CN208509327U - Dim angular adjustment circuit, LED drive chip and LED drive system - Google Patents

Abstract

The utility model discloses a kind of light modulation angular adjustment circuit, LED drive chip and LED drive systems.By introducing and the concatenated light modulation angular adjustment circuit of leadage circuit, by dimming angular adjustment checking system for PCB temperature, the light modulation angle of the phase-cut dimmer of access can be automatically adjusted, both the steady operation of the light modulator in the preferably normothermic situation of environment had been ensure that, the power consumption in the higher situation of bad environments temperature is minimized, system stability is improved.

Description

Dim angular adjustment circuit, LED drive chip and LED drive system

Technical field

The utility model relates to technical field of LED illumination more particularly to a kind of light modulation angular adjustment circuit, LED to drive core Piece and LED drive system.

Background technique

" tunable optical " is a LED light source advantage critically important relative to conventional light source, accurate to control shining for LED light source Intensity can build out different atmosphere, meet people to the diverse requirements of illumination.It can use the electricity of light modulator adjustment power supply Stream or voltage, so as to generate the light output of varying strength as the LED light of load.

Specifically, light modulator mainly has silicon-controlled forward position phase-cut dimmer (Leading-edge Dimmer) and transistor Afterwards along two kinds of phase-cut dimmer (Trailing-edge Dimmer).Silicon-controlled forward position phase-cut dimmer is to utilize silicon-controlled spy Property, cut phase is carried out when the alternating-current power supply half period starts, after have passed through a period of time corresponding with light modulation position, switch is led Lead to for load supplying until the half period terminates, after zero crossing, repetition same operation changes the virtual value of alternating current；Thus Silicon-controlled forward position phase-cut dimmer is exactly to start in AC phases 0, input voltage is chopped into, until controllable when carrying out cut phase When silicon is connected, just there is voltage input.It is the conducting when AC phases 0 start, warp after transistor along phase-cut dimmer in cut phase It is disconnected after spending a period of time corresponding with light modulation position；It along phase-cut dimmer is controlled by timing circuit in this way after transistor The turn-on and turn-off of field effect transistor make to switch the conducting when the half period starts, by one section corresponding with light modulation position It is disconnected after time, and will be switched off state and keep to the half period terminating, after zero crossing, same operation is repeated, to change exchange Current effective value.

Due to the characteristic of light modulator itself, the light modulation angle of light modulator is controlled by load.It is charged by control to light modulator Opportunity adjustable light modulation angle, by leadage circuit (Bleeder) series voltage stabilizing pipe can delay light modulator charging when Machine reduces light modulation angle.Especially in single hop linearity light adjusting scheme, when light modulation angle changing rate is big, input voltage is lower than defeated Voltage segment provides input current by leadage circuit to maintain dimmer conduction out；It is bigger to dim angle this when, loss Bigger, system temperature is also higher.

With reference to Figure 1A -1B, wherein Figure 1A is the existing LED drive system configuration diagram with phase-cut dimmer, Figure 1B For the AC sinusoidal voltage forward position cut phase signal waveforms after rectification in system shown in Figure 1A.As shown in Figure 1A, phase-cut dimmer 11 can for forward position cut phase or after along phase-cut dimmer；Leadage circuit 13 is connected in parallel on rectifier bridge stack 12 after connecting with voltage-stabiliser tube 14 Between two output ends；LED driver 15 and 16 (LED light) of load are connected in parallel between two output ends of rectifier bridge stack 12.Pass through Leadage circuit series voltage stabilizing pipe can delay phase-cut dimmer charging opportunity (input voltage be lower than pressure stabilizing tube voltage when, light modulation Device does not charge), reduce light modulation angle, reduces leadage circuit loss, improve system effectiveness.But voltage-stabiliser tube is that voltage is relatively fixed Element, when being dimmed using different light modulators, light modulation angular dimension is also different.

As shown in Figure 1B, label a, b, c corresponding position is respectively the light modulator maximum for using different voltages voltage-stabiliser tube to generate Angle is dimmed, wherein the corresponding pressure stabilizing tube voltage in the position label a is lower than the corresponding pressure stabilizing tube voltage in the position label b, the position label b Corresponding pressure stabilizing tube voltage is lower than the corresponding pressure stabilizing tube voltage in the position label c.Pressure stabilizing tube voltage is too high when light modulator can be made to charge Machine is delayed too much, so that light modulation angle lag is too many, the maximum dimmer angle that a part of light modulator can be provided will be too small, leads Cause output electric current that cannot reach full power output；The too small light modulation angle that can make part light modulator of pressure stabilizing tube voltage is still very big, System temperature improves unobvious.

