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.

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 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.

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.

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.

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 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 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.