144results about How to "Good dimming effect" patented technology

A dimmable, light-emitting diode (LED) power supply adapted to provide a direct current (DC), constant current (“constant current source”) from a conventional, phase-controlled 120 VAC, 60 Hz power source is disclosed. The constant current source of the present invention utilizes two processes to control dimming. In a first process, the phase angle of the input voltage is used to control the duty cycle of a line frequency pulse width modulation (PWM). In a second process, a proportional-current limit adjustment is used to control the average current to the LED during the ON time of the line frequency by PWM. As a result, at relatively low phase angles, peak currents can be lowered, reducing flicker and improving the audible noise levels generated by the circuit.

A hybrid power control system for providing dynamic power control to illumination systems in which a power source can supply any one of a range of AC or DC voltages. One or more switch mode power supplies incorporating one or more linear and switch mode regulator circuits combined to dynamically control current, voltage and power to the illumination system. A microprocessor or other integrated circuit device to receive and send control information in order to regulate the power to a light emitting device One or more output drive stage(s) capable of delivering a wide dynamic current range, channel bonding and protection circuitry compatible with standard or common anode illumination systems.

The invention provides a design method of an LED (light-emitting diode) dimming driving switching power supply applied to various traditional dimmers. According to the design method, the LED driving power supply achieves the resistive load input-output characteristics similar to those of an incandescent light bulb, so that LED lights (semiconductor LEDs) can be well suitable for dimming of the traditional dimmers (including traditional dimmers adjusting the phases of conduction angles through leading edge phase cut and traditional dimmers adjusting the phases of conduction angles through trailing edge phase cut, wherein silicon controlled dimmers are dimmers adjusting the phases of conduction angles through leading edge phase cut) and be used in indoor places where the traditional dimmers are needed for dimming. The LED dimming driving switching power supply designed according to the design method provided by the invention comprises a dimmer starting circuit loop, a rectifying circuit, a phase detection and isolation circuit, a phase cut detection circuit, a power-factor correction circuit, a switching power supply circuit and an LED current control circuit.

An LED dimming circuit suitable for thyristor dimmers, 50 / 60Hz AC sine wave waveforms are chopped by a triac (TRIAC), rectified by a bridge rectifier circuit (A), and separated by an isolation circuit ( U1) Take out the chopping waveform and send it to the single-chip control unit (MCU), the single-chip control unit (MCU) outputs the PWM waveform to the LED driver chip (LEDDRIVE), and the LED driver chip (LEDDRIVE) drives the light-emitting diodes (LED1, LED2) to emit light. It makes the LED lamp directly replace the incandescent lamp with the same perfect dimming effect, and the circuit is simple and the cost is low, which overcomes an important obstacle for the LED lamp to replace the incandescent lamp.

Mercury-free metal halide lamp with a warm white luminous color, the fill of which comprises the following components: an inert gas which acts as a buffer gas; a first group of metal halides (MH), the boiling point of which is above 1000° C. (preferably above 1150° C.), the first group comprising at least Dy and Ca used simultaneously as metals, and the molar ratio of the two metal halides Ca-MH:Dy-MH being between 0.1 and 10; these are components with a low volatility which are present in saturated form; a second group of metal halides, the boiling point of which is below 1000° C. (preferably below 900° C.), the second group comprising at least one of the elements In, Zn, Hf, Zr as metals; these are volatile components which are mostly present in unsaturated form; the total fill quantity of the first group of metal halides being between 5 and 100 mumol / cm3; the total fill quantity of the second group of metal halides being between 1 and 50 mumol / cm3; and the color temperature being between 2700 and 3500 K; the general color rendering index being at least Ra=90, while at the same time the red rendering index is at least R9=60.

The invention relates to an LED dimming device for a dimmer, which comprises a rectifier, a booster, a preamp voltage detecting circuit and a post voltage detecting circuit, a main control chip, a primary transformer, a secondary transformer, a secondary rectification and secondary filter circuit, and a diode switch. The LED dimming device for the dimmer can realize the brightness control of an LED bulb by using a controlled silicon dimmer and a transistor dimmer, and make the use of the energy-saving and environment-friendly LED more widely.

