CN201352879Y - Control circuit of inverter applying pulse-width modulation dimming - Google Patents
Control circuit of inverter applying pulse-width modulation dimming Download PDFInfo
- Publication number
- CN201352879Y CN201352879Y CNU200920002755XU CN200920002755U CN201352879Y CN 201352879 Y CN201352879 Y CN 201352879Y CN U200920002755X U CNU200920002755X U CN U200920002755XU CN 200920002755 U CN200920002755 U CN 200920002755U CN 201352879 Y CN201352879 Y CN 201352879Y
- Authority
- CN
- China
- Prior art keywords
- low frequency
- coupled
- output
- low
- comparator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Discharge-Lamp Control Circuits And Pulse- Feed Circuits (AREA)
- Inverter Devices (AREA)
Abstract
A control circuit of inverter applying pulse-width modulation dimming comprises a low-frequency timing capacitor, a low-frequency oscillator, a low-frequency PWM comparator, a feedback control circuit and an alternating current signal generator, wherein the output end of the low-frequency oscillator is coupled with the low-frequency timing capacitor and the input end of the low-frequency PWM comparator, and the output end of the low-frequency PWM comparator is coupled with the feedback control circuit. The alternating current signal generator can generate alternating current with proper magnitude and frequency to charge the low-frequency timing capacitor, the charging current of the low-frequency timing capacitor can be the original direct current plus the alternating current, the low-frequency ramp voltage on the output end of the low-frequency oscillator can generate disturbance according to the magnitude of the alternating current, and the low-frequency PWM signal on the output end of the low-frequency comparator can generate disturbance. The disturbed low-frequency PWM signal can expand the signal energy of an inverter in a wider range through the feedback control circuit, in order to improve the electromagnetic interference caused at the moment of the conversion during the enable energy and the forbidden energy of the inverter in low-frequency PWM signals.
Description
Technical field
The utility model relates to the control circuit of a kind of inverter (inverter), and the control circuit of the inverter of particularly a kind of use pulse-width modulation (Pulse Width Modulation is called for short PWM) light modulation.
Background technology
Figure 1A is the calcspar of traditional cold-cathode fluorescence lamp (Cold Cathode Fluorescent Lamp is called for short CCFL) power-supply system; Please refer to Figure 1A, after the electric main input conventional power source system 1, through electromagnetic interference (ElectroMagnetic Interference is called for short EMI) filter 11 filtering noise informations, 12 rectifications become dc pulse signal through bridge rectifier again.In order to meet the harmonic wave standard, the power-supply system input power must be passed through power factor corrector (Power Factor Corrector greater than its dc pulse signal of 75W person, abbreviation PFC) 13 come correcting current harmonic distortion, and the direct voltage Vbus that becomes stable representative value 400Vdc gives standby power transducer 14 and main power source transducer 15 with power supply.Standby power transducer 14 becomes direct voltage Vbus the power supply of representative value 5Vdc, it is powered under standby mode and gives microcontroller (the Micro Controller Unit of mainboard (main board), be called for short MCU) keep the work of receiver of remote-control sytem, and PFC 13 and main power source transducer 15 are closed to reduce stand-by power consumption.The power supply that main power source transducer 15 becomes direct voltage Vbus representative value 12Vdc, 14Vdc or other voltage is given audio frequency, video, control module or other module with power supply, and the power supply that becomes representative value 24Vdc is given inverter 16 with power supply.The alternating voltage Vlamp that the power supply of the representative value 24Vdc that inverter 16 provides main power source transducer 15 becomes representative value 1800Vac to be starting CCFL, and reduces to 800Vac from 1800Vac promptly be enough to make the CCFL steady operation after startup.
