1700 results about "Resonant capacitor" patented technology

A wireless power infrastructure for delivering wireless power from a wireless network to mobile devices. The infrastructure includes a plurality of power transmission hubs, each hub having: a first capacitor for transmitting a signature frequency for a defined range; and a set of second capacitors, each for transmitting resonant wireless power within the defined range at a selectable frequency. A mobile device for obtaining wireless resonant the plurality of power transmission hubs is also described, and includes: a first variable capacitor for detecting a signature frequency associated with a proximately located power transmission hub; a second variable capacitor for receiving wireless resonant capacitor from the proximately located power transmission hub; and a synchronization system for setting the second variable capacitor to a frequency that is synchronized with a wireless resonant power transmission of the proximately located power transmission hub.

An inductive power supply system in which the receiving unit includes a secondary coil and a plurality of resonating circuits with different characteristics. Each of the resonating circuits may include a resonating coil and a resonating capacitor. The resonating coils may be inductively coupled to the secondary coil so that energy may be transferred from one or more of the resonating coils to said receiving unit. The plurality of resonating circuits are configured to provide improved power transfer efficiency or performance at different distances between the primary coil and secondary coil. The present invention may also provide a method for tuning the wireless power system including the general steps of measuring an operating characteristic in the primary unit, measuring an operating characteristic in the receiver unit and tuning one or more of the components in the primary unit and the secondary unit based on a comparison of the two measurements.

A power transmission method used in a high-power wireless induction power supply system consisting of a power-supplying module and a power-receiving module is disclosed. The power-supplying module regulates its output energy by means of frequency modulation and driving power adjustment, enabling the energy to be received by the power-receiving module and transmitted through a power-receiving coil array and a primary resonant capacitor and a secondary resonant capacitor of power-receiving resonance circuit, a synchronizing rectifier, a low-power voltage stabilizer, a high-frequency filter capacitor, a first power switch, a low-frequency filter capacitor and a second power switch of a filter circuit for output to an external apparatus.

An inductive wireless power system using an array of coils with the ability to dynamically select which coils are energized. The coil array can determine the position of and provide power to one or more portable electronic devices positioned on the charging surface. The coils in the array may be connected with series resonant capacitors so that regardless of the number of coils selected, the resonance point is generally maintained. The coil array can provide spatial freedom, decrease power delivered to parasitic loads, and increase power transfer efficiency to the portable electronic devices.

A non-contact wireless communication apparatus and a mobile terminal apparatus are provided. The non-contact wireless communication apparatus includes a non-contact wireless communication antenna, a resonance capacitor, connected in parallel with the non-contact wireless communication antenna, for obtaining a predetermined resonance frequency with the non-contact wireless communication antenna, a resonance frequency adjustment unit for changing a resonance capacitance of the resonance capacitor to adjust the resonance frequency, a capacitance change amount control unit for controlling a change in resonance capacitance of the resonance capacitor in the resonance frequency adjustment unit, a resonance frequency shift unit for shifting the resonance frequency of the non-contact wireless communication antenna, and on / off control unit for performing on / off control of the resonance frequency shift unit in accordance with the amount of change in resonance capacitance of the resonance capacitor by the capacitance variation control unit.

Secondary resonant pickup coils (102) used in loosely coupled inductive power transfer systems, with resonating capacitors (902) have high Q and could support large circulating currents which may destroy components. A current limit or "safety valve" uses an inductor designed to enter saturation at predetermined resonating currents somewhat above normal working levels. Saturation is immediate and passive. The constant-current characteristic of a loosely coupled, controlled pickup means that if the saturable section is shared by coupling flux and by leakage flux, then on saturation the current source is terminated in the saturated inductor, and little detuning from resonance occurs. Alternatively an external saturable inductor (1101, 1102) may be introduced within the resonant circuit (102 and 902), to detune the circuit away from the system frequency. Alternatively DC current may be passed through a winding to increase saturation of a saturable part of a core. As a result, a fail-safe pickup offering a voltage-limited constant-current output is provided.