The invention provides a control circuit for controlling the current running through a load, comprising a power converter, a controller and a current control circuit. According to a control signal, the power converter converts a first voltage signal into a second voltage signal. Coupled with power converter, the controller adjusts the control signal in respond to the second voltage signal to make the second voltage signal maintain in a desired value. Coupled with the load, the current control circuit controls the current running through the load in respond to a dimming signal.

The invention relates to a light-emitting diode (LED) dimming driving system with a silicon controlled bypass dimming circuit. The LED dimming driving system with the silicon controlled bypass dimming circuit comprises an alternating current / direct current (AC / DC) LED constant current actuator and a LED light string, wherein the input end of the AC / DC LED constant current actuator is electrically connected with an alternating current electric supply, the output end of the AC / DC LED constant current actuator is connected with the LED light string, the silicon controlled bypass dimming circuit is arranged, the input end of the silicon controlled bypass dimming circuit is connected with the alternating current (AC) electric supply, and the output end of the silicon controlled bypass dimming circuit is connected with a dimming interface of the AC / DC LED constant current actuator. The AC / DC LED constant current actuator obtains energy from the AC electric supply, and outputs a constant current value to drive the LED light string. The AC / DC LED constant current actuator is provided with an analog dimming interface which is used for adjusting an output current value according to an analog voltage amplitude value of an input dimming signal so as to change luminance of the LED light string. According to the silicon controlled bypass dimming circuit, the input end of the silicon controlled bypass dimming circuit is connected with the AC electric supply, and the output end of the silicon controlled bypass dimming circuit generates a smooth direct current analog voltage signal to serve as a dimming signal which is input into the analog dimming interface of the AC / DC LED constant current actuator. The value of amplitude of the dimming signal output by the silicon controlled bypass dimming circuit can be adjusted by adjusting an adjustable knob of the silicon controlled bypass dimming circuit, and thus a current value and the luminance of the LED light string can be adjusted.

In embodiments, improved capabilities are described for dimming performance of lighting methods and systems, such as the improvement of dimming LED lamps that are dimmed from standard external dimming devices. Methods and systems for improving dimming performance include a fast startup override facility for overriding a default dimming function of the lamp's electronics through forcing the lamp electronics to operate with a higher than normal duty cycle to ensure the lamp electronics can deliver higher than normal power to an LED module during a dimming current level startup condition. Dimming facilities may also include a dynamic RC selection facility, an active N-level bleeder facility, a dimmer-type detection facility, an improved dimming linearity through symmetrical phase cutting facility, and a flicker reduction facility.

A luminous system based on a luminous diode and a luminous diode driver circuit and method are disclosed in the present invention. The driver circuit comprises a switch, a pulsewidth modulation signal generator and a regulator coupling with the pulsewidth modulation signal generator. To control the conducting time and the closing time of the switch according to the duty-ratio of the pulsewidth modulation signal generated by the pulsewidth modulation signal generator, so as to regulate the current provided to the luminous diode. One input end of the regulator receives the external input signal, and outputs a controlling signal to the pulsewidth modulation signal generator according to the external input signal, regulates the duty-ratio of the pulsewidth modulation signal generated by it, leads the luminous diode current to be able to increase or decrease according to the external input signal, thereby realizes to regulate the brightness of the luminous diode freely.

A LED drive circuit for SCR dimming including an external controller configured to receive AC voltage from a power network to convert the AC voltage to an AC voltage with a lacked phase by phase controlling the voltage through a thyristor, and a LED driver that includes a bridge rectifier configured to shape the AC voltage with the lacked phase output into a unidirectional pulse DC voltage, and a phase angle detecting circuit configured to shape the AC voltage signal output with lacked phase from the external controller into a saw-tooth wave pulse signal.

The invention relates to an LED dimming device which is applicable to a controllable silicon dimmer. The LED dimming device comprises a rectifier, a fictitious load circuit, a zero-crossing detection circuit, a high frequency transformer, a main power supply drive integrated circuit, a secondary rectification and filter circuit, a secondary power supply drive integrated circuit and an average voltage detection circuit. The invention has the beneficial effect that the LED dimming device is capable of realizing the brightness adjustment of an LED lamp by the controllable silicon dimmer and has the advantages of good dimming effect, long service life, simple structure and environmental protection and energy saving.