In order to reduce manufacturing cost and to promote conversion efficiency, developed the CCFL power-supply system that a kind of LIPS framework afterwards, wherein LIPS is the abbreviation of Lcd Integrated Power Supply.Figure 1B is the calcspar of the CCFL power-supply system of existing LIPS framework; Please be simultaneously with reference to Figure 1A and Figure 1B, no longer the inverter 16 as conventional power source system 1 is by 15 power supplies of main power source transducer, the direct voltage Vbus power supply of the representative value 400Vdc that the inverter 26 of LIPS power-supply system 2 is directly provided by PFC 13, therefore the electric energy that drives CCFL has reduced the one-level power conversion, promptly saved the loss of one-level conversion efficiency, and can reduce the design power and the framework complexity of main power source transducer 25, both improve heat dissipation problem and reduced manufacturing cost.But, because LIPS power-supply system 2 has been lacked the voltage regulation result of main power source transducer 25, its stability is relatively slightly inadequate, can occur excessive transient state when especially inverter 26 uses pulse-width modulation (PWM) light modulation and exchange variation on the direct voltage Vbus that PFC 13 provides.
Fig. 2 is the oscillogram of inverter 26 input/output signals of LIPS power-supply system 2 shown in Figure 1B; Please be simultaneously with reference to Figure 1B and Fig. 2, inverter 26 uses the PWM light modulation, so the dim signal that receives is low frequency pwm signal Vlpwm.The PWM light modulation because of the dimming scope broadness, the light modulation linearity is good and circuit realizes being the most general dimming mode at present easily.Each period T of low frequency pwm signal Vlpwm comprise one enable during T_OFF during T_ON and the forbidden energy.T_ON during enabling, inverter 26 operate as normal, the alternating voltage Vlamp that its generation frequency is fhosc is to drive CCFL luminous (promptly brightening); And during forbidden energy T_OFF, inverter 26 is not worked, this moment, alternating voltage Vlamp was zero, can't drive CCFL luminous (being deepening).The frequency f losc of low frequency pwm signal Vlpwm design usually is higher than 100Hz, under the temporary influence of human vision, can not see the CCFL deepening that brightens once, can only see bright dark variation, so by adjusting the purpose that bright dark ratio (promptly adjust during enabling during the T_ON and forbidden energy the ratio of T_OFF) can reach light modulation.Because LIPS power-supply system 2 has been lacked the voltage regulation result of main power source transducer 25, when inverter 26 uses the PWM light modulation, during the enabling of low frequency pwm signal Vlpwm during T_ON and the forbidden energy T_OFF both change moment, ask to eat and carry or unloading that the direct voltage Vbus that makes PFC 13 provide excessive transient state can occur and exchange variation in 26 winks of inverter.The excessive transient state of direct voltage Vbus exchanges to change easily shines upon the frequency that this interchange changes by the inductor among the PFC 13, and the low-frequency range frequency spectrum of this frequency range fundamental frequency is produced the influence of EMI.
Summary of the invention
The purpose of this utility model is exactly to propose a kind of control circuit that uses the inverter of impulse width modulation and light adjusting, improves inverter during the enabling of low frequency pulse-width signal and both change the electromagnetic interference that moment produces during the forbidden energy.
In order to reach above-mentioned purpose and other purpose, the utility model proposes a kind of control circuit that uses the inverter of impulse width modulation and light adjusting, it comprises low frequency timing circuit, low-frequency oscillator, low frequency pulse-width modulation comparator, feedback control circuit and AC signal generator.The low frequency timing circuit comprises low frequency timing resistor device and low frequency time capacitor, the size of low frequency timing resistor device decision direct current and direct current is used for to the charging of low frequency time capacitor, the low frequency time capacitor has first end and second end and second end and is coupled to earthing potential.Low-frequency oscillator has output and output is coupled to low frequency timing resistor device and low frequency time capacitor first end, and low-frequency oscillator control low frequency time capacitor is discharged and recharged repeatedly and produces the low frequency ramp voltage at low frequency time capacitor first end.Low frequency pulse-width modulation comparator has first input end, second input and output, low frequency pulse-width modulation comparator first input end receives the direct current dim signal, low frequency pulse-width modulation comparator second input is coupled to low frequency time capacitor first end, produce the low frequency pulse-width signal at low frequency pulse-width modulation comparator output terminal, its each cycle of medium and low frequency pulse-width signal comprise one enable during and during the forbidden energy.Feedback control circuit has Enable Pin and output, the feedback control circuit Enable Pin is coupled to low frequency pulse-width modulation comparator output terminal, during enabling, produce drive signal at the feedback control circuit output, do not produce drive signal at the feedback control circuit output during forbidden energy, wherein drive signal is used for driving the switching of the switching circuit in the inverter.AC signal generator has output and output is coupled to low frequency time capacitor first end, provides alternating current so that the low frequency time capacitor is charged at the AC signal generator output.
