CN208029144U - LED light adjusting circuits - Google Patents
LED light adjusting circuits Download PDFInfo
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- CN208029144U CN208029144U CN201820209767.9U CN201820209767U CN208029144U CN 208029144 U CN208029144 U CN 208029144U CN 201820209767 U CN201820209767 U CN 201820209767U CN 208029144 U CN208029144 U CN 208029144U
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Abstract
The utility model discloses a kind of LED light adjusting circuits, the light modulation precision for improving LED.The circuit includes：Control circuit, linearity light adjusting circuit, pulse width modulation (PWM) light adjusting circuit and driving IC, wherein, control circuit is connect with the input terminal of the input terminal of linearity light adjusting circuit and PWM light adjusting circuits respectively, the output end of linearity light adjusting circuit is connect with driving IC, the output end of PWM light adjusting circuits is connect with driving IC, and driving IC is used to adjust the brightness of LED；Control circuit when for being more than the first preset value in the input dimming control signal voltage for driving IC, controlling linear light adjusting circuit and exporting linear dim signal to driving IC, control PWM light adjusting circuits stop output PWM dim signals；And when the input dimming control signal voltage for driving IC is less than or equal to the first preset value, controls linear light adjusting circuit and export constant dim signal, control PWM light adjusting circuits export PWM dim signals to driving IC.
Description
Technical field
The utility model is related to field of circuit technology more particularly to a kind of LED light adjusting circuits.
Background technology
Light-emitting diode LED has that luminous efficiency is high, energy expenditure is low, long lifespan, material are recyclable and dimming behavior
Outstanding advantages of excellent, therefore, LED, are widely used in lighting area as the light source of green high-efficient.
In order to build more comfortable lighting atmosphere and energy saving, seem extremely heavy to the research of LED light regulating technologies.It is existing
When being dimmed to LED in technology, usually all it is to use a kind of single dimming mode, be easy to cause the low problem of light modulation precision.
Utility model content
In order to solve the above technical problems, the utility model embodiment provides a kind of LED light adjusting circuits, for improving LED's
Light modulation precision.
The utility model embodiment uses following technical proposals：
A kind of LED light adjusting circuits, including：Control circuit, linearity light adjusting circuit, pulse width modulation (PWM) light adjusting circuit and
Drive IC, wherein the control circuit input with the input terminal of the linearity light adjusting circuit and the PWM light adjusting circuits respectively
End connection, the output end of the linearity light adjusting circuit connect with the driving IC, the output end of the PWM light adjusting circuits with it is described
IC connections, the driving IC is driven to be used to adjust the brightness of the LED；The control circuit, in the defeated of the driving IC
When entering dimming control signal voltage more than the first preset value, controls the linearity light adjusting circuit and export linear adjust to the driving IC
Optical signal controls the PWM light adjusting circuits and stops output PWM dim signals；And the input brightness adjustment control in the driving IC
When signal voltage is less than or equal to the first preset value, the constant dim signal of linearity light adjusting circuit output is controlled, described in control
PWM light adjusting circuits export PWM dim signals to the driving IC.
Further, the control circuit, specifically for being less than in the input dimming control signal voltage of the driving IC
Or equal to the first preset value and when being more than the second preset value, the constant dim signal of linearity light adjusting circuit output is controlled, it controls
The PWM light adjusting circuits to the driving IC output period fix, the first PWM dim signals of change in duty cycle；And institute
When stating the input dimming control signal voltage of driving IC less than or equal to the second preset value, the linearity light adjusting circuit output is controlled
Constant dim signal controls the PWM light adjusting circuits and is fixed to the driving IC output pulse widths, and the second of mechanical periodicity
PWM dim signals.
Further, the control circuit, specifically for being less than in the input dimming control signal voltage of the driving IC
Or equal to the first preset value and when being more than the second preset value, the constant dim signal of linearity light adjusting circuit output is controlled, it controls
The PWM light adjusting circuits to driving IC outputs, fix, the period is fixed by peak value of pulse, the first PWM tune of pulse width variation
Optical signal；And when the input dimming control signal voltage of the driving IC is less than or equal to the second preset value, described in control
The constant dim signal of linearity light adjusting circuit output, control the PWM light adjusting circuits to the driving IC output peak value of pulse fix,
Pulse width is fixed, the 2nd PWM dim signals of mechanical periodicity.