The present invention provides a driving circuit and a driving method for light-emitting diodes (LEDs), and a display apparatus using the same. The driving circuit comprises a power switch and a dimmer circuit. The method comprising: detecting a duty of a pulse width modulation (PWM) dimming signal; and when the duty of the PWM dimming signal is less than the predetermined duty, providing an analog dimming signal to the driving circuit. The present invention can be applicable to a display apparatus, and improve a noise problem when a duty of a conventional dimming is too low.

The invention discloses a wide-voltage-range LED lamp switching and dimming driving circuit and an LED lamp dimming control system. The LED lamp dimming control system comprises a plurality of parallel-connected LED lamps and a shared power switch (S0); every LED lamp comprises a switching and dimming driving circuit, and the LED lamps are dimmed simultaneously through the power switch (S0); every switching and dimming driving circuit comprises an LED light source circuit (6), a rectification circuit (4), a constant-current source circuit (7), a stabilizing and PFC (power factor correction) circuit (5), and a dimming control circuit (8) used for generating pulse output signals, adjusting pulse width modulation duty ratio and periodically outputting pulse signals; the output end of the dimming control circuit (8) is connected with the sampling voltage end (A) of the voltage output end (B) of the stabilizing and PFC circuit (5); under the control of the power switch circuit (11), the dimming control circuit (8) can generate pulse switch signals of different duty ratios to control the stabilizing and PFC circuit (5) to provide time-share switch voltage to the LED light source circuit (6) and further to perform power control and dimming on the LED light source circuit (6). The wide-voltage-range LED lamp switching and dimming driving circuit and the LED lamp dimming control system can be applied to the field of LED lamp dimming.

An operating method, in particular a dimming method for a discharge lamp. In order to set the maximum brightness, two outer electrodes (5,6), for example, are used to generate in the discharge lamp a dielectrically impeded discharge which, through the formation of xenon excimers, emits UV radiation which is converted into light with the aid of fluorescent materials (2). In order to permit intense dimming of the discharge lamp, two cold cathodes (3, 4) are used to generate a xenon low-pressure discharge emitting UV beams, and the dielectrically impeded discharge is switched off. Both types of discharge are preferably excited by high-voltage pulses which are generated by an operating unit (7). Dimming is preferably performed by blanking pulse trains.

The invention relates to the technical field of greenhouse shed regulation and control and provides an automated shed light regulating and supplementing device. The automated shed light regulating and supplementing device comprises a shed frame and shed walls, wherein skylights are arranged on the shed wall of the top of the shed frame. The automated shed light regulating and supplementing device further comprises a light regulating system, a light supplementing system, a controller and a lighting sensor, wherein the shed walls are made of a transparent material, and the skylights are opened downwards; the light supplementing system and the lighting sensor are arranged in a shed; and the light regulating system, the light supplementing system and the lighting sensor are all in electric signal connection with the controller, the lighting sensor is used for monitoring intensity of illumination in the shed and transmitting signals to the controller, and the controller controls actions of the light regulating system and the light supplementing system. According to the automated shed light regulating and supplementing device provided by the invention, the controller is used for controlling the actions of the light regulating system and the light supplementing system, so that the intensity of illumination in the shed is always in a state which is most beneficial to crop growth, and the growth of crops is promoted; and the device is high in work efficiency and good in light regulating effect.

The invention discloses a kind of pulse width dimming control circuit for LED phase cut dimming power supply, which comprises LED phase cut dimming power supply circuit and pulse width dimming control circuit. The pulse width dimming control circuit is composed of voltage sampling amplification circuit, signal conversion circuit, photoelectric coupler and pulse width PWM control circuit. The signal input terminal of the voltage sampling amplification circuit is connected to the live wire L and the null line N after passing through the anti-interference circuit for voltage sampling. The output control part of the pulse width PWM control circuit consists of a field-effect transistor, the drain electrode of which connects to LED lamp. The Invention is a kind of pulse width dimming control circuit for LED phase cut dimming power supply, which has no restriction on load power and has strong compatibility with phase cut dimmer, wide dimming range.

