CN105338718B - It is a kind of based on linearly with the LED constant current driving method and device of PWM operating modes - Google Patents
It is a kind of based on linearly with the LED constant current driving method and device of PWM operating modes Download PDFInfo
- Publication number
- CN105338718B CN105338718B CN201510897833.7A CN201510897833A CN105338718B CN 105338718 B CN105338718 B CN 105338718B CN 201510897833 A CN201510897833 A CN 201510897833A CN 105338718 B CN105338718 B CN 105338718B
- Authority
- CN
- China
- Prior art keywords
- resistance
- circuit
- voltage
- rectification circuit
- led load
- 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.)
- Active
Links
Classifications
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- 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
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
Landscapes
- Rectifiers (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention discloses a kind of method and apparatus based on linearly with the driving of the LED constant current of PWM operating modes, this method is under the frame of linear constant current, using PWM control technologies, the electric current of LED load is controlled by changing the duty ratio of impulse waveform of the alternating current after over commutation, the calorific value of power device can be reduced and improve transfer efficiency, efficiently solving linear constant current in the prior art drives idle power consumption big, allow mains fluctuations range small, the defects such as transfer efficiency is low, it is simple with circuit structure, without inductance element, it is cheap, the advantages that without EMI.
Description
Technical field
The present invention relates to a kind of illumination lamp driving power source, especially a kind of method and apparatus of LED constant current driving.
Background technology
Using AC220V/50Hz alternating currents as in the LED illumination lamp of power supply, high-voltage linear constant current drive scheme is wide
General application, linear constant current driver have simple in structure, cheap, electromagnetic-radiation-free, high reliability and by industry
Approve, however, linear constant current driver also has following unavoidable defect simultaneously：
1, linear constant current driver is operated under linear pattern, is used in series with load (LED light source), by adjusting certainly
The pressure drop of body controls the electric current of load, to achieve the purpose that constant current, nothing caused by the linear constant current driver pressure drop of itself
Work(power can cause device heating, efficiency to decline, and must select high voltage, low current, the light source of low voltage difference, institute in the application
To be above somewhat limited in application.
2, linear constant current driver allows the fluctuating range of supply voltage smaller, once power-supply fluctuation amplitude is beyond permission
Range, efficiency will be caused, which to decline, even influences normal work.
3, existing LED light source is usually and is connected in series by several LED chips or lamp bead, single led forward voltage
For 3.2V or so, if using Linear Driving scheme, producer generally all can improve lamp string using the quantity for increasing lamp bead as cost
Voltage, reduce pressure difference, or using higher price high pressure lamp bead, cause the cost of product to increase in this way.
Invention content
For overcome the deficiencies in the prior art, the present invention provide a kind of circuit structure it is simple, without inductance element, low cost
It is honest and clean, without EMI based on linearly with the LED constant current driving method and device of PWM operating modes.
The technical solution adopted by the present invention to solve the technical problems is：
It is a kind of based on linearly with the LED constant current driving method of PWM operating modes, under the frame of linear constant current, using PWM
Control technology controls the electric current of LED load by changing the duty ratio of impulse waveform of the alternating current after over commutation.
The impulse waveform later to AC rectification is sampled, and one group of arteries and veins later with rectification is generated by impulse controller
Rush that wave period is synchronous, the identical pulse signal of frequency, by changing duty ratio, control and the concatenated semiconductor work(of LED load
The make-and-break time of rate device keeps LED load electric current constant.
The controllable square-wave signal of one group of duty ratio is generated by impulse controller, the DC pulse waveform after rectification is implemented to adjust
System, the duty ratio by modulating pulse go control with the make-and-break time of the concatenated semiconductor power device of LED load, keep LED negative
It is constant to carry electric current.
Voltage difference between supply voltage, LED load electric current, LED load and power supply is carried out at the same time signal sampling, pulse
Controller generates suitable pulse width according to sampled signal, to reach LED load constant current purpose.
