CN103138556A - Power factor correction (PFC) circuit, load driving circuit and signal control method - Google Patents
Power factor correction (PFC) circuit, load driving circuit and signal control method Download PDFInfo
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- CN103138556A CN103138556A CN2011103765938A CN201110376593A CN103138556A CN 103138556 A CN103138556 A CN 103138556A CN 2011103765938 A CN2011103765938 A CN 2011103765938A CN 201110376593 A CN201110376593 A CN 201110376593A CN 103138556 A CN103138556 A CN 103138556A
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
- H05B45/3725—Switched mode power supply [SMPS]
- H05B45/385—Switched mode power supply [SMPS] using flyback topology
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
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Abstract
The invention discloses a power factor correction (PFC) circuit, a load driving circuit and a signal control method. An input end of the PFC circuit receives chopped wave voltage. The PFC circuit comprises a main switch tube and a Ton control unit. Control signals of the Ton control unit is in positive correlation with chopped wave angles of the chopped wave voltage within a range smaller than or equal to a maximum. The PFC circuit further comprises a detection compensation unit, and the detection compensation unit is used for detecting the chopped wave angles of the chopped wave voltage, generating compensating signals with amplitude in positive correlation with the chopped wave angles and controlling comparison signals of the Ton control unit according to the compensating signals so as to enable control signals corresponding to the equal chopped wave angles within a range of the control signals smaller than or equal to the maximum. The PFC circuit, the load driving circuit and the signal control method can shorten invalid adjusting process in a light-dimming process.
Description
Technical field
The present invention relates to circuit field, relate in particular to a kind of pfc circuit, load driving circuits and signal control method.
Background technology
At lighting field, brightness or color that a lot of occasions need to be regulated light source, this just requires illuminator to have regulatory function.Comparatively commonly used is the copped wave light regulating technology at present, as shown in Figure 1, dotted portion is a kind of implementation structure of existing copped wave dimmer, line voltage Vac is after the effect of copped wave dimmer, voltage on light source load RL is chopping voltage as shown in Figure 2, and in the copped wave dimmer, phase angle [alpha] corresponding to transistor T RIAC triggering and conducting time is the copped wave angle of chopping voltage.In the copped wave dimmer, resistance R 11 is a variable resistor, and the resistance of adjusting variable resistor R11 can change the size of copped wave angle α, and concrete: variable resistor R11 resistance is less, and the triggering and conducting time of transistor T RIAC is shorter, and angle α is less in copped wave; Variable resistor R11 resistance is larger, and the triggering and conducting time of transistor T RIAC is longer, and angle α is larger in copped wave.When variable resistor R11 was adjusted to maximum value, corresponding copped wave angle α was called maximum copped wave angle, and when variable resistor R11 was adjusted to minimum resistance, corresponding copped wave angle α was called minimum copped wave angle.
But working as light source load is the non-resistance light source, and during the demand motive drives, its light modulation principle is different from above-mentioned principle.Tunable optical drive circuit when being illustrated in figure 3 as light source load and being LED, load driving circuits comprises: the first rectifier and pfc circuit, line voltage Vac is after copped wave dimmer, the first rectifier, obtain chopping voltage as the input voltage vin of pfc circuit, the input current of pfc circuit is Iin, and the output current Io of pfc circuit is used for driving load.Pfc circuit also comprises: current control unit, ton control unit and driving control unit; Wherein,
Current control unit is sampled to the output current Io of pfc circuit, and sampled signal and reference signal are compared, output control signal Vr after closed-loop adjustment, the variation of this control signal Vr and the variation inverse correlation of output current Io, namely when output current Io reduced, this control signal Vr increased, otherwise, when output current Io increased, this control signal Vr reduced.And this control signal Vr has maximum Vrmax, and namely when Vr equaled Vrmax, when output current Io continued to reduce, Vr no longer increased.
The ton control unit with control signal Vr and a comparison signal Vp relatively determines the ON time ton of main switch S1, driving control unit according to this ON time output drive signal Vd so that main switch S1 is controlled.Concrete, as shown in Figure 4, comparison signal Vp is triangular wave or sawtooth waveforms, initial time take moment that comparison signal Vp begins to increase as main switch S1 ON time Ton, the moment that equals the amplitude of control signal Vr take the peak value of comparison signal Vp is cut-off time of main switch S1 ON time Ton, namely when Vr equaled Vrmax, the ON time Ton of main switch S1 was maximum of T on-max.
