CN102480820B

CN102480820B - Lighting device and control method thereof

Info

Publication number: CN102480820B
Application number: CN201010558931.5A
Authority: CN
Inventors: 蔡坤南; 李福田
Original assignee: Welland Industrial Co Ltd
Current assignee: Welland Industrial Co Ltd
Priority date: 2010-11-22
Filing date: 2010-11-22
Publication date: 2014-07-02
Anticipated expiration: 2030-11-22
Also published as: CN102480820A

Abstract

The present invention provides a lighting device and a control method thereof, wherein the lighting device includes a first light-emitting module, a second light-emitting module, a rectifier unit and a control module. The rectifier unit converts alternating current into an input power supply. The control module is coupled to the rectifier unit, the first light-emitting module and the second light-emitting module, and receives the input power supply. When the input power supply is less than a set value, the control module controls the first light-emitting module, the second light-emitting module and the rectifier unit to form a first connection state, or when the input power supply is greater than the set value, controls the first light-emitting module, the second light-emitting module and the rectifier unit to form a second connection state. The present invention can reduce the current peak value flowing through the light-emitting module per voltage cycle, thereby achieving the effects of high luminous efficiency and long service life.

Description

Lighting device and control method thereof

Technical field

The present invention relates to a kind of lighting device, and be particularly related to a kind of lighting device of light-emitting diode.

Background technology

In the Driving technique of light-emitting diode (LED), general normal employing alternating current AC drives the mode of light-emitting diode.This kind of mode be for to input to rectification circuit BR by alternating current AC, alternating current AC after full-wave rectification, then via current-limiting resistance R1 to drive LED light lamp array LA, as shown in Figure 1.But this kind of type of drive may produce following shortcoming because of unsettled alternating current AC.

One, power output is unstable.In other words, the average electrical that flows through LED light lamp array LA fails to be convened for lack of a quorum and changes with the crest voltage of alternating current AC, cause the unstable problem large with luminance fluctuation of power output of LED light lamp array LA, and easily cause LED light lamp array LA to damage or light decay.

Two, luminous efficiency is low.The conducting voltage of LED light lamp array LA can be designed to approach the crest voltage of alternating current AC conventionally, and this design can cause the short situation of its ON time of lamp current of each voltage cycle.The in the situation that of short in the current lead-through time, must relatively increase the peak value of lamp current, can maintain fixing average current and flow through LED light lamp array LA.In general, the luminous intensity of light-emitting diode becomes non-linear relation with lamp current, and as when the specific currents 1A, luminous intensity is 1, and in the time increasing electric current 2A, luminous intensity is only 1.6 but not 2.Therefore, the conducting voltage of LED light lamp array LA is designed to approach to the crest voltage of alternating current AC, can cause LED light lamp array LA luminous efficiency step-down, and then remote-effects overall system efficiency, i.e. overall system efficiency=light-emitting diode drives conversion efficiency × light-emitting diode luminous efficiency.

Summary of the invention

The embodiment of the present invention provides a kind of lighting device and control method thereof, the wherein input power of lighting device after according to AC power rectification, the relation linking between light emitting module in corresponding change lighting device more than two and rectification unit, to reach high luminous efficiency and long useful life.

According to an embodiment, lighting device of the present invention receives an alternating current, comprises one first light emitting module, one second light emitting module, a rectification unit and a control module.Alternating current is changed into an input power by rectification unit.Control module is coupled to rectification unit, the first light emitting module and the second light emitting module, it receives input power, and in the time that input power is less than a reference value, control the first light emitting module, the second light emitting module and rectification unit and form the first connecting state, or in the time that input power is greater than reference value, controls the first light emitting module, the second light emitting module and rectification unit and form the second connecting state.

According to another embodiment, the control method of lighting device of the present invention, is applicable to the control of a control module to one first light emitting module and one second light emitting module, and its step includes: first, obtain an input power, this input power is the power supply of alternating current after rectification; Then,, in the time that input power is less than a reference value, controls the first light emitting module and the second light emitting module and input power and form the first connecting state; Then,, in the time that input power is greater than reference value, controls the first light emitting module and the second light emitting module and input power and form the second connecting state.

A foundation embodiment again, the control method of lighting device of the present invention, is applicable to the control of a control module to multiple light emitting modules, and its step includes: first, obtain an input power, this input power is the power supply of alternating current after rectification; Then,, in the time that input power is less than first reference value, controls multiple light emitting modules and input power and form the first connecting state; Then, be greater than this first reference value at input power, and while being less than second reference value, controlling multiple light emitting modules and input power and form the second connecting state; Then,, in the time that input power is greater than the second reference value, controls multiple light emitting modules and input power and form the 3rd connecting state.

In sum, the input power of the lighting device that the embodiment of the present invention provides after according to AC power rectification, the relation linking between two or more light emitting modules and rectification unit in corresponding change lighting device, and try to achieve under a fixing average current, can reduce the current peak that every voltage cycle flows through light emitting module, and then reach the effect of high-luminous-efficiency and long service life.

