545 results about "Self excited" patented technology

Disclosed is a noncontact electric power transmission system having a power transmitter circuit section 10 and a power receiver circuit section 30 which are adapted to be coupled to transmit electric power from a transmitter coil Lp provided in the power transmitter circuit section 10 to a receiver coil Ls provided in the power receiver circuit section 30, in a noncontact manner by means of electromagnetic induction. The noncontact electric power transmission system comprises: a separately-excited or self-excited switching circuit 2 provided in the power transmitter circuit section 10; a control IC 3 operable to drive the switching circuit 2; an LC series resonant circuit including a capacitor Cp connected in series to the transmitter coil Lp or an LC parallel resonant circuit including a capacitor Cp connected in parallel to the transmitter coil Lp; and an LC parallel resonant circuit including a capacitor Cs connected in parallel to the receiver coil Ls, wherein an oscillating frequency (Fosc) of the control IC 3, a resonant frequency (Fpr) of the LC series resonant circuit or the LC parallel resonant circuit in the power transmitter circuit section 10, and a resonant frequency (Fsr) of the LC parallel resonant circuit in the power receiver circuit section 30, have the following relationship: Fpr<Fosc<Fsr.

A hand-held massager capable of self-excited, impedance-matched vibration for optimal massaging of each particular body part of each particular individual. The massager includes a hollow, open-ended contact piece to which is coupled a vibrator and which is to be held against a desired body part. A pressure sensor is mounted to the contact piece for sensing pressure variations in the cavity in the contact piece while the open end thereof is held against the body part, in order to ascertain the mechanical impedance of that body part. A closed-loop, electropneumatic vibration control system makes it possible for the mechanical impedance to be fed back to the vibrator, causing the latter to make self-induced vibration. Thus the desired body part is optimally massaged at its resonance frequency.

An optical reflection element includes a mirror portion and an oscillator coupled to the mirror portion. The oscillator includes a base, an insulating layer, a drive element, and a monitor element. The insulating layer is formed on the base. The drive element and the monitor element are formed on the insulating layer, and are separated from each other by a separation groove. Each of the drive element and the monitor element includes a lower electrode layer, a piezoelectric layer, and an upper electrode layer formed in that order on the insulating layer. The monitor element has high detection accuracy, allowing the optical reflection element to perform self-excited driving with high accuracy.

The present invention is to provide a heat pipe which is high in heat transfer performance and reliability and can be low priced, compact and lightweight, and has flexibility, and a computer provided with the heat pipe. At least a part of a conduit (1) constituting a container of a self-excited oscillation heat pipe is formed in a shape having flexibility such as a waved bent shape. Alternatively, at least a part of the container of the self-excited oscillation heat pipe is formed of a material having flexibility such as super elastic alloys.

The invention discloses a system and a method for distributed optical fibre sensing measurement based on Brillouin scattering. According to the invention, the laser of the system outputs two continuous laser lights having a wavelength difference of greater than 15 nm, and the laser lights are split into a detection light and a local oscillation light via a wave combiner and a coupler; the detection light enters sensing optical fibres via an electro-optical modulator and a circulator which are connected with a pulse signal generator, and a self-excited Brillouin scattering light is accessed into the 3 dB coupler via the circulator; and the local oscillation light is accessed into the 3 dB coupler as well, and the output of the 3 dB coupler is connected with a balance detector and a data acquisition and processing unit which stores associated programs and formulas. The measurement method comprises the following steps that: the double-wavelength detection light is modulated into a detection light pulse so as to generate self-excited Brillouin scattering in the sensing optical fibres, and subjected to coherent frequency mixing with the local oscillation light; the data acquisition and processing unit performs a frequency-sweep measurement on the difference-frequency electric signal of the balance detector so as to obtain Brillouin scattering frequency spectrums and Brillouin frequency shifts along different points of the optical fibres, and calculates to obtain the change amounts of a temperature and a strain. Via the system and the method disclosed by the invention, simultaneous measurement for the temperature and the strain is realized, and the measurement accuracy is improved.

The invention discloses a double-rotor disc self-excited retarder and a control method thereof. The retarder, a generating set and two rotor discs are fixedly arranged on a transmission shaft of an automobile, wherein the two rotor discs are arranged on both sides of the retarder; the retarder comprises a retarder coil, a retarder coil iron core and a retarder bracket; the generating set comprises a permanent magnet, a generating set stator coil and a generating set shell; a control unit comprises an amplifying circuit, a voltage transformation rectifier and two relays; the transmission shaft of the automobile rotates to drive the permanent magnet to rotate; a three-phase alternating voltage generated by the generating set stator coil is input into the voltage transformation rectifier; a brake signal is input into the amplifying circuit, so that a normally open contact of a first relay is closed; the current of a storage battery is input into a second relay through the normally open contact of the first relay; the second relay switches on the retarder coil; and an electromagnetic braking torque generated by the rotor disc prevents the transmission shaft of the automobile from rotating. The retarder has the advantages of power generating and retarding functions, high system radiating performance and higher braking efficiency and chassis space utilization ratio.