Further, the linearity light adjusting signal of the linearity light adjusting circuit output is after being converted by the 3rd PWM dim signals
It obtains.
Further, the linearity light adjusting circuit includes voltage input circuit, operational amplification circuit U30, negative-feedback circuit
And voltage follower circuit, wherein the voltage input circuit is the input terminal of the linearity light adjusting circuit；The voltage output electricity
Road is the output end of the linearity light adjusting circuit；The input in the same direction of the voltage input circuit and the operational amplification circuit U30
End connection；One end of the negative-feedback circuit is connect with the reverse input end of the operational amplification circuit U30；The negative-feedback electricity
The other end on road is connect with the output end of the operational amplification circuit U30；The voltage follower circuit and the negative-feedback circuit
Connection.
Further, the negative-feedback circuit, including：First resistor R11, second resistance R12,3rd resistor R13 and
One capacitance C21；The voltage follower circuit includes the 4th resistance R14, wherein one end of the first resistor R11 and the fortune
The output end connection of amplifying circuit U30 is calculated, the other end of the first resistor R11 is connect with one end of the 4th resistance R14,
The other end of the 4th resistance R14 is connect with the driving IC；The anode of the first capacitance C21 is connected to first electricity
Between hindering R11 and the 4th resistance R14, the cathode of the first capacitance C21 connects reference ground；The one of the second resistance R12
It holds and is connect with the anode of the first capacitance C21, the other end of the second resistance R12 is with the operational amplification circuit U30's
Reverse input end connects；One end of the 3rd resistor R13 is connect with the reverse input end of the operational amplification circuit U30, institute
State another termination reference ground of 3rd resistor R13.
Further, the voltage input circuit includes the 3rd PWM dim signal input terminals, the 3rd PWM light modulations letter
Number filtered circuit of input terminal is connect with the noninverting input of the operational amplification circuit U30.
Further, the filter circuit includes two concatenated single order RC filter circuits.
Further, the filter circuit includes the 5th resistance R15, the 6th resistance R16, the second capacitance C22 and third electricity
Holding C23, wherein one end of the 5th resistance R15 is connect with the noninverting input of the operational amplification circuit U30, and described the
The other end of five resistance R15 is connect with one end of the 6th resistance R16, the other end of the 6th resistance R16 and described the
Three PWM dim signal input terminals connect；The input in the same direction of the anode and the operational amplification circuit U30 of the second capacitance C22
End connection, the cathode of the second capacitance C22 connect reference ground；The anode of the third capacitance C23 is connected to the 5th resistance
Between R15 and the 6th resistance R16, the cathode of the third capacitance C23 connects reference ground.
Further, the PWM light adjusting circuits include field-effect tube Q40, grid and the control of the field-effect tube Q40
Circuit connection processed, the source electrode of the field-effect tube Q40 are connect with the output end of the linearity light adjusting circuit, the field-effect tube
The drain electrode of Q40 connects reference ground, or, the grid of the field-effect tube Q40 is connect with the control circuit, the field-effect tube Q40
Drain electrode connect with the output end of the linearity light adjusting circuit, the source electrode of the field-effect tube Q40 connects reference ground.
The LED light adjusting circuits that the utility model embodiment provides, control circuit can be in the input brightness adjustment controls of driving IC
When signal voltage is more than the first preset value, controls the linearity light adjusting circuit and export linear dim signal, control to the driving IC
It makes the PWM light adjusting circuits and stops output PWM dim signals；And it is small in the input dimming control signal voltage of the driving IC
When the first preset value, the constant dim signal of linearity light adjusting circuit output is controlled, the PWM light adjusting circuits are controlled
PWM dim signals are exported to the driving IC, the LED light adjusting circuits provided combine linearity light adjusting and PWM light modulation two ways
The advantages of, and the shortcomings that overcome two kinds of dimming modes, the lower limit of LED dimming scopes can be widened significantly, and improve LED tune
The precision of light.
