CN210725410U

CN210725410U - LED dimmer and LED dimming system

Info

Publication number: CN210725410U
Application number: CN201920299472.XU
Authority: CN
Inventors: 叶美盼; 蔡拥军
Original assignee: Hangzhou Silan Microelectronics Co Ltd
Current assignee: Hangzhou Silan Microelectronics Co Ltd
Priority date: 2019-03-08
Filing date: 2019-03-08
Publication date: 2020-06-09
Anticipated expiration: 2029-03-08

Abstract

The application discloses LED dimmer and LED dimming system. The LED dimmer includes: a dimming module and a bypass module connected in series between the first and second ac input terminals, wherein the dimming module receives a dimming control signal and obtains dimming data from the dimming control signal, and load impedances of the dimming module and the bypass module are matched to each other to form a power carrier loop, thereby superimposing the dimming data on the ac voltage to generate a carrier signal. The LED dimmer is integrated with the signal receiving module and the bypass module, can provide carrier signals for the LED driving circuits, thereby improving the anti-interference capability, simplifying the circuit structure and the volume of the LED driving circuit packaged in the LED bulb, and being suitable for packaging the LED bulb with small size.

Description

LED dimmer and LED dimming system

Technical Field

The application relates to the power electronics related field, in particular to an LED dimmer and an LED dimming system.

Background

LED lamps have been widely used in the field of lighting. More and more users demand dimming devices suitable for LED lamps in order to adjust brightness or to dim according to environmental needs to reduce energy consumption. It is desirable to implement a dimming function even in a large crystal lamp or a ceiling lamp using an LED lamp.

Unlike lighting devices that use a single LED bulb, a crystal lamp or pendant lamp includes numerous and small-sized LED bulbs. Each LED bulb is a module including a housing, an LED lamp accommodated in the housing, and an LED driving circuit, the LED lamp being connected with the corresponding LED driving circuit. The LED driving circuit comprises a signal receiving module and a power conversion module, wherein the signal receiving module is used for receiving the dimming control signal and generating the dimming signal according to the dimming control signal, and the power conversion module is used for controlling the output current and/or the duty ratio of the LED driving circuit according to the dimming signal so as to realize dimming control.

However, the size of the LED bulbs used in crystal lamps or ceiling lamps is too small to accommodate existing LED driving circuits. In addition, the housing of the LED light bulb is, for example, a plastic-coated aluminum material, and the dimming control signal received by the signal receiving module located inside the LED light bulb is easily interfered.

SUMMERY OF THE UTILITY MODEL

In view of the above, an object of the present invention is to provide an LED dimmer and an LED dimming system, wherein the LED dimmer is adopted to convert the dimming control signal into a carrier signal, and the signal receiving module and the bypass module are integrated in the LED dimmer, so as to improve the anti-interference capability and reduce the size of the package chip in the LED bulb.

According to an aspect of the utility model, a provide a LED dimmer, include:

a dimming module and a bypass module connected in series between the first and second ac input terminals,

wherein the dimming module receives a dimming control signal and obtains dimming data from the dimming control signal, and load impedances of the dimming module and the bypass module are matched with each other to form a power carrier loop, thereby superimposing the dimming data on the ac voltage to generate a carrier signal.

Optionally, the dimming module comprises:

the alternating current input end of the first rectifying bridge is connected to an alternating current power supply, and a first direct current bus voltage is generated according to the alternating current voltage;

the signal receiving module receives a dimming control signal sent from the outside;

the control module is connected with the signal receiving module to obtain a dimming control signal and dimming data according to the dimming control signal;

the carrier signal generator is connected with the control module to obtain dimming data and generate a corresponding data signal according to the dimming data; and

and the power transmission module is connected with the carrier signal generator to obtain the data signal, is connected between the first direct current output end and the second direct current output end of the first rectifier bridge, and changes the load impedance of the first rectifier bridge according to the data signal.

Optionally, the dimming module further includes a power supply module, wherein the power supply module is connected between a first dc output terminal and a second dc output terminal of the first rectifier bridge, and the first dc bus voltage output by the first rectifier bridge is used to generate an internal power supply voltage of the dimming module.