The alternating current of suitable size of the utility model utilization and frequency charges to the low frequency time capacitor, the charging current that makes the low frequency time capacitor is that original direct current adds this alternating current, cause the low frequency ramp voltage that produces at the low-frequency oscillator output to produce disturbance according to the size of this alternating current, and then make the low frequency pulse-width signal produce disturbance, and the signal energy of inverter is expanded to one than on the wider frequency, therefore can improve inverter during the enabling of low frequency pulse-width signal and both change the electromagnetic interference that moment produces during the forbidden energy.
State with other purposes, feature and advantage and can become apparent on the utility model for allowing, preferred embodiment cited below particularly, and cooperate appended graphicly, be described in detail below.
Description of drawings
Figure 1A is the calcspar of traditional cold-cathode fluorescent light power-supply system;
Figure 1B is the calcspar of the cold-cathode fluorescent light power-supply system of existing LIPS framework;
Fig. 2 is the oscillogram of the inverter input/output signal of LIPS power-supply system shown in Figure 1B;
Fig. 3 is the calcspar according to the inverter of the use PWM light modulation of the utility model one embodiment;
Fig. 4 is the circuit diagram of a specific embodiment of control circuit shown in Figure 3;
Fig. 5 is the circuit diagram of another specific embodiment of control circuit shown in Figure 3;
Fig. 6 is the circuit diagram of the another specific embodiment of control circuit shown in Figure 3;
Fig. 7 is the circuit diagram of a specific embodiment of AC signal generator shown in Figure 4.
Description of reference numerals:
1,2-CCFL power-supply system; 11-electromagnetic interference (EMI) filter; The 12-bridge rectifier; 13-power factor corrector (PFC); 14-standby power transducer; 15,25-main power source transducer; 16,26-inverter; The 30-inverter; The 31-switching circuit; The 32-transformer; The 33-resonant circuit; The 34-voltage sensor; The 35-current sensor; 36,46,56,66-control circuit; 461,661-low-frequency oscillator; 462,662-low frequency timing circuit; 463-low frequency PWM comparator; The 464-feedback control circuit; The 4641-error amplifier; The 4642-high-frequency generator; 4643-high frequency timing circuit; 4644-high-frequency PWM comparator; The 4645-control logic circuit; The 4646-output driving circuit; 465,765-AC signal generator; The 466-comparator; 467,567-switch; 7651-Wei grace bridge-type oscillator;
The Vbus-direct voltage; Vlamp-alternating voltage (or CCFL voltage); The Vvsen-voltage sensing signal; The Visen-current sensing signal; The Vdrv-drive signal; The Vdim-dim signal; Vlpwm-low frequency pwm signal; Vhpwm-high-frequency PWM signal; Vlst-low frequency ramp voltage; Vhst-high frequency ramp voltage; The Vref-reference voltage; The Vea-error voltage; Vp1-first setting voltage; The Vdd-DC power supply; The Vgnd-earthing potential; The Ilamp-CCFL electric current; The Ic-direct current; The Ia-alternating current; R1-low frequency timing resistor device; R2-high frequency timing resistor device; R3～R7-resistor; C1-low frequency time capacitor; C2-high frequency time capacitor; C3～C6-capacitor; D1, D2-diode; The T-low frequency pwm signal cycle; During T_ON-low frequency pwm signal enables; During the T_OFF-low frequency pwm signal forbidden energy; Flosc-low frequency pwm signal frequency; Fhosc-high-frequency PWM signal frequency.