when the copped wave angle α of the chopping voltage of copped wave dimmer output was zero, current control unit was operated in the closed loop state, the output current Io substantially constant of pfc circuit, when copped wave angle α increases from zero, chopping voltage mean value reduces, the output current Io of pfc circuit is reduced, the sampled signal of the output current Io that current control unit receives reduces, the control signal Vr of its output increases, make the ON time Ton of main switch S1 elongated by the Ton control unit, keep the output current Io substantially constant of pfc circuit, angle α increases to α x when copped wave, when the control signal Vr that current control unit is exported is increased to Vrmax, current control unit is in the critical condition of closed loop open loop, that is: when copped wave angle α continues to increase from currency α x, chopping voltage mean value continues to reduce, the output current Io of pfc circuit reduces, because Vr equals Vrmax, Vr no longer increases, the ON time Ton of main switch S1 equals maximum of T on-max, also no longer increase, current control unit is in open loop situations, it is the reduction of the output current Io of pfc circuit, the control signal Vr of current control unit output is changed, therefore, can not regulate by the ON time that changes main switch S1 the output current Io of pfc circuit.Can find out, because the state of current control unit corresponding to Vrmax is closed loop open loop critical condition, so Vr is more large more near critical condition.
When current control unit is in open loop situations, the ON time Ton of main switch S1 is constant and equal maximum of T on-max, namely when copped wave angle α continues to increase from critical value α x, the mean value of the input voltage vin of pfc circuit reduces thereupon, therefore, the output current Io of pfc circuit reduces thereupon, thereby realize: in the scope greater than critical value α x, when copped wave angle α increases, the output current Io of pfc circuit reduces, when copped wave angle α reduced, the output current Io of pfc circuit increased, thereby realizes light modulation.
Therefore, in the α change procedure of copped wave angle, only when current control unit was in open loop situations, the copped wave dimmer could be realized dimming function.And the copped wave dimmer with the copped wave angle α of chopping voltage from zero process that is adjusted to critical value α x, pfc circuit output current Io remains unchanged, and is skimble-skamble for light modulation, for the user, the adjustment process in this stage is invalid adjustment process.
Therefore, the invalid adjustment process that how to shorten in the light modulation process is the problem that needs solution.
Summary of the invention
In view of this, the technical problem to be solved in the present invention is, a kind of pfc circuit, load driving circuits and signal control method are provided, and can shorten the invalid adjustment process in the light modulation process.
For this reason, the embodiment of the present invention adopts following technical scheme:
The embodiment of the present invention provides a kind of pfc circuit, and the input of described pfc circuit receives chopping voltage, and described pfc circuit comprises: main switch and Ton control unit; The control signal of described Ton control unit is within being less than or equal to maximum range, with the copped wave angle positive correlation of described chopping voltage;
Described pfc circuit also comprises:
Detect compensating unit, for detection of the copped wave angle of chopping voltage, generate amplitude and the positively related compensating signal in copped wave angle; According to described compensating signal, the comparison signal of Ton control unit is controlled, made in described control signal to be less than or equal in maximum range, equate that control signal corresponding to copped wave angle raises.
Wherein, detecting compensating unit comprises:
Detection sub-unit is for detection of the copped wave angle of chopping voltage;
Generate subelement, be used for generating amplitude and the positively related compensating signal in copped wave angle;
Control subelement, be used for according to described compensating signal, the comparison signal of Ton control unit being controlled.
Controlling subelement specifically is used for: with the be added to comparison signal of Ton control unit of described compensating signal.
Described compensating signal is current signal; Described comparison signal is sawtooth signal;
The Ton control unit comprises: constant-current source is respectively by the first electric capacity and second switch pipe ground connection, and the first unearthed first end of electric capacity connects the inverting input of the first operational amplifier; The normal phase input end of the first operational amplifier is used for reception control signal;
The control subelement comprises: two outputs that generate subelement connect respectively the two ends of the first electric capacity.
Described compensating signal is voltage signal; Described comparison signal is sawtooth signal, and compensating signal is level signal;
The Ton control unit comprises: the normal phase input end of the first operational amplifier is used for reception control signal;
The control subelement comprises:
First input end is used for receiving comparison signal, and first input end also connects the inverting input of the first operational amplifier by the first resistance; The compensating signal output that generates subelement connects the inverting input of the first operational amplifier by the second resistance.
Described detection sub-unit comprises:
First input end passes through the 3rd resistance and the 4th grounding through resistance, the second input end grounding successively; The tie point of the 3rd resistance and the 4th resistance connects the base stage of the first triode, the emitter grounding of the first triode, and collector electrode connects the first output of detection sub-unit, the second output head grounding of detection sub-unit;
The generation subelement comprises:
The first input end that generates subelement connects the first output of detection sub-unit, and the second input that generates subelement connects the second output of detection sub-unit;
The first input end that generates subelement connects supply voltage by the 5th resistance, also by the second capacity earth; Generate the first input end of subelement successively by the first diode and the 3rd capacity earth; The negative electrode of the first diode connects the base stage of the second triode, and the emitter-base bandgap grading of the second triode is by the 6th grounding through resistance, and the collector electrode of the second triode connects supply voltage; The emitter-base bandgap grading of the second triode connects with the 7th resistance the compensating signal output that generates subelement by the second diode successively.
