CN102135238A

CN102135238A - Light adjustable alternating current LED lamp and dimmer thereof

Info

Publication number: CN102135238A
Application number: CN2010100009544A
Authority: CN
Inventors: 曹永铭; 黄礼宣
Original assignee: LIGHTING DEVICE TECHNOLOGIES CORP
Current assignee: LIGHTING DEVICE TECHNOLOGIES CORP
Priority date: 2010-01-21
Filing date: 2010-01-21
Publication date: 2011-07-27

Abstract

The invention discloses a light adjustable alternating current LED lamp and a dimmer thereof so as to realize dimming control of the LED lamp. The alternating current LED lamp comprises an LED load and the dimmer used for adjusting the brightness of the LED load. The dimmer comprises a PWM (Pulse-Width Modulation) generator and a current regulator, wherein the PWM generator is used for providing a pulse width modulation signal; and the current regulator is used for determining the current supplied to the LED load according to the duty ratio of the pulse width modulation signal. The current of the LED load can be adjusted through regulating the duty cycle ratio of the pulse width modulation signal, and further the brightness of the LED load is adjusted.

Description

The AC LED lamp of tunable optical and light modulator thereof

Technical field

The present invention relates to a kind of AC LED lamp, particularly about a kind of AC LED lamp of tunable optical.

Background technology

Traditional incandescent lamp is replaced by the LED light lamp than environmental protection gradually.The LED lamp can be divided into direct-current LED lamp and AC LED lamp.Traditional incandescent lamp uses AC power, and the direct-current LED lamp needs dc source, therefore incandescent lamp will be replaced by the direct-current LED lamp and need decorate again to change circuit, and this need spend many expenses.AC LED lamp can directly drive with AC power, so need not to change original circuit.Though AC LED lamp can directly be replaced traditional incandescent lamp, present AC LED lamp does not have dimming function, therefore is not suitable for some application.

Summary of the invention

One of purpose of the present invention is to propose a kind of AC LED lamp of tunable optical.

One of purpose of the present invention is to propose a kind of light modulator of AC LED lamp.

According to the present invention, a kind of AC LED lamp of tunable optical comprises that LED load and light modulator are connected between first and second power input.This first and second power input is for connecting power supply, and this light modulator is in order to the electric current of regulating the first direction by this LED load and the electric current of second direction, and then adjusts the brightness of this LED load.

According to the present invention, a kind of light modulator of AC LED lamp comprises PWM generator and current regulator.This current regulator only allows the electric current of first direction to pass through under first state, under second state, only allow the electric current of second direction to pass through, and determine the mean value of the electric current of the mean value of electric current of this first direction and this second direction according to dutycycle from the PWM signal of this PWM generator.

The AC LED lamp of tunable optical disclosed by the invention and light modulator thereof, the responsibility week by regulating the PWM signal that the PWM generator produces is than the electric current that can adjust this LED load, and then adjusts the brightness of this LED load.

Description of drawings

Fig. 1 is embodiments of the invention;

Fig. 2 is the embodiment of two-way LED lamp string among Fig. 1;

Fig. 3 is the embodiment that bidirectional current limiting device among Fig. 1 is placed on light modulator;

Fig. 4 is the embodiment of bidirectional current limiting device and current regulator among Fig. 1;

Fig. 5 is other embodiment of protective device among Fig. 4;

Fig. 6 is the equivalent circuit of circuit during the positive half period of AC power among Fig. 4;

Fig. 7 is the equivalent circuit of circuit during the negative half-cycle of AC power among Fig. 4;

Fig. 8 is second embodiment of Fig. 1 bidirectional current limiting device 24;

Fig. 9 shows the operation the when input of bidirectional current limiting device among Fig. 8 connects positive voltage;

Figure 10 shows the operation when the two-way input of deciding current device connects negative voltage among Fig. 8;

Figure 11 shows the embodiment of protection assembly among Fig. 8;