Optionally, the dimming module further includes a power supply module and a diode, wherein the diode performs half-wave rectification on the ac voltage, the power supply module is connected to the diode, and the internal power supply voltage of the dimming module is generated by using the first dc bus voltage rectified by the diode.

Optionally, the bypass module comprises:

the alternating current input end of the second rectifier bridge is connected to the alternating current power supply, and a second direct current bus voltage is generated according to the alternating current voltage;

the zero-crossing detection module is connected to the first direct-current output end of the second rectifier bridge and used for detecting the zero-crossing time of the second direct-current bus voltage;

the data sampling module is connected to a first direct current output end of the second rectifier bridge and used for obtaining a sampling signal of the second direct current bus voltage;

the first micro control unit is connected with the zero-crossing detection module and the data sampling module and used for obtaining the waveform of the carrier signal according to the sampling signal and generating a switch control signal corresponding to the signal modulation of the carrier signal; and

an impedance module connected with the first micro control unit to receive the switch control signal, and connected between the first DC output end and the second DC output end of the second rectifier bridge to change the load impedance of the first rectifier bridge according to the switch control signal,

the alternating current input end of the first rectifier bridge and the alternating current input end of the second rectifier bridge are connected to the same power supply line of the alternating current power supply.

According to the utility model discloses an on the other hand provides a LED dimming system, include:

an LED dimmer comprising a dimming module and a bypass module connected in series between first and second AC input terminals;

a plurality of LED drive circuits connected in parallel with the bypass module of the LED dimmer,

wherein the dimming module receives a dimming control signal and obtains dimming data from the dimming control signal, load impedances of the dimming module and the bypass module are matched to each other, thereby superimposing the dimming data on the AC voltage to generate a carrier signal,

the LED driving circuits respectively receive carrier signals, obtain electric energy and dimming signals according to the carrier signals, and control electric energy transmission according to the dimming signals to achieve dimming.

Optionally, the dimming module comprises:

Optionally, the bypass module comprises:

Optionally, the plurality of LED game driving circuits respectively include:

the alternating current input end of the third rectifier bridge is connected with the alternating current input end of the second rectifier bridge in parallel, and a third direct current bus voltage is generated according to the carrier signal;

the data sampling module is connected to a first direct current output end of the third rectifier bridge and used for obtaining a sampling signal of the third direct current bus voltage;

the second micro control unit is connected with the data sampling module and used for obtaining the waveform of the carrier signal according to the sampling signal and demodulating the carrier signal to obtain a dimming signal; and

a power conversion module connected with the second micro control unit to obtain the dimming signal and connected with the DC output end of the third rectifier bridge to obtain electric energy,

the power conversion module controls driving current and/or duty ratio provided to the LED lamp according to the dimming signal, so that dimming control is realized.

Optionally, the power conversion module includes a switching power supply adopting any one of a buck-boost topology, a buck-boost topology and an inverse topology.

According to the utility model discloses LED dimmer, the integration has signal reception module in this LED dimmer's the module of adjusting luminance, therefore can convert the control signal that adjusts luminance to the encapsulation chip that carrier signal sent a plurality of LED bulbs. A signal receiving module can be omitted from a packaging chip in the LED bulb, so that the interference of the shell on the dimming control signal is avoided, and the anti-interference capability is improved. The LED dimmer also integrates a bypass module, and the load impedances of the dimming module and the bypass module are matched with each other to form a power carrier loop. An LED driving circuit in a packaging chip of the LED bulb is connected with a bypass module of the light modulator in parallel to obtain a carrier signal, and further obtain electric energy and a light modulation signal. The integration of the bypass module in the dimmer simplifies the circuit structure and volume of the LED driving circuit packaged in the LED light bulb, thereby being suitable for packaging into a small-sized LED light bulb.

