CN108235490A

CN108235490A - A kind of intelligent dimming LED lamp

Info

Publication number: CN108235490A
Application number: CN201611141887.1A
Authority: CN
Inventors: 詹志光
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-12-12
Filing date: 2016-12-12
Publication date: 2018-06-29

Abstract

The invention discloses a kind of intelligent dimming LED lamps, it includes LED array, connects driving equipment in LED array, which is made of wave filter, constant voltage circuit, constant-current circuit, optical sensor and controller.Its median filter is electromagnetic interface filter, and constant voltage circuit is L6562 single- stage PFC constant voltage circuits, and constant-current circuit is depressured constant-current circuit for HV9910, and optical sensor is BH1710 digital optical intensity sensors, and controller is AT89C2051 microprocessors.Optical sensor BH1710 passes through I after collecting environmental light intensity information²C communication protocols are sent to the control centre that controller AT89C2051 is main devices, control centre receives data and is handled, then change the duty ratio of the PWM input signals of the PWMD feet of constant-current circuit HV9910 according to data, and then achieve the purpose that with an automatic light meter.The circuitry is simple, of low cost, operability is strong, and LED light emission luminance is adjusted according to algorithm after measurement illumination data, has good booster action to reducing electric power energy consumption.

Description

A kind of intelligent dimming LED lamp

Technical field

The present invention relates to LED drive circuit field, more particularly to a kind of intelligent dimming LED lamps and lanterns.

Background technology

As the increasingly exhausted and mankind of non-renewable resources such as oil, coal, natural gas in recent years are to energy demand Increasingly increase, energy-saving and emission-reduction cause the great attention of people.LED has received pass as a kind of novel illumination light source technology Note, various countries also begin to put into effect relevant policies limitation incandescent lamp, the production and sales of fluorescent lamp, then help LED.LED light source has Very high efficiency, consumption energy relatively reduce by 80%, and not mercurous and glass with the incandescent lamp of light efficiency, are acknowledged as green energy conservation elder generation Cutting edge of a knife or a sword.

In addition, the light emission luminance of LED is mainly influenced by forward current, using this characteristic, the light modulation to LED is realized, Light visual effect can not only be adjusted, moreover it is possible to further reduce energy consumption 20% to 50%.In classroom, stadiums, street lamp Deng illumination place, since daylight influences, excessively bright illumination can cause waste of energy, and sometimes excessively dark illumination can cause vision Fatigue influences the normal study and work of people or even causes safety accident.It can be seen that accurate illumination photometry, appropriate Brightness of illumination is also extremely important in production and living.

In order to preferably play the advantages of LED illumination is energy saving, it is trend of the times to add in dimming function in LED driver. In general, the dimming mode of LED driver has 3 kinds：Controllable silicon light modulation, simulation light modulation, PWM light modulations.Each dimming mode has it Advantage and limitation.PWM light modulations are that switching circuit is made to work with frequency sufficiently high for eye recognition ability, are passed through Period and duty ratio is set to change output current average value, output current only has two states：Maximum rated operating current And zero current.Simulation light modulation is to realize dimming function by changing the amplitude of output current, and thyristor regulating just passes through adjusting The output power of power supply realizes dimming function.

PWM dims the color temperature constant that can ensure LED, and the efficiency of driver is higher, and can accurately be controlled.Mould It is simple, easy to implement to intend the opposite PWM light adjusting circuits of light modulation, but LED colour temperatures can be made to change, while efficiency is low, output current Precision is not easy to adjust, dimming scope is limited.Thyristor regulating is silicon-controlled by changing just using existing controllable silicon dimmer The angle of flow adjusts output power to realize light modulation, and advantage is not have to change original fluorescent lamp lighting network control.But shortcoming is tighter Weight：It can seriously reduce drive efficiency and power factor, while LED can also be made to generate flicker.

Therefore, LED light emission luminance how is adjusted, it is effective to drop while being supplied to one comfortable visual environment of people Low electric power energy consumption, it has also become the technical issues of being badly in need of solving.

Invention content

In view of the foregoing defects the prior art has, the object of the present invention is to provide a kind of intelligent dimming LED lamp, the lamps The driving equipment circuit of tool is simple, of low cost, operability is strong, and LED luminances are adjusted according to algorithm after measurement illumination data Degree has good booster action to reducing electric power energy consumption.

