LED light modulation toning control device
Technical field
The utility model relates to the control device of a kind of LED, in particular, relates to a kind of LED light modulation toning control device be applied in LED.
Background technology
The control circuit of the LED in existing light modulation color-temperature regulating circuit engineering is voltage stabilizing circuit, because LED is because of the reason of silicon chip own, producing the LED having various different voltage in a collection of finished product LED, even if with the LED product of a collection of finished product, each supply power voltage required for LED luminescent wafer is also discrepant, if at this moment by the LED strip of different voltage connection or be connected in parallel with voltage stabilizing circuit go drive, the light that they send also can be different, look and secretly will differ and vary in color by light, the emission uniformity of LED is poor.The technological deficiency that LED control circuit of the prior art exists, becomes the technical problem that those skilled in the art are anxious to be resolved.For These characteristics, what the stabilized voltage power supply of employing changed is constant-current supply driving.Can be controlled by corresponding button on the control panel of connection MCU control chip, also automatically can be controlled by the software program being input into MCU control chip, change to come with color LED luminance by the duty ratio changing each output.Thus realize light modulation color-temperature regulating.The scheme that the built-in touch light modulation debugging of current use Width funtion 100-265V drives not is a lot, and uses the topological structure of non-isolated constant-current driving power supply to be the few of BUCK buck configuration substantially; And make almost not having of light modulation color-temperature regulating.Principle and design: DU8623 chip, based on non-isolated BUCK topology, integrated source drive MOSFET, realize very high degree of precision LED constant current and control.The control strategy of current LED non-isolated constant current drive current field main flow, circuit is BUCK buck configuration, chip controls be the source electrode of MOSFET, this is a kind of constant current supply control mode of open loop, control principle is as follows: when MOSFET opens, and electric current by LED load, flows through inductance from DCBUS, when flowing into ground MOSFET shutoff, inductive current is from Schottky diode afterflow.Because electric current flows through LED load, if electric current is fixed, can think that the voltage Vo of LED is fixing, as long as so inductance value L fixes, fix turn-off time (1-D) T, Io more namely to fix, so, the control strategy of this open loop is, is connected to the turn-off time of the resistance setting MOSFET of Rt.In each cycle, MOSFET opens until inductive current rises to peak value Vref/Rcs, and at this moment MOSFET turns off, and the turn-off time is determined by Rt.Spent the turn-off time of setting, MOSFET opens again, works so again and again.Turn-off time controls ripple current LED average current, according to the current value wanting to export, regulates the Rcs value of CS pin, regulates Rt value, and the turn-off time of fixing each switch periods is a value, thus achieves output current constant current.This is a kind of simple and effective control strategy, but is a kind of open loop control mode due to this, and can only detect the peak current on inductance, cannot detect output current, output current precision easily occurs deviation under three circumstances: 1. input voltage fluctuation.(opened loop control, cannot feed back, system delay causes) 2. produces inductance inductance value deviation in batches.(L change causes Io to change) 3. LED load voltage not identical (Vo).For the 1st kind of deviation, the way of voltage compensation can only be taked, namely detect input voltage, adjust inner CS reference level value according to input voltage, but effect is general, for the 2nd kind and the 3rd kind of deviation, compare and be difficult to resolve certainly.
Summary of the invention
Technical purpose of the present utility model is that the inductance value overcoming inductance in input voltage fluctuation, batch production in LED light modulation of the prior art toning control device produces deviation and the not identical technical problem of LED load voltage, there is provided a kind of by master control counting circuit, the data that its utilization obtains set up internal database, by this database, signal is converted into luminous flux or the light intensity of the actual output of LED, and send corresponding control signal to constant current driver circuit for LED according to the data of setting, make LED adjust its luminous flux or light intensity ratio; And self-calibration circuit is also revised above-mentioned conversion process, guarantee that LED light modulation that actual value and set point are coincide is mixed colours control device.
For realizing above technical purpose, this practical technique scheme is:
LED light modulation toning control device, is characterized in that: comprise self-calibration circuit, data storage circuitry, input circuit and master control counting circuit;
Described data storage circuitry stores LED light source consisting output current duty ratio data, and LED light source consisting output current duty ratio data are sent to master control counting circuit by data storage circuitry;
Master control counting circuit includes MCU control chip, adjustable PWM duty cycle circuit contact control module is written with in described MCU control chip, the control module automatic control circuit of MCU control chip, change LED luminance by the duty ratio changing PWM output, after the blend of colors of various different brightness, change colour temperature
;
Described master control counting circuit utilizes above-mentioned data to set up internal database, by this database, signal is converted into luminous flux or the light intensity of the actual output of LED, and send corresponding control signal to constant current driver circuit for LED according to the data of setting, make LED adjust its luminous flux or light intensity ratio;
Self-calibration circuit is also revised above-mentioned conversion process, guarantees that actual value and set point are coincide.
