circuit through a second input end of the voltage stabilizing circuit and outputs the working voltage required by the intelligent communication module at the output end of the voltage stabilizing circuit, so that the intelligent communication module can keep normal work and improve the working efficiency of the voltage stabilizing circuit, therefore, the intelligent communication module adopts the PWM constant-current circuit with two working modes of a constant-voltage output mode to replace the existing constant-current conversion circuit, the working mode of the PWM constant current circuit is controlled through the duty ratio of the PWM signal, the output voltage between the positive output end and the negative output end of the PWM constant current circuit is lower than the light-emitting voltage threshold of the LED light-emitting circuit in the constant voltage output mode to control the light-off state, the PWM constant current circuit is controlled to be in the light-on state when being in the constant current output mode, at the moment, the power accessed by the voltage stabilizing circuit is kept unchanged, the constant power accessed by the voltage stabilizing circuit is not changed along with the power fluctuation of the intelligent communication module, therefore, even if the intelligent communication module receives and transmits communication signals, the consumed power of the intelligent communication module is changed, the change of the input power of the voltage stabilizing circuit is not influenced, the current change output by the PWM constant current circuit at the positive output end and the negative output end is not generated, the light-emitting intensity of the LED light-emitting circuit is kept unchanged, the flicker is not generated, and the voltage stabilizing circuit shifts the input voltage according to the working mode of the PWM constant current circuit, the difference between the input voltage in the constant current output mode and the input voltage in the constant voltage output mode is large, so that the voltage stabilizing circuit has high efficiency in a lighting state, a simpler voltage stabilizing circuit can be adopted to replace an auxiliary power supply adopting a switch for voltage reduction at present, the voltage and the output constant voltage or constant current are obtained from the PWM constant current circuit, the overall size of the intelligent LED lamp circuit is reduced, and the cost of the intelligent LED lamp circuit is reduced.

Drawings

FIG. 1 is a schematic block diagram of a conventional intelligent LED lamp circuit;

FIG. 2 is a schematic block diagram of the structure of the intelligent LED lamp circuit of the present invention;

FIG. 3 is a circuit diagram of a voltage regulator circuit of the intelligent LED lamp circuit of the present invention;

fig. 4 is a circuit diagram of a PWM constant current circuit of the intelligent LED lamp circuit of the present invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