For enabling further to understand feature of the present invention and technology contents, refer to following about detailed description of the present invention and accompanying drawing, but these explanations are only used for illustrating the present invention with accompanying drawing, but not interest field of the present invention are done to any restriction.

Brief description of the drawings

Fig. 1 is traditional light-emitting diode (LED) drive circuit;

Fig. 2 is the function structure schematic diagram of the embodiment of the present invention;

Fig. 3 is the circuit diagram of first embodiment of the invention;

Fig. 4 is the circuit waveform schematic diagram of Fig. 3;

Fig. 5 is the circuit diagram of second embodiment of the invention;

Fig. 6 is the circuit diagram of third embodiment of the invention;

Fig. 7 is the circuit waveform schematic diagram of Fig. 6;

Fig. 8 is the circuit diagram of fourth embodiment of the invention;

Fig. 9 is the circuit diagram of fifth embodiment of the invention; And

Figure 10 is the circuit waveform schematic diagram of Fig. 9.

Description of reference numerals in above-mentioned accompanying drawing is as follows:

Known:

Alternating current AC

Rectification circuit BR

LED light lamp array LA

Current-limiting resistance R1

The present invention:

Lighting device

1,2,3,4,5

Control module

10,20,50

Rectification unit 11,51

The first light emitting module 12

The second light emitting module 14

Alternating current AC

Earth terminal Gnd

Input power Vbr

Switch element 102

Control unit 104,501

Diode D1

The first transistor Q1

Transistor seconds Q2

Bleeder circuit 1042

Drive circuit 1044

Resistance R 12, R13

Current-limiting resistance R1, R2, R3

Transistor Q3, Q4, Q5, Q6

Input voltage ratio value VR

Set point Vth

Reference value Vref

The first reference value Vref1

The second reference value Vref2

Switch element 202

Control unit 204

Bleeder circuit 2042

Drive circuit 2044

Power back-off

module

16,46,56

Voltage-controlled Current Source 162,462

Constant current source 164,464

Offset current Ibr

Total current ILED

Flow through the electric current I D of resistance R 6

Voltage VR6, VR12

Light emitting module 52,52A, 52B, 52C, 52D

Embodiment

The lighting device that the embodiment of the present invention provides, its type of drive utilizes the input power after AC rectification directly to drive the technology of two or more light emitting modules.In the embodiment of the present invention, preferably light emitting module can be light-emitting diode (LED) or light emitting diode matrix (LED Array), and light emitting diode matrix comprises multiple light-emitting diodes connected to one another (LED).In aforementioned, these light-emitting diodes (LED) comprise be one another in series, the annexation such as parallel connection or connection in series-parallel.But light-emitting diode or light emitting diode matrix are not the unique restriction of the present invention, all light emitting modules that can directly be driven by the input power after AC rectification are all scope of the present invention.

Consult Fig. 2.Fig. 2 is the function structure schematic diagram of the embodiment of the present invention.Lighting device 1 comprises a control module 10, a rectification unit 11, one first light emitting module 12 and one second light emitting module 14, and wherein control module 10 is coupled to rectification unit 11, the first light emitting module 12 and the second light emitting module 14.An alternating current AC is changed into an input power Vbr by rectification unit 11, the voltage waveform of this input power Vbr is the alternating current AC of sinusoidal wave (sine wave) waveform after over commutation, therefore, the voltage swing of input power Vbr changes along with alternating current AC.

Referring again to Fig. 2.Control module 10 receives input power Vbr, and detects the voltage swing of input power Vbr.Meanwhile, control module 10 is provided with a reference value, and wherein, in the time that the voltage of input power Vbr is less than reference value, control module 10 is controlled the first light emitting module 12 and the second light emitting module 14 and rectification unit 11 and formed the first connecting state.In addition, in the time that the voltage of input power Vbr is greater than reference value, 10 of control modules are controlled the first light emitting module 10 and the second light emitting module 14 and rectification unit 11 and are formed the second connecting state.

So, lighting device 1 can be according to the input power Vbr after alternating current AC rectification, the corresponding connection relationship changing between the first light emitting module 10, the second light emitting module 14 and rectification unit 11, try to achieve under a fixing average current, can reduce the current peak that every voltage cycle flows through the first light emitting module 10 and the second light emitting module 14, and then reach the effect of high-luminous-efficiency and long service life.

With reference to figure 3.Fig. 3 is the circuit diagram of first embodiment of the invention.Rectification unit 11 is a full-wave rectifier, and it is used for alternating current AC to be rectified into input power Vbr, and wherein rectification unit 11 can be a rectification chip or be connected to form by 4 diode BR1～BR4, and this,, for generally knowing technology, does not repeat them here.

Control module 10 comprises a switch element 102 and a control unit 104.Switch element 102 is coupled to the first light emitting module 12 and the second light emitting module 14.Control unit 104 is coupled to rectification unit 11 and switch element 102, whether is greater than a reference value according to the voltage of input power Vbr, and the in addition action of control switch unit 102.The action of switch element 102 can change the annexation between the first light emitting module 12, the second light emitting module 14 and rectification unit 11, and the annexation between three is along with whether the voltage of input power Vbr is greater than reference value and is in the first connecting state or the second connecting state.

