CN103796389A - Largest brightness lifting module and silicon controlled light-dimmer LED driving circuit and system - Google Patents

Abstract

The invention discloses a silicon controlled light-dimmer LED driving circuit. A drain electrode of a second MOS transistor is connected with a source electrode of a power switch MOS transistor, a source electrode of the second MOS transistor is connected with a sampling resistor, the output end of a largest brightness lifting module is electrically connected with the first input end of a peak value current comparator and a feedforward resistor through a drain electrode of a first MOS transistor in the largest brightness lifting module, current signals output by the first MOS transistor pass through the feedforward resistor to generate direct-current bias voltages, the first input end of the peak value current comparator is electrically connected with the sampling resistor through the feedforward resistor, the second input end of the peak value current comparator is electrically connected with the output end of a reference voltage source, the output end of the peak value current comparator is coupled to a grid electrode of the second MOS transistor, and the peak value current comparator is used for comparing the sum of the voltage amplitude of the feedforward resistor and the voltage amplitude of the sampling resistor with a voltage threshold value of the reference voltage source, and controls the second MOS transistor to be switched on and off. When a driving circuit is connected with a silicon controlled light dimmer, the largest current is improved through the largest brightness lifting module.

Description

High-high brightness hoisting module, controllable silicon light modulation LED drive circuit and system

Technical field

The present invention relates to LED and drive field, relate in particular to controllable silicon light modulation LED drive circuit and system that a kind of high-high brightness promotes.

Background technology

Referring to Fig. 1, the rough schematic view of the controllable silicon light modulation LED drive circuit of prior art.As shown in Figure 1, inputAC AC power 101controllable silicon dimmer 102 of connecting, is connected to two inputs of rectifier bridge 103.Rectifier bridge 103 by after AC rectification through capacitor C1 filtering, produce the sinusoidal voltage after a rectification.Resistance R 4 and capacitor C2 produce a low-voltage DC starts control chip 104.Transformer T1 has three windings, comprises a former limit winding T11, is connected between capacitor C1 and the drain electrode of power switch MOS transistor M1; A secondary winding T12, is connected between sustaineddiode 1 and secondary output capacitor C4; An auxiliary winding T13, is connected in between electric diode D2 and circuit ground.When after circuit start, auxiliary winding T13 is thatcontrol chip 104 is powered; Auxiliary winding T13 also provides the information that detects sustaineddiode 1 current over-zero and detect output voltage overvoltage simultaneously.The controllable silicon light modulation LED drive circuit of prior art also comprises a bleeder resistance R1 and the switch M2 that releases conventionally; when anti exciting converter input current hour;control chip 104 is opened the switch M2 that releases, forcontrollable silicon dimmer 102 provides enough electric currents that maintains.

In above-mentioned traditional flyback LED drive circuit, there are following two shortcomings:

1) when used controllable silicon dimmer 102 maximum conduction angle degree hour, the output current of the output current of drive circuit when not using dimmer declines more;

2) bleeder resistance R1 and the switch M2 power consumption of releasing are higher, and loss LED drive circuit efficiency and temperature rise are higher, reduce system reliability.

Summary of the invention

The object of the invention is to, the problem existing for controllable silicon light modulation LED drive circuit in prior art, a kind of high-high brightness hoisting module, controllable silicon light modulation LED drive circuit and system are provided, by high-high brightness hoisting module, maximum current can improve drive circuit connection controllable silicon dimmer time, save leadage circuit simultaneously, the electric current that maintains of controllable silicon dimmer is provided with the input current of switch converters itself.

For achieving the above object, the invention provides a kind of high-high brightness hoisting module, comprising: an operational amplifier, one first MOS transistor and a reference voltage source; The first input end of described operational amplifier is the input of described high-high brightness hoisting module, in order to receive a sampled voltage signal, its second input is connected with the output electricity of described reference voltage source, its output electricity is connected to the grid of described the first MOS transistor, the conduction impedance of the first MOS transistor described in described operational amplifier control, guarantees when described operational amplifier closed loop work that two input terminal voltages equate; The source electrode electricity of described the first MOS transistor is connected to the first input end of described operational amplifier, the output that its drain electrode is described high-high brightness hoisting module, and output one current signal is in order to control the output current of a LED drive circuit.

