51results about "Sinusoidal oscillations train generator" patented technology

The invention discloses a method for producing sine and cosine signals, which comprises the steps that: an angle sequence is generated; the generated angle is treated with phase truncation; the angle after the phase truncation is parted into a high address bit including highest two address bits and a high address bit, the highest two address bits of which are wiped off, and a low address bit; the symbols of the sine and cosine signals corresponding to the angle are calculated by the highest two address bits; the corresponding sine and cosine values are obtained by inquiring a Pi/2 sine table and a Pi/2 cosine table with the high address bit, the highest two address bits of which are wiped off; the low address bit is corresponded to a trigonometric function for being equivalent to the value of the low address bit; a finite term Tylor series expansion of the trigonometric function is utilized for obtaining the sine and cosine values of the angle by the sine and cosine values and the value of the low address bit; the sine and cosine signals of the angle are obtained by the obtained symbols and the calculated sine and cosine values. The invention also discloses a numerical control oscillator. By utilizing the method, the space occupied by storage lists can be effectively compressed under the condition that phase-truncated word length is not increased.

The invention discloses a signal generation circuit. An operational amplifier and a discrete device are combined to form a square wave-triangular wave generation circuit, and triangular waves are obtained by square waves output by a hysteresis comparator through a comparator. A conversion circuit from the triangular waves to sine waves is mainly completed through a diode and a resistance voltage division circuit. According to the design principle of the conversion circuit, nonlinearity of a transmission characteristic curve of the diode is utilized. Compared with the prior art, the waveform distortion meets the index requirement, the frequency coverage range is large, the frequency is adjustable, output signals are stable and reliable, and the cost of the circuit is low.

Systems and methods for generating pulsed output signals that employ a gated RF oscillator circuit having an output that is switchably grounded through the emitter of a transistor and including feedback from the output of the circuit to the base of the transistor to create oscillations and to allow a digital input pulse of a desired length to control the start and stop of oscillations created by the transistor.

The invention relates to a switched capacitor clock generator that comprises an adjustable voltage generation circuit, a switched capacitor circuit, an integrator, a sampling hold circuit, a voltage controlled oscillator, a frequency divider and a bias generation circuit. The adjustable voltage generation circuit and the switched capacitor circuit are respectively connected with input terminals of the integrator, and the adjustable voltage generation circuit generates a voltage that is used for controlling a center frequency of the voltage controlled oscillator; the switched capacitor circuit generates discontinuous currents; the integrator generates a sawtooth wave output voltage and the output terminal of the integrator is connected with the sampling hold circuit; an output terminal of the sampling hold circuit is connected with the voltage controlled oscillator and the sampling hold circuit is used for providing a control signal for the voltage controlled oscillator; and the voltage controlled oscillator generates a frequency signal and the output terminal of the voltage controlled oscillator is connected with the frequency divider. According to the invention, the structure of the generator is simple; a clock signal with high precision can be generated; and the temperature characteristic, the technology stability and the power supply inhibition capability of the provided generator are better than those of an existing clock generator.

The invention relates to a method for generating three-phase sine waves, comprising an angle generation step and a phase voltage waveform data generation step. In the method, the range of a phase angle theta in a certain sampling period is judged according to the value of the phase angle theta, data conversion processing is carried out, the duty ratio data u of phase voltage in the sampling period are obtained and transmitted to a PWM generator, and the PWM generator sends out a pulse control signal for controlling the operation of a switching component, so that a phase voltage waveform of a certain phase is output, and a three-phase phase voltage waveform vector with the phase angle phase difference of 120 degrees is synthesized to obtain a three-phase line voltage sine wave; and when the maximum value of phase voltage is U, the maximum value of line voltage is 2U, and the obtained three-phase line voltage is sequentially symmetrical. Compared with a traditional mode that the line voltage is 2 times of the phase voltage when the three-phase phase voltage is a sine wave, the voltage utilization rate of a switching component in a power unit is enhanced, so that the purpose of lowering the power supply voltage of the power unit is realized.