Figure 12 is the 3rd embodiment of Fig. 1 bidirectional current limiting device 24;

Figure 13 shows the operation the when input of bidirectional current limiting device among Figure 12 connects positive voltage;

Figure 14 shows the operation when the two-way input of deciding current device connects negative voltage among Figure 12;

Figure 15 shows the embodiment of protection assembly among Figure 12;

Figure 16 shows the embodiment of constant current source among Fig. 8 to Figure 12;

Figure 17 shows the i-v curve of bidirectional current limiting device among Fig. 8;

Figure 18 shows second embodiment of current regulator among Fig. 1;

Figure 19 is the equivalent circuit of circuit during the positive half period of AC power among Figure 18;

Figure 20 is the equivalent circuit of circuit during the negative half-cycle of AC power among Figure 18; And

Figure 21 shows the 3rd embodiment of current regulator among Fig. 1.

Specific embodiment

Below in conjunction with Figure of description the specific embodiment of the present invention is done detailed description.Obviously, described embodiment only is a part of embodiment of the present invention, and other embodiment that those skilled in the art is obtained under the prerequisite of not paying creative work belongs to protection scope of the present invention.

As shown in Figure 1, tunable optical AC LED lamp 10 of the present invention comprises that two

power inputs

12 and 14 connect AC power 16, LED load 18 and light modulator 20.LED load 18 can be AC LED bulb or AC LED fluorescent tube, and light modulator 20 is in order to the electric current I 1 of regulating the first direction by LED load 18 and the electric current I 2 of second direction, and then regulates the brightness of LED load 18.LED load 18 comprises two-way LED lamp string 22 and bidirectional current limiting device 24.Two-way LED lamp string 22 in response to by the electric current I 1 on it and I2 and luminous, bidirectional current limiting device 24 is in order to the maximum of restriction electric current I 1 and I2.

Fig. 2 A is first embodiment of two-way LED lamp string 22, and its LED D11, D12 and D13 that comprises the first direction configuration is connected between

link

30 and 32, and LED D21, D22 and the D23 of second direction configuration are connected between

link

30 and 32.

Fig. 2 B is second embodiment of two-way LED lamp string 22, wherein pair of LEDs contains the D11 of first direction configuration and the D21 of second direction configuration, second couple of LED contains the D12 of first direction configuration and the D22 of second direction configuration, the 3rd couple of LED contains the D13 of first direction configuration and the D23 of second direction configuration, and this first couple, second couple and the 3rd couple of LED are connected between

link

30 and 32.

Light modulator 20 comprises PWM generator 26 and current regulator 28.The mean value of the duty cycle adjustment electric current I 1 of the PWM signal Spwm that current regulator 28 provides according to PWM generator 26 and the mean value of electric current I 2, and then adjust the brightness of LED load 18.Current regulator 28 only allows electric current I 1 and I2 during the positive half period of AC power 16 one of them passes through, and then only allows another electric current to pass through during the negative half-cycle of AC power 16.In this embodiment, bidirectional current limiting device 24 is placed in the LED load 18, but also can be placed in the light modulator 20, as shown in Figure 3.

Fig. 4 is the embodiment of Fig. 1 bidirectional current limiting device 24 and current regulator 28.Bidirectional current limiting device 24 comprises that current-limiting resistance RES is connected between two-way LED lamp string 22 and the current regulator 28.Current regulator 28 comprises

link

52 and 54,

protective device

40 and 42 and switch module 44 and 48.

Link

52 and 54 connects bidirectional current limiting device 24 and power input 14 respectively.Protective device 40 and switch module 44 are connected between

link

52 and 54, and 40 of protective devices allow the electric current I 1 of first direction to pass through with protection switch assembly 44.Protective device 42 and switch module 48 are connected between

link

52 and 54, and 42 of protective devices allow the electric current I 2 of second direction to pass through with protection switch assembly 48.

