CN102006710B - Power supply changeover drive circuit and fluorescent lamp drive circuit - Google Patents
Power supply changeover drive circuit and fluorescent lamp drive circuit Download PDFInfo
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- CN102006710B CN102006710B CN 200910172029 CN200910172029A CN102006710B CN 102006710 B CN102006710 B CN 102006710B CN 200910172029 CN200910172029 CN 200910172029 CN 200910172029 A CN200910172029 A CN 200910172029A CN 102006710 B CN102006710 B CN 102006710B
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Abstract
The invention discloses a power supply changeover drive circuit and a fluorescent lamp drive circuit. The power supply changeover drive circuit comprises a changeover circuit, a control circuit and a load circuit. The changeover circuit is coupled with an input voltage; the control circuit is coupled with the changeover circuit and is used for controlling the changeover circuit to convert the input voltage into an output voltage; the load circuit comprises a load detection unit and a load; the load is coupled with the output voltage; and the load detection unit is coupled with a detection voltage source. The load detection unit generates a load detection signal when the load circuit is inserted into the power supply changeover drive circuit, so that the control circuit can be restarted.
Description
Technical field
The present invention relates to a kind of power supply conversion driving circuit and fluorescent lamp drive circuit, particularly a kind of have automatically power supply conversion driving circuit and a fluorescent lamp drive circuit of closing, restarting function automatically.
Background technology
Existing power supply unit mainly can be divided into two kinds of linear formula and switched power supplies.The circuit of linear formula power supply unit is simple, ripple is little, electromagnetic interference is little, yet electronic component is bigger, so the circuit volume is big and Heavy Weight, and conversion efficiency is low.Though the switched power supply circuit is complicated, and ripple is bigger, electromagnetic interference is also bigger, the little advantage of power consumption when conversion efficiency height, zero load are arranged, the market of present power supply unit still is main flow with the switched power supply.
Please refer to Figure 1A, for having the circuit diagram in order to the switched power supply that drives fluorescent tube now.Switched power supply comprises an initial resistance R, an initial capacitance C2, a Zener diode (Zener Diode) Z, a controller CON, a high-side driver capacitor C 1, a high-side driver transformer T1, a high side transistor switch M1, a low side transistor switch M2, a diode D, an output capacitance C3 and a transformer T2, in order to a direct current input voltage VIN is converted to an ac output voltage VOUT to drive a fluorescent tube LAMP.
After DC input voitage VIN input, provide current to initial capacitance C2 by initial resistance R, make the cross-pressure of initial capacitance C2 begin to rise to till the avalanche voltage that equals Zener diode Z.Initial capacitance C2 produces a driving voltage VDD to provide controller CON operation required electric power.After surpassing the starting resistor value of controller CON, driving voltage VDD begins to start, producing the signal of control high side transistor switch M1 and low side transistor switch M2, its middle controller CON is increased to suitable accurate position with control high side transistor switch M1 by high-side driver capacitor C 1 and high-side driver transformer T1 with the position of control signal.By the switching of high side transistor switch M1 and low side transistor switch M2, it is luminous to drive fluorescent tube LAMP to produce ac output voltage VOUT that the electric power of DC input voitage VIN will be sent to output.And transformer T2 couples ac output voltage and by output power after the diode D rectification to initial capacitance C2.
Electric power by initial resistance R starts preceding required electric power as yet greater than controller CON, therefore can make initial capacitance C2 store electric power gradually.And after the controller CON startup, also provide electrical power to controller CON by transformer T2 and diode D.Therefore initial resistance R can use bigger resistance value, to reduce the power loss of initial resistance R.Yet, when circuit occurs making DC input voitage VIN can't provide electrical power to ac output voltage VOUT unusually, make transformer T2 and diode D that electric power can't be provided and whole electric power of providing controller CON normal running required are provided for electric power by initial resistance R, will make the operation generation problem of controller CON.
Please refer to Figure 1B, for existing in order to the switched power supply that the drives fluorescent tube signal waveform schematic diagram when the circuit abnormality.After being higher than starting resistor value UVLO, driving voltage VDD begins operation, because the oscillator of controller CON inside and control circuit begin action, this moment, consumed current can be much larger than the electric current that provides through resistance R by DC input voitage VIN, so the voltage of driving voltage VDD can begin to descend.Under the circuit working normal condition, because controller CON meeting output signal control high side transistor switch M1 and low side transistor switch M2 switch, output voltage VO UT is risen and begins to provide electrical power to driving voltage VDD via transformer T2 and diode D.Yet when circuit abnormal, controller CON can stop the switching of high side transistor switch M1 and low side transistor switch M2, makes output voltage VO UT decline and can't provide electrical power to driving voltage VDD again, and cause driving voltage VDD can begin to descend.When driving voltage VDD is reduced to the minimum voltage value of controller CON allowable operations, controller CON shut-down operation, therefore driving voltage VDD again bottom out to starting resistor value UVLO, controller CON is restarted again, the state that so goes round and begins again until circuit abnormality is excluded.Perhaps, existing lamp tube drive circuit extinguishes fluorescent tube LAMP for fear of possible temporary transient circuit abnormality, also can make controller CON constantly attempt lighting again fluorescent tube LAMP.And this process not only can consume lighting number of times restriction and shortening lamp tube service life of fluorescent tube, and if the user changes the danger that fluorescent tube also has electric shock forgetting under the powered-down.In addition, if user elder generation powered-down and after changing fluorescent tube power-on again, though the danger of getting an electric shock when so avoiding changing fluorescent tube has increased user's inconvenience, and different with user's now custom.