In order to achieve the above object, the present invention takes following scheme：

A kind of intelligent dimming LED lamp, it includes LED array, connects driving equipment in LED array, the driving equipment is by filtering Device, constant voltage circuit, constant-current circuit, optical sensor and controller composition, it is characterised in that：

Wave filter is electromagnetic interface filter, is connect with constant voltage circuit, for AC network medium-high frequency to be inhibited to interfere, the electromagnetic interface filter Circuit includes common mode capacitance C_y1、C_y2、C_y3、C_y4, common mode inductance L₁, differential mode capacitor C_x1、C_x2, varistor R_VAnd negative temperature The thermistor NTC of coefficient；

Constant voltage circuit is L6562 single- stage PFC constant voltage circuits, is connect respectively with wave filter and constant-current circuit, single- stage PFC constant pressure electricity Road includes switching tube, voltage stabilizing chip TL431 and photoelectrical coupler PC817；

Controller is AT89C2051 microprocessors, is connect respectively with constant-current circuit and optical sensor, and controller is received to be passed from light The data of sensor simultaneously export control signal to constant-current circuit；

Optical sensor is BH1710 new digital light intensity sensors, is connected with controller, which uses voltage stabilizing chip AMS1117 provides 3.3V operating voltages, and the pin ADDR of optical sensor BH1710 is connected to GND, pin DVI connects through 1 μ F capacitances GND, pin SCL and SDA connect P3.2 and the P3.3 foot of controller AT89C2051 by the current-limiting resistance of 1 k Ω respectively；

Constant-current circuit is depressured constant-current circuit for HV9910, is connect respectively with constant-current circuit and LED array, the PWMD pins of HV9910 It is connected with the light modulation I/O ports P1.0 pins of controller AT89C2051.

Preferably, common mode inductance L₁Be from two numbers of turn it is identical, formed around to opposite winding, common mode capacitance and differential mode electricity Hold for safety capacitance.

The present invention has the advantages that：

1）Good compatibility, integrated circuit need not use dedicated light modulation IC, and simple in structure, cost is relatively low.

2）Realize energy-efficient LED driving equipments with an automatic light meter, it more suitable for use in teaching building, street lamp, advertising lamp, park, The places such as corridor.It can set with the gradual dimmed of ambient brightness, be fed back using photosensitive probe signal, make LED illumination luminance Degree is gradually strengthened.It can not only save mass energy, also as reducing power during work and extending making for LED illumination device Use the service life.

Description of the drawings

Fig. 1 is present system theory of constitution figure；

Fig. 2 is filter circuit schematic diagram；

Fig. 3 is constant voltage circuit schematic diagram；

Fig. 4 is constant-current circuit schematic diagram；

Fig. 5 is optical sensor circuit schematic diagram；

Fig. 6 device circuit diagrams in order to control.

Specific embodiment

Embodiments of the present invention are described further below in conjunction with the accompanying drawings.

The schematic diagram of the driving equipment is as shown in Figure 1.A kind of intelligent dimming LED lamp, it includes LED array, LED array Upper connection driving equipment, the driving equipment are made of wave filter, constant voltage circuit, constant-current circuit, optical sensor and controller.Its Median filter is electromagnetic interface filter, and constant voltage circuit is L6562 single- stage PFC constant voltage circuits, and constant-current circuit is depressured Constant Electric Current for HV9910 Road, optical sensor are BH1710 new digital light intensity sensors, and controller is AT89C2051 microprocessors.Optical sensor BH1710 passes through I after collecting environmental light intensity information²C communication protocols are sent to the control that controller AT89C2051 is main devices Center processed, control centre receive data and are handled, and then change the PWM of the PWMD feet of constant-current circuit HV9910 according to data The duty ratio of input signal, and then achieve the purpose that with an automatic light meter.

Filter circuit schematic diagram is as shown in Figure 2.Electromagnetic interface filter is mainly used to inhibit the interference of AC network medium-high frequency to driving The influence of dynamic equipment, while also due to HF switch and to the influence that AC network generates, interference is mainly inhibition driving equipment Common mode interference and DM EMI.Common mode capacitance C_y1、C_y2、C_y3、C_y4With common mode inductance L₁For filtering common mode noise, L₁It is by two A number of turn is identical, is formed around to opposite winding.C_x1、C_x2It is differential mode capacitor, for filtering out DM EMI.Common mode capacitance will be selected Select Y₂Safety capacitance, differential mode capacitor selection X₁Safety capacitance, R_VIt is varistor, NTC is the thermistor of negative temperature coefficient.