Described detection sub-unit comprises: first input end passes through the 3rd resistance and the 4th grounding through resistance, the second input end grounding successively; The tie point of the 3rd resistance and the 4th resistance connects the base stage of the first triode, the emitter grounding of the first triode, and collector electrode connects the first output of detection sub-unit, the second output head grounding of detection sub-unit;
The generation subelement comprises:
The first input end that generates subelement connects the first output of detection sub-unit, and the second input that generates subelement connects the second output of detection sub-unit;
The first input end that generates subelement connects supply voltage by the 5th resistance, also by the second capacity earth; Generate the first input end of subelement successively by the first diode and the 3rd capacity earth; The negative electrode of the first diode connects the base stage of the second triode, and the emitter-base bandgap grading of the second triode is by the 6th grounding through resistance, and the collector electrode of the second triode connects supply voltage; The emitter-base bandgap grading of the second triode is as the compensating signal output that generates subelement.
The embodiment of the present invention also provides a kind of signal control method, and the method is applied to pfc circuit, and the input of described pfc circuit receives chopping voltage; Described pfc circuit comprises: main switch and Ton control unit; The control signal of described Ton control unit is within being less than or equal to maximum range, with the copped wave angle positive correlation of described chopping voltage;
The method comprises:
Detect the copped wave angle of chopping voltage;
Generate amplitude and the positively related compensating signal in copped wave angle;
According to described compensating signal, the comparison signal of Ton control unit is controlled, made in described control signal to be less than or equal in maximum range, equate that control signal corresponding to copped wave angle raises.
According to described compensating signal, the comparison signal of Ton control unit is controlled and is comprised:
Described compensating signal is added on the comparison signal of Ton control unit.
The embodiment of the present invention also provides a kind of load driving circuits, comprises above-mentioned pfc circuit.
Technique effect for technique scheme is analyzed as follows:
Increase in pfc circuit and detect compensating unit, this detects the copped wave angle that compensating unit detects chopping voltage, generates amplitude and the positively related compensating signal in copped wave angle; According to described compensating signal, the comparison signal of Ton control unit is controlled; Thereby the comparison signal in the Ton control unit is become new comparison signal, make the ON time Ton of main switch temporarily diminish, and then the output current that current control unit is kept ON time Ton and pfc circuit by closed-loop adjustment is constant, make control signal corresponding to identical copped wave angle raise, realize the value of rising control signal under the closed loop state of current control unit, also namely shortened the invalid adjustment process in the light modulation process.
Description of drawings
Fig. 1 is a kind of implementation structure schematic diagram of prior art copped wave dimmer;
Fig. 2 is a kind of chopping voltage schematic diagram of prior art;
Fig. 3 is prior art light source load driving circuit structure schematic diagram;
Fig. 4 is prior art signal relation schematic diagram;
Fig. 5 is the electrical block diagram of embodiment of the present invention pfc circuit;
Fig. 6 is the implementation structure schematic diagram that the embodiment of the present invention detects compensating unit;
Fig. 7 is the specific embodiment schematic diagram of the first pfc circuit of the present invention;
Fig. 8 is embodiment of the present invention signal relation schematic diagram;
Fig. 9 is the specific embodiment schematic diagram of the second pfc circuit of the present invention;
Figure 10 is embodiment of the present invention signal relation schematic diagram;
Figure 11 is embodiment of the present invention detection sub-unit and the circuit implementation structure schematic diagram that generates subelement;
Figure 12 is embodiment of the present invention signal control method schematic flow sheet.
Embodiment
In the α change procedure of copped wave angle, only when current control unit was in open loop situations, the copped wave dimmer could be realized dimming function.And the copped wave dimmer with the copped wave angle α of chopping voltage from zero process that is adjusted to critical value α x, pfc circuit output current Io remains unchanged, and is skimble-skamble for light modulation, for the user, the adjustment process in this stage is invalid adjustment process.