Therefore, existing switched power supply has the problem that constantly restarts when circuit abnormality, and this not only causes the useful life reduction of circuit element, and the inconvenience that the user uses or the problem that the doubt on the safety is arranged of causing also arranged.
Summary of the invention
In view of problem described in the prior art, power supply conversion driving circuit of the present invention powered-down conversion driving circuit when the load that drives continues possible the power consumption of running when reducing control circuit in the power supply conversion driving circuit in circuit abnormality, and can avoid the user to use doubt on safe.In addition, after the user changes load, the power supply conversion driving circuit will be restarted automatically, to increase the convenience in user's use.
For reaching above-mentioned purpose, the invention provides a kind of power supply conversion driving circuit, comprise a change-over circuit, a control circuit and a load circuit.Change-over circuit couples an input voltage, and control circuit couples change-over circuit, converts input voltage to an output voltage in order to control change-over circuit.Load circuit comprises a load detecting unit and a load, and load coupled output voltage, load detecting unit couple a detecting voltage source.Wherein, the load detecting unit produces a load detection signal when load circuit inserts the power supply conversion driving circuit, control circuit is restarted.
So, by the detecting load circuit insertion to restart control circuit, can reach the advantage of restarting automatically.
The present invention also provides another kind of power supply conversion driving circuit, comprises a change-over circuit, a control circuit, a load circuit.Change-over circuit couples an input voltage, and control circuit couples change-over circuit, converts input voltage to an output voltage in order to control change-over circuit.Load circuit comprises a load detecting unit and a load, and load coupled output voltage, load detecting unit couple a driving voltage source.Wherein, control circuit couples the driving voltage source to receive the operation required electric power by the load detecting unit, when load circuit removes, when load circuit removes, stops to provide control circuit operation required electric power.
The present invention provides a kind of fluorescent lamp drive circuit in addition, comprises a change-over circuit, a control circuit and a load circuit.Change-over circuit couples an input voltage, and control circuit couples change-over circuit, converts input voltage to an output voltage in order to control change-over circuit.Load circuit comprises a load detecting unit and a fluorescent lamp, and wherein fluorescent lamp couples output voltage and has two filaments, and the load detecting unit couples input voltage and ground connection and produces a load detection signal by two filaments.Control circuit shut-down operation when fluorescent lamp drive circuit generation circuit abnormality, and in after detect and restart when the load detection signal enters a predetermined voltage range.
So, when load circuit removes, stop to provide the control circuit required electric power, can make control circuit close because driving voltage is not enough to reach and reduce the control circuit power consumption.And, when load circuit inserts once again, making the control circuit required electric power is provided once again, control circuit will restart, and also can reach the advantage of restarting automatically.
Above general introduction and ensuing detailed description are all exemplary in nature, are in order to further specify claim of the present invention.And relevant other objects and advantages of the present invention will be set forth in follow-up explanation and diagram.
Description of drawings
Figure 1A is for having the circuit diagram in order to the switched power supply that drives fluorescent tube now.
Figure 1B for existing in order to the switched power supply that the drives fluorescent tube signal waveform schematic diagram when the circuit abnormality.
Fig. 2 is the circuit block diagram according to power supply conversion driving circuit of the present invention.
Fig. 3 is the circuit diagram of the power supply conversion driving circuit of one first preferred embodiment according to the present invention.
Fig. 4 is the circuit diagram of the power supply conversion driving circuit of one second preferred embodiment according to the present invention.
Fig. 5 is the circuit diagram of the power supply conversion driving circuit of one the 3rd preferred embodiment according to the present invention.
Fig. 6 is the circuit diagram of the power supply conversion driving circuit of one the 4th preferred embodiment according to the present invention.