It is a kind of realize the above method based on linearly with the LED constant current driving device of PWM operating modes, which includes whole
Current circuit, LED load, PWM controller, switching circuit, voltage sampling circuit and current sampling circuit；The LED load, switch
Circuit and current sampling circuit are connected the anode of the latter termination rectification circuit, the cathode of another termination rectification circuit；
The voltage sampling circuit one terminates the anode of the rectification circuit, the cathode of another termination rectification circuit；The PWM controls
The input of device processed terminates the voltage sampling circuit and current sampling circuit, and output terminates the switching circuit.
The switching circuit includes N-channel MOS pipe T1, and the drain D of the metal-oxide-semiconductor T1 connects the LED load, and source S connects
The cathode of the rectification circuit, grid G connect the output end of the PWM controller；Between the drain D and source S of the metal-oxide-semiconductor T1
It is parallel with resistance R6.
The current sampling circuit includes a termination MOS of NPN type triode T2 and resistance RCS, the resistance RCS
The source S of pipe T1, the cathode of another termination rectification circuit, the base stage B of the triode T2 meet the resistance RCS and MOS
The node of pipe T1 source Ss, emitter E connect the cathode of the rectification circuit, and collector C connects the PWM controller by resistance R5.
The PWM controller is voltage comparator U1；Voltage sampling circuit includes resistance R1, resistance R2, resistance R3 and steady
Pressure diode Z1, the resistance R1 and resistance R2 concatenate the anode of the latter termination rectification circuit, another whole stream of termination
After the cathode of circuit, the resistance R3 and zener diode Z1 concatenations, the anode of another termination rectification circuit of resistance R3,
The cathode of another termination current circuit of zener diode Z1, the in-phase input end of the voltage comparator U1 divide two-way, and one
Road connects the node of the resistance R1 and resistance R2, and another way connects the resistance R5, the reverse input end of the voltage comparator U1
Divide two-way, connects the node of the resistance R3 and zener diode Z1 by resistance R21 all the way, another way meets institute by resistance R22
The cathode of rectification circuit is stated, the output of voltage comparator U1 terminates the grid G of the metal-oxide-semiconductor T1；The zener diode Z1's
Both ends are parallel with capacitance C1.
Filter capacitor C2 is connected between the positive and negative anodes of the rectification circuit；The filter capacitor C2 and the rectification circuit
Anode between be connected with isolating diode D5.
The PWM controller includes triangular-wave generator U1A, voltage comparator U1B, and the voltage sampling circuit includes electricity
Hinder R12, resistance R9, resistance R10, resistance R13, resistance R14, resistance R15, resistance R16, resistance R17, resistance R18, two pole of voltage stabilizing
Pipe D6, capacitance C3 and capacitance C4；After the resistance R12, resistance R9, resistance R10 are sequentially connected in series, another termination institute of resistance R12
State the anode of rectification circuit, the cathode of another termination rectification circuit of resistance R10；The zener diode D6 and capacitance C3
The node of latter termination the resistance R12 and resistance R9 in parallel, the cathode of another termination rectification circuit；The resistance R13,
After resistance R14 series connection, the node of another termination the resistance R12 and resistance R9 of resistance R13, another termination institute of resistance R14
State the cathode of rectification circuit；After the resistance R16, resistance R17 and capacitance C4 are sequentially connected in series, another termination of the resistance R16
The node of the resistance R12 and resistance R9, the cathode of another termination rectification circuit of the capacitance C4；The resistance R15
Termination the resistance R13 and resistance R14 node, the node of another terminating resistor R16 and resistance R17, the triangular wave
The node of the homophase input terminating resistor R13 and resistance R14 of generator U1A, the knot of reverse input end connecting resistance R17 and capacitance C4
Point exports the node of terminating resistor R16 and resistance R17；The homophase input terminating resistor R9 and resistance of the voltage comparator U1B
The node of R10, the node of reverse input end connecting resistance R17 and capacitance C4, output terminates the input terminal of the switching circuit, described
The node of termination the resistance R12 and resistance R9 of resistance R18, the output end of another termination voltage comparator U1B.