Description of the drawings
Attached drawing described herein is used to provide a further understanding of the present invention, and constitutes one of the utility model
Point, the exemplary embodiment of the utility model and the description thereof are used to explain the utility model, does not constitute to the utility model
Improper restriction.In the accompanying drawings：
Fig. 1 is the structural schematic diagram for the LED light adjusting circuits that the utility model one embodiment provides；
Fig. 2 is the concrete structure schematic diagram for the LED light adjusting circuits that the utility model another embodiment provides；
Fig. 3 is the dim signal schematic diagram for the LED light adjusting circuits that the utility model one embodiment provides.
Specific implementation mode
It is specific below in conjunction with the utility model to keep the purpose of this utility model, technical solution and advantage clearer
Technical solutions of the utility model are clearly and completely described in embodiment and corresponding attached drawing.Obviously, described embodiment
Only it is the utility model a part of the embodiment, instead of all the embodiments.Based on the embodiments of the present invention, this field
The every other embodiment that those of ordinary skill is obtained without making creative work, belongs to the utility model
The range of protection.
As previously shown, when being dimmed in the prior art to LED, usually all it is to use a kind of single dimming mode, is easy to make
At the low problem of light modulation precision.
To solve the technical problem, as shown in Figure 1, the utility model embodiment provides a kind of LED light adjusting circuits, including：
Control circuit, linearity light adjusting circuit, pulse width modulation (PWM) light adjusting circuit and driving IC.
It will be seen from figure 1 that the control circuit is by PWM_A feet and PWM_B feet, respectively with the linearity light adjusting circuit
Input terminal (left side in Fig. 1) and the PWM light adjusting circuits input terminal (left side in Fig. 1) connection.The linearity light adjusting
The output end (right side in Fig. 1) of circuit is connect with the driving IC, the output end (right side in Fig. 1 of the PWM light adjusting circuits
Side) it is connect with the driving IC.Above-mentioned driving IC can be connect with external constant-current drive circuit (not shown), should to utilize
IC is driven to adjust the brightness of the LED.
Above-mentioned control circuit can be specifically microcontroller, for the input dimming control signal voltage in the driving IC
When more than the first preset value, controls the linearity light adjusting circuit and export linear dim signal to the driving IC, control the PWM
Light adjusting circuit stops output PWM dim signals；And it is less than or equal in the input dimming control signal voltage of the driving IC
When the first preset value, it (can be specifically the fixed light modulation of voltage value to control the constant dim signal of linearity light adjusting circuit output
Signal) it is constant, it controls the PWM light adjusting circuits and exports PWM dim signals to the driving IC, the driving IC's in the embodiment
Input dimming control signal voltage, or can be referred to as control it is that driving IC works, carried by the utility model embodiment
The dimming control signal voltage that the LED light adjusting circuits of confession are exported to driving IC, that is, may include above-mentioned linearity light adjusting signal electricity
Pressure, can also include the effective voltage of above-mentioned PWM dimming signal voltages.
First preset value mentioned above can be related to the input dimming control signal voltage of IC is driven, for example, driving
Upper limit 4.5V when linearity light adjusting signal voltage 100% (i.e. for 4.5V) of the input dimming control signal voltage of dynamic IC, in this way, on
The first preset value is stated, can be 10% i.e. 0.45V of the upper limit for the input dimming signal voltage for accounting for driving IC, account for 5% i.e.
0.225V or be to account for 15% i.e. 0.675V etc., the utility model embodiment is simultaneously not specifically limited.
The LED light adjusting circuits provided by the utility model embodiment, control circuit can be in the input light modulations of driving IC
When controlling signal voltage more than the first preset value, the linearity light adjusting circuit is controlled to driving IC output linearity light adjusting letters
Number, it controls the PWM light adjusting circuits and stops output PWM dim signals；And the input dimming control signal in the driving IC
When voltage is less than or equal to the first preset value, the constant dim signal of linearity light adjusting circuit output is controlled, the PWM tune is controlled
IC is driven to export PWM dim signals described in photoelectricity road direction, the LED light adjusting circuits of above-mentioned offer combine linearity light adjusting and PWM tune
The advantages of light two ways, and the shortcomings that overcome two kinds of dimming modes, the lower limit of LED dimming scopes can be widened significantly, and
And improve the precision of LED light modulations.