The invention discloses a stage dimmer based on chopping-control alternating-current voltage regulation and a regulating method of the stage dimmer. The stage dimmer based on chopping-control alternating-current voltage regulation comprises a data receiving circuit, a single-chip microcomputer, a PWM pulse circuit, an IGBT drive protection circuit, an IGBT chopping-control voltage regulating circuit and a filter circuit. After receiving signals from a stage dimming console, the data receiving circuit transmits the signals to the single-chip microcomputer; the PWM pulse circuit is electrically connected to the output end of the single-chip microcomputer, the output end of the single-chip microcomputer is electrically connected to the input end of the IGBT drive protection circuit, the output end of the IGBT drive protection circuit is electrically connected with the input end of the IGBT chopping-control voltage regulating circuit, the IGBT chopping-control voltage regulating circuit is electrically connected with the input end of the filter circuit, and the output end of the filter circuit is electrically connected with stage lamps. The stage dimmer based on chopping-control alternating-current voltage regulation and the regulating method of the stage dimmer achieve the advantages of restraining harmonic waves and radio interference of the circuits and improving dimming performance of stage light.

A ballast for operating a compact fluorescent lamp includes a power factor correction circuit and an energy storage capacitor coupled to the output thereof. The power factor correction circuit is configured to draw current from an AC power source during substantially more than half of the cycle of the input AC voltage waveform; i.e., when operated such that full power is supplied to the lamp. Energy transfer elements in the power factor correction circuit extract energy from the AC power source via an input rectifier, even when the peak voltage of the AC voltage waveform is substantially lower than the voltage of the energy storage capacitor, and transfer the energy to the energy storage capacitor a sufficient number of times during for each cycle of the input AC voltage waveform (e.g., at least 500 times for each full cycle of a 60 Hz input AC voltage waveform for a lamp operated at a frequency of 30 kHz), such that the energy storage capacitor remains substantially fully charged during steady-state ballast operation. The power factor circuit additionally provides for improved dimming capability, specifically, dimming the discharge to low levels, while maintaining steady, non-flickering operation.

The invention provides a polymer network liquid crystal dimming device. The dimming device includes an upper substrate layer, a lower substrate layer and a liquid crystal dielectric layer located between the upper substrate layer and the lower substrate layer; and the liquid crystal dielectric layer includes a polymeric compound, a nematic liquid crystal composition, dye and a photoinitiator, wherein the polymeric compound has a structure shown as a general formula I. The dimming device has appropriate threshold voltage and saturation voltage, low all-optical transmittance and good dimming performance; and the dimming device can have better light adjusting transmittance and dimming effects by adjusting the all-optical transmittance through voltage. The structure of the polymeric compound is shown as the general formula I.

The invention discloses a color temperature adjustable integrated high power LED medical lighting system that can be used for surgical lighting, check lighting and surgical indoor overall lighting. The lighting system comprises a color temperature adjustable integrated high power LED chip, optical components, a radiator, a shell, an LED drive controller, a color temperature and brightness regulator, a power converter and a connecting cable, wherein the color temperature adjustable integrated high power LED chip is fixed on the radiator; the radiator is fixedly connected with the shell; the optical components are installed on the shell; one end of the connecting cable is connected to the color temperature adjustable integrated high power LED chip, and the other end is connected to the LED drive controller; the color temperature and brightness regulator and the power converter are connected to the LED drive controller. The optical components in front of the color temperature adjustable integrated high power LED chip not only can be the combination of a paraboloid reflecting cup and a diffuse reflection transmitting film, but also can be the combination of lens groups. The invention is suitable for medical lighting and can improve medical lighting quality.