The voltage sampling circuit and current sampling circuit include NPN type triode Q1, resistance RCS1, resistance R7, resistance
The source S of a termination metal-oxide-semiconductor T1 of R8 and resistance R20, the resistance RCS1, another termination rectification circuit are born
After pole, the resistance R7 and resistance R8 series connection, the anode of another termination rectification circuit of resistance R7, resistance R8 connects described whole
The cathode of current circuit, the node of termination the resistance R7 and resistance R8 of the resistance R20, the other end divide two-way, connect all the way
The base stage of the triode Q1, another way connect the node of the resistance RCS1 and switching circuit, the collector of the triode Q1
Connect the node of the resistance R9 and resistance R10 by resistance R11, the cathode of rectification circuit described in collector.
The beneficial effects of the invention are as follows：The present invention, using PWM control technologies, passes through change under the frame of linear constant current
The duty ratio of impulse waveform of the alternating current after over commutation controls the electric current of LED load, can reduce the fever of power device
Amount and transfer efficiency is improved, efficiently solves linear constant current in the prior art and drive that idle power consumption is big, allows mains fluctuations
The defects such as range is small, transfer efficiency is low, have circuit structure it is simple, without inductance element, it is cheap, without EMI (electromagnetism spokes
Penetrate) the advantages that.
Description of the drawings
Present invention will be further explained below with reference to the attached drawings and examples.
Fig. 1 is the first embodiment circuit diagram of the present invention；
Fig. 2 is second of embodiment circuit diagram of the present invention
Specific implementation mode
Referring to Fig.1, Fig. 2, it is a kind of based on linearly with the LED constant current driving method of PWM operating modes, in the frame of linear constant current
It is negative to control LED by changing the duty ratio of impulse waveform of the alternating current after over commutation using PWM control technologies under frame
The electric current of load.
The impulse waveform later to AC rectification is sampled, and one group of arteries and veins later with rectification is generated by impulse controller
Rush that wave period is synchronous, the identical pulse signal of frequency, by changing duty ratio, control and the concatenated semiconductor work(of LED load
The make-and-break time of rate device keeps LED load electric current constant.
The controllable square-wave signal of one group of duty ratio is generated by impulse controller, the DC pulse waveform after rectification is implemented to adjust
System, the duty ratio by modulating pulse go control with the make-and-break time of the concatenated semiconductor power device of LED load, keep LED negative
It is constant to carry electric current.
Voltage difference between supply voltage, LED load electric current, LED load and power supply is carried out at the same time signal sampling, pulse
Controller generates suitable pulse width according to sampled signal, to reach LED load constant current purpose.
It is a kind of realize the above method based on the LED constant-current driver linearly with PWM operating modes, including rectification circuit,
LED load, PWM controller, switching circuit, voltage sampling circuit and current sampling circuit；The LED load, switching circuit and
Current sampling circuit is connected the anode of the latter termination rectification circuit, the cathode of another termination rectification circuit；The electricity
Pressure sample circuit one terminates the anode of the rectification circuit, the cathode of another termination rectification circuit；The PWM controller
Input terminates the voltage sampling circuit and current sampling circuit, and output terminates the switching circuit.
For the first embodiment referring to Fig. 1, the switching circuit includes N-channel MOS pipe T1, the drain D of the metal-oxide-semiconductor T1
The LED load is connect, source S connects the cathode of the rectification circuit, and grid G meets the output end of the PWM controller, the MOS
It is parallel with resistance R6 between the drain D and source S of pipe T1.
The current sampling circuit includes a termination MOS of NPN type triode T2 and resistance RCS, the resistance RCS
The source S of pipe T1, the cathode of another termination rectification circuit, the base stage B of the triode T2 meet the resistance RCS and MOS
The node of pipe T1 source Ss, emitter E connect the cathode of the rectification circuit, and collector C connects the PWM controller by resistance R5.