Referring again to Fig. 3.Switch element 102 comprises a diode D1, a first transistor Q1 and a transistor seconds Q2, and annexation and action specification between aforementioned each element are as follows.The anode tap of diode D1 connects the output T12 of the first light emitting module 12, and the cathode terminal of diode D1 connects the input T21 of the second light emitting module 14.The defeated in/out end C1 of the first transistor Q1 connects the cathode terminal of diode D1 via current-limiting resistance R3, the defeated in/out end E1 of the first transistor Q1 connects the input T11 of the first light emitting module 12, and the controlled end B1 connection control unit 104 of the first transistor Q1.Simultaneously, the defeated in/out end C2 of the Q2 of transistor seconds connects the output T22 of the second light emitting module 14 via current-limiting resistance R2, the output T22 of the second light emitting module 14 connects earth terminal Gnd and rectification unit 11 via current-limiting resistance R1, the defeated in/out end E2 of the Q2 of transistor seconds connects the anode tap of diode D1, the controlled end B2 connection control unit 104 of the Q2 of transistor seconds.

The current-limiting circuit of the present embodiment is connect and is formed by current-limiting resistance R1, R2, R3 connection in series-parallel, but this kind of mode is not unique current-limiting circuit, the every circuit that can control according to input power Vbr the electric current that flows through light emitting module is all the scope that the present invention advocates right.

Referring again to Fig. 3.Control unit 104 comprises a bleeder circuit 1042 and one drive circuit 1044.Bleeder circuit 1042 is connected in rectification unit 11, and it sets up an input voltage ratio value VR according to input power Vbr, and voltage swing and the input power Vbr of this input voltage ratio value VR are proportional.The bleeder circuit 1042 of the present embodiment is composed in series by resistance R 12, R13, but this kind of mode is not unique bleeder circuit, and the every bleeder circuit that can set up according to input power Vbr input voltage ratio value VR is all the scope that the present invention advocates right.

Drive circuit 1044 is coupled to bleeder circuit 1042, and it receives the input voltage ratio value VR that bleeder circuit 1042 is set up, and wherein drive circuit 1044 has set point Vth.Drive circuit 1044 is in the time that input voltage ratio value VR is less than set point Vth, control the first transistor Q1 and transistor seconds Q2 conducting (turn on), to make the first light emitting module 12, the second light emitting module 14 and rectification unit 11 form the first connecting state.In addition, drive circuit 1044 is in the time that input voltage ratio value VR is greater than set point Vth, control the first transistor Q1 and transistor seconds Q2 cut-off (turn off), to make the first light emitting module 12, the second light emitting module 14 and rectification unit 11 form the second connecting state.

The drive circuit 1044 of the present embodiment comprises two transistor Q3, Q4, so this kind of circuit is not unique drive circuit, every can be according to the comparative result between input voltage ratio value VR and set point Vth, the circuit that is driven the first transistor Q1 and transistor seconds Q2 is all the scope that the present invention advocates right.

With reference to figure 3 and Fig. 4.Fig. 4 is the circuit waveform schematic diagram of Fig. 3.Control unit 104 receives input power Vbr from rectification unit 11, and sets up input voltage ratio value VR in the resistance R 13 of bleeder circuit 1042.When input power Vbr during when T1, even be based upon the set point Vth (meaning is that input power Vbr is less than reference value Vref) that input voltage ratio value VR in resistance R 13 is less than transistor Q4.T1 during this period, the resistance voltage VR12 being based upon on bleeder circuit 1042 can make transistor Q3 conducting, enter conducting (turn on) state to control the first transistor Q1 and transistor seconds Q2, and then allow the first light emitting module 12 be electrically connected at rectification unit 11 in parallel with the second light emitting module 14 to form the first connecting state.Now, the electric current I 1 that flows through respectively the first light emitting module 12 and the second light emitting module 14 as shown in Figure 4.

In addition, during T2, be based upon input voltage ratio value VR in resistance R 13 is greater than transistor Q4 set point Vth (meaning is that input power Vbr is greater than reference value Vref) along with the increase of input power Vbr voltage.T2 during this period, transistor Q4 enters conducting, to make transistor Q3 enter cut-off.The transistor Q3 of cut-off controls the first transistor Q1 and transistor seconds Q2 enters cut-off (turn off) state, and then allows the first light emitting module 12 connect and to be electrically connected at rectification unit 11 to form the second connecting state with the second light emitting module 14.Now, the electric current I 2 that flows through the first light emitting module 12 and the second light emitting module 14 as shown in Figure 4.