For achieving the above object, the present invention also provides a kind of controllable silicon light modulation LED drive circuit, comprising: one second MOS transistor, a peak current comparator, feedforward resistance, a reference voltage source and a high-high brightness hoisting module of the present invention; The drain electrode electricity of described the second MOS transistor is connected to the source electrode of a power switch MOS transistor, and the source electrode electricity of described the second MOS transistor connects a sampling resistor; The output of described high-high brightness hoisting module is connected to described peak current comparator first input end and described feedforward resistance by the drain electrode electricity of described the first MOS transistor, and the current signal of described the first MOS transistor output feedforward resistance of flowing through produces direct current (DC) bias; Described peak current comparator first input end is connected with sampling resistor electricity by described feedforward resistance, its second input is connected with the output electricity of described reference voltage source, its output is coupled to the grid of described the second MOS transistor, described peak current comparator, for by the voltage threshold comparison of the voltage magnitude sum of described feedforward resistance and sampling resistor and described reference voltage source, is controlled the conducting of described the second MOS transistor and closes.

For achieving the above object, the present invention also provides a kind of controllable silicon light modulation LED drive system, comprises a controllable silicon dimmer, a rectifier bridge, a bus capacitor, a sampling resistor and controllable silicon light modulation LED drive circuit of the present invention; Described controllable silicon dimmer and one exchanges input source electricity and is connected, by adjusting the brightness of himself angle of flow control LED load; Described rectifier bridge is respectively with described controllable silicon dimmer and exchange input source electricity and is connected, for being that an amplitude is positive voltage signal by the sinusoidal signal rectification of interchange input source; Described bus capacitor is coupled to two outputs of described rectifier bridge and is connected with the drain electrode electricity of a power switch MOS transistor, is used to described power switch MOS transistor that high-frequency current path is provided; The input of described high-high brightness hoisting module is connected with the drain electrode electricity of described bus capacitor and described power switch MOS transistor respectively; The drain electrode of described the second MOS transistor is connected with the source electrode electricity of described power switch MOS transistor, and the source electrode of described the second MOS transistor is connected with described sampling resistor electricity; Described peak current comparator first input end is connected with described sampling resistor electricity by described feedforward resistance; Described sampling resistor is connected to LED load by a transformer or inductance electricity.

The invention has the advantages that: by high-high brightness hoisting module, improved maximum current when drive circuit connects controllable silicon dimmer; Save leadage circuit simultaneously, the electric current that maintains of controllable silicon dimmer is provided with the input current of switch converters itself, improved LED drive circuit efficiency and system reliability.

Accompanying drawing explanation

Fig. 1, the rough schematic view of the controllable silicon light modulation LED drive circuit of prior art;

Fig. 2, the configuration diagram of controllable silicon light modulation LED drive circuit of the present invention;

Fig. 3, the schematic diagram of voltage-dropping type controllable silicon light modulation LED drive system of the present invention;

Fig. 4, the work typical waveform figure of voltage-dropping type controllable silicon light modulation LED drive system of the present invention;

Fig. 5, the Vdim voltage of controllable silicon light modulation LED drive system of the present invention and the graph of a relation of Vcs crest voltage;

Fig. 6, the schematic diagram of buck-boost type controllable silicon light modulation LED drive system of the present invention;

Fig. 7, the schematic diagram of flyback controllable silicon light modulation LED drive system of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the execution mode of controllable silicon light modulation LED drive circuit provided by the invention and system is elaborated.

With reference to figure 2, the configuration diagram of controllable silicon light modulation LED drive circuit of the present invention, described drive circuit comprises: one second MOS transistor M2, a peakcurrent comparator 209, feedforward resistance R 6, a reference voltage source ref1 and a high-high brightness hoistingmodule 21.

Described high-high brightness hoistingmodule 21 comprises: anoperational amplifier 210, one first MOS transistor M3, a reference voltage source ref2, a voltage division processing unit and a filter unit.