The inventor finds through large quantity research, reduces critical value α x, and the time that current control unit is in the closed loop state namely can be shortened in the maximum copped wave angle that namely reduces the closed loop state, and then shortens invalid adjustment process.and reduce critical value α x, namely reduce the maximum copped wave angle of closed loop state, need to be under the copped wave corner condition that equates, the value of rising control signal Vr (because Vr is more high more near critical condition), but, because current control unit is operated in the closed loop state, therefore, the value of direct rising control signal Vr, the ON time Ton of main switch S1 is also temporarily raise, the output current Io of pfc circuit raises, the output current sampled value of current control unit raises, the control signal Vr of its output is reduced, therefore, directly rising control signal Vr can not make under less copped wave angle α x and enter critical condition.
Therefore, the embodiment of the present invention provides a kind of pfc circuit, load driving circuits and signal control method, can make in closed loop procedure, be also that described control signal is less than or equal in maximum range, equate that control signal corresponding to copped wave angle raises, thereby reduce critical value α x, realize shortening the goal of the invention of the invalid adjustment process in the light modulation process.
Below, be described with reference to the accompanying drawings the realization of embodiment of the present invention pfc circuit, load driving circuits and current control method.
Referring to Fig. 5, be a kind of pfc circuit structural representation of the embodiment of the present invention, wherein:
The input of described pfc circuit receives chopping voltage, is also described input voltage vin; Described pfc circuit comprises: main switch S1 (not shown in Fig. 5) and Ton control unit 510; The control signal Vr of described Ton control unit 510 outputs is within being less than or equal to maximum range, with the copped wave angle positive correlation of described chopping voltage; (wherein, described positive correlation refers to: angle α is larger in copped wave, and described control signal Vr is also larger, and angle α is less in copped wave, and described control signal Vr is also less.)
Described pfc circuit also comprises:
Detect compensating unit 520, for detection of the copped wave angle of chopping voltage, generate amplitude and the positively related compensating signal in copped wave angle; According to described compensating signal, the comparison signal of Ton control unit is controlled, made in described control signal to be less than or equal in maximum range, equate that control signal corresponding to copped wave angle raises.Also namely, make constant at the copped wave angle under, the control signal of current control circuit output raises.
And then, by detecting 520 pairs of relatively controls of signal of compensating unit, will obtain new comparison signal, and the Ton control unit will compare to new comparison signal and control signal according to new comparison signal, determines the ON time Ton of main switch S1.
Here, described positive correlation refers to: the copped wave angle is larger, and the amplitude of compensating signal is larger, and the copped wave angle is less, and the amplitude of compensating signal is less.
Preferably, as shown in Figure 5, pfc circuit and the first rectifier can consist of load driving circuits, and this first rectifier is used for the chopping voltage of copped wave dimmer output is carried out rectification, thereby obtains the input voltage vin of pfc circuit.
Wherein, as shown in Figure 5, two inputs that detect compensating unit 520 can connect two outputs of the first rectifier, and the chopping voltage that the first rectifier is exported carries out the detection at copped wave angle;
Perhaps, also the second rectifier can be set in addition, the second rectifier carries out rectification to the chopping voltage of copped wave dimmer output; And two inputs that detect compensating unit 520 connect two outputs of the second rectifier, and the chopping voltage that the second rectifier is exported carries out the detection at copped wave angle.
In the embodiment of the present invention, the chopping voltage of copped wave dimmer output can for forward position chopping voltage, rear along chopping voltage or front and back along chopping voltage etc., not limit here.
As shown in Figure 6, described detection compensating unit 520 can be realized by following structure:
Generate subelement 620, be used for generating amplitude and the positively related compensating signal in copped wave angle;
Preferably, controlling subelement 630 specifically can be used for: with the be added to comparison signal of Ton control unit of described compensating signal.
Take load driving circuits shown in Figure 3 as example, pfc circuit and the load driving circuits of the embodiment of the present invention more specifically illustrated.
In a kind of specific embodiment, described compensating signal can be current signal; Comparison signal can be sawtooth signal; At this moment, as shown in Figure 7:
The Ton control unit comprises: the output of constant-current source Id is respectively by the first capacitor C 1 and second switch pipe S2 ground connection, the first unearthed end of capacitor C 1 is signal output part as a comparison, output comparison signal Vp, the unearthed end of the first capacitor C 1 connects the inverting input of the first operational amplifier A 1; The normal phase input end of the first operational amplifier A 1 is used for reception control signal Vr, also namely connects the output of current control unit;
Wherein, when not comprising the control subelement, the operation principle of Ton control unit is: when second switch pipe S2 conducting, voltage on the first capacitor C 1 is zero, be also that comparison signal Vp is zero, when second switch pipe S2 turn-offs, constant-current source Id is the first capacitor C 1 charging, the increase of starting from scratch of voltage on the first capacitor C 1, be also the comparison signal Vp increase of starting from scratch, when comparison signal Vp increases to when equating with control signal Vr, second switch pipe S2 conducting, therefore, the comparison signal Vp of the unearthed end output of the first capacitor C 1 is sawtooth waveforms.