For the LED light adjusting circuits that the utility model embodiment provides are described in detail, below with reference to a specific embodiment into
Row explanation.As shown in Fig. 2, the LED light adjusting circuits that the embodiment provides include mainly：Control circuit, linearity light adjusting circuit, PWM
Light adjusting circuit and driving IC, in the embodiment, control circuit can be specifically microcontroller, be said by taking microcontroller as an example below
It is bright, and microcontroller and above-mentioned driving IC are not shown in fig. 2.
Above-mentioned linearity light adjusting circuit can specifically include voltage input circuit, operational amplification circuit U30, negative-feedback circuit and
Voltage follower circuit (being specially R14), the voltage input circuit is the input terminal of the linearity light adjusting circuit；The voltage is defeated
Go out the output end that circuit is the linearity light adjusting circuit.
In this way, one end of above-mentioned voltage input circuit can be connect with microcontroller, microcontroller can be control source electricity
Road provides voltage, which can be linear voltage, can also be the adjustable PWM voltages of duty ratio.Above-mentioned voltage input circuit
The other end can be connect with the noninverting input (5 foot of amplifier in Fig. 2) of the operational amplification circuit U30.Above-mentioned negative-feedback
One end of circuit is connect with the reverse input end (6 foot of amplifier in Fig. 2) of the operational amplification circuit U30；The negative-feedback electricity
The other end on road is connect with the output end (7 foot of amplifier in Fig. 2) of the operational amplification circuit U30；The voltage follower circuit
It is connect with the negative-feedback circuit.
Specifically, as shown in Fig. 2, above-mentioned negative-feedback circuit, may include：First resistor R11, second resistance R12, third
Resistance R13 and the first capacitance C21；Above-mentioned voltage follower circuit includes the 4th resistance R14, and the 4th resistance R14 can be that DIM feet carry
Voltage supplied.
Figure it is seen that one end of the first resistor R11 is connect with the output end of the operational amplification circuit U30,
The other end of the first resistor R11 is connect with one end of the 4th resistance R14, the other end of the 4th resistance R14 with
The driving IC connections, the DIM feet being specifically shown in Fig. 2, DIM feet are connect with driving IC.The anode connection of the first capacitance C21
Between the first resistor R11 and the 4th resistance R14, the cathode of the first capacitance C21 connects reference ground.Described second
One end of resistance R12 is connect with the anode of the first capacitance C21, and the other end and the operation of the second resistance R12 are put
The reverse input end connection of big circuit U 30；One end of the 3rd resistor R13 is reversed defeated with the operational amplification circuit U30's
Enter end connection, another termination reference ground of the 3rd resistor R13.
Above-mentioned voltage input circuit may include the 3rd PWM dim signal input terminals, the PWM_A feet being specifically shown in Fig. 2,
PWM_A feet are connect with microcontroller, and microcontroller can provide the 3rd PWM dim signals.The above-mentioned 3rd PWM light modulations that microcontroller provides
The filtered circuit of signal is connect with the noninverting input of the operational amplification circuit U30, in this way, by above-mentioned filter circuit
Filtering, you can the 3rd PWM dim signals are transformed into smooth linear voltage, and are supplied to that operational amplification circuit U30's is in the same direction
Input terminal.
As shown in Fig. 2, as a preferred embodiment, the filter circuit includes two concatenated single order RC filtered electricals
Road.That is,
The filter circuit may include the 5th resistance R15, the 6th resistance R16, the second capacitance C22 and third capacitance C23.
Wherein, one end of the 5th resistance R15 is connect with the noninverting input of the operational amplification circuit U30, the 5th resistance
The other end of R15 is connect with one end of the 6th resistance R16, and the other end of the 6th resistance R16 is connect with PWM_A feet；
The anode of the second capacitance C22 is connect with the noninverting input of the operational amplification circuit U30, the second capacitance C22's
Cathode connects reference ground；The anode of the third capacitance C23 is connected between the 5th resistance R15 and the 6th resistance R16,
The cathode of the third capacitance C23 connects reference ground.