Furthermore, a power supply module and a diode connected to the power supply module and the alternating current input end are integrated in a dimming module of the LED dimmer, the power supply module can be directly powered by voltage after half-wave rectification of the diode, and the electric energy and the loading capacity of the power supply module are improved.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

fig. 1 shows a schematic block diagram of an LED dimming system according to the prior art.

Fig. 2 shows a schematic block diagram of an LED dimming system according to a first embodiment of the present invention.

Fig. 3 shows a voltage waveform diagram of an LED dimming system according to a first embodiment of the present invention.

Fig. 4 shows a detailed block diagram of an LED dimming system according to a first embodiment of the present invention.

Fig. 5 shows a specific block diagram of a power transfer and carrier signal generator module in a dimming module according to a first embodiment of the present invention.

Fig. 6 shows a specific block diagram of the impedance module in the bypass module according to the first embodiment of the present invention.

Fig. 7 shows a graph of voltage waveforms in the dimming module and the bypass module according to the first embodiment of the present invention.

Fig. 8 shows a schematic block diagram of an LED dimming system according to a second embodiment of the present invention.

Fig. 9 shows a detailed block diagram of an LED dimming system according to a second embodiment of the present invention.

Fig. 10 shows a voltage waveform diagram of a power supply module of an LED dimming system according to a second embodiment of the present invention.

Detailed Description

The invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by like reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale. In addition, certain well known components may not be shown.

Numerous specific details of the invention, such as structure, materials, dimensions, processing techniques and techniques of the devices are described below in order to provide a more thorough understanding of the invention. However, as will be understood by those skilled in the art, the present invention may be practiced without these specific details.

The present invention may be presented in a variety of forms, some of which are described below.

Fig. 1 shows a schematic block diagram of an LED dimming system according to the prior art. The LED dimming system 100 includes a switch SW and an LED driving circuit 120. The switch SW is connected between the AC power source AC and the LED driving circuit 120, and controls power supply of the LED driving circuit 120, thereby turning on or off the LED lamp 150.

The LED driving circuit 120 includes a rectifier bridge 121, a power supply module 122, a signal receiving module 123, and a power conversion module 124. The AC input terminal of the rectifier bridge 121 is connected to the AC power source AC via the switch, and the dc output terminal is connected to the power supply module 122. The rectifier bridge 121 rectifies the ac input voltage into a dc bus voltage. The power supply module 122 performs smoothing filtering on the dc bus voltage to generate an internal power supply voltage. The signal receiving module 123 operates with an internal power supply voltage, and converts a dimming control signal sent by an external control device (e.g., a mobile phone) into a dimming signal. The input of the power conversion module 124 receives the dc bus voltage, and the output provides the driving current of the LED lamp.

During operation, the power conversion module 124 controls the driving current and/or the duty ratio of the LED driving circuit 120 according to the dimming signal, thereby implementing dimming control.

In the conventional LED dimming system described above, the LED bulbs of the same lighting device respectively include the LED driving circuit 120 and the LED lamp 150 enclosed in the housing. The LED driving circuit 120 is embedded with a signal receiving module 123, which converts the received dimming control signal into a dimming signal, thereby controlling the driving current and/or duty ratio of the power conversion module. However, the signal receiving module packaged in the LED bulb causes the problem that the LED driving circuit 120 is too bulky and susceptible to interference.

Fig. 2 shows a schematic block diagram of an LED dimming system according to a first embodiment of the present invention. The LED dimming system 200 includes a switch SW, a dimmer 210, and a plurality of LED driving circuits 220. The switch SW is connected between the AC power source AC and the dimmer 210, and controls power supply to the dimmer 210 and the plurality of LED driving circuits 220, thereby turning on or off the LED lamp 250.

The alternating current power supply AC supplies an alternating current voltage via the first power supply line and the second power supply line. The switch SW is connected to the first power supply line.

The dimmer 210 includes a dimming module 211 and a bypass module 212. The dimming module 211 is connected to any power line, and is configured to receive a dimming control signal sent by an external control device (e.g., a mobile phone), and convert the dimming control signal into a carrier signal. The bypass module 212 is connected between the first power supply line and the output terminal of the dimming module 211, and generates a corresponding bypass impedance according to an operation stage of the dimming module 211, thereby maintaining the carrier signal.