The main element symbol description
Initial resistance R; Initial capacitance C2;
Zener diode Z; Controller CON;
High-side driver capacitor C 1; High-side driver transformer T1;
High side transistor switch M1; Low side transistor switch M2;
Diode D; Output capacitance C3;
Transformer T2; Input voltage VIN;
Output voltage VO UT; Fluorescent tube LAMP;
Control circuit 100,200,300,400,500; Change-over circuit 160,260,360,460,560;
Load circuit 180,280,380,480,580; Load 182;
Load detecting unit 185,285,385,485, brownout lock cell 205,305,405,
585； 505；
Restart unit 210,310; Current feedback unit 215,415,515;
Over-temperature protection unit 230,330,530; Voltage feedback unit 235,335,535;
Protected location 240,340,440,540; Drive signal generation unit 245,345,445,
545；
Current-sensing circuit 270,570; Voltage detection circuit 275,375,575;
Light emitting diode module 282; Resistance 290a, 390a, 490a, 590a;
Current-limiting resistance 365; Light-emitting diode 382a, 382b;
Electrical isolation current-sensing circuit 470; Electrical isolation voltage detection circuit 475;
Fluorescent lamp 482,582; Unit 510 is restarted in the fluorescent tube protection;
Or door 513; Delay circuit 514;
Load detecting initial circuit 590; Frequency regulating circuit 595;
Frequency is adjusted resistance R _ f adj; Oscillator signal OSC;
Current signal Ise; Input voltage VIN;
Control signal S; Output voltage VO UT;
Detecting voltage source V DE; Load detection signal Sre;
The first common electric potential G1; The second common electric potential G2;
Inductance L; Diode D, D1, D2;
Diverter switch SW, SW1; The first connection end point a1, b1, c1, d1;
The second connection end point a2, b2, c2, d2; The 3rd connection end point a3, b3, c3;
The 4th connection end point c4; Detecting voltage signal VFB;
Current sense signal IFB; Pulse duration control signal PWM;
Overcurrent protection signal OCP; Overvoltage protection signal OVP;
Overheat protector signal OTP; Guard signal PROT;
Transformer T; Bridge rectifier BD;
Alternating-current voltage source VAC; A winding L 1;
Secondary winding L2; Auxiliary winding L 3;
Enabling signal UVLO; Start capacitor C s;
Zener diode ZD; Starting resistance Rs;
Current limliting signal Ili; Input electric capacity of voltage regulation Cin;
Restart signal Reset; Fluorescent tube undercurrent protection signal UCP;
Pressure limiting signal Vli; Switch SW 3;
The first filament 582a; The second filament 582b;
Ac output voltage VO; Fluorescent tube guard signal LD;
The first reference potential V1; The second reference potential V2;
Embodiment
Please refer to Fig. 2, Fig. 2 is the circuit block diagram according to power supply conversion driving circuit of the present invention.The power supply conversion driving circuit comprises a control circuit 100, a change-over circuit 160 and a load circuit 180.Change-over circuit 160 couples an input voltage VIN, and control circuit 100 couples change-over circuit 160, produces a control signal S and converts input voltage VIN to an output voltage VO UT with control change-over circuit 160.Load circuit 180 comprises a load 182 and a load detecting unit 185, load 182 couples output voltage VO UT, load detecting unit 185 couples a detecting voltage source V DE, and detecting voltage source V DE can be that input voltage VIN, output voltage VO UT or other can provide a voltage source of electric power.Wherein, load detecting unit VDE can produce a load detection signal Sre when coupling detecting voltage source V DE.Therefore, when load circuit 180 inserted the power supply conversion driving circuits, control circuit 100 can receive the load detection signal Sre that load detecting unit 185 produces and restart.
It should be noted that power supply conversion driving circuit of the present invention can cooperate the needs of safety and the effect of electrical isolation is provided.Refer again to Fig. 2, a side of change-over circuit 160 couples input voltage VIN and one first common electric potential G1, produce output voltage VO UT in opposite side after transformation, and this side couples one second common electric potential G2.Load one termination is received output voltage VO UT and opposite side couples the second common electric potential G2.185 of control circuit 100 and load detecting units couple the first common electric potential G1.Therefore, the load in load circuit 180 182 and load detecting unit 185 do not connect mutually directly each other and couple the effect that corresponding common electric potential is issued to electrical isolation separately.Certainly, if need not electrical isolation, load 182 and load detecting unit 185 can interconnect each other in the practical application.
Then please refer to Fig. 3, Fig. 3 is the circuit diagram of the power supply conversion driving circuit of one first preferred embodiment according to the present invention.The power supply conversion driving circuit comprises a control circuit 200, a change-over circuit 260 and a load circuit 280.Change-over circuit 260 is the DC boosting change-over circuit that always circulates, and comprises an inductance L, a diode D, a switching switch SW and an output electric capacity of voltage regulation Co, becomes output voltage VO UT in order to receive an input voltage VIN and boost conversion.Load circuit 280 comprises a light emitting diode module 282 and a load detecting unit 285.Light emitting diode module 282 couples change-over circuit 260 with reception output voltage VO UT by one first connection end point a1 of load circuit 280, and couples ground by one second connection end point a2 of load circuit 280.Load detecting unit 285 comprises a resistance, and the one end couples change-over circuit 260 by the first connection end point a1, so that output voltage VO UT is detected voltage source as one.The other end is coupled ground and produces a load detection signal Sre by a resistance 290a by one the 3rd connection end point a3 of load circuit 280.
Control circuit 200 comprises a brownout lock cell 205, and restarts unit 210, a current feedback unit 215, an over-temperature protection unit 230, a voltage feedback unit 235, a protected location 240 and a drive signal generation unit 245, to produce the switching of the diverter switch SW in the control signal control change-over circuit 260.Brownout lock cell 205 couples a driving voltage VDD, produces an enabling signal UVLO other circuit units to the control circuit 200 after driving voltage VDD arrives a scheduled operation voltage, makes other circuit units begin start-up operation.
