44results about How to "Avoid strobe" patented technology

The invention discloses a controlled-silicon adapting LED (light-emitting diode) driving circuit, method and switch power supply. The input voltage signal of the representing sine half-wave voltage signal is compared with a threshold voltage to obtain a first comparison pulse signal, and then the effective width of the first comparison pulse signal is extended for a period of time to obtain a first control signal, wherein the first control signal controls a power switch tube switches off before the input current is reduced to be equal to the maintenance current of a controlled silicon, and the power switch tube switching-off state is made to last for a period of time to the next cycle, so that the load current of the controlled silicon is made to be larger than the maintenance current all the way in the conducting time interval of the controlled silicon, the controlled silicon does not need to be re-conducted irregularly for many times, the input power of the system in each half cycle is same, and LED lamp is prevented from flicking under load and generating noise.

The invention discloses a ripple suppression circuit, a ripple suppression method, and an LED lamp applying the ripple suppression circuit. Ripple reference voltage for representing the ripple is obtained by sampling the ripple from the output voltage of a direct current converter; and controlling the voltage at a load end to change along with the ripple by a transistor based on the ripple reference voltage. Consequently, the voltages at the two ends of the load change along with the ripple so as to enable the voltages of the load to be reduced to constant voltage; and therefore, the ripple acting on the load can be suppressed or eliminated, and the flicker or stroboflash of the LED load is avoided.

The invention relates to a temperature detecting device, a temperaure detecting method and a liquid crystal driving device. The temperature detecting device comprises a state machine, a frame frequency selection unit and a frame frequency output unit. When a current temperature value jumps around a certain critical temperature value, the state machine judges whether the difference value of the current temperature value and the critical temperature value is within the preset range; if the difference value of the current temperature value and the critical temperature value is within the preset range, the state machine determines that the current state is the previous state; if the difference value of the current temperature value and the critical temperature value is out of the preset range, the state machine determines that the current state is the state corresponding to the current temperature value. The frame frequency selection unit connected with the state machine is used for selecting the frame frequency corresponding to the current state according to the current state determined by the state machine. The frame frequency output unit connected with the frame frequency selection unit is used for outputting the frame frequency. When the temperature jumps frequently in a smaller range, the temperature detecting device can avoid the frequent jump of the frame frequency and the flicker of a liquid crystal display screen caused by the frequent jump of the frame frequency, and thus the display quality of liquid crystal display screen is enhanced.

The invention provides a solar direct-current supply station which comprises a solar photovoltaic battery, a storage battery, a solar electricity-generating controller, a complementation charging controller, a mains supply charging module, a storage battery discharging module and a direct-current load. The solar electricity-generating controller is used for adjusting and controlling electric energy converted by the solar photovoltaic battery, sending the adjusted energy to the direct-current load on one hand, and sending the excess energy to the storage battery for storing on the other hand. When electricity generated by the solar photovoltaic battery can not meet the need of the direct-current load, the controller sends the electric energy of the storage battery to the direct-current load through the discharging module. The complementation charging controller is used for controlling the mains supply charging module to charge the storage battery when the electric energy of the storage battery is insufficient, and therefore the storage battery can supply direct currents continuously to the direct-current load. The solar direct-current supply station can provide the stable and continuous direct currents for villages, pasturing areas, mountainous areas and the like where power supply of a public power grid is unstable, and illumination and life of users are facilitated.

The invention discloses a parking stall guiding method and device. The method includes obtaining a plurality of vehicle-free state frame images of a parking stall, and adding to a background queue; when stroboflash of a parking stall indicator light is judged to occur, obtaining a current frame image of the parking stall; calculating Euclidean distance between an HOG feature of the current frame image and an HOG feature of each vehicle-free state frame image in the background queue, and determining a parking stall state of the current frame image; and controlling the turning-on state of the parking stall indicator light through the parking stall state of the current frame image. The method solves the problem of stroboflash of the indicator light.

The invention provides a PWM dimming device, which comprises a dimming signal interface circuit, a drive circuit, a driving power output interface circuit and a control circuit, wherein the dimming signal interface circuit is used for receiving a dimming signal; the drive circuit outputs driving voltage or driving current and the work period is Td; the driving power output interface circuit is connected with a load; the control circuit receives the dimming signal from the dimming signal interface circuit, generates a PWM signal and outputs the PWM signal to the drive circuit; and the control circuit generates the PWM signals with different frequencies during PWM dimming and normal operation of lighting equipment. After the dimming method is adopted, the PWM dimming device can be compatible with dimmer switches at different dimming levels, so that stroboflash can be effectively avoided during normal operation, and meanwhile, a more smooth and softer dimming effect can be obtained

The invention provides a direct drive LED lighting system controlled by an integrated control circuit. The direct drive LED lighting system controlled by the integrated control circuit comprises a constant-voltage unit and direct drive LED lighting devices. At least two direct drive LED lighting devices are connected between the direct current high-voltage output end VH and the reference ground end GND in parallel. Each direct drive LED lighting device comprises multiple LED circuits. Each LED circuit comprises at least two controlled LED particle circuit units and a normally-on LED particle circuit unit connected with the controlled LED particle circuit units in series. Each LED circuit is provided with at least two direct drive LED integrated control circuits. Each direct drive LED integrated control circuit is connected with at least one controlled LED particle circuit unit in the corresponding LED circuit unit. The direct drive LED integrated control circuits at least have the following functions of making a response to input information and controlling LED particles in the controlled LED particle circuit units to be switched on and short-circuited.