A pulse generator circuit that outputs pulses having a predetermined shape from an output terminal based on a start signal includes a timing generator circuit that generates (n) signals (n is an integer greater than or equal to 2), the phases of which sequentially change at predetermined time intervals from the point when the phase of the start signal changes, a pulse width signal generator circuit that generates a first pulse width signal and a second pulse width signal having a pulse width that corresponds to the duration of the pulses to be generated based on the start signal, a first filter circuit to which the first pulse width signal is inputted, the first filter circuit limiting the band of the first pulse width signal, a second filter circuit to which the second pulse width signal is inputted, the second filter circuit limiting the band of the second pulse width signal, first and second power supplies that supply predetermined potentials, a first variable impedance circuit whose impedance value is controlled by the output value from the first filter circuit, a second variable impedance circuit whose impedance value is controlled by the output value from the second filter circuit, and a switching circuit that alternately connects the output terminal to the first power supply via the first variable impedance circuit or the second power supply via the second variable impedance circuit using a logic function value based on at least part of the n signals.

The invention belongs to the technical field of integrated circuit design, and discloses an on-chip sine wave excitation generator, which comprises a lookup table LUT, a digital-to-analog converter DAC and a low-pass filter, and is characterized in that pre-stored data in the lookup table LUT is obtained by processing a sine wave signal needing to be generated through a pre-distortion method and a Sigma Delta modulator in sequence; the order L and the oversampling rate OSR of the Sigma Delta modulator are determined by the signal-to-noise ratio SNR of a sine wave signal needing to be generated, the level quantity of a quantizer of the Sigma Delta modulator is determined by the resolution of a digital-to-analog converter DAC, and according to the harmonic distortion condition of an output signal passing through the digital-to-analog converter DAC and a low-pass filter, the level quantity of a quantizer of the Sigma Delta modulator is determined by the level quantity of a quantizer of the Sigma Delta modulator. And selecting a corresponding pre-distortion method to eliminate the Nth harmonic in the sine wave signal needing to be generated. The invention further discloses a manufacturing method of the on-chip sine wave excitation generator.

The invention relates to an approximate sine carrier generator with the wide-temperature application function and stable and controllable frequency. The approximate sine carrier generator comprises a PWM generation circuit and a band-pass filter connected with the PWM generation circuit. The PWM generation circuit is composed of a wide-temperature single-chip microcomputer combination internal structure in a C language programming or assembly language programming mode. The band-pass filter is a standard voltage controlled voltage source two-stage band-pass filter. The wide-temperature single-chip microcomputer internal structure with the PWM output function comprises a duty factor register 1, a buffer 2, a comparator 3, a timer 4, a comparator 5, a period register 6, an RS trigger 7 and an output controller 8. The band-pass filter comprises a low-pass filter resistor R1, a capacitor C1, a high-pass filter capacitor C2, a resistor R2, a feedback resistor R3, an in-phase proportion operational circuit resistor Rx, a resistor Rf and an operational amplifier N1. The approximate sine carrier generator can achieve the wide-temperature application function, the frequency is stable and controllable, and generated approximate sine waves can be used as adjusted carrier waves in a digital modulation system.

The invention relates to a high-power sinusoidal signal generating circuit for cross-well electromagnetism. The high-power sinusoidal signal generating circuit comprises an IGBT switching circuit. TheIGBT switching circuit is used for generating two rectangular wave signals which are identical in amplitude and opposite in polarity and are subjected to SPWM modulation to be loaded to a load, and comprises a first IGBT module and a second IGBT module, and the first IGBT module and the second IGBT module are jointly connected with the two ends of the load. Each of the first IGBT module and the second IGBT module comprises two cascaded triodes, and the four triodes are connected to form an annular loop. The high-power sinusoidal signal generating circuit has the advantages that an IGBT high-power tube is used as the switching tube of a cross-well electromagnetic signal source, so that the radiation power of a cross-well electromagnetic antenna can be effectively increased, and signals ofa cross-well electromagnetic detection system can be radiated farther; the radiation signal waveform is a sine wave, the loss of signal energy caused by antenna impedance due to voltage change can beeffectively reduced, more phase and amplitude information can be contained compared with square waves, and more cross-well geological information is further contained.

The present invention relates to an electromagnetic acoustic transducer excitation system comprising a tone burst generator, the tone burst generator comprising: an oscillator device configured to produce a radio frequency signal; an analog switch configured to produce an output based on the radio frequency signal produced by the oscillator device and a control signal; a pre-amplifier configured to amplify the output of the analog switch and produce a tone burst output signal; and a control module configured to produce the control signal for providing to the analog switch.