The PWM controller is voltage comparator U1；Voltage sampling circuit includes resistance R1, resistance R2, resistance R3 and steady
Pressure diode Z1, the resistance R1 and resistance R2 concatenate the anode of the latter termination rectification circuit, another whole stream of termination
After the cathode of circuit, the resistance R3 and zener diode Z1 concatenations, the anode of another termination rectification circuit of resistance R3,
The cathode of another termination current circuit of zener diode Z1, the in-phase input end of the voltage comparator U1 divide two-way, and one
Road connects the node of the resistance R1 and resistance R2, and another way connects the resistance R5, the reverse input end of the voltage comparator U1
Divide two-way, connects the node of the resistance R3 and zener diode Z1 by resistance R21 all the way, another way meets institute by resistance R22
The cathode of rectification circuit is stated, the output of voltage comparator U1 terminates the grid G of the metal-oxide-semiconductor T1；The zener diode Z1's
The node that both ends are parallel with capacitance C1, resistance R1 and resistance R2 is connect with resistance R5.
220V, 50Hz electric main become peak value after the bridge rectifier being made of diode D1, D2, D3, D4
For the unidirectional pulse voltage of 311V, 100Hz, it is used as sampling voltage V1 after resistance R1, resistance R2 partial pressures, connects voltage comparator
The in-phase input end "+" of U1, the waveform and the waveform before partial pressure of sampling voltage V1 are consistent.Resistance R3, zener diode Z1
A simple regulator circuit is formed with capacitance C1, a stable operating voltage voltage supplied comparator U1 is provided and is used, resistance
The node of R3 and zener diode Z1 are supplied to voltage comparator by being used as reference voltage V 2 after resistance R22, resistance R21 partial pressures
The reverse input end "-" of U1.
When work, input voltage is at 0, V1 ＜ V2, therefore, the output end voltage of voltage comparator U1 is low level L, is connect
It, with climbing for input voltage waveform, the voltage of V1 also up climbs, and as V1 ＞ V2, voltage comparator U1 output ends turn over
Turn, exports as high level H, by the time of 5ms, impulse waveform reaches peak dot, and the level of V1 has also reached peak, then,
Input voltage impulse waveform starts to glide, and V1 also and then declines, when voltage drops to V1 ＜ V2, voltage comparator U1 output ends
Overturning, output end are low level L, are completed from pulse peak dot to the entire pulse period, also last 5ms, in this way, just completing one
Next the conversion of pulse period enters next pulse period, also the same process for repeating front, voltage comparator U1's
Output end just obtains a string of square-wave signals synchronous with input voltage.Reference voltage V 2 determines the overturning of voltage comparator U1
Threshold values changes the voltage of V2, so that it may to change the width of output pulse, also just change the duty ratio of output pulse.
Metal-oxide-semiconductor T1 is controlled with the pulse signal of voltage comparator U1 outputs, when voltage comparator U1 exports low level L,
Metal-oxide-semiconductor T1 cut-offs, LED load do not have electric current to flow through, and when voltage comparator U1 exports high level H, LED is given in metal-oxide-semiconductor T1 conductings
Load provides operating current.When the operating current of LED load is by resistance RCS, voltage a VCS, VCS can be generated at its both ends
Size it is directly proportional to the electric current by resistance RCS, VCS is connected to the base stage B of triode T2, directly affects the collector C of T2
Voltage, also just directly affect the sampling voltage V1 of voltage comparator U1.It is assumed that certain reason makes load current increase (such as
Input line voltage and the reasons such as increase), then similarly increased by the electric current of resistance RCS, voltage VCS also with increase, due to
The amplification of triode T2, the current potential of collector C declining also while therewith, by resistance R5, taking for voltage comparator U1
Sample voltage V1 is dragged down, as a result, the turn-on time of voltage comparator U1 output ends elapses backward, deadline shifts to an earlier date, defeated to make
Go out pulse width to narrow；, whereas if certain reason makes LED load electric current become smaller, similarly become by the electric current of resistance RCS
Small, voltage VCS declines, at this point, the current potential of the collector C points of triode T2 rises, on the sampling voltage V1 of voltage comparator U1
It rises and so that conducting flip-flop transition is shifted to an earlier date, deadline lag, so that output pulse width is become larger, in this manner it is possible to LED load
Electric current is controlled automatically in some setting value.
