187results about How to "Reduce input voltage" patented technology

The invention provides a pixel circuit that can cancel the influence of the mobility of a drive transistor. A drive transistor supplies to a light-emitting element, an output current dependent upon an input voltage during a certain emission period. The light-emitting element emits light with a luminance dependent upon a video signal in response to the output current supplied from the drive transistor. The pixel circuit includes a correction unit that corrects the input voltage held by a capacitive part before the emission period or at the beginning of the emission period, in order to cancel the dependence of the output current on the carrier mobility. The correction unit operates during part of a sampling period in response to control signals supplied from scan lines. Specifically, the correction unit extracts the output current from the drive transistor while the video signal is sampled, and negatively feeds back the output current to the capacitive part to thereby correct the input voltage.

A system and method is described for a driver circuit used for high speed data transmission in LVDS and CML transceiver device applications. The transceivers are intended to receive a low voltage differential input signal and interchangeably drive a standard LVDS load with a TIA / EIA-644 compliant LVDS signal, and a standard CML load with a standard CML compatible signal. The driver circuit operates at speeds up to 1.36 Gbps, making it compatible with the OC-24 signaling rate for optical transmission. To accomplish this, the driver uses a mixed combination of voltage and current mode drive sections in the output circuit when coupled to LVDS loads, and when the driver is coupled to CML loads, operates purely in a current mode using only the current mode drive section. MOS transistors and a current source are used in the current mode switch portion to switch the drive with a constant current at the high speeds, and NPN transistors in the voltage mode output portion provide variable impedance for the output circuit. A common mode compensation circuit using a feedback voltage from the load generates a compensation signal for variable impedance control of the NPN transistors to yield a regulated voltage for the common mode dc voltage.

A lens driving device including: a lens barrel having at least one lens therein and provided with a friction member; a housing for housing the lens barrel therein; an actuator having a piezoelectric body disposed at an edge of the housing to apply a driving force, the piezoelectric body having at least one output member provided at one side thereof to be in contact with the friction member; a preload member disposed between the edge of the housing and the actuator to apply an elastic force toward the lens barrel; and a guiding part disposed between the housing and the lens barrel to guide the lens barrel to move in an optical axis direction. The lens driving device is simplified in a driving mechanism and thus reduced in size, while experiencing minimum loss of a driving power and ensuring more accurate and stable movement of the lens.

This invention relates to pixel driver circuits for active matrix optoelectronic devices, in particular OLED (organic light emitting diodes) displays. We describe an active matrix optoelectronic device having a plurality of active matrix pixels each said pixel including a pixel circuit comprising a thin film transistor (TFT) for driving the pixel and a pixel capacitor for storing a pixel value, wherein said TFT comprises a TFT with a floating gate.

The invention discloses a heater based on a transparent silver nanowire conducting thin film and a preparation method of the heater. The heater is simple in structure, uniform in heating and resistant to corrosion. The heater comprises a transparent substrate, the transparent conducting thin film, a conducting electrode and a protective layer. The heater is applied to defogging glass, a thermochromic substrate, a sensor substrate and the like. The preparation method of the heater comprises the steps of hydrophilization processing of the substrate, preparation of the transparent conducting thin film, preparation of the conducting electrode and preparation of the protective layer. According to the heater, silver nanowires synthesized through a low-temperature liquid phase method are used as raw materials, the transparent substrate is coated with the transparent conducting thin film through a non-vacuum non-high-temperature filming technology, the heating uniformity of the thin film is improved through technically mature and commercial conducting polymers, and the thin-layer protective film is obtained by means of liquid phase coating of cheap organic polymers. The heater is simple in structure, the raw materials are cheap, the requirement for preparation technological conditions is low, and large-scale production is facilitated.

An apparatus and concomitant method of reducing the number of synchronization pulses transmitted to the alarm units for increasing the reliability of the overall alarm system is disclosed. The synchronization signal is implemented as a reference or reset signal from which the alarm units derive a reference time to begin activation of the alarm units. Thus, when an alarm unit receives a reference synchronization pulse, the alarm unit applies the reference synchronization pulse as a reference point in time to trigger a series of flashes or audio tones. A second signal sent in close proximity to the synchronization signal is implemented to trigger a second function of the alarm units, such as a silence function.