It, can relative to one single order RC filter circuit of setting by the way that the concatenated single order RC filter circuits of above-mentioned two are arranged
The 3rd PWM dim signals of PWM_A feet more efficiently, are fully transformed into smooth linear voltage, and it is supplied to operation
The noninverting input of amplifying circuit U30.
As shown in Fig. 2, as a preferred embodiment, above-mentioned PWM light adjusting circuits include field-effect tube Q40, the field effect
Should the grid of pipe Q40 (see the PWM_B feet in Fig. 2) can be connect with microcontroller, the drain electrode of the field-effect tube Q40 with it is described
The output end of linearity light adjusting circuit connects, and the source electrode of the field-effect tube Q40 connects reference ground.In this way, when on the 4th resistance R14
When voltage constant, if microcontroller provides PWM dim signals for PWM_B feet, at this point, due to the conducting of field-effect tube Q40, DIM feet
Also PWM dim signals will be exported to driving IC；Also, the increase of the duty ratio with the PWM dim signals of PWM_B feet, DIM feet
The duty ratio of the PWM dim signals exported to driving IC will gradually decrease.
In other examples, the grid of field-effect tube Q40 shown in Fig. 2 can also be connect with microcontroller, shown in Fig. 2
Embodiment unlike, the source electrode of field-effect tube Q40 can be connected between the 4th resistance R14 and DIM foot, this effect
Should the drain electrode of pipe Q40 connect reference ground, the application is simultaneously not specifically limited.
Preferably as one embodiment, field-effect tube Q40 mentioned above can be mos pipes as shown in Figure 2, at it
In his embodiment, field-effect tube Q40 can also be replaced by triode, in this way, the base stage of the triode can be with microcontroller
Connection, the emitter and collector of the triode can be separately connected DIM feet and reference ground.
Above-mentioned combination Fig. 2 describe in detail the utility model embodiment offer LED linear light adjusting circuit structure and
Connection relation below will be introduced its operation principle.
In fig. 2, the input terminal of the input terminal of linearity light adjusting circuit, PWM light adjusting circuits, respectively with the PWM_A of microcontroller
Foot is connected with PWM_B feet, DIM feet connection driving IC.
Microcontroller is the 3rd PWM dim signals that PWM_A feet provide, and passes through the 5th resistance R15, the 6th resistance R16, second
Capacitance C22, the filter circuit of third capacitance C23 compositions, to switch to smooth linear voltage to 5 foot of amplifier.
In a specific embodiment, the resistance value of the 5th resistance R15 and the 6th resistance R16 can be 36K ohm；The
The capacitance of two capacitance C22 and third capacitance C23 can be 1000 pico farads.
The first resistor R11 being connect with 7 foot of amplifier can provide voltage, second resistance R12 and third for the first capacitance C21
Resistance R13 can be by the Voltage Feedback of the first capacitance C21 to 6 foot of amplifier.
In a specific embodiment, the resistance of first resistor R11 can be 1K ohm, the resistance of second resistance R12
It can be 36K ohm；The resistance of 3rd resistor R13 can be 100K ohm；The capacitance of first capacitance C21 can be 1 microfarad.
The resistance of 4th resistance R14 can be 330 ohm.
By the connection relation of above-mentioned first resistor R11, second resistance R12,3rd resistor R13 and the first capacitance C21,
The ratio of voltage and 5 foot voltage of amplifier on the first capacitance C21 of common setups, while also determining the electricity on the 4th resistance R14
Pressure value, the 4th resistance R14 connect DIM feet, and driving IC is given for providing dim signal.
Specifically, referring to following formula：
In above-mentioned formula, VC21 is that first resistor R11 is the voltage that the first capacitance C21 is provided；V5 is the electricity of 5 foot of amplifier
Pressure, R12 and R13 are the resistance of second resistance R12 and 3rd resistor R13 respectively.
When specific light modulation：
(1) during LED is dimmed by maximum brightness, if the input dimming control signal voltage of driving IC is more than first in advance
If value, at this point, PWM_B foot silences keep low level, microcontroller to adjust the duty ratio of the 3rd PWM dim signals of PWM_A feet, this
Sample, DIM feet can output smoothing linear voltage, this linear voltage determined by the duty ratio of the 3rd PWM dim signals of PWM_A feet
It is fixed, i.e.,：The duty ratio of 3rd PWM dim signals increases, and the brightness of LED increases；The duty ratio of 3rd PWM dim signals reduces,
The brightness of LED subtracts secretly, at this point, driving IC is in linear analogue dimming state.