Example (b): as shown in fig. 2, an intelligent LED lamp circuit comprises a rectifying circuit, an LED light-emitting circuit, an intelligent communication module and a voltage stabilizing circuit, wherein the rectifying circuit has a first ac terminal, a second ac terminal, a positive output terminal and a negative output terminal, the rectifying circuit is used for converting an ac voltage connected between the first ac terminal and the second ac terminal into a dc voltage and outputting the dc voltage between the positive output terminal and the negative output terminal, the LED light-emitting circuit has a positive electrode and a negative electrode, a light-emitting voltage threshold value is provided between the positive electrode and the negative electrode of the LED light-emitting circuit, when a voltage connected between the positive electrode and the negative electrode of the LED light-emitting circuit is smaller than the light-emitting voltage threshold value, the LED light-emitting circuit does not emit light and no current flows, when a current flows between the positive electrode and the negative electrode of the LED light-emitting circuit and emits light, the voltage between the positive electrode and the negative electrode is greater than or equal to the light-emitting threshold voltage, and the light-emitting intensity is proportional to the dc current driving the LED light-emitting circuit, the intelligent module circuit is provided with a positive pole, a negative pole, a PWM end and an output end, the voltage stabilizing circuit is provided with a first input end, a second input end, a control end, an output end and a negative pole, the first input end and the second input end of the voltage stabilizing circuit are respectively used for accessing external voltage, when the control end of the voltage stabilizing circuit is accessed to 1 level, the voltage stabilizing circuit converts the voltage accessed by the first input end into direct current voltage and outputs the direct current voltage at the output end, when the control end of the voltage stabilizing circuit is accessed to 0 level, the voltage stabilizing circuit converts the voltage accessed by the second input end into the direct current voltage and outputs the direct current voltage at the output end, the power input by the second input end of the voltage stabilizing circuit keeps unchanged and does not change along with the fluctuation of the current or the power output by the output end of the voltage stabilizing circuit, the intelligent communication module can output a corresponding PWM signal at the PWM end under the control of the external control signal or according to the preset rule inside the intelligent communication module, and output a level signal (1 level or 0 level) corresponding to the PWM signal at the output end, the intelligent LED lamp circuit further comprises a PWM constant current circuit, the PWM constant current circuit is realized by adopting a switch type constant current output circuit with a high-frequency transformer inside, the PWM constant current circuit is provided with a positive electrode, a negative electrode, a positive output end, a negative output end, a PWM control end, a first voltage end and a second voltage end, and the PWM constant current circuit has two working modes: a constant current output mode and a constant voltage output mode, wherein the PWM constant current circuit has a PWM signal threshold interval, the PWM control end of the PWM constant current circuit is used for accessing the PWM signal output by the PWM end of the intelligent communication module, when the duty ratio of the PWM signal accessed by the PWM control end of the PWM constant current circuit is larger than the upper limit of the PWM signal threshold interval, the PWM constant current circuit is in the constant current output mode, the PWM constant current circuit converts the direct current voltage accessed between the anode and the cathode into constant current and outputs the constant current between the anode output end and the cathode output end, the magnitude of the constant current is in direct proportion to the PWM signal accessed by the PWM control end, the voltage output between the anode output end and the cathode output end is determined by the voltage of the external connection circuit, meanwhile, the output end of the intelligent communication module outputs 0 level, when the duty ratio of the PWM signal accessed by the PWM control end of the PWM circuit is smaller than the lower limit of the PWM signal threshold interval, the PWM constant-current circuit is in a constant-voltage output mode, when in the constant-voltage output mode, the PWM constant-current circuit converts direct-current voltage connected between the anode and the cathode of the PWM constant-current circuit into constant voltage and outputs the constant voltage between the anode output end and the cathode output end of the PWM constant-current circuit, the magnitude of the constant voltage is preset and is smaller than a light-emitting voltage threshold value, and meanwhile, the output end of the intelligent communication module outputs 1 level; the voltage of a first voltage end and the voltage of a second voltage end of the PWM constant-current circuit are induced voltages generated by a high-frequency transformer in the PWM constant-current circuit, the voltage of the first voltage end of the PWM constant-current circuit is greater than the voltage of the second voltage end of the PWM constant-current circuit, and the voltage of the first voltage end, the voltage of the second voltage end and the voltage between a positive output end and a negative output end of the PWM constant-current circuit are constant in proportion; the positive electrode of the PWM constant current circuit is connected with the positive output end of the rectifying circuit, the positive output end of the PWM constant current circuit is connected with the positive electrode of the LED light-emitting circuit, the negative output end of the PWM constant current circuit is connected with the negative electrode of the LED light-emitting circuit, the PWM end of the intelligent communication module is connected with the PWM control end of the PWM constant current circuit, the output end of the intelligent communication module is connected with the control end of the voltage stabilizing circuit, the first input end of the voltage stabilizing circuit is connected with the first voltage end of the PWM constant current circuit, the second input end of the voltage stabilizing circuit is connected with the second voltage end of the PWM constant current circuit, the output end of the voltage stabilizing circuit is connected with the positive electrode of the intelligent communication module, and the negative electrode of the intelligent communication module, the negative electrode of the voltage stabilizing circuit, the negative electrode of the PWM constant current circuit and the negative output end of the rectifying circuit are connected; when the alternating-current voltage of the commercial power is connected between the first alternating-current end and the second alternating-current end of the rectifying circuit, the direct-current voltage is output between the positive output end and the negative output end of the rectifying circuit, the PWM constant-current circuit defaults to be in a constant-voltage output mode, the voltage output by the positive output end and the negative output end is less than the light-emitting voltage threshold value of the LED light-emitting circuit, the LED light-emitting circuit does not emit light, meanwhile, the first voltage end and the second voltage end of the PWM constant current circuit respectively output corresponding voltages, the voltage stabilizing circuit is defaulted to be connected with the voltage through the first input end, then, outputting corresponding direct current voltage at the output end of the intelligent LED lamp circuit to supply power to the intelligent communication module, enabling the intelligent communication module to enter a normal working state at the moment, and setting a PWM (pulse width modulation) signal at a PWM (pulse width modulation) end and a level signal at the output end of the intelligent LED lamp circuit by the intelligent communication module according to a received external control signal or an internal preset rule so as to control the state of the intelligent LED lamp circuit; when the intelligent communication module controls the intelligent LED lamp circuit to be in a light-off state, the duty ratio of a PWM signal output by a PWM end of the intelligent communication module is smaller than the lower limit of a PWM signal threshold interval, and a level signal of an output end of the intelligent communication module is 1 level, at the moment, the PWM constant-current circuit is in a constant-voltage output mode, a voltage smaller than a light-emitting voltage threshold of the LED light-emitting circuit is output between a positive output end and a negative output end of the PWM constant-current circuit, the LED light-emitting circuit does not emit light, at the moment, a voltage stabilizing circuit is connected to a voltage of a first voltage end of the PWM constant-current circuit through a first input end of the voltage stabilizing circuit, and a working voltage required by the intelligent communication module is output at the output end of the voltage stabilizing circuit, so that the intelligent communication module can keep working normally; when the intelligent communication module controls the intelligent LED lamp circuit to be in a lighting state, the duty ratio of a PWM signal output by the PWM end of the intelligent communication module is larger than the upper limit of a PWM signal threshold interval, a level signal output by the output end of the intelligent communication module is 0 level, the PWM constant-current circuit is in a constant-current output mode, the PWM constant-current circuit outputs direct current corresponding to the PWM signal between the positive output end and the negative output end of the PWM constant-current circuit to drive the LED light-emitting circuit to emit light, the voltage output between the positive output end and the negative output end of the PWM constant-current circuit is working voltage of the LED light-emitting circuit, at the moment, the voltage stabilizing circuit is connected to the voltage of the second voltage end of the PWM constant-current circuit through the second input end of the voltage stabilizing circuit, and the working voltage required by the intelligent communication module is output by the output end of the voltage stabilizing circuit, so that the intelligent communication module can keep normal work, and the working efficiency of the voltage stabilizing circuit is improved.