Protective device

40 and 42 comprises diode D1 and D2 respectively, and

switch module

44 and 48 comprises photo-

coupler

46 and 50 respectively.Photo-coupler 46 has LED 56 and transistor 58, and photo-coupler 50 has LED 60 and transistor 62, when PWM signal Spwm is high levle, and

LED

56 and 60 conductings and produce light and give

transistor

58 and 62, thereby make

transistor

58 and 62 conductings.

In Fig. 4, use diode D1 and D2 to be used as

protective device

40 and 42; in other embodiments; also can use other assembly or circuit to replace diode D1 and D2; the bipolarity junction transistor shown in Fig. 5 A for example; P-type mos transistor shown in Fig. 5 B, and the N type metal oxide semiconductor transistor shown in Fig. 5 C.The also available assembly that other can be used as switch of photo-

coupler

46 and 50 in the

switch module

44 and 48 replaces, for example metal oxide semiconductor transistor.

Fig. 6 is the equivalent circuit of circuit during the positive half period of AC power 16 of Fig. 4, and Fig. 7 is the equivalent circuit of circuit during the negative half-cycle of AC power 16 of Fig. 4.With reference to Fig. 4 and Fig. 6, during the positive half period of AC power 16, the voltage of power input 12 is positive voltage, and the voltage of power input 14 is negative voltage, and therefore producing electric current I 1 flows to power input 14 by power input 12.In current regulator 28, diode D2 block current flow I1 makes diode D2 and photo-coupler 50 be equal to and opens circuit that electric current I 1 flows to power input 14 through diode D1 and photo-coupler 46.Photo-coupler 46 is controlled by PWM signal Spwm, when signal Spwm is high levle, and photo-coupler 46 conducting electric current I 1, opposite, when signal Spwm is low level, photo-coupler 46 cut-off current I1, so the mean value of electric current I 1 will be by the dutycycle decision of PWM signal Spwm.Flow the mean value of I1 by the EDM Generator of Adjustable Duty Ratio economize on electricity of adjusting PWM signal Spwm, and then adjust the brightness of two-way LED lamp string 22.With reference to Fig. 4 and Fig. 7, during the negative half-cycle of AC power 16, the voltage of power input 12 is negative voltage, and the voltage of power input 14 is positive voltage, and therefore producing electric current I 2 flows to power input 12 by power input 14.In current regulator 28, diode D1 block current flow I2 makes diode D1 and photo-coupler 46 be equal to and opens circuit that electric current I 2 flows to link 52 through diode D2 and photo-coupler 50.Photo-coupler 50 is controlled by PWM signal Spwm, when signal Spwm was high levle, photo-coupler 50 conducting electric current I 2 were when signal Spwm is low level, photo-coupler 50 cut-off current I2, so the mean value of electric current I 2 will be by the dutycycle decision of PWM signal Spwm.Put in order the mean value of electric current I 2 by the EDM Generator of Adjustable Duty Ratio of adjusting PWM signal Spwm, and then adjust the brightness of two-way LED lamp string 22.

PWM is a mature technique, so the dutycycle of PWM generator 26 and adjustment PWM signal Spwm can adopt existing circuit and method.

Fig. 8 is second embodiment of Fig. 1 bidirectional current limiting device 24; it comprises that constant

current source

74 and 76 is connected between the

link

70 and 72 of bidirectional current limiting device 24 in the reversal connection mode; protection assembly 78 is in parallel with protection constant current source 74 with constant current source 74; protection assembly 80 is in parallel with protection constant current source 76 with constant current source 76, and this

link

70 and 72 connects two-way LED lamp string 22 and light modulator 20 respectively.Constant