How not only to have guaranteed the steady operation of phase-cut dimmer, but make the power consumption of system minimize as it is existing have cut The LED drive system of phase light modulator technical problem urgently to be resolved.

Utility model content

The purpose of this utility model is that for the concatenated voltage-stabiliser tube of leadage circuit in LED drive system in the prior art The technical issues of voltage is relatively fixed, can not be adjusted according to system temperature provides a kind of light modulation angular adjustment circuit, LED Driving chip and LED drive system utilize system temperature Real-time Feedback, automatic adjustment light modulation angle, lifting system reliability.

To achieve the above object, the utility model provides a kind of light modulation angular adjustment circuit, is suitable for LED driving system System, the LED drive system includes leadage circuit；The light modulation angular adjustment circuit is connected with the leadage circuit, for connecing LED drive system temperature described in input voltage and real-time detection is received, and the leadage circuit pair is controlled according to the temperature detected The charging opportunity of corresponding phase-cut dimmer, to adjust the light modulation angle of the phase-cut dimmer.

To achieve the above object, the utility model additionally provides a kind of LED drive system, including rectifier bridge stack, vent discharge The first input end of road, LED driver and LED load, the rectifier bridge stack accesses AC power source by phase-cut dimmer Positive output end, the second input terminal of the rectifier bridge stack are electrically connected the inverse output terminal of the AC power source, the rectifier bridge Input voltage after the first output end output rectification of heap, the second output terminal ground connection of the rectifier bridge stack, the leadage circuit Lotus root connects between the first output end and second output terminal of the rectifier bridge stack, and the LED driver and LED load are in parallel Between the first output end and second output terminal of the rectifier bridge stack；The LED drive system further includes light modulation angular adjustment Circuit, the light modulation angular adjustment circuit on one side are electrically connected to the first output end of the rectifier bridge stack, and the other end passes through described Leadage circuit is electrically connected to the second output terminal of the rectifier bridge stack, for receiving described in the input voltage and real-time detection LED drive system temperature, and the leadage circuit is controlled to the charging opportunity of the phase-cut dimmer according to the temperature detected, To adjust the light modulation angle of the phase-cut dimmer.

To achieve the above object, the utility model additionally provides a kind of LED drive chip, is suitable for LED drive system, institute Stating LED drive system includes leadage circuit；Light modulation angular adjustment circuit, the light modulation angle are integrated in the LED drive chip Degree adjusts circuit and connects with the leadage circuit, for receiving LED drive system temperature described in input voltage and real-time detection, and The leadage circuit is controlled to the charging opportunity of corresponding phase-cut dimmer, to adjust the cut phase according to the temperature detected The light modulation angle of light modulator.

To achieve the above object, the utility model additionally provides a kind of LED drive system, including rectifier bridge stack, vent discharge The first input end of road, LED drive chip and LED load, the rectifier bridge stack accesses AC power source by phase-cut dimmer Positive output end, the second input terminal of the rectifier bridge stack is electrically connected the inverse output terminal of the AC power source, the rectification Input voltage after the first output end output rectification of bridge heap, the second output terminal ground connection of the rectifier bridge stack, the vent discharge Road lotus root connects between the first output end and second output terminal of the rectifier bridge stack, and the LED drive chip and LED load are equal It is connected in parallel between the first output end of the rectifier bridge stack and second output terminal；Light modulation angle is integrated in the LED drive chip Degree adjusts circuit, and the light modulation angular adjustment circuit on one side is electrically connected to the first output end of the rectifier bridge stack, and the other end is logical The second output terminal that the leadage circuit is electrically connected to the rectifier bridge stack is crossed, for receiving the input voltage and real-time detection The LED drive system temperature, and charging of the leadage circuit to the phase-cut dimmer is controlled according to the temperature detected Opportunity, to adjust the light modulation angle of the phase-cut dimmer.

Utility model has the advantages that the utility model is by introducing and the concatenated light modulation angular adjustment electricity of leadage circuit Road can automatically adjust the light modulation angle of the phase-cut dimmer of access, both by dimming angular adjustment checking system for PCB temperature It ensure that the steady operation of the light modulator in the preferably normothermic situation of environment, and make in the higher feelings of bad environments temperature Power consumption minimizes under condition, improves system stability.