Further, described MCU control chip adopts chip DU8623, and the pwm signal input of its external, programmable provided, via the output of MCU control chip pwm signal, arranges the output duty cycle of pwm signal;
Input circuit includes the touch control circuit connecting MCU control chip, touch control circuit includes following rate-determining steps: when tactile touch point short in hand, the noise signal of (ON/OFF-DIMMER on circuit) human body sensing enters MUC chip internal through resistance, activate the data storing circuit of MCU inside, the LED light source consisting output current duty ratio data that storage data circuit will have been programmed again, and these data are sent to master control counting circuit, recycle above-mentioned data and set up internal database, by this database, signal is converted into the duty cycle signals of the actual output of LED, and send corresponding control signal to DU8623 DIM light modulation pin according to the data of setting, LED is made to adjust its luminous flux or light intensity ratio.
The output duty cycle of short tactile ON/OFF DIMM key acquiescence is 100%;
Default feature pattern is reading model.
Described touch control circuit includes 5 touch-keys, is divided into 5 kinds of functional modes:
1.ON/OFF 4 sections of light modulations
2. mode of operation-colour temperature 6000K
3. reading model-colour temperature 5000K
4. leisure patterns-colour temperature 4000K
5. sleep pattern-colour temperature 3000K;
Wherein, often kind of pattern can carry out repetition 4 sections of light modulations (100%-70%-40%-5%); When short tactile ON exports 100%, then every short touching once jumps one grade, that is: 100%-70%-40%-5%, 4 sections of duty cycle parameters, carry out duty ratio light modulation, and the short tactile time is 0.2-1 second.
Further, containing memory function in described data storing circuit, this function can store according to the duty ratio data exported during shutdown, then start is the output duty cycle before recovering shutdown; When pass tester in power-down state is started shooting again, PWM is with the non-standard output signal of last time.
ON/OFF DIMME bond distance presses OFF 2 seconds, namely shuts down.
Advantageous Effects of the present utility model is: stabilized input voltage, and in batch production, the inductance value consistency of inductance is good, and LED load voltage consistency is good, in its input circuit touch control circuit have more remarkable output control model.
Accompanying drawing explanation
Fig. 1 is the circuit theory diagrams of the utility model embodiment.
Fig. 2 is the constant current chip circuit theory diagrams of the utility model embodiment.
The full closed loop control Cycle by Cycle of Fig. 3 the utility model experiment test accurately controls schematic diagram.
Fig. 4 is the closed-loop high-accuracy and constant current control schematic diagram of the utility model experiment test.
Fig. 5 is the closed-loop high-accuracy and constant current control schematic diagram of the utility model experiment test.
Fig. 6 is the functional schematic of the utility model constant current chip.
Embodiment
Composition graphs 1 to Fig. 6, enforcement of the present utility model includes 1. current constant control parts, 2. adjustable PWM duty cycle circuit touch control part, 3. color-temperature regulating scheme.
Composition graphs 1, in current constant control part, the Closed-loop Constant-current control patent that in driver, DU8623 employing is unique-
tRUEC2technology, can realize high-precision output current, guarantee the consistency of LED luminance under wide input voltage, output voltage and inductance parameters condition.In the functional schematic of Fig. 6 chip, its output current is:
vREF is average current benchmark, Rcs(resistance R15/ resistance R16) be current sampling resistor.Closed-loop Constant-current controls, and namely really detects output current value, sends pwm signal as standard.So-called open loop, does not send the reference of pwm signal with the output current value detected.From circuit topology, the two is as broad as long.But at chip internal to CS pin inductor current signal being detected, TRUEC2 part does integral processing, and simultaneously detection peak electric current.Like this, just detect the mean value of inductive current, namely the mean value of output current.Chip pins, to the value detected, controls output duty cycle, achieves closed-loop control.This control structure, make circuit very simple, due to closed loop control current, compared to open loop approach, this circuit has inductance short-circuit protection function simultaneously.This is very important in the application, and this is equivalent to the risk greatly reducing system jam.Make this scheme not only in performance, have qualitative leap, reliability also improves greatly.Full closed loop control, detect output current, sending pwm signal, is real constant-current supply Drive Control Technique.Relative to the scheme of other non-closed loops; this exclusive Closed-loop Constant-current control technology makes output current precision have qualitative leap; the current precision of complete machine power supply in full voltage, full load, inductance excursion is made to reach in industry the highest ± 0.9% at present; simultaneously; due to closed-loop control; circuit has possessed inductance short circuit, current sense resistor short/open defencive function, and compare and open loop policy, circuit reliability has had large increase.Eliminate and control fixing Rt resistance needed for the turn-off time.It is worth mentioning that, due to closed loop control current, compared to open loop approach, this circuit has inductance short-circuit protection function, possesses the open circuit of Rcs sampling resistor, short-circuit protection function simultaneously.
