203results about How to "Constant voltage" patented technology

A charge trapping floating gate is described with asymmetric tunneling barriers. The memory cell includes a source region and a drain region separated by a channel region. A first tunneling barrier structure is disposed above the channel region. A floating gate is disposed above the first tunneling barrier structure covering the channel region. A second tunneling barrier is disposed above the floating gate. A dielectric charge trapping structure disposed above the second tunneling barrier and a blocking dielectric structure is disposed above the charge trapping structure. A top conductive layer disposed above the top dielectric structure acts as a gate. The second tunneling barrier is a more efficient conductor of tunneling current, under bias conditions applied for programming and erasing the memory cell, than the first tunneling barrier structure.

The invention provides an electro-optical device having circuits for driving electro-optical elements, such as organic EL elements, and a driving device, which can employ driving elements having low driving ability, such as α-TFTs. By providing a charge storage capacitor between the source electrode and the gate electrode of a driving transistor which is between power sources, the electro-optical device can allow the driving transistor to control a driving current, even when an electro-optical element is connected to the source side of the driving transistor. In addition, driving data can be stored in the charge storage capacitor by applying a predetermined voltage to the source electrode of the driving transistor.

An active matrix display comprises a chiral smectic liquid crystal mixture which has the phase sequence I-N*-SmC*, a spontaneous polarization in the operating temperature range of <40 nC/cm2 and a pitch of >10 mum at at least one temperature in the nematic or cholesteric phase and comprises at least one compound each from at least two of the substance classes (A), (B) and (C) and one or more compounds from substance class (D):(A): compounds comprising two rings which are directly linked to one another and are selected from phenylene-1,4-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl and pyridazine-2,5-diyl with the proviso that at least one of these rings is a nitrogen heterocycle;(B): compounds comprising three rings selected from phenylene-1,4-diyl, two of the rings being directly linked to one another and the third ring being linked to one of the other two rings via an -OC(=O)- or -C(=O)-group, with the proviso that at least one of the three rings is fluorophenylene-1,4-diyl or ortho-difluorophenylene-1,4-diyl;(C): compounds comprising three rings which are directly linked to one another and are selected from phenylene-1,4-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl and pyridazine-2,5-diyl with the proviso that at least one of these rings is a nitrogen heterocycle;(D): compounds comprising mesogenic groups suitable as components of liquid crystal mixtures.

A stack of a high-k gate dielectric and a metal gate structure includes a lower metal layer, a scavenging metal layer, and an upper metal layer. The scavenging metal layer meets the following two criteria 1) a metal (M) for which the Gibbs free energy change of the reaction Si+2/y M_xO_y→2x/y M+SiO₂ is positive 2) a metal that has a more negative Gibbs free energy per oxygen atom for formation of oxide than the material of the lower metal layer and the material of the upper metal layer. The scavenging metal layer meeting these criteria captures oxygen atoms as the oxygen atoms diffuse through the gate electrode toward the high-k gate dielectric. In addition, the scavenging metal layer remotely reduces the thickness of a silicon oxide interfacial layer underneath the high-k dielectric. As a result, the equivalent oxide thickness (EOT) of the total gate dielectric is reduced and the field effect transistor maintains a constant threshold voltage even after high temperature processes during CMOS integration.

The present invention relates to a method and a control system for driving a three-strand brushless, electronically commutated electric motor (2), wherein a line AC voltage (U_N) is rectified and fed via a slim DC link (8) with minimum DC link reactance as a DC link voltage (U_Z) to an inverter (10) that can be driven to supply and commutate the electric motor (2). A pulsating DC voltage (U_G) initially generated by rectifying the line AC voltage (U_N) is dynamically increased with respect to its instantaneous values by a step-up chopper (18) in such a manner that the resulting DC link voltage (U_Z) with a reduced ripple always lies above a defined limit voltage (U₁₈/U₁) over time. The control system consists of a network rectifier (6), a downstream slim DC link (8) with minimum DC link reactance and a controllable inverter (10) that can be supplied via the DC link and driven to commutate the electric motor (2). A step-up chopper (18) is integrated therein with a controller (20) designed in such a manner that, the pulsating DC voltage (U_G) rectified by the network rectifier (6) is dynamically increased with respect to its instantaneous values in such a manner that the resulting DC link voltage (U_Z) with a reduced ripple always lies above a defined limit voltage (U₂₀/U₁) over time. Stray inductances (Ls1-Ls3) of the motor winding heads present in the electric motor (2) are used as inductor (L) for the step-up chopper (18).