current source

74 and 76 and

protection assembly

78 and 80 can be incorporated in the integrated circuit of two pins, so the space that bidirectional current limiting device 24 accounts for is very little.Fig. 9 and Figure 10 show the operation of bidirectional current limiting device 24 among Fig. 8.With reference to Fig. 9, during the positive half period of AC power 16, constant current source 74 be in reverse bias protect assembly 80 then formation open circuit, so constant current source 76 is set up the electric current I 1 that flows to link 72 from link 70 with protection assembly 78.With reference to Figure 10, during the negative half-cycle of AC power 16, constant current source 76 is in reverse bias and protects assembly 78 to form and open circuit, so constant current source 74 is set up the electric current I 2 that flows to link 70 from link 72 with protection assembly 80.Figure 11 shows with the embodiment of diode as protection assembly among Fig. 8; wherein as the anode of the diode 82 of protecting assembly and output and the input that negative electrode connects constant current source 74 respectively, as the anode of the diode 84 of protecting assembly and output and the input that negative electrode connects constant current source 76 respectively.

Figure 12 shows the 3rd embodiment of bidirectional current limiting device 24 among Fig. 1; it comprises constant

current source

74 and 76 and the

protection assembly

78 and 80 of protecting constant

current source

74 and 76 respectively, and wherein constant

current source

74 and 76 is connected between the

link

70 and 72 of bidirectional current limiting device 24 with docking mode.Figure 13 and Figure 14 show the operation of bidirectional current limiting device 24 among Figure 12.With reference to Figure 13, during the positive half period of AC power 16, constant current source 76 is in reverse bias and protects assembly 78 to form and open circuit, so constant current source 74 is set up the electric current I 1 that flows to link 72 from link 70 with protection assembly 80.With reference to Figure 14, during the negative half-cycle of AC power 16, constant current source 74 is in reverse bias and protects assembly 80 to form and open circuit, so constant current source 76 is set up the electric current I 2 that flows to link 70 from link 72 with protection assembly 78.Figure 15 shows with the embodiment of diode as protection assembly among Figure 12; wherein as the anode of the diode 82 of protecting assembly and output and the input that negative electrode connects constant current source 74 respectively, as the anode of the diode 84 of protecting assembly and output and the input that negative electrode connects constant current source 76 respectively.

Realize protecting among Fig. 8 and Figure 12 the mode of assembly 78 and 80 a lot, except using diode, the assembly and the circuit that also can use MOS transistor, BJT transistor or other permission folk prescription to pass through to electric current.

Figure 16 shows the embodiment of constant current source among Fig. 8 and Figure 12, wherein transistor M1 and M2 are connected between positive pressure side 92 and the negative pressure end 94, resistance R 1 is connected between the gate 96 of positive pressure side 92 and transistor M1, silicon reference diode (Zener diode) D1 is connected between the gate and negative pressure end 94 of transistor M1, control loop 90 connects the gate of transistor M2 to pin the voltage on the transistor M2 gate, wherein control loop 90 is a prior art, and its internal structure repeats no more.When the voltage on the positive pressure side 92 rises, voltage VA on the gate 96 of transistor M1 also begins to rise, because the relation of silicon reference diode D1, voltage VA will be limited in certain position surely at last, 8.2V for example, transistor M1 is opened when voltage VA is higher than a critical value (turn on), and therefore producing electric current I flows to the negative pressure end by positive pressure side through transistor M1 and M2, control loop 90 provides and decides the gate of voltage to transistor M2 again, so electric current I is for deciding electric current.

Figure 17 shows the i-v curve of bidirectional current limiting device 24.With reference to Fig. 8, alternating voltage VAC is provided the link 70 to bidirectional current limiting device 24, during the positive half period of alternating voltage VAC, current source 76 provides stable electric current I 1, curve as first quartile, during the negative half-cycle of alternating voltage VAC, current source 74 provides stable electric current I 2, as the curve of third quadrant.