A by-pass circuit includes a first power MOS with an intrinsic diode, a first conduction terminal coupled to a cathode, a second conduction terminal coupled to an anode, and a control terminal. A tank capacitor is coupled to the anode. A second MOS has a first and second conduction terminals, a control terminal, and a turn-on threshold smaller than that of the intrinsic diode, the first conduction terminal thereof coupled to the cathode and the control terminal coupled to the anode, so the first MOS turns on when the array of cells are sub-illuminated. An oscillator and charge pump are supplied through the second conduction terminal of the second MOS to charge the tank capacitor. A control circuit is coupled to the control terminal of the first power MOS to switch it based upon a voltage of the tank capacitor and sign of the voltage between the cathode and anode.

A non-contact wireless communication apparatus and a mobile terminal apparatus are provided. The non-contact wireless communication apparatus includes a non-contact wireless communication antenna, a resonance capacitor, connected in parallel with the non-contact wireless communication antenna, for obtaining a predetermined resonance frequency with the non-contact wireless communication antenna, a resonance frequency adjustment unit for changing a resonance capacitance of the resonance capacitor to adjust the resonance frequency, a capacitance change amount control unit for controlling a change in resonance capacitance of the resonance capacitor in the resonance frequency adjustment unit, a resonance frequency shift unit for shifting the resonance frequency of the non-contact wireless communication antenna, and on / off control unit for performing on / off control of the resonance frequency shift unit in accordance with the amount of change in resonance capacitance of the resonance capacitor by the capacitance variation control unit.

A collision prevention relational function is disclosed for RFID tags, which increases stability during system operations. The RFID tag includes a parallel resonance circuit having a coil, a resonance capacitor, an adjustment capacitor, a switching circuit, a rectification circuit, a smoothing capacitor, a constant-voltage circuit, a voltage detection circuit, an exclusive OR circuit, a timer circuit, a voltage detection circuit, a control circuit, an OR circuit, a latch circuit, an UID storage device, and a data modulator / demodulator. When a predetermined power supply voltage / operating voltage is obtained, an anti-collision algorithm identifies and adjusts RFID tags that experienced collision.

A power converter includes a transformer, a primary switch, an auxiliary switch, first and second resonance capacitors, and a secondary side rectification means. A switch mode power supply is formed to use reflected voltage and parasitic capacitance as an energy source for a transformer resonance. The auxiliary switch effectively exchanges energy between the primary inductance of the transformer and the first and second resonant capacitors. The auxiliary switch effectively switches the transformer resonance between two distinct frequencies. In one embodiment of the invention, the power converter can be, but is not limited to, a flyback converter and further includes a comparator and a driver. The comparator is for detecting the voltage across the second resonance capacitor and the driver is configured to drive the auxiliary switch based on the output state of the comparator. The resonant nature of the converter provides zero voltage (ZVS) for the primary switch as well as for the auxiliary switch.

A device (1) for feeding electrical energy from an energy source with variable source voltage into an electric power supply network (15), said device (1) including a transformer (112) for galvanic isolation, a resonant inverter (11) with semi-conductor switches (a-d; A, B), one or several resonant capacitors (17; 18, 19; 20, 21) and one rectifier (113), is: intended to provide high efficiency and have galvanic isolation. This is achieved in that the resonant inverter (11) is operated in the full resonant mode if the operating voltage is in an operation point (MPP) and in the hard-switching mode if the voltages exceed the operation point (MPP).

The invention discloses a resonant tracking non-contact power supply device and a resonant tracking non-contact power supply method and aims to mainly solve the problems that the transmission efficiency and transmission distance are reduced and induction voltage is sensitive to load change caused by the change of a resonant point in an LC resonant non-contact power supply. An excitation source with adjustable frequency and amplitude is formed through an adjustable switch power source (102) and a half-bridge switch (103) and is applied to a resonant circuit consisting of an emitting coil (112) and a resonant capacitor (113); a current signal in the resonant circuit is acquired by using a current sampler (104); an automatic resonant frequency tracking circuit consists of a comparator (105), a phase discriminator (106) and a controllable oscillator (107); when the resonant point changes, an excitation frequency is automatically adjusted and an automatic excitation voltage adjusting circuit consists of a wave detecting and filtering circuit (109), an error amplifier (110) and the adjustable switch power source (102) to automatically adjust the excitation voltage when a load changes, so a load voltage is basically constant. The resonant tracking non-contact power supply device can overcome the effects caused by resonant frequency change and load change and is applicable for the occasion of close-range and high-efficiency non-contact power transmission.