Detailed description of the invention

Figure 1A, the existing LED drive system configuration diagram with phase-cut dimmer；

Figure 1B is the AC sinusoidal voltage forward position cut phase signal waveforms after rectifying in system shown in Figure 1A；

Fig. 2, the configuration diagram of light modulation angular adjustment circuit described in the utility model；

Fig. 3 A, the circuit diagram of light modulation angular adjustment circuit first embodiment described in the utility model；

Fig. 3 B changes schematic diagram with system temperature for triode ON voltage in circuit shown in Fig. 3 A；

Fig. 3 C, the circuit diagram of light modulation angular adjustment circuit second embodiment described in the utility model；

Fig. 4, the configuration diagram of LED drive system first embodiment described in the utility model；

Fig. 5, the configuration diagram of LED drive system second embodiment described in the utility model.

Specific embodiment

Light modulation angular adjustment circuit provided by the utility model, LED drive chip and LED are driven with reference to the accompanying drawing and are System elaborates.Obviously, described embodiment is only the utility model a part of the embodiment, rather than whole implementation Example.Based on the embodiments of the present invention, those of ordinary skill in the art are obtained without making creative work The every other embodiment obtained, fall within the protection scope of the utility model.

With reference to Fig. 2, the configuration diagram of light modulation angular adjustment circuit described in the utility model.The light modulation angle tune It economizes on electricity road 21 (Dimmer Control), is suitable for LED drive system, the LED drive system includes leadage circuit 29.It is described Light modulation angular adjustment circuit 21 is connected with the leadage circuit 29, for receiving LED described in input voltage VBUS and real-time detection Drive system temperature, and when controlling charging of the leadage circuit 29 to corresponding phase-cut dimmer according to the temperature detected Machine, to adjust the light modulation angle of the phase-cut dimmer.Wherein, as LED drive system temperature increases, angular adjustment is dimmed Circuit 21 controls charging opportunity delay (i.e. of phase-cut dimmer charging that leadage circuit 29 charges to corresponding phase-cut dimmer Moment of beginning is delayed), charging opportunity postpones so that the light modulation angle of phase-cut dimmer becomes smaller, to reduce leadage circuit loss, mentions High system effectiveness.By detection system temperature, light modulation angle can be automatically adjusted, both ensure that preferably normothermic in environment In the case of light modulator steady operation, and the power consumption in the higher situation of bad environments temperature is minimized, improves system Stability.Corresponding phase-cut dimmer may include in LED drive system, or external components are (for example, and alternating current Source is equally arranged on wall) it does not include in LED drive system.

Specifically, the light modulation angular adjustment circuit 21 includes temperature detecting unit 211, partial pressure unit 212 and switch 213.The temperature detecting unit 211, one end are electrically connected the control terminal of the switch 213, and the other end is electrically connected the vent discharge Road 29；The partial pressure unit 212, first input end are released described in the electrical connection of the second input terminal for receiving input voltage VBUS Circuit 29, output end are electrically connected the control terminal of the switch 213；The switch 213, first end is for receiving input voltage VBUS, second end are electrically connected the leadage circuit 29.The conducting voltage of the switch 213 is with the temperature detecting unit 211 The LED drive system temperature detected changes and changes, charging of the leadage circuit 29 to corresponding phase-cut dimmer Opportunity changes as the conducting voltage of the switch 213 changes, to adjust the light modulation angle of the phase-cut dimmer.? That is, the initial time that the conducting voltage increase control leadage circuit 29 of switch 213 charges to phase-cut dimmer delays (input voltage Lower than switch conducting voltage when, phase-cut dimmer does not charge), charging opportunity delay so that the light modulation angle of phase-cut dimmer becomes It is small, to reduce leadage circuit loss, improve system effectiveness.Wherein, leadage circuit 29 to charging time of phase-cut dimmer= Input voltage be raised to time+phase-cut dimmer electric current of the conducting voltage of switch from 0 to extinction current time.

Next the specific embodiment of light modulation angular adjustment circuit described in the utility model is provided in conjunction with Fig. 3 A-3C.Its In, Fig. 3 A is the circuit diagram of light modulation angular adjustment circuit first embodiment described in the utility model；Fig. 3 B is Fig. 3 A institute Show that triode ON voltage is with system temperature variation schematic diagram in system；Fig. 3 C is light modulation angular adjustment described in the utility model The circuit diagram of circuit second embodiment.