A brushless DC motor has at least three stator sections and a single rotor rotating with the three stator sections. Each stator section is wound with three parallel windings having respective three nodes. Each stator section has nine terminals providing independent access to each node so that separate voltages and currents are applied to each parallel winding in the stator section. Thus, the current applied to each stator section is divided substantially equally among the three parallel windings, thereby reducing the current in each winding for the same power requirement for the motor, which reduces the I2R losses in the windings and the supply wiring and reduces the power handling requirements in the electronic switches providing the supply voltages. The three parallel windings are connected to external terminals of the motor to form either a delta winding configuration or a wye (star) winding configuration.

A wide input voltage power supply circuit for a load includes a first stage and a second stage. The first stage includes a linear regulator circuit configured to maintain an output voltage at a predetermined output voltage level. The linear regulator includes an input for shutting the linear regulator off when an input voltage exceeds a predetermined shut off threshold. The second stage includes a high voltage detection circuit coupled to the input of the linear regulator. The high voltage detection circuit is configured to detect the level of the input voltage and to shut the linear regulator off when the input voltage exceeds the predetermined shut off threshold. An under voltage lockout circuit may be included, the under voltage lockout circuit configured to set a minimum turn-on voltage for the load.

A resonant conversion system is provided, in which a resonant converter receives an input voltage to generate an output voltage, and a buck converter provides the input voltage of the resonant converter, and controls the input voltage to perform an over-current protection process.

The invention provides a pixel circuit that can cancel the influence of the mobility of a drive transistor. A drive transistor supplies to a light-emitting element, an output current dependent upon an input voltage during a certain emission period. The light-emitting element emits light with a luminance dependent upon a video signal in response to the output current supplied from the drive transistor. The pixel circuit includes a correction unit that corrects the input voltage held by a capacitive part before the emission period or at the beginning of the emission period, in order to cancel the dependence of the output current on the carrier mobility. The correction unit operates during part of a sampling period in response to control signals supplied from scan lines. Specifically, the correction unit extracts the output current from the drive transistor while the video signal is sampled, and negatively feeds back the output current to the capacitive part to thereby correct the input voltage.

A linear light-emitting diode (LED)-based solid-state lamp comprises an LED driving circuit, LED arrays, at least one rectifier, and an electric current flow control module. The LED driving circuit comprises a control loop compensation device with a control loop correction signal to precisely control an electric current to flow into the LED arrays. The electric current flow control module uses the control loop correction signal in a way that it detects and determines if the linear LED-based solid-state lamp is operated in a normal mode or in an electric shock hazard mode. When an electric shock hazard is identified, the electric current flow control module shuts off a return current flow from the LED arrays to reach the at least one rectifier, thus eliminating an overall through-lamp electric shock current. The scheme can effectively prevent a through-lamp electric shock from occurring during relamping or maintenance.

In a method for controlling a voltage regulator, first and second charge storage devices are switchably connected between a voltage source and the voltage regulator. The first storage device is switched into connection with the voltage source until the voltage on it reaches a predetermined level. The first storage device is disconnected from the voltage source and switched into connection with the second storage device and the voltage regulator until the voltage input to the voltage regulator falls below a predetermined level. The above operations are repeated.

In a portable electronic device having a digital camera function, focusing of an image may be accomplished by moving a movable image sensor assembly relative to a lens assembly that is affixed in a housing. An image sensor drive, such as a voice coil motor to move the movable image sensor assembly, may be positioned between the movable image sensor assembly and the lens assembly concentric with the lens assembly.

The invention relates to the technical field of electric welding machines, in particular to a digitized inverter welding machine which comprises a preceding public power supply circuit, an auxiliary power supply circuit, a main control circuit, a welding machine control circuit, a wire feeder control circuit and a wire feeder motor connected with the wire feeder control circuit. Current is divided into three paths after passing through the preceding public power supply circuit, and the three paths of current respectively enter the wire feeder control circuit, the welding machine control circuit and the auxiliary power supply circuit. According to the digitized inverter welding machine, the wire feeder control circuit is connected with the preceding public power supply circuit, so that the wire feeder control circuit and the welding machine control circuit use one and the same power supply, an additional power supply is not needed to be arranged, and meanwhile the input voltage of the wire feeder control circuit is lowered, so that an insulated isolation part is not needed to be additionally arranged in the wire feeder control circuit, the whole size and mass are lowered, production and selling costs are reduced, and daily production operation is facilitated.