The effect of the resistance R6 is the voltage between the source S and drain D for detecting metal-oxide-semiconductor T1, this voltage is in fact
It is the voltage difference between LED load voltage and supply voltage (output end voltage of rectification circuit), referred to as pressure difference, in linear arrangement
In, pressure difference is smaller, and efficiency is higher.When supply voltage changes, pressure difference can change correspondingly, so, resistance R6 can be by this
A pressure difference signal, which timely feedbacks, gives triode T2, when ramping the supply voltage up, the voltage between the source S and drain D of metal-oxide-semiconductor T1
Also it increases, is also increased by resistance R6, VCS, by triode T2, resistance R5, the sampling of voltage comparator U1
Voltage pull-down and so that output pulse width is narrowed, conversely, then output pulse width becomes larger, in this way, just a degree of maintain
The electric current of LED load is constant.
The appropriate parameter for selecting resistance R1, resistance R2, resistance R3, resistance R5, resistance R6 and zener diode Z1, Ke Yishe
The variation window for determining pulse width, can be such that pulse duty factor changes in the range of 10%-95%, to adapt to wide range
Mains fluctuations, even, supply voltage be less than certain amplitude when, make pulse width be more than 99, make the direct works of metal-oxide-semiconductor T1
Make, in purely linear state, to change the resistance value of resistance RCS, then can set the size of continuous current.Above-mentioned voltage comparator U1
Model LM393 can also select the comparator or operational amplifier of other any models, such as LM311, LM358；Metal-oxide-semiconductor
T1 is high pressure field-effect power tube, such as model 2N60.
On the basis of above-mentioned, increase filter capacitor C2 and isolating diode D5 in circuit, isolating diode D5 is electricity
R1, resistance R3 and LED load one-way isolation are hindered, the voltage V1 of voltage comparator U1 is made to remain the pulse signal of 100Hz, benchmark
Voltage V2 and LED load are operated in the state of pure direct current, and due to adding filter capacitor C2, capacitance C1 can be omitted.
Second of embodiment referring to Fig. 2, circuit shown in Fig. 2 and circuit shown in FIG. 1 difference lies in：Use one
A triangular-wave generator and a voltage comparator, physical circuit are as follows：
The PWM controller includes triangular-wave generator U1A, voltage comparator U1B, and voltage sampling circuit includes resistance
R12, resistance R9, resistance R10, resistance R13, resistance R14, resistance R15, resistance R16, resistance R17, resistance R18, zener diode
D6, capacitance C3 and capacitance C4；After the resistance R12, resistance R9, resistance R10 are sequentially connected in series, described in another termination of resistance R12
The anode of rectification circuit, the cathode of another termination rectification circuit of resistance R10；The zener diode D6 and capacitance C3 are simultaneously
Join the node of latter termination the resistance R12 and resistance R9, the cathode of another termination rectification circuit；The resistance R13, electricity
After hindering R14 series connection, the node of another termination the resistance R12 and resistance R9 of resistance R13, described in another termination of resistance R14
The cathode of rectification circuit；After the resistance R16, resistance R17 and capacitance C4 are sequentially connected in series, another termination institute of the resistance R16
State the node of resistance R12 and resistance R9, the cathode of another termination rectification circuit of the capacitance C4；The resistance R15's
The node of one termination the resistance R13 and resistance R14, the node of another terminating resistor R16 and resistance R17, the triangular wave hair
The node of the homophase input terminating resistor R13 and resistance R14 of raw device U1A, the knot of reverse input end connecting resistance R17 and capacitance C4
Point exports the node of terminating resistor R16 and resistance R17；The homophase input terminating resistor R9 and resistance of the voltage comparator U1B
The node of R10, the node of reverse input end connecting resistance R17 and capacitance C4, output terminates the input terminal of the switching circuit, described
The node of termination the resistance R12 and resistance R9 of resistance R18, the output end of another termination voltage comparator U1B.
The voltage sampling circuit and current sampling circuit include NPN type triode Q1, resistance RCS1, resistance R7, resistance
The source S of a termination metal-oxide-semiconductor T1 of R8 and resistance R20, the resistance RCS1, another termination rectification circuit are born
After pole, the resistance R7 and resistance R8 series connection, the anode of another termination rectification circuit of resistance R7, resistance R8 connects described whole
The cathode of current circuit, the node of termination the resistance R7 and resistance R8 of the resistance R20, the other end divide two-way, connect all the way
The base stage of the triode Q1, another way connect the node of the resistance RCS1 and switching circuit, the collector of the triode Q1
Connect the node of the resistance R9 and resistance R10 by resistance R11, the cathode of rectification circuit described in collector.