As shown in Figure 3A, in the present embodiment, the temperature detecting unit 211 of the light modulation angular adjustment circuit includes one Thermistor NTC1, partial pressure unit 212 include concatenated first resistor R1 and second resistance R2, and switch 213 uses triode Q1. Thermistor NTC1, one end are electrically connected the base stage b of triode Q1, and the other end is electrically connected leadage circuit 29, thermistor NTC1's Resistance value changes as LED drive system temperature changes, and system temperature is higher, and NTC1 resistance value is smaller.The first of first resistor R1 End is for receiving input voltage VBUS, the first end of the second end electrical connection second resistance R2 of first resistor R1, second resistance R2 Second end be electrically connected leadage circuit 29, the base stage b of the common end electrical connection triode Q1 of first resistor R1 and second resistance R2, It is divided for the voltage to input triode Q1.Triode Q1, collector c are for receiving input voltage VBUS, emitter e It is electrically connected leadage circuit 29.The conducting voltage that LED drive system temperature adjusts triode Q1 is sensed by thermistor NTC1 Vce, and then leadage circuit 29 is controlled to the charging opportunity of phase-cut dimmer, to adjust the light modulation angle of phase-cut dimmer.

Specifically, the resistance value of thermistor NTC1 reduces, the conducting of triode Q1 as LED drive system temperature increases Voltage is increased as the resistance value of thermistor NTC1 reduces, and leadage circuit 29 is to the charging opportunity of phase-cut dimmer with three poles The conducting voltage of pipe Q1 increases and postpones, and the light modulation angle of phase-cut dimmer becomes smaller as charging opportunity postpones.LED driving system Temperature of uniting increases, and thermistor NTC1 fever is so that resistance value reduces, otherwise increases.Thermistor NTC1 so just be Temperature of uniting keeps a thermal balance.LED drive system temperature is higher, and thermistor NTC1 resistance value is smaller, triode Q1 electric conduction Pressure is higher, and the initial time that leadage circuit 29 charges to phase-cut dimmer more postpones, and the light modulation angle of phase-cut dimmer is smaller, this Sample both ensure that different light modulators can steady operation, also make system temperature controllable.

Specifically, triode Q1 ends when input voltage VBUS is less than its conducting voltage, control leadage circuit 29 stops It charges to phase-cut dimmer.It is to be understood that in the system starts stage, when input voltage VBUS is lower than triode Q1 Conducting voltage when, phase-cut dimmer does not charge；In system worked well stage (the normal situation of the preferable system temperature of environment Under), phase-cut dimmer steady operation；In the higher situation of bad environments system temperature, the resistance value of thermistor NTC1 reduces So that the conducting voltage of triode Q1 increases, the triode Q1 when triode Q1 conducting voltage is increased to higher than input voltage VBUS Cut-off, phase-cut dimmer does not also charge, so that power consumption minimizes, improves system stability.

As shown in Figure 3B, the LED drive system temperature that the conducting voltage Vce of triode Q1 is detected with thermistor NTC1 Degree TEMP is increased and is increased, LED drive system temperature T2 > T1, conducting voltage V2 > V1 of corresponding triode Q1.

Specifically, the relationship of the conducting voltage of triode Q1 and the resistance value of thermistor NTC1 are as follows:

Vce=(R1*NTC1*R2/ (NTC+R2)+1) * Vbe,

Wherein, Vce is the conducting voltage of triode Q1, the bias of base stage and transmitting interpolar that Vbe is triode Q1, NTC1 For the resistance value of thermistor NTC1, R1 is the resistance value of first resistor R1, and R2 is the resistance value of second resistance R2.As input voltage VBUS When conducting voltage Vce less than triode Q1, triode Q1 cut-off, for phase-cut dimmer without charging, input voltage VBUS is low Longer in the time of conducting voltage Vce, the time of the light modulation angle lag of phase-cut dimmer is also longer.

Such as Fig. 3 C, first embodiment shown in the present embodiment and Fig. 3 A the difference is that, switched described in the present embodiment Using power MOS pipe M1.Specifically, thermistor NTC1, one end is electrically connected the grid end g of power MOS pipe M1, other end electrical connection Leadage circuit 29, the resistance value of thermistor NTC1 change as LED drive system temperature changes, and system temperature is higher, NTC1 Resistance value is smaller.The first end of first resistor R1 is for receiving input voltage VBUS, the second end electrical connection second of first resistor R1 The second end of the first end of resistance R2, second resistance R2 is electrically connected leadage circuit 29, the public affairs of first resistor R1 and second resistance R2 The grid end g of end electrical connection power MOS pipe M1 altogether, divides for the voltage to input power metal-oxide-semiconductor M1.Power MOS pipe M1, Drain terminal d is electrically connected leadage circuit 29 for receiving input voltage VBUS, source s.LED driving system is sensed by thermistor NTC1 The conducting voltage Vds of temperature of uniting adjustment power MOS pipe M1, and then control leadage circuit 29 to charging opportunity of phase-cut dimmer, To adjust the light modulation angle of phase-cut dimmer.