Constant voltage circuit schematic diagram is as shown in Figure 3.The peak current mode control chip L6562 quilts of ST Microelectronics's production It is widely used in active power factor（APFC）In correcting circuit, it is operated in critical（TM）Pattern, by controlling inductance peak value Electric current so that input current follows input voltage to change, to achieve the purpose that PFC.And single- stage PFC constant voltage circuit It is the boost inductance in active power factor correction circuit to be replaced with into transformer, and carry out other improvements, the flyback of formation is opened up Flutter circuit.

In the electronic circuit as shown in figure 3, as switching tube Q₂During opening, the AC-input voltage warp after electromagnetic interface filter The rectification of over commutation bridge, input filter capacitor C₁Later, it is added in transformer T₁Primary side inductance on, inductive current linear rise, at this time Transformer secondary rectifier diode VD₅And VD₆Reversely cut-off, output terminal is by output capacitance C_oAnd C_o1Power supply.When primary current detects Resistance R₁₂On voltage when reaching the reference voltage of L6562 CS pins, switching tube Q₂It turns off, at this time secondary rectifier diode VD₅、VD₆Conducting, vice-side winding are load supplying by rectifier diode, while charge for output capacitance.Flyback topologies structure is When switching tube is closed, energy is transmitted.When the ZCD zero current detection pins of L6562 detect no current in auxiliary winding, say Bright primary side inductance has completed magnetic reset, L6562 driving switch pipe Q again₂Conducting, so repeatedly.

The main output voltage of single- stage PFC constant voltage circuit is made of defeated voltage stabilizing chip TL431 and photoelectrical coupler PC817 Go out the divider resistance R in feedback network₁₅And R₁₇Setting, when output voltage is more than designed rated output voltage, resistance R₁₇On voltage be more than TL431 pins 2.5 V of reference voltage, at this time output terminal feedback signal L6562 is fed back to by PC817 INV pins, since the reference voltage of INV pins is 2.5 V, if the voltage of feedback signal is more than 2.5 V, then just have Electric current passes through R₆、C₇、R₇The compensation network of composition flows into the COMP pins of L6562, when the electric current is more than 40 μ A, will enter Overvoltage protection state, L6562 are stopped, and when the current reduction is to less than 10 μ A, L6562 can restart.From output Circuit is powered for device AT89C2051 in order to control, and output voltage is 5 V, when main output voltage is constant, from output voltage base This is constant.

Input filter capacitor C in circuit after rectifier bridge₁Selection it is noted that：If selection is excessive, rectification can be made The angle of flow of bridge becomes too small, while the class sinusoidal voltage waveform of the MULT pins of L6562 can be made to become all the more unlike sine wave, Reduce the power factor of circuit increases total harmonic distortion simultaneously（THD）；If capacitance selection is too small, the work of filtering is not had With this can increase the size and cost of front end electromagnetic interface filter.

Constant-current circuit schematic diagram is as shown in Figure 4.HV9910 is the general high-brightness LED of Supertex semiconductor companies production Driving chip, its main feature is that：

1）Efficiency is more than 90%；

2）The V input voltage ranges of 8 V ~ 450；

3）Constant-current LED driver；

4）Output current is from several milliamperes to more than 1 A；

5）The LED of driving goes here and there from 1 to hundreds of；

6）PWM low frequency light modulations are carried out by enabled pin.

Buck is used in the driving equipment（Decompression）Topological structure realizes LED constant current driving, and operation principle is： The constant pressure V that L6562 single- stage PFCs generate_oThe VIN pins of the circuit are linked into, when switching tube Q is opened, input current is by negative Carry LED, inductance L, switching tube Q, detection resistance R_csIt is flowed into ground.At this point, inductive current linear rise, stores energy, works as detection When ohmically voltage reaches HV9910 CS pins detection voltage, switching tube is closed.Curent change is hindered since inductance has Effect, when switching tube is closed, inductive current passes through fly-wheel diode and output capacitance C_oIt is together load LED power supplies, at this time For inductive current from peak point current linear decline, the average value of inductive current is output current.