In other words, control unit 104 is control switch unit 102 under lower input power Vbr, to make the first light emitting module 12 and the second light emitting module 14 be connected in parallel, and then allow lower input power Vbr power to the first light emitting module 12 and second light emitting module 14 of parallel connection.Because the first light emitting module 12 and second light emitting module 14 of parallel connection have lower conducting voltage, therefore, lower input power Vbr can allow the first light emitting module 12 and the second light emitting module 14 in parallel move with generation current I1.In addition, control unit 104 is control switch unit 102 under higher input power Vbr, to make the first light emitting module 12 and the second light emitting module 14 be connected in series, and then allow higher input power Vbr power to the first light emitting module 12 and second light emitting module 14 of series connection.Because the first light emitting module 12 and second light emitting module 14 of series connection have higher conducting voltage, therefore, higher input power Vbr can allow the first light emitting module 12 and second light emitting module 14 of series connection move with generation current I2.

So, utilize lower input power Vbr to power to the first light emitting module 12 and second light emitting module 14 of parallel connection, and higher input power Vbr powers to the first light emitting module 12 of series connection and the mode of the second light emitting module 14, try to achieve under a fixing average current, can reduce the current peak that every voltage cycle flows through the first light emitting module 12 and the second light emitting module 14, and then reach the effect of high-luminous-efficiency and long service life.

Referring again to Fig. 3 and Fig. 4.Input power Vbr (or input voltage ratio value VR) is the power supply after sinusoidal wave alternating current AC rectification, its voltage waveform is taking 90 degree as symmetrical increase and decrease, therefore, control unit 104 during T3, T4 to the action control of transistor Q3, Q4 corresponding and be same as during T2, T1, as shown in Figure 4.

In sum, control unit 104 can be followed the voltage swing of input power Vbr, in a voltage cycle, allow connection relationship between the first light emitting module 12, the second light emitting module 14 and rectification unit 11 sequentially do action between the first connecting state, the second connecting state, the first connecting state.So, under the type of drive of fixing average current, the control mode of control unit 104, can reduce the current peak (as electric current I 2) that every voltage cycle flows through the first light emitting module 12, the second light emitting module 14, and then improve luminous efficiency and the useful life of lighting device 1 entirety.

With reference to figure 5.Fig. 5 is the circuit diagram of second embodiment of the invention.Difference main between the lighting device 2 of the present embodiment and the lighting device 1 of Fig. 3 is control module 20.The control module 20 of lighting device 2 comprises a switch element 202 and a control unit 204.Switch element 202 is a transistor Q3, and wherein the defeated in/out end C3 of transistor Q3 connects the output T12 of the first light emitting module 12 and the input T21 of the second light emitting module 14 via current-limiting resistance R2.The defeated in/out end E3 of transistor Q3 is connected in earth terminal Gnd, and the output T22 of the second light emitting module 14 is connected in earth terminal Gnd via current-limiting resistance R1, the controlled end B3 connection control unit 204 of transistor Q3.

Referring again to Fig. 5.Control unit 204 comprises a bleeder circuit 2042 and one drive circuit 2044, and wherein bleeder circuit 2042 is identical with the bleeder circuit 1042 of Fig. 3, does not repeat them here.In addition, the drive circuit 2044 of the present embodiment comprises a transistor Q4, it is according to the comparative result between input voltage ratio value VR and set point Vth, with driving transistors Q3, and then make the first light emitting module 12, the second light emitting module 14 and rectification unit 11 form the first connecting state or the second connecting state.

So, control unit 204 receives input power Vbr from rectification unit 11, and sets up input voltage ratio value VR in the resistance R 13 of bleeder circuit 2042.During even input voltage ratio value VR is less than the set point Vth of transistor Q4, being based upon resistance voltage VR12 on bleeder circuit 2042 can a shilling transistor Q3 conducting, so allow the first light emitting module 12 independent be electrically connected at rectification unit 11 and the second light emitting module 14 cuts off rectification unit 11 to form the first connecting state.

In addition, at input voltage ratio value VR along with the increase of input power Vbr voltage during being greater than the set point Vth of transistor Q4.Transistor Q4 enters conducting, to make transistor Q3 cut-off, and then allows the first light emitting module 12 connect and to be electrically connected at rectification unit 11 to form the second connecting state with the second light emitting module 14.

In other words, control unit 204 is control switch unit 202 under lower input power Vbr, to make the independent series connection of the first light emitting module 12 be electrically connected at rectification unit 11, and then allows lower input power Vbr power to the first light emitting module 12.Because the first independent light emitting module 12 has lower conducting voltage, therefore, lower input power Vbr can allow the first independent light emitting module 12 move in advance.In addition, control unit 204 is control switch unit 202 under higher input power Vbr, to make the first light emitting module 12 and the second light emitting module 14 be connected in series, and then allow higher input power Vbr power to the first light emitting module 12 and second light emitting module 14 of series connection.Because the first light emitting module 12 and second light emitting module 14 of series connection have higher conducting voltage, therefore, higher input power Vbr can allow the first light emitting module 12 and second light emitting module 14 of series connection move.

So, utilize lower input power Vbr to power to the first independent light emitting module 12, and higher input power Vbr powers to the first light emitting module 12 of series connection and the mode of the second light emitting module 14, can reduce the current peak that every voltage cycle flows through the first light emitting module 12 and the second light emitting module 14, and then reach the effect of high-luminous-efficiency and long service life.