Specifically, the resistance value of thermistor NTC1 reduces as LED drive system temperature increases, power MOS pipe M1's Conducting voltage is increased as the resistance value of thermistor NTC1 reduces, leadage circuit 29 to charging opportunity of phase-cut dimmer with The conducting voltage of power MOS pipe M1 increases and postpones, and the light modulation angle of phase-cut dimmer becomes smaller as charging opportunity postpones. LED drive system temperature increases, and thermistor fever is so that resistance value reduces, otherwise increases.Thermistor NTC1 in this way Just a thermal balance is kept with system temperature.LED drive system temperature is higher, and thermistor NTC1 resistance value is smaller, power MOS pipe M1 conducting voltage is higher, and the initial time that leadage circuit 29 charges to phase-cut dimmer more postpones, the light modulation angle of phase-cut dimmer Spend it is smaller, both ensure that so different light modulators can steady operation, also make system temperature controllable.

Specifically, power MOS pipe M1 ends when input voltage VBUS is less than its conducting voltage Vds, leadage circuit is controlled 29 stop charging to phase-cut dimmer.It is to be understood that in the system starts stage, when input voltage VBUS is lower than function When the conducting voltage Vds of rate metal-oxide-semiconductor M1, phase-cut dimmer does not charge；In system worked well stage (the preferable system temperature of environment In normal situation), phase-cut dimmer steady operation；In the higher situation of bad environments system temperature, thermistor NTC1 Resistance value reduce so that the conducting voltage Vds of power MOS pipe M1 is increased, when power MOS pipe M1 conducting voltage raising Vds is to than defeated Power MOS pipe M1 ends when entering voltage VBUS high, and phase-cut dimmer does not also charge, so that power consumption minimizes, it is steady to improve system It is qualitative.

Specifically, the relationship of the conducting voltage of power MOS pipe M1 and the resistance value of thermistor NTC1 are as follows:

Vds=(R1*NTC1*R2/ (NTC+R2)+1) * Vgs_th,

Wherein, Vds is the conducting voltage of power MOS pipe M1, and Vgs_th is the cut-in voltage of power MOS pipe M1, and NTC1 is The resistance value of thermistor NTC1, R1 are the resistance value of first resistor R1, and R2 is the resistance value of second resistance R2.When input voltage VBUS is small When the conducting voltage Vds of power MOS pipe M1, power MOS pipe M1 cut-off, phase-cut dimmer is without charging, input voltage VBUS is longer lower than the time of conducting voltage Vds, and the time of the light modulation angle lag of phase-cut dimmer is also longer.

With reference to Fig. 4, the configuration diagram of LED drive system first embodiment described in the utility model.The LED drives Dynamic system includes rectifier bridge stack 42, leadage circuit 43, LED driver 45 and LED load 46.The first of the rectifier bridge stack 42 Input terminal accesses the positive output end of AC power source AC, the second input terminal electricity of the rectifier bridge stack 42 by phase-cut dimmer 41 Connect the inverse output terminal of the AC power source AC, the input voltage after the first output end output rectification of the rectifier bridge stack 42 VBUS, the second output terminal ground connection of the rectifier bridge stack 42；43 lotus root of leadage circuit connects the first of the rectifier bridge stack 42 Between output end and second output terminal, the LED driver 45 and LED load 46 are connected in parallel on the of the rectifier bridge stack 42 Between one output end and second output terminal.The LED drive system further includes light modulation angular adjustment circuit 44, the light modulation angle The first output end that 44 one end of circuit is electrically connected to the rectifier bridge stack 42 is adjusted, the other end is electrically connected by the leadage circuit 43 It is connected to the second output terminal of the rectifier bridge stack 42；The light modulation angular adjustment circuit 44 is for receiving the input voltage VBUS And LED drive system temperature described in real-time detection, and the leadage circuit 43 is controlled to the cut phase according to the temperature detected The charging opportunity of light modulator 41, to adjust the light modulation angle of the phase-cut dimmer 41.

As LED drive system temperature increases, light modulation angular adjustment circuit 44 controls leadage circuit 43 to phase-cut dimmer The charging opportunity delay (initial time that i.e. phase-cut dimmer 41 charges is delayed) of 41 chargings, charging opportunity delay is so that cut phase tune The light modulation angle of light device 41 becomes smaller, to reduce the loss of leadage circuit 43, improves system effectiveness.By dimming angular adjustment circuit 44 detection system temperature can automatically adjust the light modulation angle of phase-cut dimmer 41, both ensure that normal in the preferable temperature of environment In the case where light modulator steady operation, and the power consumption in the higher situation of bad environments temperature is minimized, improves system System stability.Specifically, the light modulation angular adjustment circuit 44 can use the utility model Fig. 2, Fig. 3 A, any implementation of Fig. 3 C Light modulation angular adjustment circuit described in example.