The portable magnetic field stimulator of the present invention has a microcontroller which sets sinusoidal wave or pulse voltage signals of different frequency, intensity, duty cycle through a manipulation interface, and inputs the signals to a pulse type voltage/current conversion circuit or sinusoidal wave type voltage/current conversion circuit. Finally, the current is transported to the stimulating coil to produce sinusoidal wave or pulse wave magnetic field having direct current level with frequency 1˜2 kHz and with magnetic flux 1˜300 Gauss. Thereby, not only the variation of frequency can be controlled but also the other subtle parameters such as duty cycle, multi wave form switching are also able to be manipulated and set, and different stimulating wave form of sinusoidal wave or pulse can also be produced. In addition, it can be applied in diversified symptoms.

The invention discloses a sine wave generation circuit and an audio shield having the sine wave generation circuit. The sine wave generation circuit comprises a power source input end, a micro controller, a waveform generation module, a filtering shaping module and a sine wave output end. According to the sine wave generation circuit, high level or low level signals are sequentially outputted through at least two input/output ports within a quarter of a sine period by the micro controller while square wave signals with successively-increased amplitude or successively-decreased amplitude are correspondingly generated by the waveform generation module within the quarter of the sine period, after filtering and shaping the square wave signals through the filtering shaping module, sine wave signals are outputted, so when the audio shield and audio equipment carry out communication, the stable and smooth sine wave signals are outputted by the sine wave generation circuit to the audio equipment to improve the communication speed and communication reliability of the audio shield, moreover, the sine wave generation circuit has advantages of no need for D/A conversion, simple and reasonable circuit structure and low design cost.

The invention discloses a method and circuit for converting alternating-current sine wave signals into direct-current step wave signals. The method comprises the steps that (1) the alternating-current sine wave signals are rectified into direct-current head signals; (2) the head wave signals are transmitted into a plurality of voltage adjusting devices with different amplitudes, and are divided into multiple stages of voltage signals; (3) the voltage signals are respectively transmitted into a constant current device, voltage signal waves form flat-topped waves, all flat-topped wave voltage signals are connected in sequence, and the direct-current step wave signals are obtained. The circuit comprises a rectifier bridge circuit, the voltage adjusting devices and a plurality of constant current control devices, the rectifier bridge circuit rectifies the alternating-current sine wave signals into the direct-current head wave signals, the voltage adjusting devices are connected in parallel to form a network, the voltage adjusting set values of the voltage adjusting devices are different, the direct-current head wave signals are divided into the multi-stage signals with different amplitudes, the number of the constant current control devices is equal to that of the voltage adjusting devices, the constant current control devices are correspondingly connected with the voltage adjusting devices respectively, and used for controlling the currents of the voltage adjusting devices to be kept constant, and the output signals of the voltages adjusting devices are made to be the flat-topped waves. All the flat-topped wave signals are connected in sequence, and the direct-current step wave signals are formed.

The invention provides a low-frequency wave signal generation method, a low-frequency wave signal generation system and electrical stimulation equipment. The low-frequency wave signal generation method comprises the following steps: carrying out linear superposition on two beams of high-frequency wave signals to generate a low-frequency signal; wherein the two beams of high-frequency signals meet the following conditions: the waveform of the high-frequency signals is located at the middle point of the period when the positive energy equivalent concentration action time point and the negative energy equivalent concentration action time point in the period of any starting point are not at the same time; the two beams of high-frequency signals have a frequency difference, and when the frequency difference tends to zero, the waveforms of the two beams of high-frequency signals are mutually inverted. According to the low-frequency wave signal generation method and system and the electrical stimulation equipment provided by the invention, the frequency difference exists, and the waveforms are mutually inverted when the frequency difference tends to zero; and the waveform characteristics meet the condition that the two beams of high-frequency wave signals which cannot enable the positive energy equivalent concentration action time point and the negative energy equivalent concentration action time point in the periodic waveform to be simultaneously located at the midpoint of the current period are subjected to linear superposition, so that a real low-frequency wave signal is obtained.