The plurality of LED driving circuits 220 are connected between the first power supply line and the output terminal of the dimming module 211. The plurality of LED driving circuits 220 respectively provide driving currents of the corresponding LED lamps 250, and demodulate dimming signals from carrier signals.

During operation, the plurality of LED driving circuits 220 control the driving current and/or the duty ratio according to the dimming signal, thereby implementing dimming control.

Fig. 3 shows a voltage waveform diagram of an LED dimming system according to a first embodiment of the present invention, wherein an AC voltage provided by an AC power source AC is a sine wave voltage. The operation mode of the LED dimming system 200 can be divided into three phases according to the operation state of the circuit. As shown, the first phase of the LED dimming system 200 corresponds to t0 to t1, the second phase corresponds to t1 to t2, and the third phase corresponds to t2 to t3, and the time period from t0 to t3 is a half cycle of the sine wave, and the waveform of the sine wave is greater than 0 in this time period.

During the time period t0 to t1 of the first phase, the sine wave voltage rises from zero, and at this time, the circuit makes the sine wave voltage substantially across the dimming module 211 through impedance matching of the bypass module 212 and the dimming module 211 for supplying power to the dimming module 211, so the first phase may also be referred to as a power supply phase.

During the power supply phase, the bypass module 212 has a low impedance with respect to the dimming module 211, the sine wave voltage is almost all at the dimming module 211, and there is no voltage across the bypass module 212.

Between time t0 and time t1, the current in the circuit loops through the AC power source AC, the switch SW, the bypass module 212, and the dimming module 211. During the period from t1 to t2 in the second phase, the sine wave voltage continues to rise and starts to fall after reaching the peak value, and at this time, the circuit makes the sine wave voltage substantially at the two bypass ends 212 through impedance matching of the bypass module 212 and the dimming module 211 for transmitting power to the LED driving circuit 220, so the second phase can also be referred to as a power transmission phase.

In the power transmission phase, the bypass module 212 has a high impedance with respect to the dimming module 211, the sine wave voltage is almost all at the bypass module 212, and there is no voltage across the dimming module 211.

Between time t1 and time t2, the current in the circuit forms a loop through the AC power source AC, the switch SW, the LED driving circuit 220, and the dimming module 211, and at this time, the LED driving circuit 220 and the bypass module 212 operate in parallel, and the bypass module 212 is in a high impedance state.

During the time period t 2-t 3 of the third phase, the sine wave voltage continues to drop until it drops to 0, at which time, the circuit makes the sine wave voltage across the bypass module 212 carry the dimming data through the impedance matching between the bypass module 212 and the dimming module 211, so as to provide the dimming signal to the LED driving circuit 220. Thus, the third phase may also be referred to as the data phase.

Between t2 and t3, the current in the dimming system forms a loop through the AC power source AC, the switch SW, the bypass module 212 and the dimming module 211, and the LED driving circuit 220 and the bypass module 212 operate in parallel.

Fig. 5 shows a specific block diagram of a power transfer and carrier signal generator module in a dimming module according to a first embodiment of the present invention. Fig. 6 shows a specific block diagram of the impedance module in the bypass module according to the first embodiment of the present invention.

In this embodiment, the dimming module 211 is connected in series with the bypass module 212 and the switch SW between two output terminals of the AC power source AC.

The dimmer 210 includes a dimming module 211 and a bypass module 212. The dimming module 211 includes a rectifier bridge 2111, a power transmission module 2112, a signal receiving module 2113, a control module 2114, a carrier signal generator 2115, and a power supply module 2116. The bypass module 212 includes a rectifier bridge 2121, an impedance module 2122, a zero-crossing detection module 2123, a data sampling module 2124, and a microcontroller 2125.

As shown in fig. 4, the rectifier bridge 2111 of the dimming module 211, the rectifier bridge 2121 of the bypass module 212, and the switch SW are connected in series between two power supply terminals of the alternating-current power supply AC.

