77results about How to "Improve Harmonic Distortion" patented technology

The LED lighting apparatus includes: a rectification block; an LED block including a first light emitting group and a second light emitting group; a charging / discharging block configured to charge electric charges in a charging period, and discharge electric charges in a discharging period; a driving control unit configured to determine a voltage level of a rectified voltage, controls a path selection switch to connect the rectification block to the LED block and controls the charging / discharging block to charge electric charges in the charging period, and controls the path selection switch to connect the rectification block to a ground and controls the charging / discharging block to discharge electric charges from the charging / discharging block to the LED block in the discharging period; and a path selection switch configured to connect the rectification block to the LED block in the charging period, and connect the rectification block to the ground in the discharging period.

The invention provides an MEMS (micro-electro-mechanical system) microphone which comprises an MEMS chip, an ASIC (application specific integrated circuit) chip, a first circuit substrate, a second circuit substrate, a third circuit substrate and a frame substrate. The first circuit substrate and the second circuit substrate are opposite to each other, the third circuit substrate is positioned between the first circuit substrate and the second circuit substrate, the frame substrate is respectively fixed to the first circuit substrate and the third circuit substrate, the second circuit substrate is fixed to the third circuit substrate, both the MEMS chip and the ASIC chip are mounted on the first circuit substrate, the ASIC chip is electrically connected with the third circuit substrate inside an MEMS microphone body by a lead wire, and a joint of the lead wire and the third circuit substrate is positioned on a surface, which is opposite to the second circuit substrate, of the third circuit substrate. The MEMS microphone has the advantages that the sensitivity of the product can be improved, a high-frequency response portion is improved, and the total harmonic distortion is prevented.

In a SPDT switch, a resistor for leak path is connected between a terminal for antenna and a reference potential. The resistor for leak path allows charge capacitances accumulated in electrostatic capacitor elements provided as DC cut capacitors connected to transmission signal terminals and reception signal terminals to be discharged and allows rapid lowering of a potential at the terminal for antenna. In the SPDT switch, a switching characteristic is improved and a delay in the rising edge of a low-power slot which comes after a high-power slot is reduced.

A controller for determining the duty-ratio for a pulse width modulator of a converter includes an inner current loop, an outer voltage loop and a multiplier with an input voltage feed forward to connect both loops. A prediction unit determines a correction signal icor that is added to the reference current iref by means of an adder and it further determines a sample correction signal to correct the current samples in the current loop. This error-controlled duty-ratio prediction with sample correction results in an improved total harmonic distortion as well as in an improved power factor of the converter.

A multi-driver transducer having symmetrical magnetic circuits and symmetrical coil circuits, wherein one or more pieces of circular or annular partitions made of a non-magnetic material are used to bond two or more sets of dual magnetic gap and dual coil driver units (01 or 02) into one integrated magnetic core. Four or more coaxial isodiametric annular magnetic gaps are formed between the inner circumferential face or outer circumferential face of one or two tubular magnetic yokes embedded in an open-end tubular thin wall of the bracket and the vertical circumferential face of an upper pole plate and a lower pole plate of the magnetic core, four or more coaxial and isodiametric coils are inserted in the four or more coaxial and isodiametric annular magnetic gaps, and the winding direction, connection manner, and necessary technical features of the coils are governed; thus, the multi-driver transducer having one or more pairs of mutually-repelling magnets, symmetrical magnetic circuits, and symmetrical coil circuits is constituted. Back electromotive force and inductance acquired via induction by the transducer during the working process are mutually offset. The transducer has resistive load features or near-resistive load features, and has super-high sensitivity, high resolution, and high-fidelity quality.

Disclosed herein is a rotor for a wound-rotor motor. The rotor for a wound-rotor motor includes: a rotor core including a hollow formed in a central portion thereof and coupled to a shaft; a teeth portion radially formed on an outer side surface of the rotor; and a pole shoe formed to extend from an end portion of the teeth portion in one direction and including a part of a cross section of an outer side surface formed in an arc shape of a first imaginary circle (C1) having a first radius (r1) which is a distance from a central point (CP1) of the hollow to an outermost position (P1) thereof.

The invention discloses a CMOS radio frequency (RF) switch based on silicon-on-insulator (SOI) technology, which has the circuit structure adopting two-stage type closing isolation structure and two-stage type current release path structure, and utilizes a high resistance substrate and a buried oxide layer of an SOI technical device, thus remarkably reducing crosstalk and minimized parasitic capacitance, better screening substrate noise, obtaining ideal insertion loss and insulation performance at the two ends of the switch, inhibiting nonlinear effect and reducing harmonic distortion. The RFswitch has the circuit structure, reduces the channel resistance of a transistor connected in series, reduces the insertion loss, and further improves the closing performance of a transmitting terminal and a receiving terminal; furthermore, the switch can improve the insulation, leads harmonic quantity of every time to be in good grounding, improves the harmonic current of the substrate and inhibits harmonic component.

A vibrating diaphragm assembly related to the technical field of electroacoustic products is provided. The vibrating diaphragm assembly comprises a vibrating diaphragm, wherein the vibrating diaphragm comprises a middle part and a folding ring part surrounding the periphery of the middle part. The vibrating diaphragm also comprises a vibrating diaphragm substrate layer and a silica gel layer; the silica gel layer being at least partially combined with the vibrating diaphragm substrate layer. The vibrating diaphragm substrate layer is also a high molecular material layer; the silica gel layer is combined on the surface of the folding ring part; and the silica gel layer and the high molecular material layer are formed through injection molding.