Embodiment
Fig. 3 is the calcspar according to the inverter of the use PWM light modulation of the utility model one embodiment; Please refer to Fig. 3, inverter 30 adopts the framework of the LIPS power-supply system 2 shown in Figure 1B, so the direct voltage Vbus of the representative value 400Vdc that inverter 30 is directly provided by PFC is powered, and output AC voltage Vlamp is with driving CCFL.In the present embodiment, inverter 30 comprises switching circuit 31, transformer 32, resonant circuit 33, voltage sensor 34, current sensor 35 and control circuit 36.Switching circuit 31 for example is full-bridge type, semibridge system switching circuit or other switching circuit, in order to direct voltage Vbus is become the alternating voltage of square wave form.Transformer 32 boosts in order to the alternating voltage with the square wave form.Resonant circuit 33 be in order to will becoming the alternating voltage Vlamp of approximate string ripple through the alternating voltage filtering of the square wave form of boosting, and provide resonance potential and electric current to make switching circuit 31 possess no-voltage/zero current switching characteristic.Voltage sensor 34 and current sensor 35 detect the voltage Vlamp of CCFL and electric current I lamp respectively and output voltage transducing signal Vvsen and current sensing signal Visen.Control circuit 36 uses the PWM dimming mode to adjust CCFL brightness according to dim signal Vdim; and Vdrv stablizes CCFL brightness with the switching of FEEDBACK CONTROL switching circuit 31 according to current sensing signal Visen output drive signal, again according to voltage sensing signal Vvsen with protective circuit.Because the PWM light modulation can be divided into outside PWM light modulation and inner PWM light modulation, if inverter 30 uses outside PWM light modulation, then dim signal Vdim is the low frequency pwm signal; And if inverter 30 uses inner PWM light modulation, then dim signal Vdim is a direct current signal, and control circuit 36 produces the low frequency pwm signal according to this direct current signal again, and inner PWM light modulation is because of comparatively simply more often being used in design.
Fig. 4 is the circuit diagram of a specific embodiment of control circuit 36 shown in Figure 3, and wherein CMP is the abbreviation of comparator (CoMParator), and EA is the abbreviation of error amplifier (Error Amplifier).Please refer to Fig. 4, control circuit 46 comprises low-frequency oscillator 461, low frequency timing circuit 462, low frequency PWM comparator 463, feedback control circuit 464 and AC signal generator 465.Low frequency timing circuit 462 comprises low frequency timing resistor device R1 and low frequency time capacitor C1, in the present embodiment, low frequency timing resistor device R1 first end is coupled to DC power supply Vdd, low frequency timing resistor device R1 second end is coupled to low-frequency oscillator 461 outputs and low frequency time capacitor C1 first end, and low frequency time capacitor C1 second end is coupled to earthing potential Vgnd.DC power supply Vdd produces direct current Ic by low frequency timing resistor device R1 so that be used for to low frequency time capacitor C1 charging, and low frequency timing resistor device R1 will determine the size of direct current Ic.Low-frequency oscillator 461 is controlled at and stops charging when voltage on its output or low frequency time capacitor C1 first end is charged to the first setting voltage Vp1 and begin discharge, and stops discharge and begin charging when discharging into the second setting voltage Vp2.Therefore, voltage on low-frequency oscillator 461 outputs or low frequency time capacitor C1 first end can rise and descend repeatedly, forming waveform is the low frequency ramp voltage Vlst of triangular wave or sawtooth waveforms, its peak voltage is that the first setting voltage Vp1, trough voltage are the second setting voltage Vp2, its frequency be flosc and with 1/ (R1 * C1) proportional.