Figure 18 shows second embodiment of current regulator 28; circuit among itself and Fig. 4 comprises

link

52 and 54,

protective device

40 and 42 and

switch module

44 and 48 equally; but

switch module

44 and 48 is connected between

link

52 and 54; protective device 40 is in parallel with switch module 48; and protective device 42 is in parallel with switch module 44, and

switch module

44 and 48 comprises photo-

coupler

46 and 50 respectively.Figure 19 is the equivalent circuit of current regulator 28 during the positive half period of AC power 16 of Figure 18, and Figure 20 is the equivalent circuit of current regulator 28 during the negative half-cycle of AC power 16 of Figure 18.With reference to Figure 18 and 19, during the positive half period of AC power 16, the voltage of power input 12 is positive voltage, and the voltage of power input 14 is negative voltage, and therefore producing electric current I 1 flows to power input 14 by power input 12.In current regulator 28, diode D2 block current flow I1 makes diode D2 be equal to and opens circuit, and electric current I 1 is by photo-coupler 46 and diode D1.Photo-coupler 46 is controlled by PWM signal Spwm, so the mean value of electric current I 1 will be by the dutycycle decision of PWM signal Spwm.Flow the mean value of I1 by the EDM Generator of Adjustable Duty Ratio economize on electricity of adjusting PWM signal Spwm, and then adjust the brightness of two-way LED lamp string 22.With reference to Figure 18 and Figure 20, during the negative half-cycle of AC power 16, the voltage of power input 12 is negative voltage, and the voltage of power input 14 is positive voltage, and therefore producing electric current I 2 flows to power input 12 by power input 14.In current regulator 28, diode D1 block current flow I2 makes diode D1 be equal to and opens circuit, and electric current I 2 is by photo-coupler 50 and diode D2.Photo-coupler 50 is controlled by PWM signal Spwm, so the mean value of electric current I 2 will be by the dutycycle decision of PWM signal Spwm.Put in order the mean value of electric current I 2 by the EDM Generator of Adjustable Duty Ratio of adjusting PWM signal Spwm, and then adjust the brightness of two-way LED lamp string 22.

Figure 21 is the 3rd embodiment of current regulator 28, and the circuit among itself and Fig. 4 comprises

link

52 and 54 and

switch module

44 and 48 equally, and

switch module

44 and 48 is connected between

link

52 and 54, and comprises photo-

coupler

46 and 50 respectively.During the positive half period of AC power 16, the voltage of power input 12 is positive voltage, the voltage of power input 14 is negative voltage, therefore producing electric current I 1 flows to link 54 by link 52 through photo-

coupler

46 and 50, photo-

coupler

46 and 50 all is controlled by PWM signal Spwm, so the mean value of electric current I 1 will be by the dutycycle decision of PWM signal Spwm.During the negative half-cycle of AC power 16, the voltage of power input 12 is positive voltage, the voltage of power input 14 is negative voltage, therefore producing electric current I 2 flows to link 52 by link 54 through photo-

coupler

50 and 46, photo-

coupler

46 and 50 all is controlled by PWM signal Spwm, so the mean value of electric current I 2 will be by the dutycycle decision of PWM signal Spwm.

More than; only be preferred embodiment of the present invention, but protection scope of the present invention is not limited thereto, anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain that claim was defined.

Claims

1. the AC LED lamp of a tunable optical is characterized in that, comprising:

First and second power input is for connecting power supply;

The LED load; And

Light modulator, and this LED load is connected between this first and second power input is in order to the electric current of regulating the first direction by this LED load and the electric current of second direction.

2. AC LED lamp as claimed in claim 1 is characterized in that, this light modulator comprises:

The PWM generator is in order to provide the PWM signal; And

Current regulator is used to connect this PWM generator, and connects with this LED load, determines the mean value of the electric current of the mean value of electric current of this first direction and this second direction according to the dutycycle of this PWM signal.