In order to which LED is made to be flowed through in going here and there, current ripples are smaller, and Buck converters are operated in continuous mode.Because it is operated in continuous During pattern, when duty ratio is more than 0.5, circuit will appear subharmonic oscillation, make system unstable, need to carry out harmonic compensation. And HV9910 chips do not have harmonic compensation function, so during using the chip, it is ensured that input voltage is 2 times of output voltage More than, so that duty ratio is less than 0.5, avoid the occurrence of subharmonic oscillation.The light modulation pin PWMD of HV9910 without light modulation when, When usually being connect with VDD pins, and carrying out PWM light modulations, make the light modulation I/O ports phase of PWMD pins and controller AT89C2051 Even, when PWMD pin voltages are more than 2.4 V, HV9910 normal works, when PWMD pin voltages are less than 2.4 V, HV9910 It is disabled.It is dimmed by PWM, the electric current in LED only has two states：Zero current and the output-current rating of setting.

The pulsewidth of pwm signal is adjusted using controller AT89C2051, you can adjust the average current i.e. output current of LED. Output current can be adjusted from 0 to output-current rating, i.e. dimming scope can be from 0 ~ 100%, HV9910 supports, 100 Hz ~ 1 The PWM light modulations of kHz.

Optical sensor circuit schematic diagram is as shown in Figure 5.It is by 5 V voltages voltage stabilizings to 3.3 V using voltage stabilizing chip AMS1117 BH1710 provides operating voltage.The pin ADDR of BH1710 is connected to GND, and pin DVI meets GND, pin SCL and SDA through 1 μ F capacitances P3.2 and the P3.3 foot of AT89C2051 microcontrollers are connect by the current-limiting resistance of 1 k Ω respectively.16bit built in BH1710 sensors AD converter directly exports digital quantity value, supports I²C communication protocols, application circuit are relatively simple easy without more peripheral components With.

Controller circuitry schematic diagram is as shown in Figure 6.The P3.2 pins of AT89C2051 microcontrollers simulate I with P3.3 pins²C SCL needed for communication, into row data communication, required illumination is dimmed to be obtained from SDA signal line and BH1710 sensors Intensity data.Since the operating voltage of BH1710 is the V of 2.4 V~3.6, thus in order to microcontroller that operating voltage is 5 V Normal communication is needed to connect SDA and SCL signal line into the pull-up resistor of 5.1 k Ω, is connected on 5 V power supplys.P1.0 pins be used for The PWMD feet output PWM square-wave signals of HV9910B chips, the different duty pwm signal needed for PWMD pins can be by microcontroller 16 internal bit timers carry out accurate control and generate.

4th pin of microprocessor AT89C2051 and the 5th pin connect extraneous quartz oscillator.AT89C2051 is in V_cc= The crystal oscillator of 0~12 MHz can be supported during 2.7 V~6 V, in V_ccThe crystal oscillator of 0~24 MHz can be supported during=4 V~6 V.Crystal oscillator two Two load capacitances at end choose capacitance（30±10）The capacitance of pF is more suitable.

Due to 16 bit AD, direct output digit signals built in BH1710 light intensity sensors, and support I²C leads to Believe agreement, this causes the SCM program of driver designs to become very easily.Only need the P3.2 of AT89C2051 microcontrollers with P3.3 pins simulate I²The sequential of SCL and SDA in C communications reads the digital signal of its output from sensor.Then it is right Digital signal is handled, and is judged, the interruption frequency of microcontroller timer is then changed by certain algorithm, so as to change The duty ratio of the pwm signal of P1.0 pins realizes LED drivers with an automatic light meter.

Protection scope of the present invention is not limited to the above embodiments, it is clear that those skilled in the art can be to this hair It is bright to carry out various changes and deformation without departing from scope and spirit of the present invention.If these changes and deformation belong to power of the present invention In the range of profit requirement and its equivalent technologies, then including the intent of the present invention is also changed and is deformed comprising these.

Claims

1. a kind of intelligent dimming LED lamp, it includes LED array, driving equipment is connected in LED array, it is characterised in that：The drive Dynamic equipment is made of wave filter, constant voltage circuit, constant-current circuit, optical sensor and controller,

Optical sensor is BH1710 digital optical intensity sensors, is connected with controller, which uses voltage stabilizing chip AMS1117 3.3V operating voltages are provided, the pin ADDR of optical sensor BH1710 is connected to GND, pin DVI connects GND, pin through 1 μ F capacitances SCL and SDA connects P3.2 the and P3.3 feet of controller AT89C2051 by the current-limiting resistance of 1 k Ω respectively；

2. according to the intelligent dimming LED lamps and lanterns described in claim 1, it is characterised in that：Common mode inductance L₁It is by two numbers of turn It is identical, around to opposite winding composition, common mode capacitance and differential mode capacitor are safety capacitance.