The invention relates to the technical field of LED drive circuits, in particular to a linear LED drive circuit for silicon controlled dimming. The technical problems that in the prior art, when overshoot flicker at the turn-on moment is achieved and critical voltage is reached, channels are switched repeatedly to cause switch flicker are solved. The linear LED drive circuit mainly comprises a power source, a silicon controlled switching circuit, a rectifier bridge, an integral circuit and a drive circuit, wherein a silicon controlled drive power circuit is formed by the power source, the silicon controlled switching circuit and the rectifier bridge; the integral circuit comprises a power source potential point and a sampling potential point, wherein the voltage values of the power source potential point and the sampling potential point are reduced in sequence, and the output end of the rectifier bridge is connected to the power source potential point; the drive circuit comprises a switch control and processing circuit, and the switch control and processing circuit controls a first switch transistor of a drive circuit discharge channel and a second switch transistor of a drive circuit LED channel to be connected or disconnected through voltage of the sampling potential point; the switch control and processing circuit comprises a hysteresis comparator and an LED lamp, the input end of the hysteresis comparator is connected to the sampling potential point, and the maximum potential point of the LED lamp is connected with the output end of the rectifier bridge. The invention is used for designing the LED drive circuit.

The invention discloses a greenhouse, which mainly comprises a greenhouse roof, a greenhouse lateral wall, an outside screen device, an inside screen device, a wet curtain, a lateral window and a seedling bed, wherein the greenhouse roof is arranged above the greenhouse lateral wall; the outside screen device is arranged above the greenhouse roof; the inside screen device is arranged below the greenhouse roof; the top of the wet curtain is fixed on the greenhouse lateral wall; the lateral window is arranged on the outer side of the wet curtain; the seedling bed is arranged below the greenhouse roof; and inclined through holes are distributed on an outside screen densely; and a vertical surface which is consistent with the inclined direction of the inclined through holes is parallel to a vertical surface on which an upper rotating shaft is positioned. The greenhouse has the advantages that: the integral outside screen can incline, the inclined through holes are distributed on the outside screen densely, and the light-transmitting areas of the inclined through holes are changed with the change of the inclination of the outside screen; and thus, the light-transmitting effect of the outside screen is adjustable, a mode of stepless dimming is adopted, and the dimming effect is high.

The invention discloses a PWM / PFM synchronous control dimming circuit, comprising a power supply circuit, a PWM generating circuit, a PWM control circuit, an OSC circuit, a PFM control circuit, a PWM / PEFM synchronous control circuit, a function control circuit and a drive circuit. Linearly changing adjustable circuits of impulse width and impulse frequency are generated synchronously in proportion according to the change requirements of control signals so as to control a dimming control circuit in which the loading reaches to the adjusting power through the drive circuit; and the dimming circuit can be applied to dimming gas discharge lamps such as fluorescent light, high voltage sodium lamp, Metal halogen lamp, and the like, and is applied to electronic field and microelectronic field.

The invention provides a dimming backlight partition dimming control method, an intelligent terminal and a storage medium. The dimming backlight partition dimming control method is used for regulatingand controlling the brightness of a backlight source of an intelligent terminal in a partition manner, and comprises the steps that an intelligent terminal mainboard SOC obtains the image partition information and the brightness information corresponding to the image partition information, and sends the image partition information and the brightness information to an FPGA; the FPGA receives and analyzes the image partition information and the brightness information, generates a partition control signal according to the image partition information and the brightness information, and sends thepartition control signal to a driving chip; and the driving chip receives the partition control signal and drives and controls the image partition brightness according to the partition control signal.The display images and brightness information are obtained through the SOC of the intelligent terminal mainboard, and the driving chips corresponding to the dimming backlight partitions are uniformlycontrolled by the FPGA, so that the dimming efficiency and the dimming effect of the dimming backlight partitions are improved.

The invention discloses an ultrasonic ranging-based television screen intelligent dimming device. The device includes a micro controller, a human body infrared detection module, an ultrasonic ranging module, a driving module, a micro direct-current motor, an infrared transmitting module, a television infrared receiving module and a direct-current voltage-stabilized power; the micro controller is connected with the human body infrared detection module, the ultrasonic ranging module, the driving module and the infrared transmitting module respectively; the driving module is connected with the micro direct-current motor; and the direct-current voltage-stabilized power provides power for the whole dimming device. The dimming device of the invention comprises the micro controller, the human body infrared detection module, the ultrasonic ranging module, the micro direct-current motor, the driving module, the infrared transmitting module and the television infrared receiving module. The dimming device of the invention has the advantages of simple structure, low cost and wide application scope. The invention also discloses an ultrasonic ranging-based television screen intelligent dimming method.