The phase-cut dimmer may include in LED drive system, or external components are (for example, with exchanging Power supply is equally arranged on wall) it does not include in LED drive system.Optionally, the phase-cut dimmer can cut for forward position Phase light modulator or after along phase-cut dimmer.When the phase-cut dimmer 41 is forward position phase-cut dimmer, the LED drive system It further include the trigger circuit 47 being connected in parallel between the first output end and second output terminal of the rectifier bridge stack 42, the triggering electricity Road 47 is used to provide trigger current in the forward position phase-cut dimmer start-up time.Along cut phase after the phase-cut dimmer 41 is When light modulator, then trigger circuit 47 is not necessarily to.Therefore trigger circuit 47 is illustrated using dashed box in Fig. 4, is selectable unit (SU).

The invention also discloses a kind of LED drive chips, are suitable for LED drive system, the LED drive system packet Include leadage circuit.Light modulation angular adjustment circuit is integrated in the LED drive chip, light modulation angular adjustment circuit and LED drive The leadage circuit of system is connected, for receiving input voltage and real-time detection LED drive system temperature, and according to the temperature detected Degree controls leadage circuit to the charging opportunity of corresponding phase-cut dimmer, to adjust the light modulation angle of phase-cut dimmer.Specifically , the light modulation angular adjustment circuit can be using light modulation angle described in the utility model Fig. 2, Fig. 3 A, Fig. 3 C any embodiment Degree adjusts circuit.

With reference to Fig. 5, the configuration diagram of LED drive system second embodiment described in the utility model.With reality shown in Fig. 4 Apply example the difference is that, LED drive system described in the present embodiment using LED drive chip 55 substitute LED driver 45. The LED drive chip 55 is connected in parallel between the first output end and second output terminal of the rectifier bridge stack 42, LED drive chip Light modulation angular adjustment circuit 551 is integrated in 55, described 551 one end of light modulation angular adjustment circuit is electrically connected to the rectifier bridge stack 42 the first output end, the other end are electrically connected to the second output terminal of the rectifier bridge stack 42 by the leadage circuit 43, use The LED drive system temperature described in the reception input voltage VBUS and real-time detection, and institute is controlled according to the temperature detected Leadage circuit 43 is stated to the charging opportunity of the phase-cut dimmer 41, to adjust the light modulation angle of the phase-cut dimmer 41.

As LED drive system temperature increases, light modulation angular adjustment circuit 551 controls leadage circuit 43 to phase-cut dimmer The charging opportunity delay (initial time that i.e. phase-cut dimmer 41 charges is delayed) of 41 chargings, charging opportunity delay is so that cut phase tune The light modulation angle of light device 41 becomes smaller, to reduce the loss of leadage circuit 43, improves system effectiveness.By dimming angular adjustment circuit 551 detection system temperature can automatically adjust the light modulation angle of phase-cut dimmer 41, both ensure that normal in the preferable temperature of environment In the case where light modulator steady operation, and the power consumption in the higher situation of bad environments temperature is minimized, improves system System stability.Specifically, the light modulation angular adjustment circuit 551 can use the utility model Fig. 2, Fig. 3 A, any reality of Fig. 3 C Apply light modulation angular adjustment circuit described in example.

The phase-cut dimmer may include in LED drive system, or external components are (for example, with exchanging Power supply is equally arranged on wall) it does not include in LED drive system.Optionally, the phase-cut dimmer can cut for forward position Phase light modulator or after along phase-cut dimmer.When the phase-cut dimmer 41 is forward position phase-cut dimmer, the LED drive system It further include the trigger circuit 47 being connected in parallel between the first output end and second output terminal of the rectifier bridge stack 42, the triggering electricity Road 47 is used to provide trigger current in the forward position phase-cut dimmer start-up time.Along cut phase after the phase-cut dimmer 41 is When light modulator, then trigger circuit 47 is not necessarily to.Therefore trigger circuit 47 is illustrated using dashed box in Fig. 4, is selectable unit (SU).

The above is only the preferred embodiment of the utility model, it is noted that for the common skill of the art Art personnel can also make several improvements and modifications without departing from the principle of this utility model, these improvements and modifications Also it should be regarded as the protection scope of the utility model.