A phased-array RF pulse generator is disclosed which includes a video-pulse generator arranged to generate video pulses each having a leading edge. An array of nonlinear and dispersive transmission lines, are arranged to generate RF pulses from the video pulses. At least one sensor is arranged to detect the leading edge of the video pulses after they have passed along the transmission lines. A phase controller is arranged to set the velocity of the video pulses in each transmission line to put the detected leading edges, and hence the generated RF pulses, into a desired phase relationship.

Disclosed is an apparatus for generating high-quality sine waves through a simple circuit structure. The apparatus comprises a square wave generator for generating a plurality of square waves different in frequency from one to another; a combined circuit for combining the plurality of square waves into a synthetic wave; and a filter circuit for filtering the synthetic wave through a low-pass filter. Also, a method for generating high-quality sine waves is provided.

The invention discloses a rotary transformer excitation signal generation system and method, and the system comprises a main control module which is used for generating a digital modulation wave which changes according to a sine rule; a low-pass filter which is used for converting the digital modulation wave into a sine wave; a first-stage operation amplification circuit which is used for carrying out the first-stage amplification of the sine wave; a high-pass filter circuit which is used for blocking sine waves; a second-stage operational amplification circuit which is used for carrying out second-stage amplification on the sine waves; and a phase inverting circuit which is used for inverting the sine waves to generate rotary transformer excitation signals. The problems of large weight, large size, high cost and difficulty in integration of the existing rotary transformer excitation signal generation method are solved, and the rotary transformer excitation signal generation method has the advantages of low cost, small size, light weight, easiness in integration and the like.

Disclosed herein is a sine wave oscillator. The sine wave oscillator includes an operational amplification unit, a first resistor, a first capacitor, a second capacitor, a second resistor, a third resistor, a fourth resistor, and a startup circuit. The first ends of the first resistor and the first capacitor are connected to the plus input terminal of the operational amplification unit. The first end of the second capacitor is connected to the plus input terminal. The first end of the second resistor is connected to the second end of the second capacitor and its second end is connected to the output terminal of the operational amplification unit. The first end of the third resistor is connected to the minus input terminal of the operational amplification unit. The fourth resistor is connected between the minus input terminal and the output terminal. The first end of the startup circuit is connected to the minus input terminal.

A radio frequency (RF) generator includes a pulse generator circuit configured to receive input signals indicative of a pulse pattern defining an envelope of a pulse RF signal. The pulse generator circuit stores data values defining power levels and durations of segments of the pulse pattern. The pulse generator generates a pulse modulation control signal responsive to the stored data values, the pulse modulation control signal being indicative of the power level and the duration of each segment of the pulse pattern, the pulse modulation control signal being provided to a control circuit to generate a control signal to adjust the amplitude and to modulate the duration or width of the RF signal to generate the pulse RF signal having the pulse pattern.

The invention discloses a flexible and agile high-accuracy carrier generation system and method, and the method comprises the steps: determining a carrier generation control parameter according to a sampling frequency and a carrier frequency, placing the control parameter into a digital carrier generation module to generate a parallel digital intermediate frequency carrier signal, converting the parallel digital intermediate frequency signal into an analog radio frequency carrier signal through a high-speed DA, and outputting the analog radio frequency carrier signal. The radio frequency carrier wave generated by the invention has smaller phase jitter and in-band stray, carrier wave frequency adjustment with faster response time and larger dynamic range can be realized, and the integration degree and the software degree are higher.

The invention discloses a sine wave pulse signal generation circuit and a related electronic device. The sine wave pulse signal generation circuit comprises: an inductor, a first end of which is coupled to a first reference voltage; a capacitor, wherein the first end of the capacitor is coupled to the second end of the inductor, the second end of the capacitor is coupled to a second reference voltage, and the first reference voltage is higher than the second reference voltage; a first diode, wherein the anode of the first diode is coupled with the first end of the capacitor; a first switch which is coupled between the cathode of the first diode and the second reference voltage, wherein the sine wave pulse signal generating circuit generates a sine wave pulse signal at the second end of the inductor, the sine wave pulse signal has a pulse period, the pulse period comprises a first time period and a second time period, in the first time period, the voltage of the sine wave pulse signal is fixed, and in the second time period, the voltage of the sine wave pulse signal is not fixed and is a sine wave.