3. AC LED lamp as claimed in claim 2 is characterized in that, this current regulator comprises:

First protective device only allows the electric current of this first direction to pass through;

First switch module, and this first protective device is connected between this LED load and the second source input, and connect this PWM generator, be controlled by this PWM signal to regulate the mean value of this first direction electric current;

Second protective device only allows the electric current of this second direction to pass through; And

The second switch assembly, and this second protective device is connected between this LED load and the second source input, and connect this PWM generator, be controlled by this PWM signal to regulate the mean value of this second direction electric current.

4. AC LED lamp as claimed in claim 3 is characterized in that, this first protective device and second protective device respectively are selected from any one in bipolarity junction transistor, diode or the metal oxide semiconductor transistor.

5. as claim 3 or 4 described AC LED lamps, it is characterized in that this first switch module and/or second switch assembly are photo-coupler.

6. AC LED lamp as claimed in claim 2 is characterized in that, this current regulator comprises:

First switch module connects this PWM generator, is controlled by this PWM signal to regulate the mean value of this first direction electric current;

The second switch assembly, and this first switch module is connected between this LED load and the second source input, and connect this PWM generator, be controlled by this PWM signal to regulate the mean value of this second direction electric current;

First protective device, in parallel with this second switch assembly, only allow the electric current of this first direction to pass through; And

Second protective device, in parallel with this first switch module, only allow the electric current of this second direction to pass through.

7. AC LED lamp as claimed in claim 6 is characterized in that, this first protective device and second protective device respectively are selected from any one in bipolarity junction transistor, diode or the metal oxide semiconductor transistor.

8. as a request claim 6 or 7 described AC LED lamps, it is characterized in that this first switch module and/or second switch assembly are photo-coupler.

9. AC LED lamp as claimed in claim 2 is characterized in that, this current regulator comprises:

First switch module connects this PWM generator, is controlled by this PWM signal; And

The second switch assembly, and this first switch module is connected between this LED load and the second source input, and connect this PWM generator, be controlled by this PWM signal.

10. AC LED lamp as claimed in claim 9 is characterized in that, this first switch module and/or second switch assembly are photo-coupler.

11. AC LED lamp as claimed in claim 2 is characterized in that, this LED load comprises:

Two-way LED lamp string is luminous in response to the electric current of this first direction or second direction, and its brightness is by the mean value decision of the electric current of this first direction or second direction;

Bidirectional current limiting device, and this two-way LED lamp string is connected between this first power input and the light modulator is in order to the maximum of the electric current that limits this first direction and second direction.

12. AC LED lamp as claimed in claim 11 is characterized in that, this two-way LED lamp string comprises:

First and second link; And

Many LED is connected between this first and second link, every pair of LEDs contains the LED of first direction configuration and the LED of second direction configuration; Perhaps by be connected between this first and second link and correspond respectively to first direction and second direction two the string LED form.

13. AC LED lamp as claimed in claim 2 is characterized in that,

This light modulator comprises that more the bidirectional current limiting device connects with this current regulator, in order to the maximum of the electric current that limits this first direction and second direction;

This LED load comprises two-way LED lamp string, and is luminous in response to the electric current of this first direction or second direction, and its brightness is by the mean value decision of the electric current of this first direction or second direction.

14., it is characterized in that this bidirectional current limiting device comprises resistance as claim 11 or 13 described AC LED lamps.

15., it is characterized in that this bidirectional current limiting device comprises as claim 11 or 13 described AC LED lamps:

First and second link;

First and second current source is connected between this first and second link;

The first protection assembly, in parallel with this first current source; And

The second protection assembly, in parallel with this second current source;

Wherein, under first state, this first current source and this second protection assembly are set up the electric current that flows to this first direction of this second link from this first link; And under second state, this second current source and this first protection assembly are set up the electric current that flows to this second direction of this first link from this second link.

16. AC LED lamp as claimed in claim 15 is characterized in that, this first and second current source is with reversal connection or docking mode series connection.

17. AC LED lamp as claimed in claim 15 is characterized in that, this first protection assembly and/or the second protection assembly are diode.