In the present embodiment, inverter 30 uses inner PWM light modulation, so dim signal Vdim is a direct current signal.Low frequency PWM comparator 463 first input ends receive direct current dim signal Vdim, its second input is coupled to low frequency time capacitor C1 first end to receive low frequency ramp voltage Vlst, produces low frequency pwm signal Vlpwm by comparing direct current dim signal Vdim and low frequency ramp voltage Vlst at its output.The embodiment of low frequency pwm signal Vlpwm as shown in Figure 2, its each period T (=1/flosc) comprise one enable during T_OFF during T_ON and the forbidden energy.Feedback control circuit 464 Enable Pins are coupled to low frequency PWM comparator 463 outputs to receive low frequency pwm signal Vlpwm.T_ON during the enabling of low frequency pwm signal Vlpwm produces drive signal Vdrv with driving switch circuit 31 at feedback control circuit 464 outputs, and making inverter 30 operate as normal and producing frequency is that the alternating voltage Vlamp of fhosc is luminous to drive CCFL; And during the forbidden energy of low frequency pwm signal Vlpwm T_OFF, do not produce drive signal Vdrv at feedback control circuit 464 outputs, be that drive signal Vdrv is zero and can't driving switch circuit 31, inverter 30 is not worked, this moment, alternating voltage Vlamp was zero, can't drive CCFL luminous (being deepening).AC signal generator 465 outputs are coupled to low frequency time capacitor C1 first end, provide alternating current Ia at AC signal generator 465 outputs.So, the charging current of low frequency time capacitor C1 is that original direct current Ic adds alternating current Ia, the low frequency ramp voltage Vlst that makes in low-frequency oscillator 461 outputs or the generation of low frequency time capacitor C1 first end can produce disturbance according to the size of alternating current Ia, and the low frequency pwm signal Vlpwm that cause low frequency PWM comparator 463 outputs to produce produces disturbance.The low frequency pwm signal Vlpwm of disturbance expands to one than on the wider frequency by feedback control circuit 464 with the signal energy of inverter 30, therefore can improve inverter 30 during the enabling of low frequency pwm signal Vlpwm during T_ON and the forbidden energy T_OFF both change the electromagnetic interference that moment produces.
In the present embodiment, control circuit 46 more comprises comparator 466 and switch 467.Comparator 466 first input ends receive direct current dim signal Vdim, and its second input receives the first setting voltage Vp1, and this first setting voltage is the peak voltage of low frequency ramp voltage Vlst.Switch 467 for example is the PNP bipolar transistor, its first end (or emitter-base bandgap grading end) is coupled to AC signal generator 465 outputs, its second end (or collector terminal) is coupled to low frequency time capacitor C1 first end, and its control end (or base terminal) is coupled to comparator 466 outputs.As direct current dim signal Vdim during more than or equal to the first setting voltage Vp1, be the peak voltage of direct current dim signal Vdim more than or equal to low frequency ramp voltage Vlst, there is not T_OFF during the forbidden energy in T_ON for maximum (being T_ON=T) during this moment the enabling of low frequency pwm signal Vlpwm, both change the problem that moment produces electromagnetic interference not have during enabling during the T_ON and forbidden energy T_OFF, therefore can disconnect by comparator 466 output output signal control switchs 467 for energy-conservation, AC signal generator 465 outputs and low frequency time capacitor C1 first end are disconnected.Otherwise as direct current dim signal Vdim during less than the first setting voltage Vp1,467 conductings of comparator 466 output output signal control switchs make AC signal generator 465 outputs be coupled to low frequency time capacitor C1 first end.In addition, if the design that the not anti-stop signal of AC signal generator 465 flows backwards, then must between switch 467 and low frequency time capacitor C1, diode D1 be set unidirectional conducting function is provided, as shown in Figure 4, diode D1 anode tap is coupled to switch 467 second ends, and diode D1 cathode terminal is coupled to low frequency time capacitor C1 first end; Perhaps, diode (not illustrating) is set between switch 467 and AC signal generator 465, the diode anode end is coupled to AC signal generator 465 outputs, and the diode cathode end is coupled to switch 467 first ends.