A start up circuit (4-1) for a boost circuit (10) includes an adjustable-duty-cycle oscillator (1-2) that turns on a switch transistor (MSW) connected to an inductor (L) receiving an input voltage (VIN). If a voltage (V9) of a junction between the transistor and the inductor exceeds a predetermined value corresponding to a maximum inductor current (IL), an amplifier (A1) immediately terminates a first phase of an oscillator cycle, which turns off the transistor. Built-up inductor current is steered into a load. Duty-cycle-adjustment circuitry (R1,R2,C1) causes the oscillator to complete a normal second phase of the cycle before a new cycle begins.

Disclosed are a semiconductor light emitting device, which can improve characteristics of the semiconductor light emitting device such as a forward voltage characteristic and a turn-on voltage characteristic, increase light emission efficiency by lowering an input voltage, and increase reliability of the semiconductor light emitting device by a low-voltage operation, and a method of manufacturing the same. The semiconductor light emitting device includes: an n-type GaN semiconductor layer; an active layer formed on a gallium face of the n-type GaN semiconductor layer; a p-type semiconductor layer formed on the active layer; and an n-type electrode formed on a nitrogen face of the n-type GaN semiconductor layer and including a lanthanum (La)-nickel (Ni) alloy.

An auxiliary power supply or bias voltage supply employs a step up switch mode DC / DC power converter topology to supply regulated bias supply voltages, from very low input voltages (e.g., less than 2V). The supply will synchronize to dynamic loads making it particularly useful in circuits with periodic high peak current power demands, for example, gate drive circuits employed in regulated switched mode power converters. When unladed, the supply will efficiently adjust its cycle period to the minimum required to maintain the desired boosted output voltage. Additional transformer windings or a charge pump may be used to generate additional vias voltage sources.

A DC / DC converter, a power converter and a control method thereof are disclosed, wherein the DC / DC converter includes an output circuit, a rectangular wave generator, a resonant tank, a detection unit and a control unit. The output circuit has a load. The rectangular wave generator converts an input voltage into driving pulses. The resonant tank provides a first voltage based on the driving pulses for the output circuit. The detection unit detects a signal related to a state of the load. When the state of the load is a light-load or a no-load, the control unit controls the rectangular wave generator in a hiccup mode to reduce a ratio of a work period to a stop period, or makes that number of the driving pulses within the current work period is less than the number of the driving pulses when a duty ratio is 50%.

The embodiment of the invention discloses a method for controlling a photovoltaic inverter circuit. The method includes the steps that after a starting command is received, a positive total bus capacitor and a negative total bus capacitor are charged; after a first preset condition is met, charging operation is stopped, and a phase-locking loop of a power grid is controlled to conduct phase-locking operation; after the phase-locking loop finishes the phase-locking operation, a five-level inverter is started in a three-level mode, and voltage loop control and current loop control are conducted on the five-level inverter; when a second preset condition is met, a first Boost converter and a second Boost converter are controlled to be started without loads, and voltage loop control is conducted on the two Boost converters; after input voltage and input current of the first Boost converter and the second Boost converter are stable, the five-level inverter is controlled to run in a five-level mode. According to the method for controlling the photovoltaic inverter circuit, fluctuation of input voltage and input power of a solar cell array can be reduced when the photovoltaic inverter circuit is started, and the starting process is smoother. The invention further discloses a corresponding control device.

