184results about How to "Reduce input voltage" patented technology

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.

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.

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.

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.

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 (M_SW) connected to an inductor (L) receiving an input voltage (V_IN). If a voltage (V₉) of a junction between the transistor and the inductor exceeds a predetermined value corresponding to a maximum inductor current (I_L), 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.

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 a three-valued inverter based on CNFETs. The three-valued inverter comprises a first CNFET, a second CNFET, a third CNFET, a fourth CNFET, a fifth CNFET, and a sixth CNFET. 0.9V voltage is inputted into the source electrode of the second CNFET, the base electrode of the second CNFET, the base electrode of the third CNFET, and the base electrode of the sixth CNFET. The drain electrode of the third CNFET, the drain electrode of the fourth CNFET, the drain electrode of the fifth CNFET, and the drain electrode of the sixth CNFET are connected. 0.45V voltage is inputted into the source electrode of fourth CNFET and the source electrode of the fifth CNFET. -0.9V voltage is inputted into the base electrode of the fourth CNFET and the base electrode of the fifth CNFET. The grid electrode of the first CNFET, the grid electrode of the second CNFET, the grid electrode of the third CNFET, the grid electrode of the fourth CNFET, the grid electrode of the fifth CNFET, and the grid electrode of the sixth CNFET are connected and a connection point of the same is a signal input end. The drain electrode of the first CNFET, the drain electrode of the second CNFET, the drain electrode of the third CNFET, and the drain electrode of the sixth CNFET are connected and a connection point of the same is a signal output end. The three-valued inverter based on CNFETs has an advantage of low power consumption and satisfies intermediate level needed by users.