32results about How to "No flickering phenomenon" patented technology

The invention relates to an LED dimming driving circuit, which includes a rectifying unit and an N-level LED direct current driving circuit. Wherein, the i-th LED DC drive circuit is composed of an i-th voltage sampling unit, an i-th switching unit and an i-th LED light source module. N is a natural number, i=1,2,3,...,N; the first end of the i-th voltage sampling unit and the input end of the i-th LED light source module are jointly connected to the first output end of the rectification unit when i is 1 , when i is not 1, they are commonly connected to the output end of the i‑1th LED light source module. The second end of the i-th voltage sampling unit is grounded, and the voltage dividing end of the i-th voltage sampling unit is connected to the second input end of the i-th switch unit. The first input end of the i-th switch unit is connected to the output end of the i-th LED light source module, and the output end of the i-th switch unit and the second output end of the rectification unit are grounded. The invention is compatible with traditional thyristor dimmers, and realizes adjustment of brightness, color temperature or color without separate wiring.

Disclosed is an alternating current dimming drive circuit for an LED, comprising a rectification unit and N stages of LED direct current drive circuits. In the ith stage of LED direct current drive circuit, a first end of the ith voltage sampling unit and an input end of the ith LED light source module directly or indirectly receive the output voltage of the rectification unit; a voltage division end of the ith voltage sampling unit is connected to a second input end of the ith switch unit; and a first input end of the ith switch unit is connected to an output end of the ith LED light source module, and an output end of the ith switch unit, a second end of the ith voltage sampling unit and a second output end of the rectification unit are grounded. When the ith switch unit is switched on, the first to the ith LED light source modules emit light. When the ith switch unit is switched off, if i is less than N, the first to the (i + 1)th LED light source modules emit light, and if i is equal to N, the first to the Nth LED light source modules stop emitting light. The present invention realizes an alternating current directly-driven LED light source module and will not flicker in the case of alternating current voltage fluctuation.

The invention discloses a method for preparing a barium tungsten electrode, which comprises the following steps of: uniformly mixing Ba(Ca) ZrO3 powder with tungsten powder and a paraffin wax solution, removing a solvent, and pressing an electrode; raising the temperature of the pressed electrode to remove wax, and then warming to 1800-2000 DEG C to preserve heat; and carrying out hydrogen burning treatment for the electrode, and obtaining the barium tungsten electrode. The method for preparing the barium tungsten electrode is simple to operate, and the quality of product is easily controlled. The electron emission ability of the prepared barium tungsten electrode is improved, the electronic current density of electronic emission is increased, and the light intensity is increased. The glow starting speed of an HID lamp can be improved. When the lamp is used in a stroboscopic state, the stroboscopic frequency can be obviously increased, and the non-flickering phenomenon does not exist.The working temperature of the electrode is reduced, and the service life of the lamp is prolonged.

Thyristor dimming circuits and methods are disclosed herein. In one embodiment, a thyristor dimming circuit can include: (i) a thyristor and a rectifier bridge configured to receive a sinusoidal AC voltage, and to generate a phase-loss input voltage; (ii) a power stage circuit configured to have the phase-loss input voltage applied thereto, the power stage circuit having a main switch and being configured to drive a lamp load through electrical conversion; and (iii) a discharging circuit configured, during a first predetermined time interval, to control the main switch to operate with a fixed duty cycle at a fixed frequency, where the first predetermined time interval begins prior to an absolute value of the sinusoidal AC voltage being reduced to zero, the first predetermined time interval ending when the phase-loss input voltage is again applied to the power stage circuit.

A light emitting diode driving circuit comprises a voltage source, a plurality of current control circuits, at least one third resistor and at least one transmission gate, wherein the voltage source is used for providing an input voltage, each current control circuit comprises a first switch, a comparator, a first resistor and a second resistor, the first switch is coupled to a corresponding group of light emitting diodes, the comparator is coupled to a corresponding reference voltage and the switch, the first resistor is coupled to the comparator and the first switch, the second resistor is coupled to the first switch and a common reference voltage, the third resistor is coupled to the first switch of one of the current control circuits, and the transmission gate is coupled between the third resistor and the comparator of another current control circuit of the plurality of current control circuits.

The invention discloses a display device and its driving method. The display device includes: a display panel and a clearing voltage generation module. A plurality of pixel areas and a plurality of clearing voltage lines are defined; the clearing voltage generation module outputs the clearing voltage to the clearing voltage line, and outputs the common voltage to the common electrode; each pixel area is provided with a first thin film transistor and a second thin film transistor; The gate of the second thin film transistor is connected to the clearing voltage line, the source is connected to the pixel electrode, and the drain is connected to the common voltage line; The pixel electrode connected to it is short-circuited with the common electrode, and the display screen is in a black state without flickering; at the same time, the residual charge in the pixel area is completely released; the invention also discloses its driving method.

The invention provides a dual-frequency lighting mixed pulse width modulation dimming electronic ballast, relating to an electronic ballast. The invention provides a dual-frequency lighting mixed pulse width modulation dimming electronic ballast which can ensure the lightness of the lamp to be in 100% to 30% with reliable light modulation, leads to no flashing lamp phenomenon, is convenient for being applied in single-line illumination control circuits and can be widely applied to existing energy-saving lamps and ballasts. The invention is provides with a rectification circuit, a zero cross detection circuit, a system control circuit, a dual-frequency point power output circuit and a lamp driving circuit. The input terminal of the rectification circuit is externally connected with a powersupply; the input terminal of the zero cross detection circuit is connected with the output terminal of the rectification circuit; the input terminal of the system control circuit is connected with the output terminal of the zero cross detection circuit; the power supply input terminal of the dual-frequency point power output circuit is connected with the output terminal of the rectification circuit; the control input terminal of the dual-frequency point power output circuit is connected with the system control circuit; the input terminal of the lamp driving circuit is connected with the output terminal of the dual-frequency point power output circuit; the output terminal of the lamp driving circuit is externally connected with loads.

A flat panel display inspection apparatus automatically controls brightness of a backlight source according to the magnitude of a flat panel display by means of a ballast stabilizer with a dimming control circuit for brightness adjustment. The flat panel display inspection apparatus for inspecting an appearance of a flat panel display using a backlight lamp emitting light includes: a support unit for supporting the flat panel display; a ballast stabilizer for including a dimming control circuit continuously adjusting brightness of the backlight lamp, and applying a constant voltage to the backlight lamp; a converter controller for transmitting a DC voltage of a predetermined range, adapted to control an output signal of the ballast stabilizer, to the dimming control circuit; and a controller for transmitting a dimmer value adapted to establish a magnitude of the DC voltage to the converter controller.

The invention relates to a novel fluorescent lamp which comprises a lighting tube, electrodes, an inductance, a resistance and a capacitor, wherein, the left end and the right ends of the lighting tube are respectively provided with an electrode which are of a semicircle spherical shape in the lighting tube; the fluorescent lamp also comprises a trigger diode and bidirectional thyristors; in a circuit, one bidirectional thyristor is adopted to generate pulse voltage which is pressurized by a resistance-capacity coupling circuit to trigger the other bidirectional controlled silicon, thus arousing fluorescent powder or saturated inert gases in the lighting tube. As the fluorescent lamp is provided with a filament loop in the lighting tube, the problem of burning out filament does not exist,and part of electrical energy can not be consumed since the filament emits heat. In addition, the bidirectional thyristors are arranged, so that high voltage of the capacitance can be prevented from discharging towards the lighting tube suddenly after the lighting tube normally shines, and the lighting tube does not generate twinkle, thus the luminance brightness is stable.