The invention discloses a multi-mode control LED dimming constant-current constant-voltage output circuit which comprises an EMI circuit, a full-bridge rectification circuit, a power factor correctioncircuit, a phase detection circuit, a dimming signal detection conversion circuit, a constant-current power supply, a high-voltage oscillation control circuit, a constant-current driving circuit, a detection feedback control circuit and a signal processing circuit. The resonance frequency conversion control is adopted, according to a connected load, an optocoupler with high interference resistance is adopted to return various feedback signals to a resonance control end, and a power factor correction circuit and a phase detection circuit are combined with a control circuit, so that stable implementation of stepless dimming is ensured. After various dimmers are connected, the stable driving of the LED can be realized in the whole dimming process; the starting speed is high, and no flickering phenomenon exists when the brightness is adjusted; no noise exists in any working state; the driving output can be adjusted according to a load LED lamp connection mode used by a client, so that theuniversality of the circuit is ensured; and the full voltage (AC 100-277V) input is achieved, so that the circuit is suitable for various environments.

The invention provides a lighting system, which comprises an integrating circuit, a driving circuit and a light source. A pulse width modulation signal is connected into the input end of the integrating circuit, and the integrating circuit is used to convert the pulse width modulation signal into an analog signal. The control end of the driving circuit is connected into the output end of the integrating circuit. The output end of the driving circuit is connected with the light source. The duty cycle corresponding to the pulse width modulation signal is directly proportional to the voltage corresponding to the analog signal. The lighting system of the invention avoids the stroboflash problem of the light source caused by direct PWM dimming. At the same time, because the voltage value of theanalog signal output by the integrating circuit is directly proportional to the duty cycle of the input pulse width modulation signal, the process of adjusting the brightness of the light source through the analog signal is synchronized with the PWM dimming signal. Therefore, flicker-free dimming is realized on the premise of ensuring the dimming accuracy, and the damage to the human body causedby the stroboflash of the light source is avoided.

A high performance linear driving circuit converting an AC voltage of an external power supply into a DC output current and then outputs the DC current to at least one LED includes a detection unit, a control unit and a current unit. In a 180-degree phase sine wave period of the AC voltage, the total current of the output current is formed by a first working section, an energy saving section and a second working section, and the detection unit detects at least a voltage value of the AC voltage or a current value of the output current to generate a detection signal, and drives the control unit to modulate the duty cycle and current value of the first working section, energy saving section and second working section, and the amounts of current of the first and second working sections are greater than that of the energy saving section.

The invention relates to an LED (light-emitting diode) desk lamp, which comprises a transparent plate, a lamp panel, a lampshade, a screw, an adjusting handle, a universal movable head, a lamp pole, an L-shaped handle, a counterweight handle, a full-tooth tube, a base, a level switch, a power switch, a base rubber pad, a lead and a power adapter, wherein the transparent plate and the lampshade are fixed through the screw, the lamp panel is sealed inside, the lampshade is connected with the lamp pole through the universal movable head, the adjusting handle is arranged on the universal movable head, the lamp pole and the counterweight handle are fixed through the L-shaped handle, the full-tooth tube is arranged between the counterweight handle and the base, the lead penetrates through the base, the full-tooth tube and the like and is connected with the lamp panel, the level switch, the power switch and the base rubber pad are arranged on the base, and the base is externally connected with the power adapter. By introducing the LED lamp panel to avoid flashing, the eyesight of users is effectively protected, the service life is long, the luminous efficiency is high and the LED desk lamp is an energy-saving eye-protection LED desk lamp.

The electron ballast is used for driving fluorescent lamp and HID lamp to emit light and comprises: a rectifying power supply circuit connected to the AC power supply and used for providing DC power for the half-bridge type electronic ballast; a central control circuit connected to the inverse frequency control end of the electronic ballast; a voltage sampling circuit connected to the input of voltage detecting signals in the central control circuit; a transform rectify and voltage stable circuit connected to the AC power supply and used for providing power for the central control circuit and the voltage sampling circuit. The voltage sampling circuit is used for detecting the voltage fluctuation of AC power supply through the transform rectify and voltage stable circuit; the central control circuit is used for controlling the inverse frequency according to said voltage fluctuation.

The invention discloses a display brightness adjusting method and a device thereof and a display device. The display brightness adjusting method comprises the following steps: an initial dimming conversion brightness level of the display device is set; the mura degree of a display image of the display device between the dimming conversion brightness level and the highest display brightness level is determined; wherein the display brightness is adjusted in a PWM dimming mode in an interval formed by the lowest display brightness level and the dimming conversion brightness level, and the displaybrightness is adjusted in a DC dimming mode in an interval formed by the dimming conversion brightness level and the highest display brightness level; and the dimming conversion brightness level is adjusted according to the mura degree of the display image to obtain an optimal dimming conversion brightness level, wherein the mura degree of the display image of the display device between the optimal dimming conversion brightness level and the highest display brightness level meets a preset mura degree. According to the technical scheme, the probability of uneven display brightness of the display device is reduced, and the display effect of the display device is optimized.

The present invention pertains to a tunnel lighting technology, which is object to reduce the stroboscopic the driver generates to the traditional lighting means and lights in the moveing vehicles in an one-way tunnel. The present invention designs two new lamps, one lamp installed along the location of the traditional lights collocation, the second lamp installed on the roof surface of the tunnel. The lights irradiated by both lamps have a rear cut-off angle designed based on the installation angle of the car windshieldsed, thereby reducing the stroboscopic; and at the same time the lamps all have a shining surface with a certain brightness which sends the light backwards, which alows the driver in the moving vehicles to understand the direction of the front road, playing a guiding role.