In sum, control unit 204 can be followed the voltage swing of input power Vbr, in a voltage cycle, allow connection relationship between the first light emitting module 12, the second light emitting module 14 and rectification unit 11 sequentially do action between the first connecting state, the second connecting state, the first connecting state.So, under the type of drive of fixing average current, the control mode of control unit 204, can reduce every voltage cycle and flow through the current peak of the first light emitting module 12, the second light emitting module 14 and then luminous efficiency and the useful life of improving lighting device 2 entirety.

Coordinate Fig. 3, please refer to Fig. 6.Fig. 6 is the circuit diagram of third embodiment of the invention.Difference main between the lighting device 3 of the present embodiment and the lighting device 1 of Fig. 3 is, the lighting device 3 of the present embodiment more comprises a power back-off module 16.Power back-off module 16 is coupled to rectification unit 11, control module 10, the first light emitting module 12 and the second light emitting module 14, and it is according to the voltage swing of input power Vbr, and the total current ILED of the first light emitting module 12 and the second light emitting module 14 is flow through in corresponding adjustment.In other words, power back-off module 16 is along with the voltage swing of input power Vbr, so that the total current ILED that flows through the first light emitting module 12 and the second light emitting module 14 is compensated, to make under specified alternating current AC scope, allow input power maintain in a rated range.

In aforementioned, lighting device 3, by the compensating action of power back-off module 16 to electric current, can effectively suppress to flow through the current peak of the first light emitting module 12 and the second light emitting module 14.Compared to Fig. 4, as shown in Figure 7, during T1 to flow through electric current I 1 peak value of the first light emitting module 12 and the second light emitting module 14 comparatively smooth.In addition, during T2, electric current I 2 peak values that flow through the first light emitting module 12 and the second light emitting module 14 are also comparatively smooth.

It is worth mentioning that, power back-off module 16 does not need the control module 10 of arranging in pairs or groups, also can be independent couple and form a kind of lighting device (do not indicate) with rectification unit 11, the first light emitting module 12 and the second light emitting module 14, using the current compensation as this kind of lighting device, make the input power of this kind of lighting device can maintain in a rated range.

Power back-off module 16 comprises a Voltage-controlled Current Source 162 and a constant current source 164.Voltage-controlled Current Source 162 is coupled to rectification unit 11, according to the voltage swing of input power Vbr, and corresponding output one offset current Ibr.For instance, the voltage of input power Vbr is larger, and it is large that the offset current Ibr of corresponding output also becomes relatively, otherwise the voltage of input power Vbr is less, and the offset current Ibr of corresponding output also diminishes relatively.In aforementioned, Voltage-controlled Current Source 162 comprises resistance R 1, R2 and Zener diode ZD1, and it utilizes front end sampling mode to obtain the voltage swing of input power Vbr, then according to the voltage swing of input power Vbr, corresponding output offset current Ibr, using the compensation as total current ILED.

In addition, constant current source 164 couples Voltage-controlled Current Source 162, control module 10, the first light emitting module 12 and the second light emitting module 14, it receives offset current Ibr from Voltage-controlled Current Source 162, and according to the size of offset current Ibr, adjusted the total current ILED that flows through the first light emitting module 12 and the second light emitting module 14.For instance, offset current Ibr is larger, flows through relative the diminishing of total current ILED of the first light emitting module 12 and the second light emitting module 14, otherwise, offset current Ibr is less, flows through the first light emitting module 12 large with the relative change of total current ILED of the second light emitting module 14.

In sum, power back-off module 16 obtains the voltage of input power Vbr, and follow the voltage swing of input power Vbr, cross the total current ILED of the first light emitting module 12 and the second light emitting module 14 with corresponding flow compensated, and then allow within total current ILED can maintain rated range.

So, the lighting device 3 of the present embodiment can utilize the compensation of power back-off module 16 as total current ILED, allow total current ILED be unlikely to be subject to unsettled input power Vbr impact, and then input power can be maintained in rated range, solved the impact that the first light emitting module 12 and the second light emitting module 14 be subject to unsettled alternating current AC and caused the problem of damaging with light decay.

Referring again to Fig. 6.Constant current source 164 comprises transistor Q5, Q6, resistance R 4, R5, R6.Resistance R 4 is coupled to input power Vbr, and the drive current of transistor Q5 bias current and transistor Q6 is provided, and the controlled end B6 of transistor Q6 is controlled by transistor Q5.The electric current I D that now flows through resistance R 6 is about total current ILED, and the voltage VR6 that electric current I D sets up in resistance R 6, to allow transistor Q5 be operated in active region (active region).So, the transistor Q5 that is connected in the controlled end B6 of transistor Q6 can be used for adjusting the total current ILED that flows through transistor Q6, makes it maintain a fixing current value.