The power supply conversion driving circuit has comprised a current-sensing circuit 270 and a voltage detection circuit 275, wherein current-sensing circuit 270 couples load circuit 280, with detecting flow through light emitting diode module 282 a load current and produce a current sense signal IFB, and voltage detection circuit 275 couples change-over circuit 260, to detect output voltage VO UT and to produce a detecting voltage signal VFB.Current feedback unit 215 receives by current sense signal IFB producing a pulse duration control signal PWM, and produces an overcurrent protection signal OCP when load current surpasses a scheduled current higher limit.Voltage feedback unit 235 receives by detecting voltage signal VFB, produces an overvoltage protection signal OVP when output voltage VO UT surpasses a pre-determined upper voltage limit value.The temperature of over-temperature protection unit 230 detecting light emitting diode module 282 produces an overheat protector signal OTP when temperature surpasses a predetermined temperature higher limit.Protected location 240 couples current feedback unit 215, over-temperature protection unit 230, voltage feedback unit 235 and current-sensing circuit 270; when receiving overvoltage protection signal OVP, overcurrent protection signal OCP and overheat protector signal OTP arbitrary; produce a guard signal PROT to drive signal generation unit 245, produce control signal to stop drive signal generation unit 245.Drive signal generation unit 245 received pulse width control signal PWM, and the duty ratio of adjusting control signal accordingly is sent to the electric power size of change-over circuit 260 with the control input voltage VIN, the load current of the light emitting diode module 282 of flowing through is stable on the predetermined current value, and then makes light emitting diode module 282 stabilized illuminations.And when drive signal generation unit 245 receives guard signal PROT, then stop immediately exporting control signal till no longer receiving guard signal PROT.240 lasting scheduled times received overvoltage protection signal OVP or overcurrent protection signal OCP if circuit abnormality causes protected location; when perhaps a lasting scheduled time current sense signal IFB is zero (; continuing a scheduled time load current is zero); protected location 240 produces and lasting output protection signal PROT, to stop control circuit 200 control change-over circuits 260 and to pin in protected mode till control circuit 200 is restarted.
When load 182 appearance are unusual, to make control circuit 200 stop to export control signal, descend gradually because of the leakage current of circuit and make output voltage VO UT, make diode D conducting until being lower than input voltage VIN, output voltage VO UT will maintain and be lower than on diode forward bias voltage drop of input voltage VIN at this moment.Restart unit 210 and couple load detecting unit 285 to receive load detection signal Sre.Owing to be built within the load circuit 280 in the load detecting unit 285, when load 282 occurs unusual and the user removes load circuit 280 when changing, load detecting unit 285 will together be removed with load circuit 280.At this moment, by resistance 290a, load detection signal Sre is low level, restarts unit 210 and enters the preparation rebooting status.Be inserted into the power supply conversion driving circuit and work as new load circuit 280, load this moment detecting unit 285 couples the 3rd connection end point a3 again to output voltage VO UT.Therefore, after new load circuit 280 inserted the power supply conversion driving circuit, load detection signal Sre rose to one again and restarts on the current potential.At this moment, restart unit 210 output one and restart signal Reset and make protected location 240 state that unlocks, control circuit 200 is restarted.
Next, please refer to Fig. 4, Fig. 4 is the circuit diagram of the power supply conversion driving circuit of one second preferred embodiment according to the present invention.The power supply conversion driving circuit comprises a control circuit 300, a change-over circuit 360 and a load circuit 380.Change-over circuit 360 is a flyback change-over circuit, comprises a transformer T, one first diode D1, one second diode D2, a switching switch SW 1 and an output electric capacity of voltage regulation Co, becomes output voltage VO UT in order to receive an input voltage VIN and boost conversion.Input voltage VIN system is produced through a bridge rectifier BD rectification and after an input electric capacity of voltage regulation Cin voltage stabilizing by an alternating-current voltage source VAC.Transformer T has winding L 1, a secondary winding L3 and an auxiliary winding L 2 one one times.One time winding L 1 one ends couple input voltage VIN, and opposite side couples diverter switch SW1.Secondary winding L3 couples the first diode D1 with rectification, and becomes output voltage VO UT through output electric capacity of voltage regulation Co voltage stabilizing.Auxiliary winding L 2 is through the second diode D2, to transmit the stored part electric power of transformer T to control circuit 300.
The power supply conversion driving circuit comprises an input starter 350, and it has one and starts capacitor C s, a Zener diode ZD and a starting resistance Rs, to receive input voltage VIN and to convert a driving voltage VDD to control circuit 300.Control circuit 300 comprises a brownout lock cell 305, and restarts unit 310, a current limliting unit 320, an over-temperature protection unit 330, a voltage feedback unit 335, a protected location 340 and a drive signal generation unit 345, to produce the switching of the diverter switch SW1 in the control signal control change-over circuit 360.Brownout lock cell 305 couples a driving voltage VDD, produces an enabling signal UVLO other circuit units to the control circuit 300 after driving voltage VDD arrives a predetermined starting resistor, makes other circuit units begin start-up operation.