The electric main of AC220V, 50Hz, the bridge rectifier rectification of rectified diode D1, D2, D3, D4 composition with
Afterwards, become the high-voltage dc pulse that peak value is 311V, frequency is 100Hz, output cathode is connected to the positive terminal of LED load, and LED is negative
The cathode of load is connected to the drain D of metal-oxide-semiconductor T1.One simple direct current is formed by resistance R12, zener diode D6, capacitance C3
Decompression voltage regulator provides a stable voltage to triangular-wave generator U1A, voltage comparator U1B, resistance R13, resistance
R14, resistance R15, resistance R16, resistance R17 and capacitance C4 form a general triangular-wave generator, and pulse frequency depends on
In the charge and discharge electrical time constant of resistance R17, capacitance C4, triangular signal is exported from the node of capacitance C4 and resistance R17, is sent into electricity
The reverse input end of comparator U1B, the reference voltage of triangular-wave generator U1A is pressed to divide gained by resistance R13 and resistance R14,
The sampling voltage of voltage comparator U1B is divided gained by resistance R9 and resistance R10 from 12V power supplys, and triangular-wave generator U1A is defeated
The triangular wave gone out is shaped as one group of square-wave signal by voltage comparator U1B, which is sent to the grid G of metal-oxide-semiconductor T1,
Control metal-oxide-semiconductor T1 on and off.
In work, it just will produce the size of voltage a VCS1, VCS1 at the both ends of resistance RCS1 and pass through LED load
Size of current is directly proportional, and VCS1 is connected to the base stage of triode Q1, due to the amplification of triode Q1, the small change of VCS1
Change, the collector potential of triode Q1 can be made while being changed, also just become the sampling voltage of voltage comparator U1B
Change, and the variation of sampling voltage means that threshold voltage changes, at this point, the pulse duty factor of its output is also just sent out simultaneously
It is raw to change.For example, under the conditions of certain operating current, the pulse duty factor of voltage comparator U1B outputs is 80%, if certain
Kind reason (such as supply voltage increases) makes the electric current of LED load increase, at this point, VCS1 is just and then risen due to the increase of electric current
Height, at this moment, the base potential of triode Q1 increase the increase for just causing collector current, and collector potential is dragged down, and lead to
Resistance R6 is crossed, the homophase input terminal potential of voltage comparator U1B is dragged down, the output duty cycle of voltage comparator U1B is made to become smaller,
For example 70%, 60% etc. is fallen to, so that the electric current of LED load is become smaller to control the turn-on time of metal-oxide-semiconductor T1, makes to pass through
The electric current of LED load is stablized in the range of setting.
So that LED load operating voltage is in the state of pure direct current if necessary, an electrolysis electricity can be added in circuit
Hold and one only isolates diode to realize.
Above embodiment simply to illustrate that the invention operation principle, the concrete structure of circuit is not in embodiment
The restriction to the invention protection domain can be constituted, the personnel of professional skill field can also be according to the characteristic of circuit, by MOS
Pipe T1 is changed to the metal-oxide-semiconductor of P-channel, triode T2, triode Q1 is replaced with positive-negative-positive etc., and do to the connection type of device
The adjustment of adaptation, PWM controller may be microcontroller etc., as long as the variation done according to the general idea of the invention
With improvement, still fall within the scope of the invention covers.
