101results about How to "Maintain voltage" patented technology

A burst mode resonant power converter with high conversion efficiency has a rectifier, a power factor correction circuit, a resonant circuit, a controller, and a burst mode triggering unit. The maximum frequency switching end of the controller is connected to a maximum frequency variable circuit. When the load is medium or heavy, the maximum frequency variable circuit increases the maximum switch frequency of the controller. When the load is in the no-load or the light conditions, it reduces the maximum switch frequency thereof. Therefore, the controller reduces the number of times that the resonant circuit switches the bridge switch circuit. The conduction cycle of the 50% pulse signal output to the bridge switch circuit becomes longer. Larger energy can be transmitted at a time to the secondary coil of the transformer. This increases the overall efficiency.

In a low-pass filter which is preferably used as a loop filter in a PLL or DLL, filter characteristics which are the same as those of a conventional low-pass filter are realized without causing collateral problems, such as an increase in the circuit area, the circuit complexity, or the resistance value, which may be caused due to size reduction of a capacitive element in the conventional low-pass filter. Thus, in a loop filter including a capacitive element and a resistive element which are connected in series, the first input terminal is provided at the side including the resistive element, and the second input terminal is provided at a connection point of the capacitive element and the resistive element. The first input terminal is supplied with the first electric current. On the other hand, the second electric current, which is a part of the first electric current supplied to the first input terminal, is extracted from the second input terminal, so that the electric current flowing into the capacitive element is smaller than the electric current flowing through the resistive element.

A display unit with touch detection function includes a plurality of pixel signal lines each transmitting a pixel signal for display; a pixel signal line drive section applying the pixel signal to each of the pixel signal lines; display elements each performing display based on the pixel signal; touch detection electrodes each outputting a detection signal based on a change in capacitance occurring due to an external proximity object; and a touch detection section detecting, in a touch detection period, a touch event based on the detection signal, the touch detection period being different from a display period for the display elements to perform display operation. The pixel signal line drive section maintains a voltage of each of the pixel signal lines at a certain level during the touch detection period.

The present invention describes circuitry and a method of providing a low power WRITE mode of operation for an integrated circuit comprising an SRAM memory to provide a reduced IDDQ relative to the IDDQ of a full active mode. In one aspect, the circuitry includes an SRAM memory array, mode control circuitry coupled to the array and configured to alter a supply voltage level to the SRAM array based on a mode of operation. The circuitry also includes control inputs coupled to the mode control circuitry for selecting one of the low power write mode, the full active mode, and optionally a retention mode of operation. The mode control circuitry is configured to receive the control inputs to select one of the three modes of operation, and to alter one or more supply voltage levels to the array, for example, the Vss supply voltage using a Vss supply circuit and the Vdd supply voltage using a Vdd supply circuit, based on the selected mode of operation. The mode control circuitry may also comprise a bitline precharge circuit configured to alter a bitline precharge voltage.

A pixel circuit includes a pixel electrode, a pixel transistor of a first conduction type, and a flip-flop. The pixel transistor has a control node connected to a scanning line, a first node connected to a data line, and a second node. The flip-flop has an inverter and a feedback transistor of a second conduction type opposite to the first conduction type. The inverter has an input node connected to the second node of the pixel transistor, and an output node connected to the pixel electrode. The feedback transistor is controlled to be turned on or off in accordance with an output of the inverter for supplying a high-level power source voltage or a low-level power source voltage to a common connection point of the second node of the pixel transistor and the input node of the inverter, in the ON state.

A light-emitting diode element includes: an n-type conductive layer 2 being made of a gallium nitride-based compound, a principal surface being an m-plane; a semiconductor multilayer structure 21 provided on a first region 2a of the principal surface of the n-type conductive layer 2, the semiconductor multilayer structure 21 including a p-type conductive layer 4 and an active layer 3; a p-electrode 5 provided on the p-type conductive layer 4; a conductor portion 9 provided on a second region 2b of the principal surface of the n-type conductive layer 2, the conductor portion 9 being in contact with an inner wall of a through hole 8; and an n-type front surface electrode 6 provided on the second region 2b of the principal surface of the n-type conductive layer 2, the n-type front surface electrode 6 being in contact with the conductor portion 9.

A display apparatus includes a display element that includes an electrolyte solution layer containing an electrochemical luminescent material; and a voltage applying unit that applies a voltage with a waveform having a gradient for a first period and a flat top for a second period following the first period, to the electrolyte solution layer, so that the electrochemical luminescent material emits light.

A control IC controls a switching power supply configured to supply a driving voltage Vout to one terminal of an LED string to be intermittently driven. In the on period of the LED string, a pulse modulator generates a pulse signal having a duty ratio adjusted such that a detection voltage VLED that corresponds to the output voltage Vout of the switching power supply matches a predetermined reference voltage Vref. A driver drives a switching transistor included in the switching power supply according to the pulse signal. After transition from the on period to the off period, the pulse modulator reduces the duty ratio of the pulse signal over time.