The power supply conversion driving circuit has comprised a voltage detection circuit 375 and a current-limiting resistance 365.Current-limiting resistance 365 couples the diverter switch SW1 in the change-over circuit 360, produces a current signal Ise according to the size of current of the diverter switch SW1 that flows through.Current limliting unit 320 received current signal Ise produce a current limliting signal Ili to drive signal generation unit 345 when the electric current of the diverter switch SW1 that flows through surpasses a cut-off current.Voltage detection circuit 375 couples change-over circuit 360, to detect output voltage VO UT and to produce a detecting voltage signal VFB.Voltage feedback unit 335 receives detecting voltage signal VFB producing a pulse duration control signal PWM, and produces an overvoltage protection signal OVP when output voltage surpasses a pre-determined upper voltage limit value.The temperature of over-temperature protection unit 330 detecting light emitting diode module 382 produces an overheat protector signal OTP when temperature surpasses a predetermined temperature higher limit.Protected location 340 couples over-temperature protection unit 330, voltage feedback unit 335; when receiving overvoltage protection signal OVP and overheat protector signal OTP arbitrary; produce a guard signal PROT to drive signal generation unit 345, produce control signal to stop drive signal generation unit 345.Drive signal generation unit 345 received pulse width control signal PWM, and the duty ratio of adjusting control signal accordingly is sent to the electric power size of change-over circuit 360 with the control input voltage VIN, output voltage VO UT is stable on the scheduled voltage, and when when a certain switching cycle, receiving current limliting signal Ili, immediately till diverter switch SW1 finishes to this switching cycle, to avoid the diverter switch super-high-current of flowing through.And when drive signal generation unit 345 receives guard signal PROT, then stop immediately exporting control signal till no longer receiving guard signal PROT.340 lasting scheduled times received overvoltage protection signal OVP if circuit abnormality causes protected location; protected location 340 produces and lasting output protection signal PROT, to stop control circuit 300 control change-over circuits 360 and to pin in protected mode till control circuit 300 is restarted.
Please refer to Fig. 5, Fig. 5 is the circuit diagram of the power supply conversion driving circuit of one the 3rd preferred embodiment according to the present invention.The power supply conversion driving circuit comprises a control circuit 400, a change-over circuit 460 and a load circuit 480.Change-over circuit 460 is that a full-bridge type direct current is delivered the stream translation circuit, its primary side couples one first common circuit G1, and primary side couples one second common circuit G2, in order to convert a direct current input voltage VIN to an ac output voltage VO, to drive the fluorescent lamp 482 in the load circuit 480.Load circuit 480 has comprised fluorescent lamp 482 and a load detecting unit 485, fluorescent lamp 482 couples ac output voltage VO and the second common electric potential G2 respectively by one first connection end point c1, one second connection end point c2, load detecting unit 485 couples input starter 450 and first a common electric potential G1 respectively by one the 3rd connection end point c3, one the 4th connection end point c4, and produces a load detection signal Sre.Because load detecting unit 485 couples input voltage VIN via a resistance 490a, so when load circuit 480 is removed, the accurate position of load detection signal Sre rises to the accurate position of input voltage VIN, and when load circuit 480 was inserted into, the accurate position of load detection signal Sre can descend.In addition, because the common electric potential of fluorescent lamp 482 and a load detecting unit 485 is inequality and directly do not connect, so electrical isolation each other.
The power supply conversion driving circuit also comprises an input starter 450, and input starter 450 all couples the first common electric potential G1 with control circuit 400.Input starter 450 receives input voltage VIN and converts a driving voltage VDD to control circuit 400.Control circuit 400 comprises a brownout lock cell 405, a current feedback unit 415, a concussion unit 416, a pressure limiting unit 435, a protected location 440 and a drive signal generation unit 445, to produce the switching of the diverter switch in the control signal control change-over circuit 460.Brownout lock cell 405 couples a driving voltage VDD, produces an enabling signal UVLO other circuit units to the control circuit 400 after driving voltage VDD arrives a predetermined starting resistor, makes other circuit units begin start-up operation.
The power supply conversion driving circuit has comprised an electrical isolation current-sensing circuit 470 and an electrical isolation voltage detection circuit 475, can have the element of electrical isolation for optical coupler or other.Electrical isolation voltage detection circuit 475 couples fluorescent lamp 482, with detecting flow through fluorescent lamp 482 lamp current size and produce a current sense signal IFB.Electrical isolation voltage detection circuit 475 couples change-over circuit 460, with the amplitude size of detecting ac output voltage VOUT and produce a detecting voltage signal VFB.Concussion unit 416 received current detection signal IFB also produce an oscillator signal OSC.Concussion unit 416 is oscillator signal OSC when current sense signal IFB represent lamp current and is zero, exports the oscillator signal OSC of upper frequency to light fluorescent lamp 482; Represent lamp current (represent fluorescent lamp 482 has lighted) greater than zero time in current sense signal IFB, export the oscillator signal OSC of lower frequency.Current feedback unit 415 received current detection signal IFB and oscillator signal OSC to be producing a pulse duration control signal PWM, and continue a scheduled time when being zero in lamp current, produces a fluorescent tube undercurrent protection signal UCP.Pressure limiting unit 435 receives detecting voltage signal VFB, produces a pressure limiting signal Vli when output voltage VO surpasses a pre-determined upper voltage limit value.Drive signal generation unit 445 received pulse width control signal PWM, and the duty ratio of adjusting control signal accordingly is sent to the electric power size of change-over circuit 460 with the control input voltage VIN, lamp current is stable on the predetermined current value, and when receiving pressure limiting signal Vli, make the voltage FEEDBACK CONTROL into, the cross-pressure when making fluorescent lamp 482 on lighting process is unlikely too high.
Protected location 440 couples current feedback unit 415, concussion unit 416, pressure limiting unit 435; and judge according to oscillator signal OSC whether fluorescent tube undercurrent protection signal UCP or pressure limiting signal Vli continue to produce when surpassing a scheduled time; if then continue to produce a guard signal PROT to drive signal generation unit 445, drive signal generation unit 445 produces control signal and pinning is restarted until control circuit 400 to stop.