Described voltage division processing unit receives outside amplitude to be positive voltage signal Vbus and to process.As preferred embodiment, described voltage division processing unit comprises on one divider resistance R2 and divider resistance R3 once; It is positive voltage signal Vbus that described upper divider resistance R2 one end receives outside amplitude, and the other end is connected with described lower divider resistance R3 electricity, described lower divider resistance R3 other end ground connection (for example chip ground).Upper divider resistance R2 and lower divider resistance R3 can pass through the processing to voltage signal Vbus, detect the cut angle information of outside controllable silicon dimmer.

Described filter unit respectively electricity is connected to the first input end of described voltage division processing unit and describedoperational amplifier 210, described filter unit is for carrying out filtering to the voltage signal after described voltage division processing cell processing, obtains d. c. voltage signal Vdim and export to the first input end of described operational amplifier 210.As preferred embodiment, described filter unit comprises a filter resistance R4 and a filter capacitor C3; Described filter resistance R4 one end is coupled between described upper divider resistance R2 and lower divider resistance R3, and the other end respectively electricity is connected to the first input end of described filter capacitor C3 and describedoperational amplifier 210, described filter capacitor C3 other end ground connection.

The first input end of describedoperational amplifier 210 receives d. c. voltage signal Vdim, its second input is connected with the output electricity of described reference voltage source ref2, its output electricity is connected to the grid G of described the first MOS transistor M3, describedoperational amplifier 210 is controlled the conduction impedance of described the first MOS transistor M3, when the 210 closed loops work of described operational amplifier, guarantee that two input terminal voltages equate, thereby have the electric current first MOS transistor M3 that flows through.

Wherein, described voltage division processing unit and filter unit are selectable unit, the described first input end of statingoperational amplifier 210 can be directly the input of described high-high brightness hoistingmodule 21, in order to receive a sampled voltage signal, in order to compare with the voltage signal of described reference voltage source ref2, described sampled voltage signal can be d. c. voltage signal Vdim.

The source S electricity of described the first MOS transistor is connected to the first input end of describedoperational amplifier 210, and its drain D is the output of described high-high brightness hoistingmodule 21, the output current of output current signal control LED drive circuit.The output of described high-highbrightness hoisting module 21 is connected to described peakcurrent comparator 209 first input ends and described feedforward resistance R 6 by the drain D electricity of described the first MOS transistor M3, the drain D output current signal of described the first MOS transistor M3 is injected into an input ofpeak current comparator 209, because the input impedance ofpeak current comparator 209 is very high, this electric current is all flowed through and is feedovered resistance R 6 and on R6, produce a DC offset voltage.

As optional execution mode, described high-high brightness hoistingmodule 21 further comprises an input resistance R5; Described input resistance R5 is serially connected between described filter resistance R4 and the first input end of describedoperational amplifier 210, and is connected with the source S electricity of described the first MOS transistor M3, for obtaining dividing potential drop and exporting described the first MOS transistor M3 to.Described input resistance R5 can omit, when omission described in input resistance R5 short circuit.Operational amplifier 210 is controlled the conduction impedance of the first MOS transistor M3, guarantee that two input terminal voltages equate, thereby input resistance R5 two ends can obtain a voltage whenoperational amplifier 210 closed loop work, and this voltage is Vdim-Vref2; The upper generation current of input resistance R5, its size is (Vdim-Vref2)/R5; This electric current first MOS transistor M3 that flows through, and be injected into the input of peakcurrent comparator 209, because the input impedance ofpeak current comparator 209 is very high, all flow through feedforward resistance R 6 produce a DC offset voltage on R6 of this electric current.

The drain D electricity of described the second MOS transistor M2 is connected to the source S of a power switch MOS transistor M1, and the source S of M2 connects a sampling resistor R7.