As shown in fig. 3, in this embodiment, the voltage regulator includes a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a first MOS transistor M1, a second MOS transistor M2, and an LDO integrated circuit U1, where the first capacitor C1, the second capacitor C2, and the fourth capacitor C4 are electrolytic capacitors, the first diode D1 and the second diode D2 are rectifier diodes, the third diode D3 and the fourth diode D4 are zener diodes, the first MOS transistor M1 is a PMOS transistor, the second MOS transistor M2 is an NMOS transistor, the LDO integrated circuit U1 has an input pin, an output pin, and a ground pin, an anode of the first diode D1 is a first anode of the first voltage regulator, a cathode of the first diode D2 is a cathode of the first voltage regulator, and an input terminal of the first diode D1 is a cathode of the first voltage regulator 46d 1 of the first voltage regulator, The negative electrode of the third diode D3 is connected with the source electrode of the first MOS transistor M1, the drain electrode of the first MOS transistor M1 is connected with one end of the second resistor R2, the grid electrode of the first MOS light, the positive electrode of the third diode D3 and one end of the first resistor R1 are connected, the other end of the first resistor R1 is connected with the drain electrode of the second MOS transistor M2, the grid electrode of the second MOS transistor M2 is the control end of the voltage stabilizing circuit, the negative electrode of the second diode D2, the positive electrode of the first capacitor C1 and one end of the third resistor R3 are connected, the other end of the third resistor R6342, the other end of the second resistor R2, the negative electrode of the fourth diode D4, the positive electrode of the second capacitor C2 and the input pin of the LDO integrated circuit U1 are connected, the output pin of the LDO integrated circuit U1, one end of the third capacitor C3 and the positive electrode of the fourth capacitor C4 are connected, the output end of the first capacitor C68642, the negative electrode of the first capacitor C4 and the negative electrode of the third capacitor C599 are connected, the output terminal of the third capacitor C599 and the voltage stabilizing circuit C599 of the third capacitor C3, The cathode of the fourth capacitor C4, the anode of the fourth diode D4, the source of the second MOS transistor M2 and the ground pin of the LDO integrated circuit U1 are connected, and the connection end thereof is the cathode of the voltage stabilizing circuit.