Please refer to Fig. 6, Fig. 6 is the circuit diagram of the power supply conversion driving circuit of one the 4th preferred embodiment according to the present invention.The power supply conversion driving circuit comprises a control circuit 500, an input starter 550, a change-over circuit 560, a current-sensing circuit 570 and a voltage detection circuit 575, a load circuit 580 and a frequency regulating circuit 595.Change-over circuit 560 is the ac conversion circuit that always circulates, its primary side couples a direct current input voltage VIN, and convert an ac output voltage VO in primary side, to drive the fluorescent lamp 582 in the load circuit 580, its secondary side is imported starter 550 by a diode rectification to provide electrical power to.Input starter 550 is coupled to the secondary side of DC input voitage VIN and change-over circuit 560, when the power supply conversion driving circuit does not operate, receive the electric power of DC input voitage VIN to provide a driving voltage VDD to control circuit 500, when the power supply conversion driving circuit operates, also receive the electric power from secondary side simultaneously.Load circuit 580 has comprised fluorescent lamp 582 and a load detecting unit 585, fluorescent lamp 582 is for having one first filament 582a and one second filament 582b, the end of the end of the first filament 582a and the second filament 582b couples by load detecting unit 585, and the other end of the first filament 582a couples ac output voltage VO and is coupled to DC input voitage VIN by resistance 590a through one first connection end point d1, and the other end of the second filament 582b couples ground by one second connection end point d2.The detecting voltage signal VFB that the current sense signal IFB that control circuit 500 received current circuit for detecting 570 produce and voltage detection circuit 575 produce is to produce the electric power conversion of control signal control change-over circuit 560.
Current-sensing circuit 570 couples load circuit 580, with detecting flow through fluorescent lamp 582 a load current and produce a current sense signal IFB, and voltage detection circuit 575 couples change-over circuit 560, to detect output voltage VO and to produce a detecting voltage signal VFB.Concussion unit 516 produces an oscillator signal OSC, at the beginning of circuit start, the frequency of oscillator signal OSC continues a warm-up time and maintains a upper frequency with preheating fluorescent lamp 582, frequency is carried out frequency sweep lighting fluorescent lamp 582 toward a lower frequency of operation afterwards, and in after frequency dimension is held on the frequency of operation.Current feedback unit 515 receives by current sense signal IFB and oscillator signal OSC producing a pulse duration control signal PWM, and produces an overcurrent protection signal OCP when load current surpasses a scheduled current higher limit.Voltage feedback unit 535 receives by detecting voltage signal VFB, produces an overvoltage protection signal OVP when output voltage VO surpasses a pre-determined upper voltage limit value.Whether fluorescent tube protection is restarted unit 510 and is coupled load detecting unit 585, damage or whether fluorescent lamp 582 is removed in order to the first filament 582a, the second filament 582b that detects fluorescent lamp 582, if then produce a fluorescent tube guard signal LD.The temperature of over-temperature protection unit 530 detecting control circuits 500 produces an overheat protector signal OTP when temperature surpasses a predetermined temperature higher limit.Protected location 540 couples concussion unit 516, unit 510, current feedback unit 515, over-temperature protection unit 530, voltage feedback unit 535 and current-sensing circuit 570 are restarted in the fluorescent tube protection; when receiving overvoltage protection signal OVP, overcurrent protection signal OCP, fluorescent tube guard signal LD and overheat protector signal OTP arbitrary; produce a guard signal PROT to drive signal generation unit 545, produce control signal to stop drive signal generation unit 545.Drive signal generation unit 545 received pulse width control signal PWM, and the duty ratio of adjusting control signal accordingly makes fluorescent lamp 582 stabilized illuminations with the electric power size that control DC input voitage VIN is sent to change-over circuit 560.And when drive signal generation unit 545 receives guard signal PROT, then stop immediately exporting control signal till no longer receiving guard signal PROT.540 lasting scheduled times received overvoltage protection signal OVP or overcurrent protection signal OCP if circuit abnormality causes protected location; when perhaps a lasting scheduled time current sense signal IFB is zero; protected location 540 is according to oscillator signal OSC timing; foregoing circuit occurs in judgement and produce when unusual and continue output protection signal PROT, to stop control circuit 500 control change-over circuits 560 and to pin in protected mode till control circuit 500 is restarted.
Load circuit 580 is installed on the power supply conversion driving circuit; load detecting unit 585 is coupled to DC input voitage VIN to produce and to produce a load detection signal Sre; the current potential of load detection signal Sre can drop on the fluorescent tube protection and restarted between the one first reference potential V1 and one second reference potential V2 in the unit 510 this moment, and wherein the first reference potential V1 is higher than the second reference potential V2.And be removed or the first filament 582a of fluorescent lamp 582 damages and during open circuit, load detection signal Sre is coupled to ground by load detecting initial circuit 590, makes the current potential of load detection signal Sre be lower than the second reference potential V2 when load circuit 580.And the second filament 582b that works as fluorescent lamp 582 damages and opens a way, and then load detection signal Sre is coupled to DC input voitage VIN and is higher than the first reference potential V1 by a resistance 590a.Fluorescent tube protection is restarted unit 510 and is comprised one first comparator 511, one second comparator 512, one or door 513, one delay circuit 514.Whether first comparator 511 and second comparator drop between one first reference potential V1 and the one second reference potential V2 in order to compare load detection signal Sre.When load detection signal Sre is higher than the first reference potential V1 or is lower than the second reference potential V2; 512 of first comparator 511 or second comparators produce exporting to of high levle or door 513, make or door 513 produces fluorescent tube guard signal LD and makes control circuit 500 enter protected mode to protected location 540.