The present invention provides a power configuration system for a fuel cell hybrid vehicle and a method for controlling the same, in which a second blocking diode is installed in a main bus terminal at an output terminal of a fuel cell (in front of a first blocking diode) separately from the existing first blocking diode installed in the main bus terminal, the positions of high voltage components for driving the fuel cell are changed from the rear of the first blocking diode to the front of the first blocking diode, and the operations of the high voltage components are appropriately controlled during regenerative braking such that the voltage of the fuel cell may be maintained below that of the supercapacitor.

A LED driving circuit includes a regulator to provide an output voltage to a LED light source, a current source to control the driving current of the LED light source, and a controller to detect the voltage of the current source to generate a control signal for the regulator to regulate the output voltage at a low level. There are no resistors on the current path established by the LED light source and current source, and the regulator may maintain the voltage of the current source as low as possible, thereby improving the power efficiency and reducing the power consumption.

A chip includes a memory that stores confidential data, a power supply device to apply a voltage and / or or a current, and an interface to transfer the data from and / or to another device. To secure the data in the memory, the power supply device is an integrated component of the chip. The power supply device is equipped with a limited, non-replenishable fuel reservoir so that data can be maintained in the memory over a limited service life. In other embodiments, voltage provided by the power supply device can also be employed actively to delete data in the memory in the event of unauthorized access to the chip.

In a power supply apparatus 40, a power supply circuit is formed by a primary power supply circuit 50 which includes a high-voltage battery 51 and a step-down circuit 55 for stepping down the voltage of the high-voltage battery 51, and a secondary power supply circuit 60 which includes a low-voltage battery 61 and a step-up circuit 70 for stepping up the voltage of the low-voltage battery 61. The primary power supply circuit 50 and the secondary power supply circuit 60 are connected in parallel. An output voltage of the secondary power supply circuit 60 is set to be lower than an output voltage of the primary power supply circuit 50. When the output voltage of the primary power supply circuit 50 becomes lower than a target voltage of the secondary power supply circuit 60, the voltage stepped-up by the step-up circuit 70 is supplied to a motor drive circuit 32. Accordingly, power supply backup of an electric power steering apparatus can be performed as low cost.

The present invention discloses a direct electric current superconducting cable having a core and a plurality of superconducting layers provided over the core with end portions of the superconducting layers exposed in a step-by-step manner from an outer layer to an inner layer and connected individually to outgoing conductors. The superconducting layers are insulated from each other. An insulating fixing member is used to support the core and the outgoing conductors. An electrical insulation layer, a return-current conductor layer and an insulating protective layer in that order surrounds the outermost superconducting layer.

A device for supplying power to a load, requiring both a pre-determined supply of electrical power and high power for short durations of the operating cycle of the load, where the operating cycle is repeated. The power supply device includes a connection to an electrical grid, an AC voltage transformation circuit, a voltage rectification means and a plurality of DC / DC converters mounted in series to terminals of the load. Each of the DC / DC converters has a storage capacitor mounted in parallel to it and at least one of the DC / DC converters is supplied directly by the voltage rectification means. At least another one of the DC / DC converters is not supplied directly by the voltage rectification means. The power supply device may compensate for losses in the power supply device and load, and may substantially continually and uniformly balance voltages at terminals of the storage capacitors.

A pulse width modulation (PWM) control circuit for a multimode electrical machine and a multimode electrical machine equipped with such a control circuit, including a configuration circuit that detects the operation mode of the electrical machine and produces a pulse width modulation to control a reversible current inverter circuit such that the electrical machine operates optimally in torque in engine modes and in current generator modes. The invention applies to vehicle alternators and starters.

A non-contact electrical power transmission system is capable of providing a large supply current of uniform level at an optimum transmission efficiency. The system includes a power circuit including a power supply of providing a high frequency voltage across a power winding, and a load circuit for energizing a load. The load circuit is composed of a secondary winding, a matching capacitor, a rectifier, and a choke coil. The secondary winding is magnetically coupled to the power winding so as to generate an induced high frequency voltage and to provide a leakage inductance to the load circuit. The matching capacitor is connected across the secondary winding to be cooperative with the leakage inductance and with the secondary winding to form an oscillatory circuit which provides an oscillating voltage across the matching capacitor for generating a supply current being fed through the rectifier and the choke coil to the load. The matching capacitor is selected to have a specific capacitance such that the oscillating voltage reaches its extreme each time the inducted high frequency voltage reverses its polarity. The choke coil is connected in circuit to smoothen the supply current. Thus, the supply current of uniform level can be fed to the load, reducing a possibility of incurring a noise on the supply current, yet minimizing an impedance between the supply circuit and the load circuit for realizing an optimum efficiency of converting the high frequency voltage into the supply current.