18. AC LED lamp as claimed in claim 15 is characterized in that, this first current source comprises:

Positive pressure side and negative pressure end;

First and second strings of transistors is associated between this positive pressure side and the negative pressure end;

Be connected with resistance between the control electrode of this positive pressure side and this first transistor;

Being connected with silicon reference diode between the control electrode of this first transistor and this negative pressure end connects; And

The control electrode of this transistor seconds connects control loop, and this control loop is used to pin the voltage on this transistor seconds gate.

19. AC LED lamp as claimed in claim 15 is characterized in that, this second current source comprises:

Positive pressure side and negative pressure end;

20. the light modulator of an AC LED lamp is characterized in that, comprising:

The PWM generator is in order to provide the PWM signal; And

Current regulator, be used to connect this PWM generator, under first state, only allow the electric current of first direction to pass through, under second state, only allow the electric current of second direction to pass through, and determine the mean value of the electric current of the mean value of electric current of this first direction and this second direction according to the dutycycle of this PWM signal.

21. the light modulator of AC LED lamp as claimed in claim 20 is characterized in that, this current regulator comprises:

First and second link;

First switch module, and this first protective device is connected between this first and second link, and connect this PWM generator, be controlled by this PWM signal to regulate the mean value of this first direction electric current;

The second switch assembly, and this second protective device is connected between this first and second link, and connect this PWM generator, be controlled by this PWM signal to regulate the mean value of this second direction electric current.

22. the light modulator of AC LED lamp as claimed in claim 21 is characterized in that, this first protective device and second protective device respectively are selected from any one in bipolarity junction transistor, diode or the metal oxide semiconductor transistor.

23. the light modulator as claim 21 or 22 described AC LED lamps is characterized in that, this first switch module and/or second switch assembly are photo-coupler.

24. the light modulator of AC LED lamp as claimed in claim 20 is characterized in that, this current regulator comprises:

First and second link;

The second switch assembly, and this first switch module is connected between this first and second link, and connect this PWM generator, be controlled by this PWM signal to regulate the mean value of this second direction electric current;

25. the light modulator of AC LED lamp as claimed in claim 24 is characterized in that, this first protective device and second protective device respectively are selected from any one in bipolarity junction transistor, diode or the metal oxide semiconductor transistor.

26. the light modulator as a request claim 24 or 25 described AC LED lamps is characterized in that this first switch module and/or second switch assembly are photo-coupler.

27. the light modulator of AC LED lamp as claimed in claim 20 is characterized in that, this current regulator comprises:

First and second link;

The second switch assembly, and this first switch module is connected between this first and second link, and connect this PWM generator, be controlled by this PWM signal.

28. the light modulator of AC LED lamp as claimed in claim 27 is characterized in that, this first switch module and/or second switch assembly are photo-coupler.

29. the light modulator of AC LED lamp as claimed in claim 20 is characterized in that,

This light modulator comprises that more the bidirectional current limiting device connects with this current regulator, in order to the maximum of the electric current that limits this first direction and second direction.

30. the light modulator of AC LED lamp as claimed in claim 29 is characterized in that, this bidirectional current limiting device comprises resistance.

31. the light modulator of AC LED lamp as claimed in claim 29 is characterized in that, this bidirectional current limiting device comprises:

First and second link;

The first protection assembly, in parallel with this first current source; And

The second protection assembly, in parallel with this second current source;

32. the light modulator of AC LED lamp as claimed in claim 31 is characterized in that, this first and second current source is with reversal connection or docking mode series connection.

33. the light modulator of AC LED lamp as claimed in claim 31 is characterized in that, this first protection assembly and/or the second protection assembly are diode.

34. the light modulator of AC LED lamp as claimed in claim 31 is characterized in that, this first current source comprises:

Positive pressure side and negative pressure end;

35. the light modulator of AC LED lamp as claimed in claim 31 is characterized in that, this second current source comprises:

Positive pressure side and negative pressure end;