(2) with the reduction of LED luminance, if the input dimming control signal voltage of driving IC is less than the first preset value, such as
Fruit continues to further decrease the duty ratio of the 3rd PWM dim signals of PWM_A feet by above-mentioned linearity light adjusting mode, then light modulation will
Become unstable and light modulation precision substantially reduces.At this time if you need to further turn down brightness, then the 3rd PWM tune of PWM_A feet is kept
The duty ratio of optical signal is constant, starts to enable the progress PWM light modulations of PWM_B feet, may refer to Fig. 3, Fig. 3 is schematically shown
The first PWM dim signals and the 2nd PWM tune that the PWM dim signals and DIM feet of PWM_B accesses are finally exported to driving IC
Optical signal schematic diagram.
Specifically, it is less than or equal to the first preset value and more than the in the input dimming control signal voltage of the driving IC
When two preset values, keep the duty ratio of the 3rd PWM dim signals of PWM_A feet constant, microcontroller control is connected in PWM_B feet
PWM dim signals, with the increase for the PWM dim signal duty ratios connected in PWM_B feet, the PWM dim signals of DIM feet output
Duty ratio can reduce, to allow the output power of driving IC to reduce, the brightness of LED further decreases.
In the embodiment, when adjusting the PWM dim signals that PWM_B feet are connected, the PWM light modulations of PWM_B feet can be to maintain
The period of signal is fixed, and low level time reduces, i.e., high level time (pulse width) increases.On the contrary, then being exported in DIM feet
Period is fixed, the first PWM dim signals that duty ratio reduces.Can specifically be fixed in DIM feet output peak value of pulse (high level),
Period is fixed, and pulse width reduces the first PWM dim signals of (i.e. duty ratio reduces), referring specifically to 2/3 of DIM feet in Fig. 3
The first PWM dim signals exported when duty ratio and 1/2 duty ratio of DIM feet.
(3) further decreasing with LED luminance is less than second in the input dimming control signal voltage of the driving IC
When preset value, i.e., the duty ratio increase of the PWM dim signals of PWM_B feet to a certain extent when, DIM foot duty ratios are reduced to high electricity
After pulse-width can only cover a few waveform of driving IC work periods, output work will all be given by often reducing by a wave period
Rate brings the variation of enormous proportions to jump, and such as continues to adjust duty ratio method using above-mentioned fixed frequency (or period), then adjusts
Photoreduction process starts apparent flickering occur.
DIM foot high pulse widths can be fixed at this time, increase low level time, that is, increase the method in period to realize into one
The brightness of the low LED of step.At this point, seeing Fig. 3, microcontroller can be in PWM_B feet connection PWM dim signals, PWM_B foot low levels
Between remain unchanged, high-level pulse width increases, and the period gradually lengthens.On the contrary, then exporting high-level pulse width in DIM feet
Fixed, mechanical periodicity the 2nd PWM dim signals, can be specifically fix in DIM feet output peak value of pulse, high level pulse it is wide
Degree is fixed, the 2nd PWM dim signals that the period lengthens, and 1/10 of 1/3 duty ratio and DIM feet referring specifically to DIM feet in Fig. 3 accounts for
Sky than when the 2nd PWM dim signals.
The above-mentioned dimming process principle for describing LED in detail from high brightness to low-light level, from low-light level light modulation to high brightness
The process of light modulation is with the above process on the contrary, details are not described herein.So realize the smooth low sudden strain of a muscle of whole process or the nothing of LED driving light modulations
It dodges, and realizes and dim while kept compared with high accurancy and precision compared with low depth.
The utility model passes through circuit and single-chip programming control PWM designs, the advantages of light modulation in conjunction with linearity light adjusting and PWM, PWM
Frequency conversion and PWM duty cycle combination light modulation switch each brightness when making steady operation and are dimmed smooth without apparent in change procedure without stroboscopic
Flicker, and realize whole precisely depth light modulation, improve light modulation depth, light modulation accuracy while solving stable state stroboscopic and adjusting
The problem of being flickered in light change procedure.