Claims (18)

1. a kind of light modulation angular adjustment circuit is suitable for LED drive system, the LED drive system includes leadage circuit；It is special Sign is that the light modulation angular adjustment circuit is connected with the leadage circuit, for receiving described in input voltage and real-time detection LED drive system temperature, and the leadage circuit is controlled to the charging opportunity of corresponding phase-cut dimmer according to the temperature detected, To adjust the light modulation angle of the phase-cut dimmer.

2. light modulation angular adjustment circuit as described in claim 1, which is characterized in that the light modulation angular adjustment circuit includes temperature Spend detection unit, partial pressure unit and switch；

The temperature detecting unit, one end are electrically connected the control terminal of the switch, and the other end is electrically connected the leadage circuit；

The partial pressure unit, first input end are electrically connected the leadage circuit for receiving the input voltage, the second input terminal, Output end is electrically connected the control terminal of the switch；

The switch, first end are electrically connected the leadage circuit for receiving the input voltage, second end；

The LED drive system temperature that the conducting voltage of the switch is detected with the temperature detecting unit changes and changes Becoming, the leadage circuit changes the charging opportunity of the phase-cut dimmer as the conducting voltage of the switch changes, from And adjust the light modulation angle of the phase-cut dimmer.

3. light modulation angular adjustment circuit as claimed in claim 2, which is characterized in that the temperature detecting unit includes a temperature-sensitive Resistance, the partial pressure unit include concatenated first resistor and second resistance, and the switch uses triode；

The thermistor, one end are electrically connected the base stage of the triode, and the other end is electrically connected the leadage circuit, the temperature-sensitive The resistance value of resistance changes as the LED drive system temperature changes；

The first end of the first resistor is for receiving the input voltage, the second end electrical connection of the first resistor described the The second end of the first end of two resistance, the second resistance is electrically connected the leadage circuit, the first resistor and described second The common end of resistance is electrically connected the base stage of the triode；

The triode, collector are electrically connected the leadage circuit for receiving the input voltage, emitter.

4. light modulation angular adjustment circuit as claimed in claim 3, which is characterized in that the resistance value of the thermistor is with described LED drive system temperature increases and reduces, and the conducting voltage of the triode rises as the resistance value of the thermistor reduces Height, the leadage circuit postpone the charging opportunity of the phase-cut dimmer as the conducting voltage of the triode increases, The light modulation angle of the phase-cut dimmer becomes smaller as charging opportunity postpones.

5. light modulation angular adjustment circuit as claimed in claim 3, which is characterized in that the triode is small in the input voltage End when the conducting voltage of the triode, controls the leadage circuit stopping and charge to the phase-cut dimmer.

6. as claimed in claim 3 light modulation angular adjustment circuit, which is characterized in that the conducting voltage of the triode with it is described The relationship of the resistance value of thermistor are as follows: Vce=(R1*NTC1*R2/ (NTC1+R2)+1) * Vbe,

Wherein, Vce is the conducting voltage of the triode, and Vbe is the base stage of the triode and the bias of transmitting interpolar, NTC1 For the resistance value of the thermistor, R1 is the resistance value of the first resistor, and R2 is the resistance value of the second resistance.

7. light modulation angular adjustment circuit as claimed in claim 2, which is characterized in that the temperature detecting unit includes a temperature-sensitive Resistance, the partial pressure unit include concatenated first resistor and second resistance, and the switch uses power MOS pipe；

The thermistor, one end are electrically connected the grid end of the power MOS pipe, and the other end is electrically connected the leadage circuit, described The resistance value of thermistor changes as the LED drive system temperature changes；

The first end of the first resistor is for receiving the input voltage, the second end electrical connection of the first resistor described the The second end of the first end of two resistance, the second resistance is electrically connected the leadage circuit, the first resistor and described second The common end of resistance is electrically connected the grid end of the power MOS pipe；

The power MOS pipe, drain terminal are electrically connected the leadage circuit for receiving the input voltage, source.

8. light modulation angular adjustment circuit as claimed in claim 7, which is characterized in that the resistance value of the thermistor is with described LED drive system temperature increases and reduces, the conducting voltage of the power MOS pipe with the resistance value reduction of the thermistor and Increase, the leadage circuit to the phase-cut dimmer charging opportunity with the power MOS pipe conducting voltage increase and Delay, the light modulation angle of the phase-cut dimmer become smaller as charging opportunity postpones.

9. light modulation angular adjustment circuit as claimed in claim 7, which is characterized in that the power MOS pipe is in the input electricity Pressure is ended when being less than the conducting voltage of the power MOS pipe, is controlled the leadage circuit and is stopped carrying out the phase-cut dimmer Charging.