The invention relates to a resonant switched capacitor direct current voltage converter which comprises a first voltage node, a second voltage node, a first switch, a second switch, a first diode, a second diode and a control circuit, wherein a first voltage exists between the first voltage node and a negative wire; a second voltage exists between the second voltage node and the negative wire; and the control circuit provides switching gate signals for the first and the second switches. The resonant switched capacitor direct current voltage converter further comprises a center-tapped inductor and a resonant capacitor, wherein the center-tapped inductor is connected between the first switch and the second switch; and the resonant capacitor is connected between the common node of the first and the second diodes and the central node of the center-tapped inductor. Compared with the conventional switched capacitor direct current voltage converter, the invention has the advantages of reducing complexity, loss and cost, improving the speed, and avoiding the limitation.

A power-supply unit which comprises a transformer, a full bridge circuit consisting of four arm switches provided on a primary side of the transformer, a rectifier and smoothing circuit including two synchronous rectifier switches provided on a secondary side of the transformer, a choke coil, and a capacitor, an output terminal provided in the rectifier and smoothing circuit, a control circuit controlling ON / OFF of the four arm switches of the full bridge circuit and the two synchronous rectifier switches of the rectifier and smoothing circuit, a resonant inductor consisting of a leakage inductor component of the transformer and a parasitic inductor component of wirings on the primary side of the transformer, and a resonant capacitor consisting of a parasitic capacitor component of the arm switches of the full bridge circuit, and in which the control circuit comprises timing variable means which varies switching timings of the two synchronous rectifier switches of the rectifier and smoothing circuit based on an output current flowing in the output terminal provided in the rectifier and smoothing circuit.

Disclosed is inductive coupling of power to devices having negative resistances, such as gas-filled discharge lamps (fluorescent tubes, neon signs, and the like) from a primary inductive loop, using resonant conditioning of the power provided to the device. A "C" shaped inductor (202) around the loop and a resonating capacitor (406) in parallel with the inductor provide a current source to the lamp (403) from across the capacitor. The circuit is capable of first igniting a lamp using a higher voltage available when the Q of the unloaded circuit is high, then running the lamp or other device at a controlled current. The lamp current is substantially proportional to the primary inductive loop flux, and substantially independent of the lamp resistance. A second inductor (404) in series with the first though not itself a collector of flux acts as a current limit. Applications include lighting, displays (optionally isolated and dimmable), and production of ultraviolet radiation.

A resonant DC-DC converter used to drive an LED array includes a half-bridge converter configured to receive DC input power and produce a square wave voltage. A resonant tank circuit that includes an inductive element, a first resonance capacitor, and a second resonance capacitor, is coupled to the half-bridge converter to receive the square wave voltage such that a generally sinusoidal AC voltage is produced across the second resonance capacitor. An output transformer with a primary winding and one or more secondary windings, is coupled in parallel to the second resonance capacitor, and a clipping circuit is coupled to the primary winding such that the voltage across the primary winding does not substantially exceed the voltage of the DC input power. An output rectifier is coupled to the one or more secondary windings of the output transformer and is configured to produce a generally DC output voltage.

Buck converters having a resonant inductor Lr, resonant capacitor Cr, and synchronous switch Q3 that together provide reduced switching loss and soft switching. In operation, the resonant inductor Lr is charged during a time period A. Then, Lr is freewheeling and provides current to an output inductor Lo. Then, Q3 is turned OFF, and energy from the resonant inductor Lr charges the resonant capacitor Cr. Finally, energy from the resonant capacitor Cr is provided to the output inductor and load. The output power can be adjusted by phase control of the operation of switch Q3. In alternative embodiments, the circuit has a pair of coupled inductors L1 L2 or an isolation transformer 40. The coupled inductors have a polarity selected so that the output voltage is reduced, thereby allowing top switch Q1 to have a greater duty cycle. These circuits feature no body diode loss in the switch Q3.

There is provided a power transmission control device provided in a power transmission device included in a contactless power transmission system in which power is transmitted from the power transmission device to a power receiving device by electromagnetically coupling an elementary coil and a secondary coil and the power is supplied to a load of the power receiving device. The power transmission control device includes a load state detection circuit that detects a load state of the power receiving device on the basis of a first signal from a first end of a resonance capacitor forming a resonant circuit with the elementary coil and a second signal from a second end of the resonance capacitor.