It these are only the embodiments of the present invention, be not intended to limit the utility model.For art technology
For personnel, various modifications and changes may be made to the present invention.It is all the utility model spirit and principle within made by
Any modification, equivalent substitution, improvement and etc. should be included within the right of the utility model.
Claims (10)
1. a kind of LED light adjusting circuits, which is characterized in that including：Control circuit, linearity light adjusting circuit, pulse width modulation (PWM) tune
Optical circuit and driving IC, wherein
The control circuit is connect with the input terminal of the input terminal of the linearity light adjusting circuit and the PWM light adjusting circuits respectively,
The output end of the linearity light adjusting circuit is connect with the driving IC, the output end of the PWM light adjusting circuits and the driving IC
Connection, the driving IC are used to adjust the brightness of LED；
The control circuit, for when the input dimming control signal voltage of the driving IC is more than the first preset value, controlling
The linearity light adjusting circuit exports linear dim signal to the driving IC, controls the PWM light adjusting circuits and stops output PWM tune
Optical signal；And
When the input dimming control signal voltage of the driving IC is less than or equal to the first preset value, the linearity light adjusting is controlled
The constant dim signal of circuit output controls the PWM light adjusting circuits and exports PWM dim signals to the driving IC.
2. light adjusting circuit according to claim 1, which is characterized in that
The control circuit is specifically used for default less than or equal to first in the input dimming control signal voltage of the driving IC
When being worth and being more than the second preset value, the constant dim signal of linearity light adjusting circuit output is controlled, the PWM light adjusting circuits are controlled
It is fixed to the driving IC output periods, the first PWM dim signals of change in duty cycle；And
When the input dimming control signal voltage of the driving IC is less than or equal to the second preset value, the linearity light adjusting is controlled
The constant dim signal of circuit output controls the PWM light adjusting circuits and is fixed to the driving IC output pulse widths, mechanical periodicity
The 2nd PWM dim signals.
3. light adjusting circuit according to claim 2, which is characterized in that
The control circuit is specifically used for default less than or equal to first in the input dimming control signal voltage of the driving IC
When being worth and being more than the second preset value, the constant dim signal of linearity light adjusting circuit output is controlled, the PWM light adjusting circuits are controlled
To driving IC outputs, peak value of pulse is fixed, the period is fixed, the first PWM dim signals of pulse width variation；And
When the input dimming control signal voltage of the driving IC is less than or equal to the second preset value, the linearity light adjusting is controlled
The constant dim signal of circuit output, control the PWM light adjusting circuits to the driving IC output peak value of pulse fix, pulse width
It is fixed, the 2nd PWM dim signals of mechanical periodicity.
4. light adjusting circuit according to any one of claims 1 to 3, which is characterized in that
The linearity light adjusting signal of the linearity light adjusting circuit output obtains after being converted by the 3rd PWM dim signals.
5. light adjusting circuit according to claim 4, which is characterized in that the linearity light adjusting circuit includes control source electricity
Road, operational amplification circuit U30, negative-feedback circuit and voltage follower circuit, wherein
The voltage input circuit is the input terminal of the linearity light adjusting circuit；The voltage follower circuit is the linearity light adjusting
The output end of circuit；
The voltage input circuit is connect with the noninverting input of the operational amplification circuit U30；
One end of the negative-feedback circuit is connect with the reverse input end of the operational amplification circuit U30；The negative-feedback circuit
The other end connect with the output end of the operational amplification circuit U30；
The voltage follower circuit is connect with the negative-feedback circuit.