In color-temperature regulating scheme: the PWM1 output of described MCU control chip connects a road constant-current control circuit, constant-current control circuit is that first group of coloured light LED module is powered; PWM2 output connects another road constant-current control circuit, and constant-current control circuit is that second group of coloured light LED module is powered.
Further, described first group of LED module is white light LEDs module, and described second group of LED module is yellow light LED module.
Further, described first group of LED module is white light LEDs module, and described second group of LED module is green light LED module.
Described first group of LED module is white light LEDs module, and described second group of LED module is blue-ray LED module.
Described first group of LED module is yellow light LED module, and described second group of LED module is blue-ray LED module.
Described first group of LED module is green light LED module, and described second group of LED module is blue-ray LED module.
Described first group of LED module is white light LEDs module, and described second group of LED module is red-light LED module.
Described first group of LED module is red-light LED module, and described second group of LED module is blue-ray LED module.
Described first group of LED module is green light LED module, and described second group of LED module is red-light LED module.
Described first group of LED module is red-light LED module, and described second group of LED module is yellow light LED module.
When regulating, PWM1 exports first group of LED module brightness of controlling from 100% toward lowering, and PWM2 exports second group of LED module brightness of controlling from 0% toward rise, will produce different-colour after the light of two groups of colors mixes.
In another execution mode of light modulation color-temperature regulating scheme, can select following combination: 1. first group of LED module is white light LEDs module, second group of LED module is green light LED module.2. first group of LED module is white light LEDs module, and second group of LED module is blue-ray LED module.3. first group of LED module is yellow light LED module, and second group of LED module is blue-ray LED module.4. first group of LED module is green light LED module, and second group of LED module is blue-ray LED module.5. first group of LED module is white light LEDs module, and second group of LED module is red-light LED module.6. first group of LED module is red-light LED module, and second group of LED module is blue-ray LED module.7. first group of LED module is green light LED module, and described second group of LED module is red-light LED module.8. first group of LED module is red-light LED module, and second group of LED module is yellow light LED module.In circuit of the present utility model, what stabilized voltage power supply prior art adopted changed is constant-current supply driving.When regulating, PWM1 exports first group of LED module brightness of controlling from 100% toward lowering, and PWM2 exports second group of LED module brightness of controlling from 0% toward rise, will produce different-colour after the light of two groups of colors mixes.
In a word, this circuit improves light that LED sends because voltage is inconsistent and secretly to differ problem.The consistency of LED luminescence is high, thus improves the utilization rate of LED, more energy-conservation more environmental protection.
Non-isolated of the present utility model can input built-in touch light modulation color-temperature regulating driving by Width funtion 100-265V, inputted by AC Width funtion, AC/DC conversion is carried out by BR1 rectifier bridge stack, at the EMI anti-interference filtration circuit by being made up of (CE1-L1-C6), the useful signal of low frequency is passed through smoothly, and have inhibitory action to High-frequency Interference, reduce by external interference.(R9-12) resistance adds voltage stabilizing didoe as pressure-limit current-limit circuit provides stabilized power supply to MCU chip, and Q1 triode is in this circuit arrangement as a switching device; (R1-R2, R7-R8) resistance is also for pressure limiting current-limiting circuit can be supplied to two groups of DU8623 driving chip voltages.(D2-L3 – CE3 – R6) (D1-L2 – CE2 – R5) forms buck configuration circuit, to meet the output of Width funtion 10-36V safe voltage.Resistance R15/R16 is in this circuit arrangement as the output current of the adjustable 10-360mA of detection sampling resistor of ± 1% precision.MCU chip touch control two groups of circuit, change LED luminance by the duty ratio changing PWM output.When contacting touch point (as Fig. 1: 5 touch points), the noise signal of human body sensing enters MUC chip (as resistance R17 etc. through resistance, contribute to promoting EMC and safety characteristic), and this signal is processed, again by the duty ratio data of MCU chip inside, change LED luminance by the duty ratio changing PWM output, light modulation and toning are carried out to LED.5 touch points can be divided into 5 kinds of functional mode: 1.ON/OFF, 4 sections of light modulation 2. mode of operations-colour temperature 6000K 3. reading models-colour temperature 5000K 4. leisure patterns-colour temperature 4000K 5. sleep patterns-colour temperature 3000K; Often kind of pattern can carry out repetition 4 sections of light modulations (100%-70%-40%-5%).
When testing, we have selected an input voltage range: 180 ~ 265VAC/50Hz power factor: " 0.5 efficiency: " 88% output voltage range: 3 ~ 50VDC output current: 60mA; For under input voltage, load LED situation of change, we obtain following cross regulation rate result at test: Fig. 3 is visible, line regulation is 0, because full closed loop control Cycle by Cycle accurately controls, input has any change, and chip can detect at once and do relevant adjustment to obtain same output; In like manner, as Fig. 4 and Fig. 5, when output voltage change, during inductance value change, chip also can do the adjustment of being correlated with; Exactly because our closed-loop high-accuracy and constant method of flow control, power supply is accomplished real constant current.