As shown in Figure 7, controlling subelement 630 comprises: two outputs that generate subelement 620 connect respectively the two ends of the first capacitor C 1.thereby, the compensating signal that generates subelement 620 generations is converted to sawtooth signal in the Ton control unit, and with described comparison signal same-phase, concrete: the two ends that are connected in parallel on the first capacitor C 1 by two outputs that will generate subelement 620, make the compensating signal that generates subelement 620 outputs identical with the generation principle of comparison signal Vp at the voltage that the two ends of the first capacitor C 1 produce, namely all controlled by second switch pipe S2, the voltage signal and the comparison signal Vp same-phase that make compensating signal produce on the first capacitor C 1, and the voltage on the first capacitor C 1 is stack both, and the slope of the voltage Vp ' after stack is greater than the slope of comparison signal Vp, with reference to Fig. 8.
Under circuit structure shown in Figure 7, as shown in Figure 8, compensating signal I α (not shown) is converted to a voltage signal on the first capacitor C 1 of Ton control unit be sawtooth signal V α, dotted line is comparison signal Vp, after the sawtooth signal V α that compensating signal I α produces and comparison signal Vp stack, obtain new comparison signal Vp '=Vp+V α, waveform is as shown in solid line in figure, and new comparison signal Vp ' will replace original comparison signal Vp to be input to the inverting input of the first operational amplifier.
new comparison signal Vp ', with current control signal Vr relatively after, obtain ON time Ton ', this ON time Ton ' is less than ON time Ton corresponding to comparison signal Vp, at this moment, because current Ton ' diminishes, therefore, the output current Io of pfc circuit (being also load driving circuits) can diminish, the current control unit sampled signal that sampling obtains to output current Io diminishes, the control signal Vr of current control unit output raises, and then the ON time Ton ' of main switch S1 is increased, the ON time of keeping main switch is constant, the output current Io that keeps pfc circuit (being also load driving circuits) is constant.
Therefore, in the situation that copped wave angle α is constant, when comparison signal becomes new comparison signal Vp ' from Vp, after input Ton control unit, the dynamic adjustments of current control unit finally makes the ON time Ton of main switch S1 constant, the output current Io of pfc circuit is constant, and control signal Vr is raise.Along with the increase of copped wave angle α, control signal Vr also can increase thereupon, and when Vr increases to Vr-max (corresponding copped wave angle be α x), current control unit is about to enter open loop situations.Also namely, make within described control signal Vr is less than or equal to the scope of maximum Vr-max, equate that control signal Vr corresponding to copped wave angle α raises, make constant at the copped wave angle under, more near closed loop open loop critical condition, thereby reduce critical value α x, shortened the invalid adjustment process in the light modulation process.
In another kind of embodiment, described compensating signal V α can be voltage signal; Described comparison signal Vp can be sawtooth signal, and compensating signal V α can be level signal; At this moment, as shown in Figure 9:
The Ton control unit comprises: the normal phase input end of the first operational amplifier A 1 is used for reception control signal;
Controlling subelement 630 comprises:
First input end is used for receiving comparison signal Vp, and first input end also connects the inverting input of the first operational amplifier A 1 by the first resistance R 1; The compensating signal output that generates subelement 620 connects the inverting input of the first operational amplifier A 1 by the second resistance R 2.
Wherein, described comparison signal Vp can generate subelement and obtain by comparison signal as shown in Figure 7, concrete, this comparison signal generates subelement and comprises: the output of constant-current source Id is respectively by the first capacitor C 1 and second switch pipe S2 ground connection, the first unearthed end of capacitor C 1 is the comparison signal output of signal generation subelement as a comparison, output comparison signal Vp.
In Fig. 9, with compensating signal V α and the comparison signal Vp of voltage signal form, by the first resistance R 1 and the stack of the second resistance R 2, the new comparison signal Vp ' after being superposeed is input to the inverting input of the first operational amplifier in the Ton control unit.And the dc offset voltage of new comparison signal Vp ' is higher than the dc offset voltage of original comparison signal Vp, with reference to Figure 10.
In Figure 10, compensating signal V α is level signal, and dotted line is comparison signal Vp, after compensating signal V α and comparison signal Vp stack, obtains new comparison signal Vp '=Vp+V α, and waveform is as shown in solid line in figure, and its dc offset voltage raises.