Zero volt switching during a light load is performed in such a manner that through an ON / OFF control of switches provided for a full bridge circuit and the synchronous rectifier switches in a rectifier and smoothing circuit, a resonant peak voltage necessary for the zero voltage switching determined by the output current flowing to output terminals, a resonant inductor and a resonant capacitor capacitance is ensured so that an energy accumulated in the rectifier and smoothing circuit is returned to the full bridge circuit so as to act as equivalent as when the output current is increased and to increase the current flowing through the full bridge circuit.

A system comprises a primary switch network coupled to a power source, wherein the primary switch network comprises a plurality of power switches, a primary resonant tank coupled to the plurality of power switches, wherein a resonant capacitor of the primary resonant tank is formed by a first variable capacitance network, and wherein the first variable capacitance network is modulated to improve soft switching of the plurality of power switches through reducing a voltage level and a current level of a switch at a turn-on instant and a primary coil coupled to the primary resonant tank.

The invention discloses an electromagnetic resonance-based nondestructive testing method for metal materials. According to the method, responding resonance signals of eddy current testing are obtained through multipled resonant capacitors in testing coils, comparative analysis of the responding resonance signals is carried out, and the relationships between a defect size and a signal amplitude and between defect depth and a signal phase are calibrated in advance, thereby enabling convenient nondestructive testing of metal materials. The electromagnetic resonance-based nondestructive testing method not only can produce same defect detection effects as a plurality of conventional electromagnetic testing methods like single-frequency eddy current and pulsed eddy current do, but also can effectively detect internal defects in a workpiece and detect workpieces with complicated surface conditions such as a casting surface, an unsmooth surface, a surface with oil stains, a rust-resisting paint, a corrosion layer or other pollutants, etc., without contact under the condition of a high liftoff value; according to the method, no cleaning is needed for test pieces, and particularly, no cumbersome processes like magnetization and demagnetization of magnetic metal materials are needed.

Discussed is an input system that includes a sensor panel including plural first and second channels intersecting each other, a stylus pen including a first core and a second core divided from each other, a primary coil and a secondary coil wound on the first and second cores, an elastic member interposed between the first core and the second core, a resonant capacitor and a switch connected to the secondary coil in series, and a conductive tip connected to the primary coil, a ground unit connected to the stylus pen, an antenna loop formed at the edge area of the sensor panel, and a touch controller connected to the first and second channels and the antenna loop.

Disclosed is a synchronous rectifier type SRC for operating in an intermittence mode, which includes: an input power for supplying the input DC voltage; an input-side switching unit for switching four input-side switching devices to convert the input DC voltage to AC voltage, the input-side switching unit being connected to the input power, an LC resonance circuit for storing energy in a resonance inductor and a resonance capacitor by means of LC resonance, and outputting resonance voltage, the LC resonance circuit being connected to the input-side switching unit; a transformer with a primary winding and a secondary winding for converting the resonance voltage to voltage of a predetermined level according to a turn ratio to generate secondary voltage, and transferring the secondary voltage through the secondary winding, the primary winding being connected to the LC resonance circuit; an output-side switching unit for switching four output-side switching devices to convert the secondary voltage to the output DC voltage, the output-side switching unit being connected to the secondary winding of the transformer; and a gate driving circuit for detecting a polarity of secondary current flowing in the secondary winding, generating dead time, generating driving signals for driving the output-side switching device of the output-side switching unit according to the polarity, and then controlling turn-on or turn-off of the output-side switching devices, the gate driving circuit being connected to both the secondary winding of the transformer and the output-side switching unit. According to the synchronous rectifier type SRC, a no-load characteristic can be controlled with an easy scheme and a simple construction. In addition, a simple resistor is added, and thus dead time can be generated. Consequently, it is possible to simply reduce switching loss that may occur in zero voltage switching.