In addition, when delay circuit 514 receives guard signal PROT, start, whether remove with the abnormality of judging fluorescent lamp 582.When the abnormality of fluorescent lamp 582 is disengaged, for example: the user replaces new fluorescent lamp 582, then or the output signal of door 513 output low levels.When delay circuit 514 continues to receive or the low level output signal of door 513 after the scheduled time, produce one and restart signal Reset to protected location 540, make protected location 540 state that unlocks, control circuit 500 is restarted.
Concussion unit 516 can couple a frequency regulating circuit 595, to adjust the frequency of operation of control circuit 500, the i.e. frequency of oscillator signal OSC.As shown in Figure 6, frequency regulating circuit 595 is a current-mirror structure, comprise the bipolar transistor that two base stages connect, the emitter grounding of two bipolar transistors, the bipolar transistor that collector is connected with base stage is adjusted resistance R _ f adj by a frequency and is connected to driving voltage VDD (or other decide voltage source) with the frequency adjustment electric current I fadj that flows through, and through another bipolar transistor mirror image generation and input concussion unit 516, with the charging or discharging current size of adjustment concussion unit 516, and then the frequency of change oscillator signal OSC.Frequency regulating circuit 595 can reach the function of light modulation, the adjustment resistance R _ f adj that adjusts frequency in the present embodiment is adjustable resistance, user's resistance size of adjusting resistance R _ f adj of adjusting frequency decides frequency to adjust electric current I fadj size, and then adjusts the frequency of operation of circuit 500.When frequency was heightened, the power that fluorescent lamp 582 receives can descend and the brightness deepening, and when frequency was turned down, the power that fluorescent lamp 582 receives can rise and brightness brightens.
When frequency regulating circuit 595 is connected to input voltage VIN, then has the function of adjusting power output with input voltage VIN.When input voltage VIN is higher (for example: the civil power by 220V provides after rectification), frequency adjustment electric current I fadj can rise frequency is increased, with the power output of compensation input voltage VIN rising, otherwise instead then.The means that said frequencies is adjusted circuit 595 utilization adjustment charging and discharging currents only are one of means of adjusting frequency, can cooperate the circuit structure that shakes unit 516 during practical application, for example: for the voltage controlled oscillator adjustable inside up and down reference voltage current potential or produce the capacitance size of ramp signal.
Therefore, shown in above-mentioned embodiment, power supply conversion driving circuit of the present invention powered-down conversion driving circuit when the load that drives continues possible the power consumption of running when reducing control circuit in the power supply conversion driving circuit in circuit abnormality, and can avoid the user to use doubt on safe.In addition, after the user changes load, the power supply conversion driving circuit will be restarted automatically, to increase the convenience in user's use.
It should be noted that at last: above embodiment is only in order to technical scheme of the present invention to be described but not limit it, although with reference to preferred embodiment the present invention is had been described in detail, those of ordinary skill in the art is to be understood that: it still can make amendment or be equal to replacement technical scheme of the present invention, and these modifications or be equal to replacement and also can not make amended technical scheme break away from the spirit and scope of technical solution of the present invention.
Claims (25)
1. power supply conversion driving circuit comprises:
One change-over circuit couples an input voltage;
One control circuit couples this change-over circuit, converts this input voltage to an output voltage in order to control this change-over circuit; And
One load circuit comprises a load detecting unit and a load, and this output voltage of this load coupled, this load detecting unit couple a detecting voltage source;
Wherein, this load detecting unit produces a load detection signal when this load circuit inserts this power supply conversion driving circuit, this control circuit is restarted.
2. power supply conversion driving circuit according to claim 1, its characteristic should detecting voltage source be this input voltage or this output voltage at what.
3. power supply conversion driving circuit according to claim 2, its characteristic is the DC converting circuit that always circulates at this change-over circuit of what, this load is a light emitting diode module, and this control circuit is according to this change-over circuit of detecting voltage signal controlling that represents this output voltage.
4. power supply conversion driving circuit according to claim 3, its characteristic at this control circuit of what also according to flow through this change-over circuit of current sense signal controlling of a load current of this load of representative.
5. power supply conversion driving circuit according to claim 2, its characteristic is the ac conversion circuit that always circulates at this change-over circuit of what, this load is a fluorescent lamp, and this control circuit is according to flow through this change-over circuit of current sense signal controlling of a load current of this load of a detecting voltage signal that represents this output voltage and representative.
6. according to claim 3 or 5 described power supply conversion driving circuits; its characteristic comprises a protected location at this control circuit of what, and this protected location surpasses a predetermined protection magnitude of voltage, this load current in this output voltage and surpasses and stop this control circuit when a predetermined protective current value or this load current are lower than a predetermined current value and control this change-over circuit and pin.
7. power supply conversion driving circuit according to claim 6, its characteristic unlocks when receiving this load detection signal at this protected location of what, and this control circuit is restarted.
8. power supply conversion driving circuit according to claim 1, its characteristic directly is not connected with this load at this load detecting unit of what.
9. power supply conversion driving circuit according to claim 8, its characteristic also comprises an input starter at this power supply conversion driving circuit of what, this input starter couples this input voltage to produce a driving voltage, and this control circuit couples this driving voltage to receive the operation required electric power.