In addition, the offset current Ibr that Voltage-controlled Current Source 162 is exported flow to resistance R 6 via the resistance R 5 of constant current source 164, when resistance R 5 is during much larger than resistance R 6, voltage VR6 can form the offset voltage (Offset Voltage) of Ibr × R5, can try to achieve ID × R6=VR6-Ibr × R5 according to Thevenin's theorem.So, the offset current Ibr that Voltage-controlled Current Source 162 is exported can be used as the compensation of total current ILED, make the total current ILED can be along with the corresponding variation of the voltage swing of input power Vbr, and then input power can be maintained in rated range, the impact that is subject to unsettled alternating current AC to solve the first light emitting module 12 and the second light emitting module 14 is caused the problem of damaging with light decay.

Referring again to Fig. 6.Voltage-controlled Current Source 162 also can be coupled to the output T12 of the first light emitting module 12 and the output T22 of the second light emitting module 14, and then according to the voltage difference delta V between input power Vbr and the first light emitting module 12 and the second light emitting module 14, with correspondence output offset current Ibr.Aforesaid Voltage-controlled Current Source 162 comprises resistance R 3 and Zener diode ZD2, and it utilizes rear end sampling mode to obtain voltage difference delta V, then according to the corresponding output of voltage difference delta V offset current Ibr, using the compensation as total current ILED.

For instance, form under connecting state in parallel with the second light emitting module 14 at the first light emitting module 12, voltage difference delta V approximates greatly conducting forward bias voltage drop (forward biased) V1 that input power Vbr deducts the first light emitting module 12 or conducting forward bias voltage drop (forward biased) V2 that deducts the second light emitting module 14, i.e. Δ V=Vbr-V1 or Δ V=Vbr-V2.Form and connect under connecting state with the second light emitting module 14 at the first light emitting module 12, voltage difference delta V approximates greatly the conducting forward bias voltage drop (forward biased) that input power Vbr deducts the first light emitting module 12 and the second light emitting module 14, i.e. Δ V=Vbr-(V1+V2).

Referring again to Fig. 6.Aforesaid Voltage-controlled Current Source 162 also can comprise resistance R 1～R3, Zener diode ZD1～ZD2, and it is simultaneously in conjunction with front end and rear end sampling mode, and corresponding output offset current Ibr, using the compensation as total current ILED.

Coordinate Fig. 5, please refer to Fig. 8.Fig. 8 is the circuit diagram of fourth embodiment of the invention.Difference main between the lighting device 4 of the present embodiment and the lighting device 2 of Fig. 5 is, the lighting device 4 of the present embodiment more comprises a power back-off module 46.Power back-off module 46 is coupled to rectification unit 11, control module 20, the first light emitting module 12 and the second light emitting module 14, and it is according to the voltage swing of input power Vbr, and the total current ILED of the first light emitting module 12 and the second light emitting module 14 is flow through in corresponding adjustment.In aforementioned, the enforcement of power back-off module 46 is identical with the power back-off module 16 shown in Fig. 6, does not repeat them here.

With reference to figure 9.Fig. 9 is the circuit diagram of fifth embodiment of the invention.Lighting device 5 comprises a control module 50 and multiple light emitting modules 52, and multiple light emitting modules 52 comprise four light emitting module 52A, 52B, 52C, 52D, so not as limit.Control module 50 couples rectification unit 51 and multiple light emitting modules 52, and wherein control module 50 receives input power Vbr from rectification unit 51.

The input power Vbr of control unit 501 in control module 50 after according to alternating current AC rectification, corresponding control switch (S_H1～S_H3, S_L1～S_L3, S_M1～S_M3), to change the relation linking between multiple light emitting modules 52 and rectification unit 51, and then reduce every voltage cycle and flow through the current peak of light emitting module 52, reach lighting device 5 and have the effect of high-luminous-efficiency and long service life.

With reference to figure 9 and Figure 10.Figure 10 is the circuit waveform schematic diagram of Fig. 9.T1 during input power Vbr is less than one first set point Vref1, the controlled conducting of switch S _ H1～S_H3, S_L1～S_L3 of control module 50 inside, the controlled cut-off of switch S _ M1～S_M3, and then allow light emitting module 52A, 52B, the common parallel connection of 52C, 52D be electrically connected at rectification unit 51 to form the first connecting state.Now, the electric current I 11 that flows through respectively light emitting module 52A, 52B, 52C, 52D as shown in figure 10.

Then, T2 during input power Vbr is greater than the first set point Vref1 and is less than one second set point Vref2, the controlled cut-off of switch S _ H1, S_H3, S_L1, S_L3, S_M2 of control module 50 inside, switch S _ H2, S_L2, the controlled conducting of S_M1, S_M3, and then allow light emitting module 52A, 52B series connection be electrically connected at rectification unit 51 and light emitting module 52C, 52D series connection to be electrically connected at rectification unit 51 to form the second connecting state.Now, flow through respectively light emitting module 52A, 52 and the electric current I 12 of 52C, 52D as shown in figure 10.