The invention relates to a nuclear magnetic resonance detection device and a nuclear magnetic resonance detection method for the advanced detection of a water bodies in the front. In the device, a computer is connected with a system controller, a high-power power supply and a signal acquisition unit by a serial port bus respectively; and the system controller is formed by connecting a bridge circuit driver, a high-power H-shaped transmitting bridge circuit, a resonant capacitor and a transmitting coil. Compared with the prior art, the device can detect important information such as the existence of water-bearing bodies in the front, the water content of the water-bearing bodies and the like accurately and effectively. The occupied area of the coil is reduced effectively by a mode of arranging the coil vertically, so that the device can perform exploration in narrow space. The device can detect the underground geological condition within a certain distance in the front directly and accurately in production fields of coal fields and mines or construction sites of tunnels so as to reduce mine accidents caused by geological disasters such as water burst, mud gushing and the like due to unclear geological conditions in the front or various incidents caused by the geological disasters in the process of tunnel construction.

A loop antenna has a first antenna generating a first magnetic field and a second antenna generating a second magnetic field such that the first magnetic field and the second magnetic field each have a different axis. A serial resonant circuit and a parallel resonant circuit are provided for the first antenna and the second antenna, respectively. The serial resonant circuit has a ferrite member, a first coil wound around the ferrite member, a resonant capacitor, and a power source connected thereto in series. The in-series connection of the resonant capacitor and the power source are connected across the first coil. The parallel resonant circuit has a link coil wound around the ferrite member, a second coil connected to the link coil in series and wound around a member outside the ferrite member, and a resonant capacitor connected in parallel to the series connection of the second coil and the link coil.

A series circuit in which a first switching element and a second switching element are connected in series at both ends of an output of an input rectifier circuit for rectifying an alternating current of an alternating current power supply, a resonant circuit in which a primary winding of a transformer and a current resonant capacitor are connected in series at both ends of the first switching element or the second switching element, a rectifying and smoothing circuit for rectifying and smoothing a voltage generated across a secondary winding of the transformer during an on-period of the first switching element or the second switching element, a control circuit for alternately turning on / off the first switching element and the second switching based on a voltage from the rectifying and smoothing circuit, and a voltage detecting circuit for outputting a voltage detecting signal when a voltage at both ends of one switching element of the first switching element and the second switching element, which is turned on at a time of transmitting electric power to the rectifying and smoothing circuit, becomes equal to a predetermined voltage or more. The control circuit turns on the other switching element of the first switching element and the second switching element based on the voltage detecting signal from the voltage detecting circuit.

The present invention employs a resonant inductor, a resonant capacitor and a hybrid transformer using a Hybrid-switching method with three switches which results in two distinct switched-networks: one for ON-time interval and another for OFF-time interval. Resonant inductor is placed in series with the hybrid transformer primary to insure the continuity of primary and secondary currents at the switching transitions. The hybrid transformer converts both inductive and capacitive energy storage from the source to the load. The two-phase extension results in tenfold reduction of the output current ripple.Despite the presence of the resonant inductor current during the OFF-time interval, the output voltage is neither dependent on resonant component values nor on the load current but depends on duty ratio D and turns ratio n of the hybrid transformer only. Thus a simple regulation of output voltage is achieved using duty ratio D control.

A position indicator (100) has a variable capacitor 200, a resonant circuit (36) configured with a position indicating coil (13) and a resonant capacitor (15a), and a rod (11). The variable capacitor (200) has a flat disc-shaped dielectric (1) having two mutually opposite surfaces (1a, 1b), an electrode (2) provided on one surface (1a) of the dielectric (1), a hole (1c) extending between the two mutually opposite surfaces of the dielectric, a conductive portion electrically connecting both ends of the hole, and a conductive elastic member (3) provided near the other surface (1b) of the dielectric (1). The conductive elastic member (3) is arranged on one end of the rod (11). When a pen pressure in the direction of arrow “a” is applied to the other end of the rod (11), the conductive elastic member (3) is pressed against the dielectric (1) so as to be flattened, and the capacitance of the variable capacitor (200) changes in response to the change in the contact area between the conductive elastic member (3) and the dielectric (1).

A series resonant converter of the present invention includes an inverter circuit having at least a pair of a first and second switching device connected between two input terminals, a transformer having a primary winding and a secondary winding connected to the inverter circuit, a first and second resonant capacitor connected to a secondary side of the transformer and connected in series to each other between two output terminals, a first and second unidirectional device connected in series to each other, and a resonant induction device that is operated along with the first and second resonant capacitor and resonates in series. The first and second unidirectional device are configured such that current does not flow from the first and second resonant capacitor to the input terminal by preventing electric charge of the first and second resonant capacitor from being discharged to a primary side of the transformer.