As shown in fig. 4, in the present embodiment, the PWM constant current circuit includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R7, a ninth resistor R7, a tenth resistor R7, an eleventh resistor R7, a twelfth resistor R7, a thirteenth resistor R7, a fifth capacitor C7, a sixth capacitor C7, a seventh capacitor C7, an eighth capacitor C7, a ninth capacitor C7, a tenth capacitor C7, an eleventh capacitor C7, a twelfth capacitor C7, a fifth diode D7, a sixth diode D7, a seventh diode D7, an eighth diode D7, a ninth diode D7, a transistor Q7, a third MOS transistor M7, a dimming integrated circuit U7 with model number SY5882, and a high frequency transformer, where the twelfth capacitor C7 is an electrolytic capacitor, the sixth diode D7, the fifth diode Q7, the ninth diode M7, the ninth diode 7, the ninth rectifying diode 7 and the ninth rectifying diode 7, the third MOS transistor M3 is an NMOS transistor, the high-frequency transformer includes a primary winding Np, a secondary winding Ns, an auxiliary winding Na, a first winding N1 and a second winding N2, one end of the auxiliary winding Na, an anode of a fifth diode D5 and one end of a seventh resistor R7 are connected, a cathode of a fifth diode D5 and one end of a fourth resistor R4 are connected, the other end of a fourth resistor R4, one end of a fifth resistor R5 and one end of a fifth capacitor C5 are connected to a collector of a transistor Q1, the other end of a fifth resistor R5, a cathode of a sixth diode D6 and a base of a transistor Q1 are connected, an emitter of the transistor Q1 and an anode of a seventh diode D7 are connected, a cathode of a seventh diode D7, one end of a sixth capacitor C6, one end of a sixth resistor R6 and a pin 6 of a dimming integrated circuit U2 are connected, the other end of the seventh resistor R6342, an anode of an eighth resistor R28 and a pin 2 of the dimming integrated circuit U2 are connected to the first pin U592, a pin 7 of the dimming integrated circuit U2 is connected to one end of a ninth capacitor C9, a pin 1 of the dimming integrated circuit U2 and one end of a tenth capacitor C10 are connected to one end of an eleventh capacitor C11, the other end of the eleventh capacitor C11 is connected to one end of an eleventh resistor R11, a pin 5 of the dimming integrated circuit U2 is connected to one end of a tenth resistor R10, the other end of the tenth resistor R10 is connected to a gate of a third MOS transistor M3, a source of the third MOS transistor M3, one end of a twelfth resistor R12 are connected to a pin 3 of the dimming integrated circuit U2, a drain of the third MOS transistor M3, an anode of an eighth diode D8 and one end of a primary winding Np of the high-frequency transformer, a cathode of the eighth diode D8, one end of an eighth capacitor C84 and one end of a ninth resistor R3742 are connected, the other end of the primary winding Np of the high-frequency transformer, the other end of the ninth resistor R9 and one end of the eighth capacitor C8 are connected to one end of the high-frequency transformer, The other end of the sixth resistor R6 is connected with one end of the seventh capacitor C7, the connection end of the sixth resistor R6 is the positive electrode of the PWM constant current circuit, the other end of the fifth capacitor C5, the other end of the sixth capacitor C6, the other end of the seventh capacitor C7, the positive electrode of the sixth diode D6, the other end of the auxiliary coil Na of the high-frequency transformer, one end of the first coil N1 of the high-frequency transformer, the other end of the eighth resistor R8, the other end of the eleventh resistor R11, the other end of the twelfth resistor R12, the other end of the ninth capacitor C9, the other end of the tenth capacitor C10, the connection end of the tenth capacitor C10 and the 4 th pin of the dimming integrated circuit U2 are connected, and the connection end of the negative electrode of the PWM constant current circuit, the other end of the first coil N1 of the high-frequency transformer is connected with one end of the second coil N2 of the high-frequency transformer, and the connection end of the high-frequency transformer is the second voltage end of the PWM constant current circuit, the second coil N2 is the first voltage end of the PWM constant current circuit, the 8 th pin of the dimming integrated circuit U2 is a PWM control terminal of the PWM constant current circuit, one end of the secondary coil Ns of the high frequency transformer is connected to the anode of the ninth diode D9, the cathode of the ninth diode D9, the anode of the twelfth capacitor C12 and one end of the thirteenth resistor R13 are connected, and the connection end thereof is a positive output terminal of the PWM constant current circuit, and the other end of the secondary coil Ns of the high frequency transformer, the cathode of the twelfth capacitor C12 and the other end of the thirteenth resistor R13 are connected, and the connection end thereof is a negative output terminal of the PWM constant current circuit.