Described peakcurrent comparator 209 first input ends are connected with sampling resistor R7 electricity by described feedforward resistance R 6, and its second input is connected with the output electricity of described reference voltage source ref1, and its output is coupled to the grid G of the second MOS transistor M2.Described peakcurrent comparator 209, for by the voltage threshold comparison of the voltage magnitude sum of described feedforward resistance R 6 and sampling resistor R7 and described reference voltage source ref1, is controlled the conducting of described the second MOS transistor M2 and closes; If the voltage magnitude sum of R6 and R7 reaches the voltage threshold of reference voltage source ref1, peakcurrent comparator 209 output upsets, close the second MOS transistor M2.

As preferred embodiment, described controllable silicon light modulation LED drive circuit further comprise one maximumservice time timer 207, one orgate 208 and a rest-set flip-flop 205.

Described maximum service time timer one end of 207 respectively electricity is connected to the grid G of output Q and the second MOS transistor M2 of described rest-set flip-flop 205, described maximumservice time timer 207 other end electricity be connected to an input of described orgate 208; Another input electricity described orgate 208 is connected to the output of described peakcurrent comparator 209, and output electricity described orgate 208 is connected to the reset terminal R of described rest-set flip-flop 205.In the time that the electric current of described the second MOS transistor M2 makes the output upset of described peakcurrent comparator 209, or described maximumservice time timer 207 detects when the service time of described the second MOS transistor M2 reaches Preset Time, described orgate 208 output signals reset described rest-set flip-flop 205, thereby close described the second MOS transistor M2.Also,, in a power frequency period, in the time that Vbus voltage is higher, peakcurrent comparator 209 determines the shutoff moment of the second MOS transistor M2; In the time that Vbus voltage is lower, maximumservice time timer 207 determines the shutoff moment of the second MOS transistor M2.

As preferred embodiment, described controllable silicon light modulation LED drive circuit further comprises ademagnetization detector 204; The input of describeddemagnetization detector 204 is connected with the source S electricity of described power switch MOS transistor M1, and its output electricity connects the set end S of described rest-set flip-flop 205.Describeddemagnetization detector 204 changes for detection of the source voltage of described power switch MOS transistor M1, and output signal makes described rest-set flip-flop 205 set, thereby opens described the second MOS transistor M2.

As optional execution mode, described controllable silicon light modulation LED drive circuit further comprises aswitch drive module 206, it is serially connected between the output Q and the second MOS transistor M2 grid of rest-set flip-flop 205, and with maximumservice time timer 207 electricity is connected (in the time that circuit does not arrange maximumservice time timer 207,switch drive module 206 is connected with the output electricity of peakcurrent comparator 209).Switch drive module 206, according to the output signal of rest-set flip-flop 205, closes or conducting the second MOS transistor M2.

With reference to figure 3, the schematic diagram of voltage-dropping type controllable silicon light modulation LED drive system of the present invention.Described controllable silicon light modulation LED drive system comprises acontrollable silicon dimmer 202, arectifier bridge 203, a bus capacitor C1, a sampling resistor R7 and controllable silicon light modulation LED drive circuit of the present invention (circuit as shown in Figure 2, same components symbol represents same or similar assembly).

Describedcontrollable silicon dimmer 202 withexchange input source 201 electricity and be connected, by adjusting the brightness of himself angle of flow control LED load; Describedrectifier bridge 203 is respectively with describedcontrollable silicon dimmer 202 andexchange input source 201 electricity and is connected, for being that an amplitude is positive voltage signal Vbus by the sinusoidal signal rectification ofinterchange input source 201; Described bus capacitor C1 is coupled to two outputs of describedrectifier bridge 203 and is connected with the drain D electricity of a power switch MOS transistor M1, is used to described power switch MOS transistor M1 that high-frequency current path is provided; The input of described high-high brightness hoistingmodule 21 is connected with the drain D electricity of described bus capacitor C1 and described power switch MOS transistor M1 respectively; The drain D of described the second MOS transistor M2 is connected with the source S electricity of described power switch MOS transistor M1, and the source S of described the second MOS transistor M2 is connected with described sampling resistor R7 electricity; Described peakcurrent comparator 209 first input ends are connected with described sampling resistor R7 electricity by described feedforward resistance R 6; Described sampling resistor R7 is connected to LED load byinductance L 1 electricity.