Fig. 5 is the circuit diagram of another specific embodiment of control circuit 36 shown in Figure 3; Please be simultaneously with reference to Fig. 4 and Fig. 5, the difference of control circuit 56 and control circuit 46 only is to control the execution mode that whether AC signal Ia is provided to low frequency time capacitor C1.Control circuit 56 utilizes comparator 466 relatively the direct current dim signal Vdim and the first setting voltage Vp1, so that output control signal control switch 567.Switch 567 for example is the NPN bipolar transistor, its first end (or collector terminal) is coupled to AC signal generator 465 outputs and diode D2 anode tap, its second end (or emitter-base bandgap grading end) is coupled to earthing potential Vgnd, and its control end (or base terminal) is coupled to comparator 466 outputs.As direct current dim signal Vdim during more than or equal to the first setting voltage Vp1,567 conductings of comparator 466 output output signal control switchs, make diode D2 anode tap be coupled to earthing potential Vgnd, so diode D2 ends and AC signal generator 465 outputs and low frequency time capacitor C1 first end are disconnected.Otherwise as direct current dim signal Vdim during less than the first setting voltage Vp1, comparator 466 output output signal control switchs 567 disconnect, and AC signal generator 465 outputs are coupled to low frequency time capacitor C1 first end certainly.
Fig. 6 is the circuit diagram of the another specific embodiment of control circuit 36 shown in Figure 3; Please be simultaneously with reference to Fig. 4 and Fig. 6, the difference of control circuit 66 and control circuit 46 only is the execution mode of low-frequency oscillator and low frequency timing circuit.The output of the low-frequency oscillator 661 of control circuit 66 has first output and second output.The low frequency timing circuit 662 of control circuit 66 comprises low frequency timing resistor device R1 and low frequency time capacitor C1, low frequency timing resistor device R1 first end couples low-frequency oscillator 661 first outputs, low frequency time capacitor C1 first end is coupled to low-frequency oscillator 661 second outputs, and low frequency timing resistor device R1 and low frequency time capacitor C1 second end all are coupled to earthing potential Vgnd.Low-frequency oscillator 661 provides direct current Ic to low frequency time capacitor C1 charging, and the size of low frequency timing resistor device R1 decision direct current Ic.This moment, low frequency PWM comparator 463 second inputs and AC signal generator 465 outputs were coupled to low-frequency oscillator 661 second outputs and low frequency time capacitor C1 first end, and were not coupled to low-frequency oscillator 661 first outputs and low frequency timing resistor device R1.
Fig. 7 is the circuit diagram of a specific embodiment of AC signal generator 465 shown in Figure 4; Please refer to Fig. 7, AC signal generator 765 comprises a Wei grace bridge-type oscillator (Wien bridge oscillator) 7651, and wherein Wei grace bridge-type oscillator 7651 is made up of operational amplifier OPA, resistor R 4～R7 and capacitor C3～C6.Wei grace bridge-type oscillator 7651 outputs are coupled to resistor R 3, so the string wave voltage signal of its output output produces alternating current Ia by resistor R 3.
In sum, the alternating current that the control circuit of the inverter of use PWM of the present utility model light modulation utilizes AC signal generator to produce suitable size and frequency charges to the low frequency time capacitor, so the charging current of low frequency time capacitor is that original direct current adds this alternating current, the low frequency ramp voltage that produces at the low-frequency oscillator output can produce disturbance according to the size of this alternating current, and the low frequency pwm signal that low frequency PWM comparator output terminal is produced produces disturbance.The low frequency pwm signal of disturbance expands to one than on the wider frequency by feedback control circuit with the signal energy of inverter, therefore can improve inverter during the enabling of low frequency pwm signal and both change the electromagnetic interference that moment produces during the forbidden energy.
Above embodiment only is preferred embodiment of the present utility model, and it is illustrative for the utility model, and nonrestrictive.Those skilled in the art carries out conversion, modification even equivalence to it under the situation that does not exceed the utility model spirit and scope, these changes all can fall into claim protection range of the present utility model.