Claims (4)
1. it is a kind of based on linearly with the LED constant current driving method of PWM operating modes, it is characterised in that this method is：Linear permanent
Under the frame of stream, using PWM control technologies, controlled by changing the duty ratio of impulse waveform of the alternating current after over commutation
The electric current of LED load；The impulse waveform later to AC rectification is sampled, by impulse controller generate one group with rectification with
The identical pulse signal of impulse waveform cycle synchronisation, frequency afterwards, by changing duty ratio, control and LED load concatenated half
The make-and-break time of conductor power device keeps LED load electric current constant；
This method is for including rectification circuit, LED load, PWM controller, switching circuit, voltage sampling circuit and current sample
Circuit based on linearly with the LED constant current driving device of PWM operating modes, it is characterised in that the LED load, switching circuit and
Current sampling circuit is connected the anode of the latter termination rectification circuit, the cathode of another termination rectification circuit；The electricity
Pressure sample circuit one terminates the anode of the rectification circuit, the cathode of another termination rectification circuit；The PWM controller
Input terminates the voltage sampling circuit and current sampling circuit, and output terminates the switching circuit；
The switching circuit includes that the drain D of the metal-oxide-semiconductor T1, the metal-oxide-semiconductor T1 of N-channel connect the LED load, and source S meets institute
The cathode of rectification circuit is stated, grid G connects the output end of the PWM controller；Between the drain D and source S of the metal-oxide-semiconductor T1 simultaneously
It is associated with resistance R6；
The current sampling circuit includes a termination metal-oxide-semiconductor T1 of NPN type triode T2 and resistance RCS, the resistance RCS
Source S, the cathode of another termination rectification circuit, the base stage B of the triode T2 meets the resistance RCS and metal-oxide-semiconductor T1
The node of source S, emitter E connect the cathode of the rectification circuit, and collector C connects the PWM controller by resistance R5；It is described
PWM controller is voltage comparator U1；Voltage sampling circuit includes resistance R1, resistance R2, resistance R3 and zener diode Z1, institute
State the anode that resistance R1 and resistance R2 concatenates the latter termination rectification circuit, the cathode of another whole rectification circuit of termination,
After the resistance R3 and zener diode Z1 is concatenated, the anode of another termination rectification circuit of resistance R3, zener diode
The cathode of another termination rectification circuit of Z1, the in-phase input end of the voltage comparator U1 divide two-way, connect all the way described
The node of resistance R1 and resistance R2, another way meet the resistance R5, and the reverse input end of the voltage comparator U1 divides two-way, and one
Road connects the node of the resistance R3 and zener diode Z1 by resistance R21, and another way connects the rectification circuit by resistance R22
Cathode, the output of voltage comparator U1 terminates the grid G of the metal-oxide-semiconductor T1；The both ends of the zener diode Z1 are parallel with
Capacitance C1.
2. it is according to claim 1 based on linearly with the LED constant current driving method of PWM operating modes, it is characterised in that by
Impulse controller generates the controllable square-wave signal of one group of duty ratio, implements modulation to the DC pulse waveform after rectification, passes through tune
The duty ratio of pulse processed goes control with the make-and-break time of the concatenated semiconductor power device of LED load, keeps LED load electric current permanent
It is fixed.
3. it is according to claim 1 based on linearly with the LED constant current driving method of PWM operating modes, to supply voltage,
Voltage difference between LED load electric current, LED load and power supply is carried out at the same time signal sampling, impulse controller according to sampled signal,
Suitable pulse width is generated, to reach LED load constant current purpose.