The invention provides a liquid cooling auto-excitation-type eddy current retarder without an electric brush structure and belongs to an auxiliary braking device for retarding a vehicle. The eddy current retarder provided by the invention comprises a retarder rotor, a retarder stator, a control module and a generator device, wherein the retarder rotor consists of a retarder coil, an electromagnetcore and a core retainer; the retarder coil is wound on a coil frame, and the electromagnet core is inserted into the coil frame; the electromagnet core, the retarder coil and the coil frame are uniformly distributed on the circumference of the core retainer; the retarder rotor is connected with a transmission shaft, and the inner circle of the retarder stator and the excircle of the electromagnetic core of the retarder rotor are coaxial; and the generator device comprises a generator exciting winding, a generator excitation magnetic pole, a generator armature winding and a generator armaturecore and positioned in the retarder rotor. Compared with the traditional eddy current retarder, the eddy current retarder provided by the invention has the advantages of better safety, high reliability, no need of maintenance, compact overall structure, small volume and weight, and easiness for realization of intelligent control on the brake torque and constant-speed cruising of the retarder.

The invention is a torsion property measuring method and apparatus for flexible material. The method is that upper end of simple holds to measure torsion moment and lower end hangs a weight to be revolved to a certain torsion moment or torsion angle then released to rotate back and reciprocate naturally, measuring autooscillation property and torsion modulus of the sample; or lower end is holded to have forced rotation or positive and negative, measuring once of the sample. The apparatus is consisted of moving beam, force, displacement sensor, torsion moment measuring mechanism, upper and lower holder, rotation mechanism, micro polarized light optical circuit and camera mechanism, moving and focusing mechanism, temperature cap, driving system and control circuit, program control and signal processing system, finishing measurement of self excited vibration, torsional fatigue and relaxation performance of flexible material with stationary load or stretch and observing degree of twist transfer of sample in and property change under different temperature, having simple but practical structure, convenient installation, many measurable parameters and accurate measurement.

A self-excited DC-DC converter comprises a switching element that chops a direct-current input voltage; a smoothing circuit that smoothes the chopped voltage to generate a DC output voltage; a switching control signal generation circuit that generates a switching control signal for the on/off control of the switching element by comparing a feedback voltage of the output voltage and a comparison voltage; an output correction circuit that adjusts the comparison voltage according to an error between the feedback voltage and the reference voltage and, when the output current is in the overcurrent state, reduces the level of the comparison voltage; an overcurrent protection signal generation circuit that, when the output current is in an overcurrent state, generates an overcurrent protection signal for turning off the switching element regardless of the switching control signal; and a delay circuit that delays the overcurrent protection signal. Also, a switching control circuit is provided therein.

The invention discloses a self-excited push-pull type converter which comprises a Royer circuit. An inductor connects a power supply terminal of the Royer circuit with a center tap of a transformer primary winding in the Royer circuit. An inductance value of the inductor is less than one-tenth of an inductance value of a primary winding in the transformer. The center tap of the primary winding isa connection point of two primary windings of the transformer. The self-excited push-pull type converter of the present invention has the characteristics of high consistency, easy debugging, low technology requirement, and good short circuit protection performance.

The invention discloses a two-stage hybrid excitation brushless synchronous motor, which is characterized by comprising a hybrid excitation main generator, an exciter and a rotating rectifier, wherein the main generator is a rotating magnetic pole type hybrid excitation generator of which a rotor is provided with an exciting winding and a permanent magnet source; the exciter is a rotating armature type synchronous generator; an input end and an output end of the rotating rectifier are connected with an exciter armature winding and a main generator exciting winding respectively; and the rotating rectifier is arranged on the rotor. When the motor operates, alternating current generated by an exciter armature is rectified through the rotating rectifier and then is supplied to the main generator exciting winding. The invention has the advantages that: a motor exciting problem is solved without the addition of the initial excitation equipment by utilizing a permanent magnet field of the hybrid excitation main generator, so that the generator achieves stable voltage gradually and is completely self-excited. A special permanent magnet auxiliary exciter or an auxiliary exciting power supply is eliminated, and a two-stage hybrid excitation synchronous motor with a brushless structure is formed; moreover, the synchronous motor has a simple structure and high power density, and is self-excited and convenient to control.

A self-excited multi-phase DC-DC converter having satisfactory responsiveness when its load suddenly changes. A control unit of the converter compares output currents of first and second converter units. Based on the comparison result, the control unit generates control signals to operate a converter unit through which a smaller output current flows. For example, when an output voltage of the converter decreases due to a sudden change in the load while the first converter unit is operating to supply current, the second converter unit through which a smaller output current flows is operated to increase the output voltage.