10. as claimed in claim 7 light modulation angular adjustment circuit, which is characterized in that the conducting voltage of the power MOS pipe with The relationship of the resistance value of the thermistor are as follows: Vds=(R1*NTC1*R2/ (NTC1+R2)+1) * Vgs_th,

Wherein, Vds is the conducting voltage of the power MOS pipe, and Vgs_th is the cut-in voltage of the power MOS pipe, and NTC1 is The resistance value of the thermistor, R1 are the resistance value of the first resistor, and R2 is the resistance value of the second resistance.

11. a kind of LED drive system, including rectifier bridge stack, leadage circuit, LED driver and LED load, the rectifier bridge The first input end of heap accesses the positive output end of AC power source, the second input terminal of the rectifier bridge stack by phase-cut dimmer It is electrically connected the inverse output terminal of the AC power source, the first output end of the rectifier bridge stack exports the input voltage after rectification, The second output terminal of the rectifier bridge stack is grounded, and the leadage circuit lotus root connects in the first output end of the rectifier bridge stack and second Between output end, the LED driver and LED load are connected in parallel on the first output end of the rectifier bridge stack and second and export Between end；It is characterized in that,

The LED drive system further includes light modulation angular adjustment circuit, and the light modulation angular adjustment circuit on one side is electrically connected to institute The first output end of rectifier bridge stack is stated, the other end is electrically connected to the second output of the rectifier bridge stack by the leadage circuit End controls institute for receiving LED drive system temperature described in the input voltage and real-time detection, and according to the temperature detected Leadage circuit is stated to the charging opportunity of the phase-cut dimmer, to adjust the light modulation angle of the phase-cut dimmer.

12. LED drive system as claimed in claim 11, which is characterized in that the phase-cut dimmer is forward position phase-cut dimming Device, the LED drive system further include the triggering being connected in parallel between the first output end of the rectifier bridge stack and second output terminal Circuit, the trigger circuit are used to provide trigger current in the forward position phase-cut dimmer start-up time.

13. LED drive system as claimed in claim 11, which is characterized in that the light modulation angular adjustment circuit is further adopted The light modulation angular adjustment circuit described in claim 2-10 any one.

14. a kind of LED drive chip is suitable for LED drive system, the LED drive system includes leadage circuit；Its feature exists In, it is integrated in the LED drive chip and dims angular adjustment circuit, the light modulation angular adjustment circuit and the leadage circuit Series connection, for receiving LED drive system temperature described in input voltage and real-time detection, and according to the temperature control detected Leadage circuit is to charging opportunity of corresponding phase-cut dimmer, to adjust the light modulation angle of the phase-cut dimmer.

15. LED drive chip as claimed in claim 14, which is characterized in that the light modulation angular adjustment circuit is further adopted The light modulation angular adjustment circuit described in claim 2-10 any one.

16. a kind of LED drive system, including rectifier bridge stack, leadage circuit, LED drive chip and LED load, the rectification The first input end of bridge heap accesses the positive output end of AC power source, the second input of the rectifier bridge stack by phase-cut dimmer End is electrically connected the inverse output terminal of the AC power source, the input electricity after the first output end output rectification of the rectifier bridge stack Pressure, the rectifier bridge stack second output terminal ground connection, the leadage circuit lotus root connect the rectifier bridge stack the first output end and Between second output terminal, the LED drive chip and LED load are connected in parallel on the first output end and of the rectifier bridge stack Between two output ends；It is characterized in that,

Light modulation angular adjustment circuit is integrated in the LED drive chip, the light modulation angular adjustment circuit on one side is electrically connected to First output end of the rectifier bridge stack, the other end are electrically connected to the second output of the rectifier bridge stack by the leadage circuit End controls institute for receiving LED drive system temperature described in the input voltage and real-time detection, and according to the temperature detected Leadage circuit is stated to the charging opportunity of the phase-cut dimmer, to adjust the light modulation angle of the phase-cut dimmer.

17. LED drive system as claimed in claim 16, which is characterized in that the phase-cut dimmer is forward position phase-cut dimming Device, the LED drive system further include the triggering being connected in parallel between the first output end of the rectifier bridge stack and second output terminal Circuit, the trigger circuit are used to provide trigger current in the forward position phase-cut dimmer start-up time.

18. LED drive system as claimed in claim 16, which is characterized in that the light modulation angular adjustment circuit is further adopted The light modulation angular adjustment circuit described in claim 2-10 any one.