Claims (7)
1. a control circuit that uses the inverter of impulse width modulation and light adjusting is characterized in that, comprising:
One low frequency timing circuit, comprise a low frequency timing resistor device and a low frequency time capacitor, low frequency timing resistor device determines the size of a direct current electric current, direct current charges to the low frequency time capacitor, the low frequency time capacitor has one first end and one second end, and low frequency time capacitor second end is coupled to an earthing potential;
One low-frequency oscillator, has an output, the low-frequency oscillator output is coupled to low frequency timing resistor device and low frequency time capacitor first end, and control low frequency time capacitor is discharged and recharged repeatedly and produces a low frequency ramp voltage at low frequency time capacitor first end;
One low frequency pulse-width modulation comparator, have a first input end, one second input and an output, low frequency pulse-width modulation comparator first input end receives a direct current dim signal, low frequency pulse-width modulation comparator second input is coupled to low frequency time capacitor first end, produce a low frequency pulse-width signal at low frequency pulse-width modulation comparator output terminal, each cycle of low frequency pulse-width signal comprise one enable during and a forbidden energy during;
One feedback control circuit, have an Enable Pin and an output, the feedback control circuit Enable Pin is coupled to low frequency pulse-width modulation comparator output terminal, produces a drive signal at the feedback control circuit output during enabling, and does not produce drive signal at the feedback control circuit output during forbidden energy; And
One AC signal generator has an output, and the AC signal generator output is coupled to low frequency time capacitor first end, provides an alternating current at the AC signal generator output.
2. the control circuit of the inverter of use impulse width modulation and light adjusting according to claim 1 is characterized in that, more comprises:
One comparator has a first input end, one second input and an output, and the comparator first input end receives the direct current dim signal, and comparator second input receives a setting voltage, and setting voltage is the peak voltage of low frequency ramp voltage; And
One switch has one first end, one second end and a control end, and switch first end is coupled to the AC signal generator output, and switch second end is coupled to low frequency time capacitor first end, and the switch control end is coupled to comparator output terminal,
Wherein, when direct current dim signal during more than or equal to setting voltage, comparator output terminal output signal control switch disconnects, AC signal generator output and low frequency time capacitor first end are disconnected, when direct current dim signal during less than setting voltage, the conducting of comparator output terminal output signal control switch makes the AC signal generator output be coupled to low frequency time capacitor first end.
3. the control circuit of the inverter of use impulse width modulation and light adjusting according to claim 2 is characterized in that, more comprises:
One diode has an anode tap and a cathode terminal, and the diode anode end is coupled to switch second end, and the diode cathode end is coupled to low frequency time capacitor first end.
4. the control circuit of the inverter of use impulse width modulation and light adjusting according to claim 2 is characterized in that, more comprises:
One diode has an anode tap and a cathode terminal, and the diode anode end is coupled to the AC signal generator output, and the diode cathode end is coupled to switch first end.
5. the control circuit of the inverter of use impulse width modulation and light adjusting according to claim 1 is characterized in that, more comprises:
One comparator has a first input end, one second input and an output, and the comparator first input end receives the direct current dim signal, and comparator second input receives a setting voltage, and setting voltage is the peak voltage of low frequency ramp voltage; And
One diode has an anode tap and a cathode terminal, and the diode cathode end is coupled to low frequency time capacitor first end; And
One switch has one first end, one second end and a control end, and switch first end is coupled to AC signal generator output and diode anode end, and switch second end is coupled to earthing potential, and the switch control end is coupled to comparator output terminal,
Wherein, when direct current dim signal during more than or equal to setting voltage, the conducting of comparator output terminal output signal control switch makes the diode anode end be coupled to earthing potential, when direct current dim signal during less than setting voltage, comparator output terminal output signal control switch disconnects.
6. the control circuit of the inverter of use impulse width modulation and light adjusting according to claim 1, it is characterized in that, low frequency timing resistor utensil has one first end and one second end, low frequency timing resistor device first end is coupled to a direct current power supply, and low frequency timing resistor device second end is coupled to low-frequency oscillator output and low frequency time capacitor first end.