An active power conditioner includes a first power electronic switch set, a second power electronic switch set, a third power electronic switch set, an input filter and an output filter. The active power conditioner can supply a stable AC voltage to a load when a voltage variation is occurred at an AC power source by controlling either the second power electronic switch set or the third power electronic switch set via high-frequency switching, and the other power electronic switch sets that are not switched in high frequency are controlled to switch in low-frequency switching.

The PLL circuit of the present invention includes a voltage-controlled oscillator, a loop filter, and a charge pump which controls a voltage of the loop filter while the voltage-controlled oscillator is not oscillating. Therefore, it is possible, even while the voltage-controlled oscillator is not oscillating, to control a voltage for the charge pump so that it is equal to a voltage when the voltage-controlled oscillator is oscillating at a predetermined frequency. Accordingly, by the loop filter outputting a voltage signal to the voltage-controlled oscillator when the PLL circuit is turned on, the pull-in time can be shortened.

Control mode switching determination is made as a part of a main loop (control period (Tm)) for overall control of an AC electric motor. Control period (Tc) of a rectangular wave voltage control mode is shorter than the execution period (Tm) of the control mode switching determination. When switching from the rectangular wave voltage control mode to PWM control mode is determined, change in voltage phase of the rectangular wave voltage is inhibited from the timing (time t0) of control mode switching determination until the next execution of the main loop, that is, until the timing (time t1) at which the control mode is actually switched, to maintain voltage phase of the rectangular wave voltage at the time of control mode switching determination. Consequently, in a drive controller for an AC electric motor allowing switching between control modes, control mode can appropriately be switched without making unstable the operation of the AC electric motor.

A method and system for supply voltage regulation in a motor circuit protector (MCP) that includes a current transformer coupled to a rectifier and a stored energy circuit. A solenoid is actuated by that circuit when a sufficient voltage is present. A controller having a configurable input is coupled to the stored energy circuit. Upon startup of the motor circuit protector, the controller causes the stored energy circuit to be charged to a startup voltage level via secondary current from the current transformer. The controller periodically interrupts the charging to measure the secondary current to detect fault levels. During startup, the configurable input is set to a comparator input for rapid current measurements. During run mode, the configurable input is set to an A / D input for accurate measurements. The controller measures the voltage of the stored energy circuit while charging it to a power level sufficient to actuate the solenoid.

A hot standby power supply for a variable frequency drive of a floating vessel is provided. The variable frequency drive may power an electric motor of the floating vessel. The hot standby power supply includes a power input for receiving electric power from a main power supply of the floating vessel. The hot standby power supply also includes a first electric connection configured to supply electric power at a first voltage level to a converter power input of the variable frequency drive, and a second electric connection configured to supply electric power at a second voltage level to control power input of the variable frequency drive. The first voltage level is higher than the second voltage level. A transformer is further provided for transforming received electric power to the first voltage level or to the second voltage level.

The invention relates to a voltage stabilization system for power supply lines, comprising a variable inductance, an autotransformer and a system for controlling the variable inductance to automatically compensating for voltage variations of the power supply lines. The system can include a control system that includes a processor unit, a setpoint adjustment unit, a feedback unit and a rectifier circuit.

This invention generally relates to synchronous rectifier controllers for an SMPS. One controller comprises: a sensor to sense a signal on a secondary side, to detect turn off of the switch; a charge source to, in response to a said detection, charge a control terminal of the rectifier to a voltage beyond a threshold voltage of the synchronous rectifier to allow the synchronous rectifier to conduct current of the secondary winding; and a linear amplifier having an output to sink current from the control terminal dependent on a difference between a voltage across the synchronous rectifier and an amplifier reference value, said voltage across the synchronous rectifier being a voltage across a controllable conduction path for current of the secondary winding, the linear amplifier to inhibit discharge of the control terminal from the voltage beyond the threshold voltage until the voltage across the synchronous rectifier reaches the amplifier reference value.

Semiconductor devices for high voltage application are presented. A high power semiconductor device includes a first type doped semiconductor substrate and a second type doped epitaxial layer deposited thereon. A first type doped body region is disposed in the second type doped epitaxial layer. A heavily doped drain region is formed in the second type doped epitaxial layer and isolated from the first type doped body region with an isolation region and a channel. A second type deep heavily doped region extends from the heavily doped drain region to the semiconductor substrate. A pair of inversed type heavily doped source regions is disposed in the first type doped body region. A gate electrode is disposed overlying the channel with a dielectric layer interposed therebetween. The high power semiconductor device is isolated from the other semiconductor devices with a first type deep heavily doped region.

A control IC controls a switching power supply configured to supply a driving voltage Vout to one terminal of an LED string to be intermittently driven. In the on period of the LED string, a pulse modulator generates a pulse signal having a duty ratio adjusted such that a detection voltage VLED that corresponds to the output voltage Vout of the switching power supply matches a predetermined reference voltage Vref. A driver drives a switching transistor included in the switching power supply according to the pulse signal. After transition from the on period to the off period, the pulse modulator reduces the duty ratio of the pulse signal over time.