Bi-stable permanent magnet actuation is a technique employed to move and magnetically hold an armature in electromechanical devices including some valves, wherein, permanent magnets are employed in a manner that places their magnetic field in a bi-stable state to allow a control coil to divert the permanent magnet's magnetic field in one of two directions within the surrounding magnetic material. Control is established using an actuation system comprising, a power source to deliver the desired level of energy, a voltage conditioner such as a DC / DC converter matched to the power source and electromechanical device, an energy storage device such as a capacitor, an output circuit such as an H-Bridge switching circuit, and a control circuit for controlling delivery of short duration current pulses from the energy storage device through the output circuit to the electromechanical device's control coil. Thus, an energy efficient bi-stable permanent magnet actuation system is produced.

The invention is applicable to the field of LED lamps, and provides a buck chopper circuit, an LED drive circuit and an LED lamp, wherein the buck chopper circuit comprises a filtering unit, a first-stage voltage-reducing unit, a second-stage voltage-reducing unit and a control unit. In the embodiment of the invention, the buck chopper circuit is provided with the first-stage voltage-reducing unit and the second-stage voltage-reducing unit; and compared with the adoption of one-stage voltage reduction, the adoption of two-stage voltage reduction can greatly reduce the input voltage under the condition of the same duty cycle, therefore, compared with the adoption of the one-stage voltage reduction, the adoption of the buck chopper circuit can greatly increase the input scope of the voltage under the precise that the input voltage is constant.

A DC / DC converter, a power converter and a control method thereof are disclosed, where the DC / DC converter includes an output circuit having a load, a rectangular wave generator having a bridge arm, a resonant tank, a detection unit and a control unit. The bridge arm includes a first and a second switches connected each other. The detection unit detects a signal related to a state of the load. When the state of the load is a light-load or a no-load, the control unit controls ON / OFF state of the first and second switches by pulse width modulation mode to convert an input voltage into at least one rectangular wave for the resonant tank. A duty ratio of the first switch is within a first or second predetermined range, and a duty ratio of the second switch is complementary to the duty ratio of the first switch, whereby a voltage gain of the DC / DC converter is greater than 1.

The present invention relates to a USB multi-functional LED clip lamp belonging to a technical field of lighting equipments, including: a lightshade, an LED light source, a supporting column and a base, wherein the LED light source is mounted inside the lightshade; the base comprises a clip for clamping, and a connecting box at a top of the clip; a main control circuit board comprises a USB module; wherein an interface module is fixed inside the connecting box, which comprises a USB interface for electrically connecting the USB module, and a power socket. The present invention has a simple while reasonable structure, which is able to be fixed by directly fixing the clip at a table edge or other positions which is able to be clamped, and stability thereof is high. Furthermore, the interface module is directly fixed on the connecting box, so as to be easily assembled.

The invention discloses an electrolytic cell device provided with separated cathode and anode chambers and used for preparing ozone water through electrolysis. The electrolytic cell device comprises an electrolytic cell, wherein cathode electrodes and anode electrodes are arranged inside the electrolytic cell; the bottoms of the cathode electrodes and anode electrodes are in complete contact with the bottom end of the electrolytic cell to divide the electrolytic cell into anode chambers and cathode chambers independent to one another; a proton exchange membrane for allowing ions to permeate, but preventing hydrogen from permeating into the anodic area is arranged at the separated part of each anode chamber and the corresponding cathode chamber. Through the adoption of the structural design, the anode chambers and the cathode chambers are separated and not communicated, so that water in the cathode chambers cannot enter the anode chambers, and further, the situation that hydrogen generated in the cathode chambers enters the anode chambers to be in neutralization reaction with ozone O3 is avoided; therefore, the consumption amount of ozone O3 is reduced, the production efficiency of ozone O3 is improved, and the content of ozone O3 is increased.

A rail-to-rail-Input Buffer with constant mutual conductance includes a differential input; a first differential stage supplied with a first reference current; a second differential stage supplied with a second reference current; a switching PMOS-transistor which switches through when the input signal is higher than a first threshold voltage to divert the first reference current to a first current mirror circuit; a switching NMOS-transistor which switches through when an input signal is lower than a second threshold voltage to divert the second reference current to a second current mirror circuit; a third differential stage supplied with the mirrored first reference current and replaces the first differential stage when the input signal is higher than the first threshold voltage; and a fourth differential stage supplied with the mirrored second reference current and replaces the second differential stage when the input signal is lower than the second threshold voltage.