In the dimming module 211, the rectifier bridge 2111 rectifies the ac voltage into the dc bus voltage. The power transfer module 2112 and the power supply module 2116 are connected in parallel between the positive and negative output terminals of the rectifier bridge 2111. The power supply module 2116 generates a supply voltage using the dc voltage output from the rectifier bridge 2111, and supplies the supply voltage to the signal receiving module 2113 and the control module 2114.

The signal receiving module 2113 is, for example, a module such as bluetooth, ZIGBEE, WIFI, infrared, and the like, and mainly functions to receive a dimming control signal sent by an external control device (e.g., a mobile phone). The control module 2114 decodes the dimming control signal to obtain dimming data, and controls the operation of the power transfer module 2112 and the carrier signal generator 2115 in accordance with the dimming data.

The power transfer module 2112 may be switched between a high impedance state and a low impedance state. For example, as shown in fig. 5, the power transfer module 2112 includes a transistor Q1 and a resistor R1, and controls the load impedance of the rectifier bridge 2111 by controlling the voltage or current at the control terminal of the transistor Q1 to make the transistor Q1 in saturation conduction or linear conduction. The carrier signal generator 2115 includes a transistor Q2, a voltage regulator tube Z1 and a diode D1 connected in series for generating a square wave signal of a fixed frequency. The control module 2114 obtains a data signal according to the level state of the square wave signal generated by the carrier signal generator 2115. For example, the level state of the square wave signal is controlled according to the value of the corresponding data bit in each clock cycle of the square wave signal, so that dimming data is converted into a data signal of a varying sequence of the corresponding level states, and the data signal is superimposed on the alternating voltage. Further, the data signal is used to control the switching state in the power transmission module 2112, and the change sequence of the impedance state of the power transmission module 2112 is obtained in a plurality of clock cycles, so that signal modulation is performed in at least a part of the time period of the alternating voltage half power frequency cycle, and a carrier signal is obtained.

In the bypass module 212, the rectifier bridge 2121 rectifies the ac voltage to a dc bus voltage. The rectifier bridge 2111 and the alternating current input end of the rectifier bridge 2121 are connected in series on the same power supply line. The impedance block 2122 is connected between the positive and negative output terminals of the rectifier bridge 2121. For example, as shown in fig. 6, the impedance module 2122 includes a switch Q3 and a resistor R2 connected in series, and further includes a switch SW2 connected in parallel with the resistor R2, and the impedance module 2122 controls the load impedance of the rectifier bridge 2121 by using the switching state transformation of the switch Q3.

The zero-crossing detection module 2123 and the data sampling module 2124 are respectively connected to the positive output end of the rectifier bridge 2121, and respectively obtain a zero-crossing time of the dc bus voltage and a sampling signal. The bypass module 212 also includes a Micro Control Unit (MCU) 2125. The micro control unit 2125 obtains a waveform of the carrier signal according to the sampling signal, and generates a switching control signal corresponding to the signal modulation of the carrier signal, thereby controlling the switching tube Q3 in the impedance module 2122.

In the dimmer 210, at least during signal modulation, the load impedance of the rectifier bridge 2111 of the dimming module 211 matches the load impedance of the rectifier bridge 2121 in the bypass module 212, thereby forming a power carrier loop.

For example, to transmit a data value of "0", the power transmission module 2112 is in a low impedance state with respect to the impedance module 2122 during one clock cycle, such that substantially no voltage drop occurs across the rectifier bridge 2111 of the dimming module 211 and substantially all of the voltage drop is experienced by the rectifier bridge 2121 of the bypass module 212, thereby transmitting a complete waveform of the ac voltage to the plurality of LED driving circuits 250. To transmit the data value "1", the power transmission module 2112 is in a high impedance state with respect to the impedance module 2122 during one clock cycle, such that substantially all of the voltage drop is experienced across the rectifier bridge 2111 of the dimming module 211 and substantially no voltage drop is experienced across the rectifier bridge 2121 of the bypass module 212, thereby transmitting the open-phase ac voltage waveform to the plurality of LED driving circuits 250.