10. power supply conversion driving circuit according to claim 1, its characteristic also comprise a frequency regulating circuit at this power supply conversion driving circuit of what and adjust the power that this change-over circuit exports this load to a frequency of operation of adjusting control circuit.
11. power supply conversion driving circuit according to claim 10, its characteristic couples this input voltage at this frequency regulating circuit of what, and this frequency of operation is changed with this input voltage.
12. a power supply conversion driving circuit comprises:
One change-over circuit couples an input voltage;
One control circuit couples this change-over circuit, converts this input voltage to an output voltage in order to control this change-over circuit; And
One load circuit comprises a load detecting unit and a load, this output voltage of this load coupled, and this load detecting unit couples a driving voltage source;
Wherein, this control circuit couples this driving voltage source to receive the operation required electric power by this load detecting unit, when this load circuit removes, stops to provide this control circuit operation required electric power.
13. power supply conversion driving circuit according to claim 12, its characteristic also comprises an input starter at this power supply conversion driving circuit of what, this input starter couples this input voltage to produce a driving voltage, and this control circuit couples this driving voltage to receive the operation required electric power.
14. power supply conversion driving circuit according to claim 13, its characteristic comprises a switch element at this input starter of what and couples this load detecting unit, in order to transmit this operation required electric power, when removing, this load circuit stops to transmit this operation required electric power.
15. power supply conversion driving circuit according to claim 14, its characteristic comprises a transformer at this change-over circuit of what, this transformer has winding, a secondary winding and an auxiliary winding one one times, this winding couples this input voltage, this secondary winding couples this output voltage, and this auxiliary winding couples this input starter.
16. power supply conversion driving circuit according to claim 14, its characteristic is this input voltage in this driving voltage source of what, and this input starter couples this input voltage by this load detecting unit.
17. power supply conversion driving circuit according to claim 12, its characteristic is in this load detecting unit of what and this load electrical isolation each other.
18. power supply conversion driving circuit according to claim 12, its characteristic also comprise a frequency regulating circuit at this power supply conversion driving circuit of what and adjust the power that this change-over circuit exports this load to a frequency of operation of adjusting control circuit.
19. power supply conversion driving circuit according to claim 18, its characteristic couples this input voltage at this frequency regulating circuit of what, and this frequency of operation is changed with this input voltage.
20. a fluorescent lamp drive circuit comprises:
One change-over circuit couples an input voltage;
One control circuit couples this change-over circuit, converts this input voltage to an output voltage in order to control this change-over circuit; And
One load circuit comprises a load detecting unit and a fluorescent lamp, and this fluorescent lamp couples this output voltage and has two filaments, and this load detecting unit couples this input voltage and ground connection and produces a load detection signal by this two filament;
Wherein, the shut-down operation when this fluorescent lamp drive circuit generation circuit abnormality of this control circuit, and in after detect and restart when this load detection signal enters a predetermined voltage range.
21. fluorescent lamp drive circuit according to claim 20; its characteristic comprises a protected location at this control circuit of what, and this protected location surpasses a predetermined protection magnitude of voltage or surpasses in this load current in this output voltage and produces a guard signal to stop the operation of this control circuit when a predetermined protective current value or this load current are lower than a predetermined current value.
22. fluorescent lamp drive circuit according to claim 21; its characteristic comprises one at this control circuit of what and restarts the unit; this is restarted the unit and starts when receiving this guard signal, and in after detect and produce one when this load detection signal enters this predetermined voltage range and restart signal to restart this control circuit.
This is restarted the unit and also comprises a delay circuit 23. fluorescent lamp drive circuit according to claim 22, its characteristic are at what, in judging that producing this after this load detection signal enters one scheduled time of this predetermined voltage range length restarts signal.
24. fluorescent lamp drive circuit according to claim 20, its characteristic also comprise a frequency regulating circuit at this fluorescent lamp drive circuit of what and adjust the power that this change-over circuit exports this load to a frequency of operation of adjusting control circuit.
25. fluorescent lamp drive circuit according to claim 24, its characteristic couples this input voltage at this frequency regulating circuit of what, and this frequency of operation is changed with this input voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910172029 CN102006710B (en) | 2009-09-03 | 2009-09-03 | Power supply changeover drive circuit and fluorescent lamp drive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910172029 CN102006710B (en) | 2009-09-03 | 2009-09-03 | Power supply changeover drive circuit and fluorescent lamp drive circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102006710A CN102006710A (en) | 2011-04-06 |
| CN102006710B true CN102006710B (en) | 2013-08-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200910172029 Expired - Fee Related CN102006710B (en) | 2009-09-03 | 2009-09-03 | Power supply changeover drive circuit and fluorescent lamp drive circuit |
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| Country | Link |
|---|---|
| CN (1) | CN102006710B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109256942B (en) * | 2018-11-01 | 2020-03-31 | 电子科技大学 | Self-adaptive starting circuit suitable for primary side feedback flyback converter |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1615675A (en) * | 2001-12-28 | 2005-05-11 | 松下电工株式会社 | Ballast for discharge lamp |
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Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1615675A (en) * | 2001-12-28 | 2005-05-11 | 松下电工株式会社 | Ballast for discharge lamp |
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| CN102006710A (en) | 2011-04-06 |
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