6. light adjusting circuit according to claim 5, which is characterized in that the negative-feedback circuit, including：
First resistor R11, second resistance R12,3rd resistor R13 and the first capacitance C21；The voltage follower circuit includes the 4th
Resistance R14, wherein
One end of the first resistor R11 is connect with the output end of the operational amplification circuit U30, the first resistor R11's
The other end is connect with one end of the 4th resistance R14, and the other end of the 4th resistance R14 is connect with the driving IC；
The anode of the first capacitance C21 is connected between the first resistor R11 and the 4th resistance R14, and described first
The cathode of capacitance C21 connects reference ground；
One end of the second resistance R12 is connect with the anode of the first capacitance C21, the other end of the second resistance R12
It is connect with the reverse input end of the operational amplification circuit U30；
One end of the 3rd resistor R13 is connect with the reverse input end of the operational amplification circuit U30, the 3rd resistor
Another termination reference ground of R13.
7. light adjusting circuit according to claim 5, which is characterized in that the voltage input circuit is dimmed including the 3rd PWM
Signal input part, the filtered circuit of the 3rd PWM dim signal input terminals are in the same direction defeated with the operational amplification circuit U30's
Enter end connection.
8. light adjusting circuit according to claim 7, which is characterized in that the filter circuit includes two concatenated single order RC
Filter circuit.
9. light adjusting circuit according to claim 7, which is characterized in that the filter circuit includes the 5th resistance R15, the 6th
Resistance R16, the second capacitance C22 and third capacitance C23, wherein
One end of the 5th resistance R15 is connect with the noninverting input of the operational amplification circuit U30, the 5th resistance
The other end of R15 is connect with one end of the 6th resistance R16, the other end and the 3rd PWM tune of the 6th resistance R16
Optical signal input connects；
The anode of the second capacitance C22 is connect with the noninverting input of the operational amplification circuit U30, second capacitance
The cathode of C22 connects reference ground；
The anode of the third capacitance C23 is connected between the 5th resistance R15 and the 6th resistance R16, the third
The cathode of capacitance C23 connects reference ground.
10. light adjusting circuit according to any one of claims 1 to 3, which is characterized in that
The PWM light adjusting circuits include field-effect tube Q40,
The grid of the field-effect tube Q40 is connect with the control circuit, the source electrode of the field-effect tube Q40 and the linear tune
The output end of optical circuit connects, and the drain electrode of the field-effect tube Q40 connects reference ground, or,
The grid of the field-effect tube Q40 is connect with the control circuit, the drain electrode of the field-effect tube Q40 and the linear tune
The output end of optical circuit connects, and the source electrode of the field-effect tube Q40 connects reference ground.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820209767.9U CN208029144U (en) | 2018-02-06 | 2018-02-06 | LED light adjusting circuits |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820209767.9U CN208029144U (en) | 2018-02-06 | 2018-02-06 | LED light adjusting circuits |
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| Publication Number | Publication Date |
|---|---|
| CN208029144U true CN208029144U (en) | 2018-10-30 |
Family
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820209767.9U Withdrawn - After Issue CN208029144U (en) | 2018-02-06 | 2018-02-06 | LED light adjusting circuits |
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| Country | Link |
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| CN (1) | CN208029144U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108419331A (en) * | 2018-02-06 | 2018-08-17 | 欧普照明股份有限公司 | LED light adjusting circuits and light-dimming method |
| CN109451631A (en) * | 2018-12-29 | 2019-03-08 | 无锡安特源科技股份有限公司 | A kind of LED drive power light adjusting circuit |
| CN114698178A (en) * | 2020-12-30 | 2022-07-01 | 华润微集成电路(无锡)有限公司 | LED dimming circuit |
-
2018
- 2018-02-06 CN CN201820209767.9U patent/CN208029144U/en not_active Withdrawn - After Issue
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108419331A (en) * | 2018-02-06 | 2018-08-17 | 欧普照明股份有限公司 | LED light adjusting circuits and light-dimming method |
| CN108419331B (en) * | 2018-02-06 | 2024-03-05 | 欧普照明股份有限公司 | LED dimming circuit and dimming method |
| CN109451631A (en) * | 2018-12-29 | 2019-03-08 | 无锡安特源科技股份有限公司 | A kind of LED drive power light adjusting circuit |
| CN114698178A (en) * | 2020-12-30 | 2022-07-01 | 华润微集成电路(无锡)有限公司 | LED dimming circuit |
| CN114698178B (en) * | 2020-12-30 | 2022-11-22 | 华润微集成电路(无锡)有限公司 | LED dimming circuit |
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