In this embodiment, a plurality of LED driving circuits 220 are connected in parallel with the bypass module 212.

The LED driving circuit 220 includes a rectifier bridge 2211, a data sampling module 2212, a Micro Control Unit (MCU) 2213 and a power conversion module 2214. The two ac input terminals of the rectifier bridge 2211 are respectively connected to the two ac input terminals of the rectifier bridge 2121. Rectifier bridge 2211 rectifies the ac input voltage to dc bus voltage. The data sampling module 2122 is connected to the positive output terminal of the rectifier bridge 2211 to obtain a sampling signal of the dc bus voltage. The mcu 2123 obtains the waveform of the carrier signal according to the sampling signal, demodulates the dimming data from the carrier signal, generates a corresponding dimming signal, and further controls the power conversion module 2214.

In the LED driving circuit 220, an input terminal of the power conversion module 2214 is connected to positive and negative output terminals of the rectifier bridge 2211. The output of the power conversion module 2214 is used to power a load fixture (e.g., an LED lamp). The micro control unit 2123 provides a dimming signal to the power conversion module 2214. The power conversion module 2214 controls the driving current and/or the duty ratio provided to the LED lamp 250 according to the dimming signal, thereby implementing the dimming control.

The power conversion module 2214 can be implemented by using a switching power supply or a linear constant current control circuit. For example, the power conversion module 2214 may be implemented by using a switching power supply with various topologies, such as a BUCK (BUCK) topology, a BUCK-BOOST (BUCK-BOOST) topology, and a FLYBACK (FLYBACK) topology.

Fig. 7 shows voltage waveform diagrams in the dimming module and the bypass module according to the first embodiment of the present invention, as shown in fig. 5 and 6, V1 is a control signal of the switch Q1, V2 is for controlling the switch Q2, V3 is a control signal of the switch Q3, and V4 is a control signal of the switch SW 2.

As shown in fig. 7, in the dimming module 211, when the control signal V2 is at a high level, the transistor Q1 is fully turned on through the driving resistor R1 in the power transmission module 2112, and the voltage is fully transmitted to both ends of the circuit of the bypass module 212, and when the control signal V2 is at a low level, the impedance of the transistor Q1 is determined by the carrier signal generator 2115.

When the control signal V2 is at a low level and V1 is at a high level, the voltage V across the rectifier bridge 2111 of the dimming module 211_DimmingThe voltage rises until the diode D1, the voltage regulator Z1 and the transistor Q2 in the carrier signal generator 2115 are broken down, the gate voltage of the transistor Q1 in the power transmission module 2112 rises, the voltage is finally stabilized on a Miller platform, current flows through the two ends of the drain D and the source S of the transistor Q1, a loop is formed through the bypass module 212, and therefore the voltage V at the two ends of the output voltage of the rectifier bridge 2111 in the dimmer_DimmingVd1+ Vz1+ Vds2+ Vgs1, where Vd1 is the diode D1 forward voltage drop, Vz1 is the zener Z1 breakdown voltage, Vds2 is the voltage across the D and S poles of transistor Q2, and Vgs1 is the voltage across the G and S poles of transistor Q1. The loop path comprises an alternating current source AC, a rectifier bridge 2111, a diode D1, a voltage regulator tube Z1, a transistor Q2, a transistor Q1, a rectifier bridge 2121, a transistor Q3 and a resistor R2.

In the bypass module 212, when the voltage V3 is high and V4 is low, the current I of the transistor Q3 in the impedance module 2122 is (V3-Vgs3)/R2, where Vgs3 is the voltage between the G pole and the S pole of the transistor Q3, and when the voltage V4 is high, the transistor Q3 is fully turned on, and the current magnitude is determined by the dimming module 211.

Fig. 8 shows a schematic block diagram of a LED dimming system according to a second embodiment of the present invention. The main difference between the LED dimming system according to the second embodiment and the first embodiment is that the dimming module 211 includes a diode D2, so that the power supply module 2116 can independently supply power using a diode D2, and the anode of the diode D2 is directly connected to any end of the ac power source, so that the LED dimming system is more optimized in terms of power supply.