Then, T3 during input power Vbr is greater than the second set point Vref2, the controlled cut-off of switch S _ H1, S_H3, S_L1, S_L3, S_H2, S_L2 of control module 50 inside, the controlled conducting of switch S _ M1～S_M3, and then allow light emitting module 52A, 52B, 52C, 52D be one another in series to be electrically connected at rectification unit 51 to form the 3rd connecting state.Now, the electric current I 13 that flows through light emitting module 52A, 52B, 52C, 52D as shown in figure 10.

Referring again to Figure 10 and Fig. 9.Input power Vbr is the power supply after sinusoidal wave alternating current AC rectification, its voltage waveform is taking 90 degree as symmetrical increase and decrease, therefore, control module 50 during T4, T5, T6 to the action control of inner switch S _ H1～S_H3, S_L1～S_L3, S_M1～S_M3 corresponding and be same as during T3, T2, T1, as shown in figure 10.

In sum, control module 50 can be followed the voltage swing of input power Vbr, allow connection relationship between light emitting module 52A, 52B, 52C, 52D and rectification unit 51 sequentially do action between the first connecting state, the second connecting state, the 3rd connecting state, the second connecting state, the first connecting state.So, under the type of drive of fixing average current, the control mode of control module 50, can reduce every voltage cycle and flow through the current peak of light emitting module 52A, 52B, 52C, 52D and then luminous efficiency and the useful life of improving lighting device 5 entirety.

Referring again to Fig. 9.Lighting device 5 more comprises a power back-off module 56.Power back-off module 56 is coupled to rectification unit 51, control module 50 and multiple light emitting module 52, and it is according to the voltage swing of input power Vbr, and the total current ILED of multiple light emitting modules 52 is flow through in corresponding adjustment.In aforementioned, the enforcement of power back-off module 56 is identical with the power back-off module 16 shown in Fig. 6, does not repeat them here.

The switch control time sequence that the control module 50 of fifth embodiment of the invention discloses according to Figure 10, use the connection relationship between symmetric mode control light emitting module 52A, 52B, 52C, 52D and rectification unit 51, this kind of mode is not unique sequencing control mode, and the every circuit that can control according to input power Vbr the connection relationship between light emitting module is all the scope that the present invention advocates right.

The foregoing is only embodiments of the invention, it is not in order to limit to the scope of the claims of the present invention.

Claims

1. A lighting device, characterized in that, receiving an alternating current, comprising:

a first light-emitting module;

a second light-emitting module;

a rectifier unit to convert the alternating current into an input power; and

A control module, coupled to the rectifier unit, the first light-emitting module and the second light-emitting module, the control module receives the input power, and when the input power is less than a reference value, controls the first light-emitting module, the second light-emitting module The second light-emitting module and the rectifier unit form a first connection state, or when the input power is greater than the reference value, control the first light-emitting module, the second light-emitting module and the rectification unit to form a second connection state; and

A power compensation module, the power compensation module is coupled to the rectifier unit, the control module, the first light-emitting module and the second light-emitting module, and outputs a compensation current according to the voltage of the input power supply, and according to the compensation current Correspondingly adjusting the total current flowing through the first light-emitting module and the second light-emitting module;

Wherein, when the voltage of the input power source is larger, the compensation current corresponding to the output is relatively larger, and when the voltage of the input power source is smaller, the compensation current corresponding to the output is also relatively smaller;

Wherein, when the compensation current is larger, the total current flowing through the first light emitting module and the second light emitting module becomes relatively smaller, and when the compensation current is smaller, the total current flowing through the first light emitting module and the second light emitting module becomes smaller. The total current of the module becomes relatively large.

2. The lighting device according to claim 1, wherein the control module comprises:

a switch unit, coupled to the first light emitting module and the second light emitting module; and

A control unit, coupled to the rectifier unit and the switch unit, the control unit controls the switch unit to make the first light-emitting module, the second light-emitting module and the rectifier unit form a first connection state or make the first light-emitting module The light emitting module, the second light emitting module and the rectifying unit form a second connection state.

3. The lighting device according to claim 2, wherein the first connection state is a state in which the first light-emitting module and the second light-emitting module are electrically connected to the rectifier unit in parallel, and the second connection state is the The first light emitting module and the second light emitting module are electrically connected in series to the state of the rectifying unit.

4. The lighting device according to claim 2, wherein the first connection state is a state in which the first light emitting module is electrically connected to the rectifying unit, and the second light emitting module is disconnected from the rectifying unit, and the second light emitting module is connected to the rectifying unit. The second connection state is a state in which the first light emitting module and the second light emitting module are electrically connected in series to the rectifying unit.

5 . The lighting device according to claim 1 , wherein both the first light emitting module and the second light emitting module comprise a light emitting diode or a plurality of light emitting diodes connected to each other.

6. The lighting device according to claim 1, wherein the power compensation module comprises:

A voltage-controlled current source, coupled to the rectifier unit, correspondingly outputs the compensation current according to the voltage of the input power supply; and

A constant current source, coupled to the voltage control current source, the control module, the first light-emitting module, and the second light-emitting module, the constant current source receives the compensation current, and adjusts the current to flow through the first light-emitting module according to the compensation current with the total current of the second light-emitting module.