Presented is a converter circuit having main switching circuiton a primary side of a transformer, for controlling supply of a current to a storage inductor on the primary side when the main switching circuit is conductive. The convertor circuit comprises: a control circuit operatively coupled to the main switching circuit and for controlling the main switching circuit, the control circuit comprising a control capacitor adapted to enable the control circuit and turn off the main switching circuit; an auxiliary inductor magnetically coupled to the storage inductor and adapted to trigger the control circuit to operate and turn off the main switching circuit in response to a voltage change in the storage inductor when the main switching circuit being conductive; and a charging circuit coupled between the auxiliary inductor and the control capacitor and adapted to enable the auxiliary inductor to charge the control capacitor. The charging circuit comprises first and second charging paths within the primary side between the auxiliary inductor and the control capacitor, the first charging path being conductive and the second charging path being conductive when a voltage across the auxiliary inductor is above a threshold value.

The invention discloses an LED dimming and color adjusting circuit. The LED dimming and color adjusting circuit comprises a rectifying module, a fuse, a voltage transformation module, a protecting module, a filter module, a control module, a PWM adjustment module, a color adjusting module and a dimming module. The rectifying module is used for converting an alternating current into a direct current. The fuse is connected between the rectifying module and an alternating-current power source. The voltage transformation module is connected with the output end of the rectifying module and used for transforming the voltage of the direct current output by the rectifying module. The protecting module is connected with the input end of the voltage transformation module. The filtering module is used for filtering the current output by a transformer. The rectifying module, the voltage transformation module and the protecting module are all connected with the control module. The control module is used for controlling the voltage output by the voltage transformation module. The PWM adjusting module is connected with the filtering module and used for generating PWM control signals. The color adjusting module is connected with the PWM adjusting module and is used for adjusting the color of an LED lamp. The dimming module is connected with the PWM adjusting module and is used for adjusting the brightness of the LED lamp. The LED dimming and color adjusting circuit can achieve constant-voltage power supply and has good dimming and color adjusting effects.

The invention discloses a thermochromatic vanadium dioxide-based composite film with adjustable contact angles and a preparation method thereof, aiming at achieving the purpose of simple structure and easiness in implementation of preparation process; the composite film provided by the invention comprises a transparent substrate and a composite film; the composite film comprises a vanadium dioxide film positioned on the transparent substrate and an oxide or hydroxide nano array positioned on the vanadium dioxide film; the chemical component of the vanadium dioxide film is VO2-x, wherein x is more than -0.3 and less than 0.6; the oxide or hydroxide nano array is composed of one or more of sheet, rodlike, needle-like and strip-shaped oxide or hydroxide nano particles; the sharp angle between the sheet, rodlike, needle-like and strip-shaped oxide or hydroxide nano particle and the plane of the vanadium dioxide film is more than 35 degrees; the preparation method of the composite film provided by the invention comprises the steps of: firstly depositing the vanadium dioxide film 10-500 nanometers thick on the transparent substrate, and then preparing the zinc oxide nano array by the chemical bath method.

The invention discloses an LED driver based on Internet of Things. The LED driver comprises an AC / DC power supply, a DC / DC isolated power supply, a first linear voltage-stabilized power supply, a second linear voltage-stabilized power supply, a dimming driving circuit, a Bluetooth module and a radio frequency impedance matching network, wherein the Bluetooth module is connected with one end of a digital communication isolation circuit, the other end of the digital communication isolation circuit is connected with the dimming driving circuit, a connection point between the Bluetooth module andthe digital communication isolation circuit is connected with an environment light sensor, one end of a zero-cross isolation detection circuit is connected with a live wire and a null wire, the otherend of the zero-cross isolation detection circuit is connected with the Bluetooth module, and the Bluetooth module is connected with a relay control circuit. The invention also discloses an implementation method of the LED driver based on Internet of Things. The LED driver provided by the invention has the characteristics of being simple in structure, low in cost, excellent in dimming performance,high in safety and excellent in using effects, and so on.