7. the control circuit of the inverter of use impulse width modulation and light adjusting according to claim 1, it is characterized in that, the low-frequency oscillator output comprises one first output and one second output, low frequency timing resistor utensil has one first end and one second end, low frequency timing resistor device first end is coupled to low-frequency oscillator first output, low frequency timing resistor device second end is coupled to earthing potential, and low frequency time capacitor first end is coupled to low-frequency oscillator second output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU200920002755XU CN201352879Y (en) | 2009-02-16 | 2009-02-16 | Control circuit of inverter applying pulse-width modulation dimming |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU200920002755XU CN201352879Y (en) | 2009-02-16 | 2009-02-16 | Control circuit of inverter applying pulse-width modulation dimming |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201352879Y true CN201352879Y (en) | 2009-11-25 |
Family
ID=41376261
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU200920002755XU Expired - Fee Related CN201352879Y (en) | 2009-02-16 | 2009-02-16 | Control circuit of inverter applying pulse-width modulation dimming |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201352879Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102387630A (en) * | 2010-09-03 | 2012-03-21 | 成都芯源系统有限公司 | multi-mode dimming circuit and dimming method |
| CN106932736A (en) * | 2015-12-30 | 2017-07-07 | 德克萨斯仪器股份有限公司 | Calibrated using the closed-loop device of broadband signal |
-
2009
- 2009-02-16 CN CNU200920002755XU patent/CN201352879Y/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102387630A (en) * | 2010-09-03 | 2012-03-21 | 成都芯源系统有限公司 | multi-mode dimming circuit and dimming method |
| CN102387630B (en) * | 2010-09-03 | 2014-03-19 | 成都芯源系统有限公司 | Multi-mode dimming circuit and dimming method |
| CN106932736A (en) * | 2015-12-30 | 2017-07-07 | 德克萨斯仪器股份有限公司 | Calibrated using the closed-loop device of broadband signal |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102752940B (en) | High-efficiency LED (light-emitting diode) drive circuit and drive method thereof | |
| CN1191738C (en) | Device for driving lamp and method for driving discharge tube | |
| CN100576965C (en) | Led drive circuit and control method | |
| CN101894530B (en) | Driving circuit and protection method thereof, light-emitting device and display device | |
| CN201349354Y (en) | Analogy and digital dimming backlight source drive device | |
| CN101227780A (en) | LED lamp set drive power supply device | |
| CN105960070A (en) | Single-feedback direct-push type DC light-dimming LED tube driving circuit | |
| JP2003513602A (en) | Electronic ballast circuit | |
| EP2249470B1 (en) | Capacitance reducing method for a pulsed activiated device and associated devices | |
| CN201349353Y (en) | Double-dimming backlight source drive device | |
| TW201419725A (en) | Startup circuit of supply voltage for PFC circuit and switching power supply using the same | |
| CN201352879Y (en) | Control circuit of inverter applying pulse-width modulation dimming | |
| TWM460457U (en) | Startup circuit structure of supply voltage for power factor correction circuit and switching power supply | |
| CN201374865Y (en) | Inverter control circuit | |
| CN102892245A (en) | Discharge lamp system and control method thereof | |
| TWI418253B (en) | A novel single-stage high-power-factor square-wave electronic ballast | |
| CN100482009C (en) | Inverter microwave oven and method for controlling the same | |
| JP2019536405A (en) | AC / DC converter with power factor correction | |
| CN210093612U (en) | LED double-color dimming built-in power supply | |
| CN204697378U (en) | Small-power HID lamp drive circuit | |
| US6225755B1 (en) | High power factor electronic ballast with simplified circuit topology | |
| CN101155456A (en) | Driving method for electric ballast and fluorescent lamp | |
| CN108337795B (en) | Two-stage low-frequency square wave electronic ballast | |
| TWI404458B (en) | Controller circuit of inverter using pulse width modulation (pwm) dimming | |
| CN214756993U (en) | Non-stroboscopic alternating-current direct-drive LED driving system based on BCD process |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20091125 Termination date: 20120216 |