Fig. 9 shows a detailed block diagram of an LED dimming system according to a second embodiment of the present invention. The main difference between the LED dimming system of the second embodiment and the first embodiment is that the dimming module 211 includes a diode D2, so that the power supply module 2116 can independently supply power using a diode D2. Only the differences between the first embodiment and the second embodiment will be described below, and the same parts will not be described in detail.

The diode D2 has an anode connected to one end of the AC power source AC and a cathode connected to the high potential input terminal of the power supply module 2116. Further, the low potential terminal of the power supply module 2116 is grounded. The alternating voltage of the alternating current power source AC is half-wave rectified by the diode D2, and then the power is supplied to the power supply module 2116, and the internal power supply voltage is further generated. For example, when the voltage of the second output terminal of the AC source AC is higher than the voltage of the first output terminal, the AC voltage supplies power to the power supply module 2116 through the diode D2, which is much higher than the voltage of both terminals of the dimming module 211 in the dimming system according to the first embodiment, so that the load capacity of the power supply module 2116 becomes strong.

Fig. 10 shows a voltage waveform diagram of a power supply module of an LED dimming system according to a second embodiment of the present invention. The voltage at the two ends of the power supply module 2116 is shown in the figure, and the current in the circuit forms a loop through an alternating current power supply AC, a diode D2, the power supply module 2116 and a rectifier bridge 2111 to form a half-wave rectifier circuit. Since the transistor Q1 is turned on most of the time, the voltage V is seen from the interior of the dimming module 211 when it is turned on_DimmingAnd an alternating current directly connected to the rectifier bridge 2111The voltage level at one end of the AC power source is substantially the same, and the other end of the AC power source can provide power to the power supply module 2116 through the diode D2.

The embodiments of the invention are described above, and these embodiments do not set forth any exhaustive details, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and its various embodiments with various modifications as are suited to the particular use contemplated. The protection scope of the present invention should be subject to the scope defined by the claims of the present invention.

Claims

1. An LED dimmer, comprising:

2. The LED dimmer of claim 1, wherein the dimming module comprises:

3. The LED dimmer according to claim 2, the dimming module further comprising a power supply module, wherein the power supply module is connected between the first dc output terminal and the second dc output terminal of the first rectifier bridge, and the internal supply voltage of the dimming module is generated using the first dc bus voltage output by the first rectifier bridge.

4. The LED dimmer according to claim 2, the dimming module further comprising a power supply module and a diode, wherein the diode half-wave rectifies the ac voltage, the power supply module is connected to the diode, and the internal power supply voltage of the dimming module is generated using the diode rectified first dc bus voltage.

5. The LED dimmer of claim 2, wherein the bypass module comprises:

an impedance module connected with the first micro control unit to receive the switch control signal, and connected between the first DC output end and the second DC output end of the second rectifier bridge to change the load impedance of the second rectifier bridge according to the switch control signal,

6. An LED dimming system comprising:

7. The LED dimming system of claim 6, wherein the dimming module comprises:

8. The LED dimming system of claim 7, further comprising a power supply module, wherein the power supply module is connected between the first dc output terminal and the second dc output terminal of the first rectifier bridge, and the first dc bus voltage output by the first rectifier bridge is used to generate an internal supply voltage of the dimming module.

9. An LED dimming system as claimed in claim 7, the dimming module further comprising a power supply module and a diode, wherein the diode half-wave rectifies the ac voltage, the power supply module is connected to the diode, and the internal supply voltage of the dimming module is generated using the diode rectified first dc bus voltage.

10. An LED dimming system as claimed in claim 7, wherein the bypass module comprises:

11. The LED dimming system of claim 10, wherein the plurality of LED driving circuits respectively comprise:

12. The LED dimming system of claim 11, wherein the power conversion module comprises a switching power supply employing any one of a buck, buck-boost, and anti-topology.