7. The lighting device according to claim 1, wherein the power compensation module comprises:

A voltage-controlled current source, coupled to the output terminals of the first light-emitting module and the second light-emitting module, the voltage-controlled current source is based on a voltage between the input power supply and the first light-emitting module and the second light-emitting module difference, corresponding to output a compensation current; and

8. The lighting device according to claim 2, wherein the switch unit comprises:

A diode has an anode end and a cathode end, the anode end is connected to the output end of the first light-emitting module, and the cathode end is connected to the input end of the second light-emitting module;

A first transistor has a first output/input terminal, a second output/input terminal and a first controlled terminal, wherein the first output/input terminal is connected to the cathode terminal of the diode, and the second output/input terminal The terminal is connected to the input terminal of the first light-emitting module, and the first controlled terminal is connected to the control unit; and

A second transistor has a third output/input terminal, a fourth output/input terminal and a second control terminal, wherein the third output/input terminal is connected to the output terminal of the second light-emitting module, a ground terminal and In the rectifying unit, the fourth output/input terminal is connected to the anode terminal of the diode, and the second controlled terminal is connected to the control unit.

9. The lighting device according to claim 8, wherein the control unit comprises:

a voltage divider circuit connected to the rectifier unit to establish an input voltage proportional value according to the input power; and

A drive circuit, coupled to the voltage divider circuit, the drive circuit controls the first transistor and the second transistor to turn on when the input voltage ratio value is less than a set value, so as to make the first light-emitting module, the The second light-emitting module and the rectifier unit form a first connection state, and the drive circuit controls the first transistor and the second transistor to be cut off when the input voltage ratio is greater than the set value, so as to make the first light-emitting module , the second light emitting module and the rectifying unit form a second connection state.

10. The lighting device according to claim 9, wherein the first connection state is a state in which the first light-emitting module and the second light-emitting module are electrically connected to the rectifier unit in parallel, and the second connection state is the The first light emitting module and the second light emitting module are electrically connected in series to the state of the rectifying unit.

11. The lighting device according to claim 2, wherein the switch unit is a transistor having a first output/input terminal, a second output/input terminal and a controlled terminal, wherein the first The output/input terminal is connected between the first light emitting module and the second light emitting module through a current limiting resistor, the second output/input terminal is connected to a ground terminal, and the controlled terminal is connected to the control unit.

12. The lighting device according to claim 11, wherein the control unit comprises:

a drive circuit, coupled to the voltage divider circuit, the drive circuit controls the transistor to turn on when the proportional value of the input voltage is less than a set value, so that the first light-emitting module, the second light-emitting module and the rectifier The unit forms a first connection state, and the drive circuit controls the transistor to turn off when the input voltage ratio value is greater than the set value, so that the first light-emitting module, the second light-emitting module and the rectifying unit form a second link status.

13. The lighting device according to claim 12, wherein the first connection state is a state in which the first light-emitting module is electrically connected to the input power and the second light-emitting module is disconnected from the rectifying unit, and the second The connected state is a state in which the first light emitting module and the second light emitting module are electrically connected in series to the rectifying unit.

14. A method for controlling a lighting device, characterized in that it is suitable for a control module to control a first light-emitting module and a second light-emitting module, comprising:

Obtaining an input power source, the input power source is a rectified AC power source;

When the input power is less than a reference value, control the first light-emitting module, the second light-emitting module and the input power to form a first connection state;

When the input power is greater than the reference value, control the first light-emitting module, the second light-emitting module and the input power to form a second connection state; and

Correspondingly output a compensation current according to the voltage of the input power supply, and correspondingly adjust the total current flowing through the first light-emitting module and the second light-emitting module according to the compensation current;

15. The control method of a lighting device according to claim 14, wherein the first connection state is a state in which the first light-emitting module and the second light-emitting module are electrically connected to the input power in parallel, and the second connection The state is a state in which the first light-emitting module and the second light-emitting module are electrically connected in series to the input power.

16. The control method of a lighting device according to claim 14, wherein the first connection state is a state in which the first light-emitting module is electrically connected to the input power source, and the second light-emitting module is disconnected from the input power source , the second connection state is a state in which the first light-emitting module and the second light-emitting module are electrically connected in series to the input power.

17. A control method for a lighting device, characterized in that it is suitable for a control module to control multiple light emitting modules, including:

When the input power is less than a first reference value, controlling the plurality of light emitting modules to form a first connection state;

When the input power is greater than the first reference value and less than a second reference value, controlling the plurality of light emitting modules to form a second connection state;

When the input power is greater than the second reference value, controlling the plurality of light emitting modules to form a third connection state; and

Correspondingly outputting a compensation current according to the voltage of the input power supply, and correspondingly adjusting the total current flowing through the plurality of light emitting modules according to the compensation current;

Wherein, when the compensation current is larger, the total current flowing through the plurality of light emitting modules is relatively smaller, and when the compensation current is smaller, the total current flowing through the plurality of light emitting modules is relatively larger.