The invention discloses a stored energy type standard-Z source photovoltaic power generation control system and method. The control system comprises a controller and a stored energy type standard-Z source inverter, wherein the controller comprises a capacitor voltage outer ring and a stored energy battery current inner ring and is used for regulating the direct-connection duty ratio of the inverter, thus the voltage of a DC (direct-current) bus can be constant, although the photovoltaic cell voltage is changed in a wide range; and the output power of the inverter is controlled by a power ring, and the output power of photovoltaic cells and the inverter is controlled so as to carry out charge-discharge management on stored energy batteries, thus realizing maximum power tracking. According to the invention, single-stage power transform is used to complete boosting, reduction voltage, inversion and energy storage, so that a simpler structure is used to realize minimum inverter capacity, thus ensuring the voltage of the DC bus to be constant and a power grid to obtain stable power, thereby maximally collecting solar energy and improving generating efficiency.

Embodiments of this disclosure describe an electrode biasing scheme that enables maintaining a nearly constant sheath voltage and thus creating a mono-energetic IEDF at the surface of the substrate that consequently enables a precise control over the shape of IEDF and the profile of the features formed in the surface of the substrate.

An improved battery charging method is usable by a battery charger to charge a battery. The charging method may include an optional desulfation process, a first constant current process, a constant voltage process, a second constant current process and a float charge process. The charging method preferably improves various charge and usage characteristics of the battery through a single or continued use of the battery charger utilizing the charging method.

The invention relates to an electrified railway in-phase power supply device and a multi-target coordinated instantaneous current control method adopted by the device. After the in-phase power supply device is used, the electrified railway whole-line in-phase power supply can be realized, the output power of two power supply arms of a traction transformer can be balanced, and the negative sequence problem can be thoroughly solved; the load reactive power and the harmonic current can be compensated, and the electric energy quality of a traction power supply system can be comprehensively improved; the voltage of a traction electric network can be stabilized, the transient state stability of the voltage can be improved, the power supply distance of the power supply arms can be increased, and the amount of power substations can be reduced; the electrified railway in-phase power supply device and the multi-target coordinated instantaneous current control method are multiple in targets, the multi-target can be simultaneously controlled, the control harmony at two sides can be guaranteed, the dynamic response capability is stronger; a rectification side inverter takes the active power transfer and the stable direct voltage as a control target, and participates the reactive power control; and an inversion side inverter performs active power, reactive power and harmonic wave control, and participates the stable control of the direct voltage.

A method for the low-loss regulation of a collectorless direct current motor and a semiconductor circuit has, during the commutation phase given by a position sensor and with reduced motor output and number of revolutions, transistors or one end transistor which initially operates temporarily as a switch and thereafter operates temporarily as an analog amplifier element. During the analog period, a current is available which changes slowly according to a ramp function.

A method controls a micro-grid connected to a power distribution system. The method determines parameters of a model of dynamics of the micro-grid using measurements of power flow at a point of common coupling (PCC) of the micro-grid with the power distribution system. The model is exponentially stable on a voltage set-point at the PCC and the method determines, using the parameters of the model, an amount of reactive power required to maintain the voltage at the PCC asymptotically stable on the voltage set-point. Next, the method controls a generator of the micro-grid to produce the amount of reactive power.