The first operational amplifier with new comparison signal Vp ' and current control signal Vr relatively, the ON time Ton ' of the main switch that draws is less than ON time Ton corresponding to original comparison signal Vp, at this moment, because the ON time Ton ' of current main switch diminishes, therefore, the output current Io of pfc circuit can diminish, the current control unit sampled signal that sampling obtains to output current Io diminishes, the control signal Vr of its output raises, ON time Ton ' is increased, thereby the output current Io that keeps pfc circuit is constant.
Therefore, in the situation that copped wave angle α is constant, after comparison signal became Vp ' from Vp, the dynamic adjustments of current control unit finally made the ON time Ton of main switch constant, and the output current Io of pfc circuit is constant, and control signal Vr is raise.Along with the increase of copped wave angle α, control signal Vr also can increase thereupon, and when Vr increased to Vr-max, current control unit was about to enter open loop situations.Also namely, make within described control signal Vr is less than or equal to the scope of maximum Vr-max, equate that control signal Vr corresponding to copped wave angle α raises, make constant at the copped wave angle under, more near closed loop open loop critical condition, thereby reduce critical value α x, shortened the invalid adjustment process in the light modulation process.
Wherein, the compensating signal in the embodiment of the present invention can obtain by circuit structure as shown in figure 11, also namely detects the detection sub-unit 610 in compensating unit 520 and generate subelement 620 to obtain by circuit structure as shown in figure 11.With reference to Figure 11:
The first input end of detection sub-unit 610 is successively by the 3rd resistance R 3 and the 4th resistance R 4 ground connection, the second input end grounding of detection sub-unit (here indication " " be the output negative terminal of rectifier bridge in pfc circuit); The tie point of the 3rd resistance R 3 and the 4th resistance R 4 connects the base stage of the first triode Q1, the emitter grounding of the first triode Q1, and collector electrode connects the first output of detection sub-unit, the second output head grounding of detection sub-unit;
The first input end that generates subelement 620 connects the first output of detection sub-unit 610, and the second input that generates subelement 620 connects the second output of detection sub-unit 610;
The first input end that generates subelement 620 connects power source voltage Vcc by the 5th resistance R 5, also by the second capacitor C 2 ground connection; Generate the first input end of subelement 620 successively by the first diode D1 and the 3rd capacitor C 3 ground connection; The negative electrode of the first diode D1 connects the base stage of the second triode Q2, and the emitter-base bandgap grading of the second triode Q2 is by the 6th resistance R 6 ground connection, and the collector electrode of the second triode Q2 connects power source voltage Vcc;
At this moment, generate in subelement the 6th resistance R 6 two ends as two outputs that generate subelement, the compensating signal of output is voltage signal;
Perhaps, as shown in figure 11, the emitter-base bandgap grading of the second triode Q2 can connect an end of series arm, this series arm is the second diode D2 and the 7th resistance R 7, at this moment, the earth terminal of the other end of series arm and the 6th resistance R 6 also can be used as two outputs that generate subelement, and this moment, the compensating signal of output was current signal.
in circuit shown in Figure 11, the 3rd resistance R 3 and the 4th resistance R 4 are divider resistance, to what input, chopping voltage after rectification is sampled, by the first triode Q1, the low level signal in chopping voltage is detected, the output sawtooth voltage, i.e. voltage on the second capacitor C 2, the peak value of this sawtooth voltage is along with the increase at copped wave angle and increase, peak value by the first diode D1 and the 3rd capacitor C 3 keeps, obtain a level signal on the 3rd capacitor C 3, the value of this level signal is along with the increase at copped wave angle and increase, follow circuit by the second triode Q2, voltage signal on the 6th resistance R 6, also along with the increase at copped wave angle and increase.The value of the current signal by the second diode D2 and the output of the 7th resistance R 7 is also along with the increase at copped wave angle increases.
Above-mentioned embodiment of the present invention pfc circuit can be directly as load driving circuits, perhaps, also can with the circuit combination such as the first rectifier, jointly consist of load driving circuits.
Corresponding with above-mentioned pfc circuit and load driving circuits, the embodiment of the present invention provides a kind of signal control method, and the method can be applied in pfc circuit, and the input of described pfc circuit receives chopping voltage; Described pfc circuit comprises: main switch and ton control unit; The control signal of described Ton control unit is within being less than or equal to maximum range, with the copped wave angle positive correlation of described chopping voltage; (wherein, described positive correlation refers to: the copped wave angle is larger, and described control signal Vr is also larger, and the copped wave angle is less, and described control signal Vr is also less.)
As shown in figure 12, the method comprises:
Step 1201: the copped wave angle of detecting chopping voltage;
Step 1202: generate amplitude and the positively related compensating signal in copped wave angle;
Step 1203: according to described compensating signal, the comparison signal of Ton control unit is controlled, made in described control signal to be less than or equal in maximum range, equate that control signal corresponding to copped wave angle raises.