The invention provides a telescopic double-edged deep-hole boring cutter, aims to provide a deep-hole drilling boring cutter which has large length-diameter ratio, small self-excited vibration of a boring bar, reliable and stable feeding operation, no radial motion of a cutter arbor, and radial feeding of a cutting edge in a cutting process, and solves the problem that the deep-hole bottle cavity with large length-diameter ratio has large processing difficulty. The boring cutter comprises the boring bar which can extend to the deep-hole bottle cavity, wherein the central axis of the boring bar is provided with a through hole which runs through the central axis; a push rod (2) which is connected with a radial feeding device of the head of the boring bar is arranged in the through hole; the rear end of the push rod (2) is provided with a rotating handle; the rotating handle rotates a screw (5) and pushes the push rod (2) to do radial telescopic motion in the through hole of the boring bar; and the push rod (2) moves by way of pushing or pulling to drive the radial feeding device connected with the push rod and adjust the cutting edge of the double-edged boring cutter on a cutter block (3) to radically feed in the deep-hole bottle cavity.

A form of gearing having teeth with different face widths along the tooth height and a method thereof of designing and manufacturing. Different gear tooth face widths are introduced along the tooth height to alter the tooth stiffness characteristic to provide a pair of gears with reduced mesh stiffness variation. The use of variable face widths along the tooth height changes both the geometric properties of the tooth and the load distribution/concentration to reduce the self-excited component of dynamic load, in effect reducing gear noise and increasing power density.

An electromagnetic alarm device includes a current interrupter to interrupt an electricity supply to a coil on application of a self-excited voltage to oscillate a diaphragm with a moving core to generate a first alarm sound including a fundamental tone at a first predetermined frequency, when a switch is manipulated by an occupant. A proximity notification device includes an ultrasonic speaker to emit an ultrasonic wave, which is generated by implementing ultrasonic modulation on a proximity notification sound, to an outside of the vehicle for notifying a pedestrian of proximity of the vehicle, according to a traveling state of the vehicle and/or when a sensor detects a pedestrian. The ultrasonic speaker emits an ultrasonic wave, which is generated by implementing ultrasonic modulation on a second alarm sound including a fundamental tone at a second frequency, when the switch is manipulated.

The invention is applicable to the communication field and can carry out relay amplification on a wireless communication system with various frequency bands and simultaneously eliminate self-excited interference of signals. The repeater comprises a downlink which is composed of a multi-frequency band branching/combining unit, a downlink power amplification module and multi-frequency band branching/combining units which are sequentially connected, and an uplink which is composed of a multi-frequency band branching/combining unit, an uplink power amplification module and multi-frequency band branching/combining units which are sequentially connected. The repeater system can process wireless signals with multiple frequency bands, thereby being capable of containing a plurality of downlinks and a plurality of uplinks. The downlink power amplification module and the uplink power amplification module in the embodiment of the invention are both provided with self-excited interference elimination modules, thereby being capable of eliminating the self-excited interference of the repeater. The multi-frequency band self-excited interference elimination repeater can reduce the number of equipments which are used for the repeater and installed by mobile communication operators and increase the wireless coverage range.

The invention relates to a transient electromagnetic splay transmitting and receiving coil, which is characterized in that on the basis of conventional independent frame-shaped transmitting and receiving coils, the transmitting coil and the receiving coil are respectively twisted for 180 degrees from middle parts and then are transformed into two splay coils. The invention achieves the purpose of eliminating external interference of electromagnetic waves in the early process of signal acquisition by geometrical splay transmitting and receiving coils. The coil eliminates the interference of electromagnetic waves and simultaneously ensures that self-excited electromagnetic waves can be effectively received; and the coil is relatively convenient in use and is suitable for practical work of a transient electromagnetic method.

When a steering speed reaches a steering speed determination threshold, a steering speed gain is set to “0”. As a result, a final basic assist controlled variable becomes “0”, and application of an assist force to a steering system is stopped. Therefore, repetition of so-called reverse assist that is a cause of occurrence of an unintended steering behavior, such as self-excited vibration, is stopped. Accordingly, the steering behavior is improved.

An over-power protection apparatus for self-excited power converter comprises a soft-start unit, an adjusting unit and a timing unit. A PWM unit of the self-excited power converter generates a switching signal in response to a compensating signal of the soft-start unit to control the output power of the self-excited power converter. The soft-start unit couples to the adjusting unit. The adjusting unit drives the soft-start unit and the PWM unit for modulating the switching signal to reduce the pulse width of the switching signal and the output power of the self-excited power converter once the short-circuit and over-load are happened at the output of the self-excited power converter. In the meantime, a timing unit starts to count. The timing unit drives the self-excited power converter to stop supplying the power source after the counting and the over-power lasting for a period of time.

Disclosed herein is a multi-mesh gear system, such as an epicyclic gear system, in which (a) optimal performance is not load-specific and (b) the same profile modifications can be applied on both flanks of the common gear. This is accomplished through a novel combination of a constant system contact ratio and gearing having mesh stiffness variation reducing, or MSVR, modifications. An MSVR modification, such as Differential Crowning, will minimize the self-excited component of dynamic load for gear meshes across different operating loads, resulting in an optimized gearset. The specification of a substantially constant contact ratio for the multi-mesh gear system allows the same MSVR modification to be used on both tooth flanks of the common gear, reducing the cost and complexity of manufacture.