The grid G of power switch MOS transistor M1 is further coupled between the supplying resistance R1 and powersupply capacitor C 2 of series connection, simultaneously by a voltage stabilizing didoe ZD1 ground connection.The further electricity in one end that sampling resistor R7 andinductance L 1 are joined is connected to the negative electrode of a sustaineddiode 1, the negative terminal of the anodic bonding bus capacitor C1 of sustained diode 1.LED load two ends also meet an output capacitance C4.In other embodiments, described sampling resistor R7 also can be connected to LED load by a transformer electricity.

As preferred embodiment, described controllable silicon light modulation LED drive circuit further comprise one maximumservice time timer 207, one orgate 208 and a rest-set flip-flop 205; Described maximum service time timer one end of 207 respectively electricity is connected to the grid G of output Q and the second MOS transistor M2 of described rest-set flip-flop 205, described maximumservice time timer 207 other end electricity be connected to an input of described orgate 208; Another input electricity described orgate 208 is connected to the output of described peakcurrent comparator 209, and output electricity described orgate 208 is connected to the reset terminal R of described rest-set flip-flop 205.In the time that the electric current of described the second MOS transistor M2 makes the output upset of described peakcurrent comparator 209, or described maximumservice time timer 207 detects when the service time of described the second MOS transistor M2 reaches Preset Time, described orgate 208 output signals reset described rest-set flip-flop 205, thereby close described the second MOS transistor M2.

As preferred embodiment, described controllable silicon light modulation LED drive circuit further comprises ademagnetization detector 204; The input of describeddemagnetization detector 204 is connected with the source S electricity of described power switch MOS transistor M1, the set end S of rest-set flip-flop 205 described in its output termination.Describeddemagnetization detector 204 changes for detection of the source voltage of described power switch MOS transistor M1, and output signal makes described rest-set flip-flop 205 set, thereby opens described the second MOS transistor M2.

As optional execution mode, described controllable silicon light modulation LED drive circuit further comprises aswitch drive module 206, it is serially connected between the output Q and the second MOS transistor M2 grid of rest-set flip-flop 205, and with maximumservice time timer 207 electricity is connected (in the time that circuit does not arrange maximumservice time timer 207,switch drive module 206 is connected with the output electricity of peakcurrent comparator 209).Switch drive module 206, according to the output signal of rest-set flip-flop 205, closes or conducting the second MOS transistor M2.

LED drive circuit of the present invention uses source class type of drive.Electric current on sampling resistor R7 has reflected the electric current on the second MOS transistor M2.Voltage on sampling resistor R7 is CS signal, and CS signal is connected to the first input end of peakcurrent comparator 209 by feedforward resistance R 6 electricity.In the time that the second MOS transistor M2 opens, also conducting of power switch MOS transistor M1;Inductance L 1 Current rise, the voltage on sampling resistor R7 also rises; In the time that the voltage on sampling resistor R7 reaches reference voltage ref1 threshold values with feedforward resistance R 6 voltage sums, the output upset ofpeak current comparator 209, orgate 208 output signals reset rest-set flip-flop 205,switch drive module 206 output signals are closed the second MOS transistor M2.M2 closes power switch MOS transistor M1 simultaneously and also closes, andsustained diode 1 starts conducting simultaneously, andinductance L 1 electric current starts to decline; In the time that the electric current ofinductance L 1 drops to zero, the drain voltage of power switch MOS transistor M1 also starts to decline; Due to the capacitive coupling effect of M1 drain electrode and source electrode, the source voltage of M1 also starts to decline simultaneously; Thedetector 204 that now demagnetizes detects that the source voltage of M1 changes and output signal makes rest-set flip-flop 205 set, and drivingswitch driver module 206 makes the second MOS transistor M2 again open-minded.Maximumservice time timer 207 detects the service time of the second MOS transistor M2; In the time that the service time of M2 is greater than systemic presupposition threshold values, output signal to orgate 208, rest-set flip-flop 205 is resetted, drivingswitch driver module 206 is closed the second MOS transistor M2.Also in a power frequency period, in the time that Vbus voltage is higher, peakcurrent comparator 209 determines the shutoff moment of the second MOS transistor M2; In the time that Vbus voltage is lower, maximumservice time timer 207 determines the shutoff moment of the second MOS transistor M2.

Below in conjunction with accompanying drawing 3-5, the operation principle of voltage-dropping type controllable silicon light modulation LED drive system of the present invention is described.

With reference to figure 4, the work typical waveform figure of voltage-dropping type controllable silicon light modulation LED drive system of the present invention, wherein solid line is the circuit working waveform while not connecingcontrollable silicon dimmer 202, dotted line is the circuit working waveform while connecingcontrollable silicon dimmer 202.

In conjunction with Fig. 3, Fig. 4, in the time not connecingcontrollable silicon dimmer 202, the mean value of Vbus voltage is higher, and in process, divider resistance R2 and lower divider resistance R3 voltage signal mean value after treatment are also higher; This voltage signal obtains a d. c. voltage signal Vdim after resistance R 4 and filter capacitor C3 after filtering, and same, in the time not connecingcontrollable silicon dimmer 202, this d. c. voltage signal Vdim is also higher.Operational amplifier 210 is controlled the conduction impedance of the first MOS transistor M3, guarantee that two input terminal voltages equate, thereby input resistance R5 two ends can obtain a voltage whenoperational amplifier 210 closed loop work, and this voltage is Vdim-Vref2.The upper generation current of input resistance R5, its size is (Vdim-Vref2)/R5; This electric current first MOS transistor M3 that flows through, and be injected into the input of peak current comparator 209.Because the input impedance ofpeak current comparator 209 is very high, this electric current is all flowed through and is feedovered resistance R 6 and on R6, produce a DC offset voltage, and this DC offset voltage is added on CS voltage, makes the peak value V of CS voltage_{cS_TH}reduce, the peak current ofinductance L 1 reduces, thereby output current is reduced.

In the time connecingcontrollable silicon dimmer 202, if the maximum conduction angle degree ofcontrollable silicon dimmer 202 is lower, the mean value of Vbus voltage is also lower, as shown in Fig. 3 dotted line.The d. c. voltage signal Vdim that this voltage signal obtains after upper divider resistance R2, lower divider resistance R3, filter resistance R4 and filter capacitor C3 process is also lower; Thereby the voltage Vdim-Vref2 at input resistance R5 two ends is also lower; Electric current on input resistance R5 is flowed through the first MOS transistor M3 to the resistance R 6 that feedovers, and the DC offset voltage producing on R6 is also lower, makes the peak value V of CS voltage_{cS_TH}higher, the peak current of inductance is improved.Thereby the maximum output current ratio that the maximum output current while making circuit connect controllable silicon dimmer accounts for while not connecing controllable silicon dimmer improves.

In the time that the angle of flow ofcontrollable silicon dimmer 202 continues to reduce, Vdim voltage signal can continue to decline, until be less than Vref2 voltage, now,operational amplifier 210 cannot continue closed loop work, and the first MOS transistor M3 closes, on input resistance R5, do not have electric current to flow through, in feedforward resistance R 6, also do not have electric current to flow through, now feed forward circuit is oninductance L 1 peak current without impact, and the angle of flow of following controllable silicon dimmer of output current linearity changes.

In conjunction with Fig. 3, Fig. 5, wherein Fig. 5 is the Vdim voltage of controllable silicon light modulation LED drive system of the present invention and the graph of a relation of Vcs crest voltage.When Vdim voltage is during higher than Vref2 voltage, the crest voltage V of Vcs_{cS_TH}decline, the peak current ofinductance L 1 also declines; In the time that Vdim voltage is less than Vref2 voltage, the crest voltage V of Vcs_{cS_TH}remain unchanged, the peak current ofinductance L 1 also remains unchanged.

While using controllable silicon dimmer 202 light modulation,controllable silicon dimmer 202 provides dim signal by the mode that changes angle of flow.In the time thatcontrollable silicon dimmer 202 is blocked input voltage, Vbus voltage is output voltage V out, andinductance L 1 electric current is also zero.In the time ofcontrollable silicon dimmer 202 conducting, Vbus voltage equals input voltage absolute value, and LED drive circuit is normally worked, for LED load provides energy.By changing the angle of flow ofcontrollable silicon dimmer 202, the power of LED load changes, and realizes the object of light modulation.By high-high brightness hoistingmodule 21, improve maximum current when drive circuit connectscontrollable silicon dimmer 202; Save leadage circuit simultaneously, the electric current that maintains ofcontrollable silicon dimmer 202 is provided with the input current of switch converters itself, improved LED drive circuit efficiency and system reliability.

Controllable silicon light modulation LED drive circuit of the present invention can be applied in buck-boost type controllable silicon light modulation LED driving system structure and in flyback controllable silicon light modulation LED driving system structure equally.With reference to figure 6, Fig. 7, wherein Fig. 6 is the schematic diagram of buck-boost type controllable silicon light modulation LED drive system of the present invention, and Fig. 7 is the schematic diagram of flyback controllable silicon light modulation LED drive system of the present invention.Wherein, the drive system of voltage-dropping type controllable silicon light modulation LED shown in the drive principle of controllable silicon light modulation LED drive system and control logic and Fig. 3 is similar, does not repeat them here.

The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (10)

1. a high-high brightness hoisting module, is characterized in that, comprising: an operational amplifier, one first MOS transistor and a reference voltage source;

The first input end of described operational amplifier is the input of described high-high brightness hoisting module, in order to receive a sampled voltage signal, its second input is connected with the output electricity of described reference voltage source, its output electricity is connected to the grid of described the first MOS transistor, the conduction impedance of the first MOS transistor described in described operational amplifier control, guarantees when described operational amplifier closed loop work that two input terminal voltages equate;

The source electrode electricity of described the first MOS transistor is connected to the first input end of described operational amplifier, the output that its drain electrode is described high-high brightness hoisting module, and output one current signal is in order to control the output current of a LED drive circuit.

2. high-high brightness hoisting module according to claim 1, is characterized in that, described module further comprises: a voltage division processing unit and a filter unit;

Described voltage division processing unit receives outside amplitude to be positive voltage signal and to process;

Described filter unit respectively electricity is connected to the first input end of described voltage division processing unit and described operational amplifier, described filter unit is for carrying out filtering to the voltage signal after described voltage division processing cell processing, obtains sampled voltage signal and export to the first input end of described operational amplifier.

3. high-high brightness hoisting module according to claim 2, is characterized in that, described voltage division processing unit comprises on one divider resistance and divider resistance once, and described filter unit comprises a filter resistance and a filter capacitor;

It is positive voltage signal that described upper divider resistance one end receives outside amplitude, and the other end is connected with described lower divider resistance electricity, described lower divider resistance other end ground connection;

Described filter resistance one end is coupled between described upper divider resistance and lower divider resistance, and the other end respectively electricity is connected to one end of described filter capacitor and the first input end of described operational amplifier, described filter capacitor other end ground connection.

4. high-high brightness hoisting module according to claim 3, is characterized in that, described module further comprises: an input resistance; Described input resistance is serially connected between described filter resistance and the first input end of described operational amplifier, and is connected with the source electrode electricity of described the first MOS transistor, for obtaining dividing potential drop and exporting described the first MOS transistor to.

5. a controllable silicon light modulation LED drive circuit, is characterized in that, comprising: the high-high brightness hoisting module described in one second MOS transistor, a peak current comparator, feedforward resistance, a reference voltage source and claim 1 to 4 any one; The drain electrode electricity of described the second MOS transistor is connected to the source electrode of a power switch MOS transistor, and the source electrode electricity of described the second MOS transistor connects a sampling resistor; The output of described high-high brightness hoisting module is connected to described peak current comparator first input end and described feedforward resistance by the drain electrode electricity of described the first MOS transistor, and the current signal of described the first MOS transistor output feedforward resistance of flowing through produces direct current (DC) bias; Described peak current comparator first input end is connected with sampling resistor electricity by described feedforward resistance, its second input is connected with the output electricity of described reference voltage source, its output is coupled to the grid of described the second MOS transistor, described peak current comparator, for by the voltage threshold comparison of the voltage magnitude sum of described feedforward resistance and sampling resistor and described reference voltage source, is controlled the conducting of described the second MOS transistor and closes.