Preferably, describedly according to described compensating signal, the comparison signal of Ton control unit is controlled and can be comprised: described compensating signal is added on the comparison signal of Ton control unit.
And then, in step 1203, will obtain new comparison signal by described control; Afterwards, the Ton control unit will compare new comparison signal and control signal according to new comparison signal, determines the ON time Ton of main switch S1.
Based on above embodiment, detect the copped wave angle of chopping voltage, generate amplitude and the positively related compensating signal in copped wave angle; According to described compensating signal, the comparison signal of Ton control unit is controlled.thereby the comparison signal in the Ton control unit is become new comparison signal, the Ton control unit uses new comparison signal and control signal relatively, determine the ON time Ton of main switch, because the rising of comparison signal makes the ON time Ton of main switch temporarily diminish, and then the output current that current control unit is kept ON time Ton and pfc circuit by closed-loop adjustment is constant, make control signal corresponding to identical copped wave angle raise, realized the value of rising control signal under the closed loop state of current control unit, thereby reduce critical value α x, realize shortening the goal of the invention of the invalid adjustment process in the light modulation process.。
One of ordinary skill in the art will appreciate that, realize that the process of the method for above-described embodiment can complete by the hardware that program command is correlated with, described program can be stored in read/write memory medium, and this program is carried out the corresponding step in said method when carrying out.Described storage medium can be as ROM/RAM, magnetic disc, CD etc.
The above is only the preferred embodiment of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle 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 pfc circuit, is characterized in that, the input of described pfc circuit receives chopping voltage, and described pfc circuit comprises: main switch and Ton control unit; The control signal of described Ton control unit is within being less than or equal to maximum range, with the copped wave angle positive correlation of described chopping voltage;
Described pfc circuit also comprises:
Detect compensating unit, for detection of the copped wave angle of chopping voltage, generate amplitude and the positively related compensating signal in copped wave angle; According to described compensating signal, the comparison signal of Ton control unit is controlled, made in described control signal to be less than or equal in maximum range, equate that control signal corresponding to copped wave angle raises.
2. circuit according to claim 1, is characterized in that, detects compensating unit and comprise:
Detection sub-unit is for detection of the copped wave angle of chopping voltage;
Generate subelement, be used for generating amplitude and the positively related compensating signal in copped wave angle;
Control subelement, be used for according to described compensating signal, the comparison signal of Ton control unit being controlled.
3. circuit according to claim 2, is characterized in that, controls subelement and specifically be used for: with the be added to comparison signal of Ton control unit of described compensating signal.
4. circuit according to claim 3, is characterized in that, described compensating signal is current signal; Described comparison signal is sawtooth signal;
The Ton control unit comprises: constant-current source is respectively by the first electric capacity and second switch pipe ground connection, and the first unearthed first end of electric capacity connects the inverting input of the first operational amplifier; The normal phase input end of the first operational amplifier is used for reception control signal;
The control subelement comprises: two outputs that generate subelement connect respectively the two ends of the first electric capacity.
5. circuit according to claim 3, is characterized in that, described compensating signal is voltage signal; Described comparison signal is sawtooth signal, and compensating signal is level signal;
The Ton control unit comprises: the normal phase input end of the first operational amplifier is used for reception control signal;
The control subelement comprises:
First input end is used for receiving comparison signal, and first input end also connects the inverting input of the first operational amplifier by the first resistance; The compensating signal output that generates subelement connects the inverting input of the first operational amplifier by the second resistance.
6. circuit according to claim 4, is characterized in that, described detection sub-unit comprises:
First input end passes through the 3rd resistance and the 4th grounding through resistance, the second input end grounding successively; The tie point of the 3rd resistance and the 4th resistance connects the base stage of the first triode, the emitter grounding of the first triode, and collector electrode connects the first output of detection sub-unit, the second output head grounding of detection sub-unit;
The generation subelement comprises:
The first input end that generates subelement connects the first output of detection sub-unit, and the second input that generates subelement connects the second output of detection sub-unit;
The first input end that generates subelement connects supply voltage by the 5th resistance, also by the second capacity earth; Generate the first input end of subelement successively by the first diode and the 3rd capacity earth; The negative electrode of the first diode connects the base stage of the second triode, and the emitter-base bandgap grading of the second triode is by the 6th grounding through resistance, and the collector electrode of the second triode connects supply voltage; The emitter-base bandgap grading of the second triode connects with the 7th resistance the compensating signal output that generates subelement by the second diode successively.