4. it is according to claim 1 based on linearly with the LED constant current driving method of PWM operating modes, it is characterised in that institute
It states and is connected with filter capacitor C2 between the positive and negative anodes of rectification circuit；Between the filter capacitor C2 and the anode of the rectification circuit
It is connected with isolating diode D5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510897833.7A CN105338718B (en) | 2015-12-08 | 2015-12-08 | It is a kind of based on linearly with the LED constant current driving method and device of PWM operating modes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510897833.7A CN105338718B (en) | 2015-12-08 | 2015-12-08 | It is a kind of based on linearly with the LED constant current driving method and device of PWM operating modes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105338718A CN105338718A (en) | 2016-02-17 |
| CN105338718B true CN105338718B (en) | 2018-09-18 |
Family
ID=55288883
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510897833.7A Active CN105338718B (en) | 2015-12-08 | 2015-12-08 | It is a kind of based on linearly with the LED constant current driving method and device of PWM operating modes |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105338718B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106851906B (en) * | 2017-02-07 | 2019-06-11 | 贵州大学 | A kind of piecewise linearity constant current LED drive circuit |
| CN106604481B (en) * | 2017-02-20 | 2018-04-13 | 王汉忠 | A kind of LED linear constant current soft start drive circuit |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101852374A (en) * | 2010-06-03 | 2010-10-06 | 深圳市亮百佳电子科技有限公司 | Unflickering LED MR16 spot light with light regulating function |
| CN102762011A (en) * | 2011-04-29 | 2012-10-31 | 海洋王照明科技股份有限公司 | LED (Light Emitting Diode) constant-current dimming drive circuit device |
| CN103889125A (en) * | 2014-04-03 | 2014-06-25 | 电子科技大学 | Dimming system of LED illuminating lamp |
| CN103917028A (en) * | 2014-04-16 | 2014-07-09 | 泉芯电子技术(深圳)有限公司 | LED constant-current source and control method thereof |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8294377B2 (en) * | 2010-06-25 | 2012-10-23 | Power Integrations, Inc. | Power converter with compensation circuit for adjusting output current provided to a constant load |
| CN103442484B (en) * | 2013-08-15 | 2015-08-12 | 辉芒微电子（深圳）有限公司 | A kind of linear switch constant current LED drive circuit and LED lamp |
-
2015
- 2015-12-08 CN CN201510897833.7A patent/CN105338718B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101852374A (en) * | 2010-06-03 | 2010-10-06 | 深圳市亮百佳电子科技有限公司 | Unflickering LED MR16 spot light with light regulating function |
| CN102762011A (en) * | 2011-04-29 | 2012-10-31 | 海洋王照明科技股份有限公司 | LED (Light Emitting Diode) constant-current dimming drive circuit device |
| CN103889125A (en) * | 2014-04-03 | 2014-06-25 | 电子科技大学 | Dimming system of LED illuminating lamp |
| CN103917028A (en) * | 2014-04-16 | 2014-07-09 | 泉芯电子技术(深圳)有限公司 | LED constant-current source and control method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105338718A (en) | 2016-02-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103491682B (en) | Linear switching constant-current LED drive circuit for control over peak current | |
| CN103428969B (en) | A kind of linear constant current LED drive circuit and LED lamp | |
| CN106455227B (en) | A kind of LED linear constant-current control circuit and LED light emission device | |
| CN103648202B (en) | Active power factor correction control circuit, chip and LED (Light Emitting Diode) drive circuit | |
| CN103582217B (en) | The LED drive circuit that a kind of current ripples is controlled | |
| CN201813599U (en) | LED (Light-Emitting Diode) dimmer power | |
| CN104703358B (en) | Wide-voltage-range LED (light emitting diode) lamp switching and dimming driving circuit and LED lamp dimming control system | |
| CN102014557A (en) | LED dimming power supply | |
| CN102769981A (en) | Intelligent constant-current driver realized by embedded chip and control method of intelligent constant-current driver | |
| CN106464126A (en) | Primary side controlled led driver with ripple cancellation | |
| CN103458557A (en) | LED drive control circuit and LED lamp | |
| CN103582257A (en) | LED driving device and method | |
| CN102833916A (en) | DC (direct current) dimming type LED (Light Emitting Diode) drive circuit | |
| CN103716952B (en) | A kind of LED switch power supply and control method thereof | |
| CN202889703U (en) | DC light-modulation type LED drive circuit | |
| CN104066246B (en) | Light emitting element driving method, light emitting element driver and controller thereof | |
| CN102833902B (en) | Booster type constant current driver circuit for LED | |
| CN105338718B (en) | It is a kind of based on linearly with the LED constant current driving method and device of PWM operating modes | |
| CN104994638B (en) | The device of the remote adjusting brightness of LED lamps of controlled rectification ripple | |
| CN204886731U (en) | Switching power supply controller and contain switching power supply of this switching power supply controller | |
| CN104768271B (en) | Constant current driver circuit for LED with an automatic light meter | |
| CN203590562U (en) | LED switch constant current driving circuit | |
| CN202721869U (en) | Embedded realization-based intelligent constant-current driver | |
| CN105101539A (en) | Light-emitting diode (LED) constant current driving circuit | |
| CN204616156U (en) | A kind of LED drive circuit being applicable to controllable silicon light modulation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |