3946 results about "Square waveform" patented technology

Various techniques of simple modifications to TCP/IP protocol and other susceptible protocols and related network's switches/routers configurations, are presented for immediate ready implementations over external Internet of virtually congestion free guaranteed service capable network, without requiring use of existing QoS/MPLS techniques nor requiring any of the switches/routers softwares within the network to be modified or contribute to achieving the end-to-end performance results nor requiring provision of unlimited bandwidths at each and every inter-node links within the network.

The invention discloses a square wave-sine wave signal transformation method comprising the steps as follows: a square wave signal generates N square wave control signals with the same period; the N square wave control signals arrayed in sequence respectively generate N square wave secondary signals; the amplitude sum of the N square wave secondary signals is a; the amplitude of the square wave signal n is a right type; the N square wave secondary signals are processed through superposition to obtain a false sine wave signal; and the false sine wave signal is processed through filtration to obtain a sine wave signal. A square wave-sine wave signal transformation circuit is also disclosed, and the superposition of the N square wave secondary signals in the method is realized by controlling the superposition of current so as to obtain the sine wave signal. The square wave-sine wave signal transformation method and the square wave-sine wave signal transformation circuit avoid adopting a higher order high-frequency filter directly, greatly save the area and the power consumption of a chip, and reduce the design complexity.

Apparatus for conditioning power generated by an energy source includes an inverter for converting a DC input voltage from the energy source to a square wave AC output voltage, and a converter for converting the AC output voltage from the inverter to a sine wave AC output voltage.

A small-sized, low-profile fluid pump having high pumping capabilities includes an actuator and a planar section including a metal plate. The actuator includes a disk-shaped piezoelectric element attached to a disk-shaped diaphragm. As a result of application of a square-wave or sine-wave drive voltage, the actuator performs a bending vibration from the central portion to the peripheral portion. The peripheral portion of the actuator is not restrained. The actuator performs a bending vibration in the state in which it is in proximity to the planar section while facing the planar section. A center vent is provided at or in an area adjacent to the center of an actuator facing area of the planar section that faces the actuator.

A resonant converter includes a square wave generator including a first switch and a second switch, and generating a first square wave corresponding to an input voltage by alternately turning on/off the first and second switches; a resonator including a first coil of a primary coil of a transformer, and generating a resonance waveform corresponding to the first square wave; and an output unit including a second coil of a secondary coil of the transformer, and outputting a voltage corresponding to a current generated in the second coil corresponding to the resonance waveform. The square wave generator includes a pulse frequency modulation controller for turning on/off the first and second switches, comparing a first voltage linearly increased while the second switch maintains the turn-on state and a second voltage corresponding to an integration value on the time of the current flowing to the second switch when the second switch is turned off, and changing on/off drive frequencies of the first and second switches according to a comparison result. Therefore, a resonant converter driven with safety is realized.

The invention discloses an interfacial rheological testing method and an interfacial rheological testing apparatus by using liquid drop imagery. According to the invention, after least squares fitting and secondary optimization by using a Newton iteration method are carried out on a discretized Young-lapalace equation theoretical calculated curve and an actual liquid drop contour boundary curve, interfacial chemical properties like surface tension, interfacial tension and a contact angle value, the volume, the area and the wetting line of liquid drops, etc. can be calculated; then interfacial rheological properties like interfacial dilational elasticity Epsilon d and interfacial dilational viscosity Eta d can be obtained through analysis by using an interfacial tension relaxation method; a set of liquid drop sample introduction system and a set of testing apparatus are provided, liquid drop oscillation is realized through corresponding control software so as to increase or reduce the amount of liquid drops and allow oscillation process to accord with sine, cosine, square wave and sawtooth changes. The apparatus provided by the invention enlarges the application field of optical interface chemical analysis apparatuses and meets requirements for high-precision automatic testing of dynamic/static contact angle values, dynamic/static surface tension values, interfacial tension values and interface rheological measurement values.

A TENS apparatus includes a portable TENS device having a housing with a lower surface, a pair of integral electrodes that are incorporated in the lower surface of the housing, and a pulse driver that is located within the housing and adapted to generate a program of pulse waveforms, each of which is an asymmetrical biphasic square waveform.

The invention relates to a pulse-width modulation (PWM) output method for solving the problem of nonuniform heating of a bridge arm switch of a single-phase full-bridge inverter circuit. The PWM output method is characterized in that two bridge arms use the modulation wave period T as an interval for alternately outputting PWM waves and square wave voltage. The problem of nonuniform heating caused by great work frequency differences of two bridge arm switches is solved, the temperature of an overheat switch is obviously reduced, insulated gate bipolar translator (IGBT) power switch device faults caused by overheat is effectively overcome, the reliability of a switch device is favorably improved, and the service life is prolonged.

A pump having a substantially cylindrical shape and defining a cavity formed by a side wall closed at both ends by end walls wherein the cavity contains a fluid is disclosed. The pump further comprises an actuator operatively associated with at least one of the end walls to cause an oscillatory motion of the driven end wall to generate displacement oscillations of the driven end wall within the cavity. The pump further comprises a valve for controlling the flow of fluid through the valve.

The present invention is directed to a high-powered (e.g., >500 W) ultrasonic generator for use especially for delivering high-power ultrasonic energy to a varying load including compressible fluids. The generator includes a variable frequency triangular waveform generator coupled with pulse width modulators. The output from the pulse width modulator is coupled with the gates of an Isolated Gate Bipolar Transistor (IGBT), which amplifies the signal and delivers it to a coil that is used to drive a magnetostrictive transducer. In one embodiment, high voltage of 0-600 VDC is delivered across the collector and emitter of the IGBT after the signal is delivered. The output of the IGBT is a square waveform with a voltage of ±600V. This voltage is sent to a coil wound around the ultrasonic transducer. The voltage creates a magnetic field on the transducer and the magnetorestrictive properties of the transducer cause the transducer to vibrate as a result of the magnetic field. The use of the IGBT as the amplifying device obviates the need for a Silicon Controlled Rectifier (SCR) circuit, which is typically used in low powered ultrasonic transducers, and which would get overheated and fail in such a high-powered and load-varying application.

Disclosed is a control device capable of ending strong field control based on a voltage index, such as a modulation factor. A voltage waveform control unit performs PWM control when a voltage index indicating the magnitude of voltage command values with respect to a DC voltage is less than a predetermined square wave threshold value, and performs square wave control when the voltage index is equal to or greater than the threshold. A field adjusting unit performs strong field control on the condition that the voltage index is equal to or greater than a predetermined strong field threshold value less than the square wave threshold value. A mode control unit ends the strong field control when a rotational speed is less than a rotational speed threshold value determined on the basis of a target torque and the DC voltage.

The invention discloses a DSP-based electromagnetic flowmeter signal processing system, which comprises a hardware system and a software system. The hardware system consists of an excitation driving module, a signal modulation and acquisition module, a signal processing control module, a man-machine interface module, a communication module and a power supply management module. The signal control module uses DSP as a core. In the system, a high frequency square wave excitation control scheme is adopted, and the DSP generates an excitation time sequence to control the excitation driving module to perform high frequency square wave excitation of a magnet exciting coil; the signal modulation and acquisition module amplifies and filters an output signal of an electromagnetic flowmeter, performs the analog-to-digital conversion of the output signal and outputs the output signal to the DSP; the software system processes an acquired signal to obtain a flowmeter measurement result and send the result to a liquid crystal display; and the parameters of the flowmeter are set by keyboard operation or by the interaction between a master computer and the flowmeter by the communication module. The system can realize the high-accuracy and high-speed measurement of fluid flow, particularly the measurement of flow of liquid-solid two-phase fluid such as pulp.

The new type compound probe is used to measure the parameter of plasma in high accuracy, real time and with certain space resolution, which belongs to the technical area of plasma diagnosis. The character is that installing Langmuir single probe and the difference emission probe into the same probe tube forms the compound probe. Measuring the parameter of plasma in high accuracy and real time is realized by combining following circuits and software. These circuits and software are: Langmuir single probe scanning circuit, the automatic follow circuit of the space electric potential for the difference emission probe, the pulse generating circuit of square wave, computer interface circuit as well as software for automatic collecting and analyzing data.

The invention relates to a method for measuring high reflector reflection index which is characterized in that it adopts square wave or sinusoidal wave modulated wide-spectrum continuous laser as light source which enters into the stable resonator formed by two blocks of high reflectors; it uses square wave to modulate the up stage and down stage of the single period wave to obtain the lasting time and the channel reflecting index or uses fixed phase mode to detect the one-time or odd harmonic of light channel output signal; it uses the amplitude and the phase spiked value to modulate the angle frequency changing curve to obtain the lasting time and the channel reflecting index.

The present invention facilitates serial communication by performing duty cycle correction. A duty cycle correction component 302 performs duty cycle corrections on a pair of differential sinusoidal signals according to a pair of adjustment signals and, as a result, generates a differential pair of square wave signals. A cross coupled buffer 306 buffers the differential pair of square wave signals and provides the buffered signals to a feedback circuit 304 that measures duty cycles of the signals and generates the pair of adjustment signals accordingly. The buffer 306 can also remove skew from the signals. In a transmitter 102, the buffered signals are also generally provided to a multiplexer 112 or encoder and in a receiver 106, the buffered signals are also generally provided to a sampling component 122.

The invention discloses a method for positioning a permanent magnet synchronous motor rotor initial position. Firstly a motor is started by a square wave drive mode and rotor position information detected by a hall element, then sine wave drive is started, and number of pole-pairs of the motor is positioned. By means of the method for positioning the permanent magnet synchronous motor rotor initial position, the full automation of the motor from starting to operating can be achieved, external force or manual starting is not required, simultaneously the method is simple, and the accuracy is high.