7. circuit according to claim 5, is characterized in that, described detection sub-unit comprises: first input end passes through the 3rd resistance and the 4th grounding through resistance, the second input end grounding successively; The tie point of the 3rd resistance and the 4th resistance connects the base stage of the first triode, the emitter grounding of the first triode, and collector electrode connects the first output of detection sub-unit, the second output head grounding of detection sub-unit;
The generation subelement comprises:
The first input end that generates subelement connects the first output of detection sub-unit, and the second input that generates subelement connects the second output of detection sub-unit;
The first input end that generates subelement connects supply voltage by the 5th resistance, also by the second capacity earth; Generate the first input end of subelement successively by the first diode and the 3rd capacity earth; The negative electrode of the first diode connects the base stage of the second triode, and the emitter-base bandgap grading of the second triode is by the 6th grounding through resistance, and the collector electrode of the second triode connects supply voltage; The emitter-base bandgap grading of the second triode is as the compensating signal output that generates subelement.
8. a signal control method, is characterized in that, the method is applied to pfc circuit, and the input of described pfc circuit receives chopping voltage; Described pfc circuit comprises: main switch and Ton control unit; The control signal of described Ton control unit is within being less than or equal to maximum range, with the copped wave angle positive correlation of described chopping voltage;
The method comprises:
Detect the copped wave angle of chopping voltage;
Generate amplitude and the positively related compensating signal in copped wave angle;
According to described compensating signal, the comparison signal of Ton control unit is controlled, made in described control signal to be less than or equal in maximum range, equate that control signal corresponding to copped wave angle raises.
9. method according to claim 8, is characterized in that, according to described compensating signal, the comparison signal of Ton control unit controlled to comprise:
Described compensating signal is added on the comparison signal of Ton control unit.
10. a load driving circuits, is characterized in that, comprises the described pfc circuit of claim 1 to 7 any one.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110376593.8A CN103138556B (en) | 2011-11-23 | 2011-11-23 | Pfc circuit, load driving circuits and signal control method |
| PCT/CN2012/078153 WO2013075504A1 (en) | 2011-11-23 | 2012-07-04 | Pfc circuit, load drive circuit and signal control method |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201110376593.8A CN103138556B (en) | 2011-11-23 | 2011-11-23 | Pfc circuit, load driving circuits and signal control method |
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| CN103138556A true CN103138556A (en) | 2013-06-05 |
| CN103138556B CN103138556B (en) | 2015-08-19 |
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| CN (1) | CN103138556B (en) |
| WO (1) | WO2013075504A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104780670A (en) * | 2015-03-30 | 2015-07-15 | 成都颉隆科技有限公司 | Variable-frequency and energy-saving control system for smart power grid |
| CN104797041A (en) * | 2015-03-30 | 2015-07-22 | 成都颉隆科技有限公司 | Bootstrap trigger type smart grid frequency conversion energy-saving control system |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104219855B (en) * | 2014-09-28 | 2017-03-29 | 广东工业大学 | Based on APFC without stroboscopic LED constant current drive control circuit |
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| US20110254525A1 (en) * | 2010-04-20 | 2011-10-20 | Power Integrations, Inc. | Dimming control for a switching power supply |
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| CN101686587B (en) * | 2008-09-25 | 2015-01-28 | 皇家飞利浦电子股份有限公司 | Drive for providing variable power for LED array |
| TWI405502B (en) * | 2009-08-13 | 2013-08-11 | Novatek Microelectronics Corp | Dimmer circuit of light emitted diode and isolated voltage generator and dimmer method thereof |
| TW201141303A (en) * | 2010-05-07 | 2011-11-16 | Light Engine Ltd | Triac dimmable power supply unit for LED |
| CN201995174U (en) * | 2011-01-28 | 2011-09-28 | 英飞特电子（杭州）有限公司 | Back-porch small-phase-angle light dimming circuit |
| CN102143638B (en) * | 2011-04-08 | 2013-07-24 | 矽力杰半导体技术(杭州)有限公司 | Silicon-controlled light-dimming circuit, light-dimming method and LED (light-emitting diode) driver applying the same |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1106175A (en) * | 1993-09-07 | 1995-08-02 | 株式会社东芝 | Power conversion system |
| US20110254525A1 (en) * | 2010-04-20 | 2011-10-20 | Power Integrations, Inc. | Dimming control for a switching power supply |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104780670A (en) * | 2015-03-30 | 2015-07-15 | 成都颉隆科技有限公司 | Variable-frequency and energy-saving control system for smart power grid |
| CN104797041A (en) * | 2015-03-30 | 2015-07-22 | 成都颉隆科技有限公司 | Bootstrap trigger type smart grid frequency conversion energy-saving control system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103138556B (en) | 2015-08-19 |
| WO2013075504A1 (en) | 2013-05-30 |
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