6. controllable silicon light modulation LED drive circuit according to claim 5, is characterized in that, described circuit further comprise one maximum service time timer, one or gate and a rest-set flip-flop; One end of described maximum service time timer respectively electricity is connected to the output of described rest-set flip-flop and the grid of the second MOS transistor, and the other end electricity of described maximum service time timer is connected to an input of described or gate; Another input electricity described or gate connects the output of described peak current comparator, and output electricity described or gate is connected to the reset terminal of described rest-set flip-flop; When making the output of described peak current comparator, the electric current of described the second MOS transistor overturns, or described maximum service time timer detects when the service time of described the second MOS transistor reaches Preset Time, described or gate output signal resets described rest-set flip-flop, thereby closes described the second MOS transistor.

7. controllable silicon light modulation LED drive circuit according to claim 6, is characterized in that, described circuit further comprises a demagnetization detector; The input of described demagnetization detector is connected with the source electrode electricity of described power switch MOS transistor, its output electricity is connected to the set end of described rest-set flip-flop, described demagnetization detector changes for detection of the source voltage of described power switch MOS transistor, and output signal makes described rest-set flip-flop set, thereby open described the second MOS transistor.

8. a controllable silicon light modulation LED drive system, comprises a controllable silicon dimmer, a rectifier bridge, a bus capacitor and a sampling resistor, it is characterized in that, further comprises controllable silicon light modulation LED drive circuit claimed in claim 5; Described controllable silicon dimmer and one exchanges input source electricity and is connected, by adjusting the brightness of himself angle of flow control LED load; Described rectifier bridge is respectively with described controllable silicon dimmer and exchange input source electricity and is connected, for being that an amplitude is positive voltage signal by the sinusoidal signal rectification of interchange input source; Described bus capacitor is coupled to two outputs of described rectifier bridge and is connected with the drain electrode electricity of a power switch MOS transistor, is used to described power switch MOS transistor that high-frequency current path is provided; The input of described high-high brightness hoisting module is connected with the drain electrode electricity of described bus capacitor and described power switch MOS transistor respectively; The drain electrode of described the second MOS transistor is connected with the source electrode electricity of described power switch MOS transistor, and the source electrode of described the second MOS transistor is connected with described sampling resistor electricity; Described peak current comparator first input end is connected with described sampling resistor electricity by described feedforward resistance; Described sampling resistor is connected to LED load by a transformer or inductance electricity.

9. controllable silicon light modulation LED drive system according to claim 8, is characterized in that, described controllable silicon light modulation LED drive circuit further comprise one maximum service time timer, one or gate and a rest-set flip-flop; One end of described maximum service time timer respectively electricity is connected to the output of described rest-set flip-flop and the grid of the second MOS transistor, and the other end electricity of described maximum service time timer is connected to an input of described or gate; Another input electricity described or gate is connected to the output of described peak current comparator, and output electricity described or gate is connected to the reset terminal of described rest-set flip-flop; When making the output of described peak current comparator, the electric current of described the second MOS transistor overturns, or described maximum service time timer detects when the service time of described the second MOS transistor reaches Preset Time, described or gate output signal resets described rest-set flip-flop, thereby closes described the second MOS transistor.

10. controllable silicon light modulation LED drive system according to claim 8, is characterized in that, described controllable silicon light modulation LED drive circuit further comprises a demagnetization detector; The input of described demagnetization detector is connected with the source electrode electricity of described power switch MOS transistor, its output electricity is connected to the set end of described rest-set flip-flop, described demagnetization detector changes for detection of the source voltage of described power switch MOS transistor, and output signal makes described rest-set flip-flop set, thereby open described the second MOS transistor.

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