87results about How to "Stable output frequency" patented technology

A lossless equalization controller and a control method belong to the technical field of battery equalization control. The controller comprises a battery pack formed by a plurality of cells, an equalization switch control module, an equalization power control module, an equalization power transformation module, an equalization charging control module, a system power supply module and a master control module, wherein the system power supply module supplies power to the equalization switch control module, the equalization charging control module and the master control module. The controller has the advantages of rapid equalization speed, safe and reliable equalization process, low cost and easy promotion and application. The control method includes detecting battery equalization degree, equalizing laggard cells in the battery pack when the battery equalization degree is equal to or greater than 0.3%, detecting system fault, clearing system fault and other detection steps. The equalization precision is high, and the equalization process is safe and reliable.

The invention discloses a method for coordinating and controlling the power between a series-connected micro-grid and micro-sources of the series-connected micro-grid, which has two normal operating states, namely islanding and grid connecting, simultaneously. According to the structure, the overall system consists of three symmetrical subsystems of A, B and C; H-bridge micro-source inverters of the three internal symmetrical subsystems are connected together in series. Different main micro-source direct-current links are configured with energy storage systems so as to inhibit the fluctuation of the voltages of the direct-current links. In addition, the splitting/recovering operation of the micro-sources can also be realized through corresponding switching operations. According to the structure, the harmonic content of the output voltage of the system is low; the sine degree of a waveform is good; the rated working voltage level of each micro-source is low; the system construction cost is relatively low; the output frequencies and the currents of all micro-source inverters are equal to one another; the output frequency of the system is stable and the power coordination and control are relatively simple.

The invention relates to a method for stabilizing output of an optical pump gas THz laser based on an opto-acoustic effect and a frequency regulator for achieving the method, and belongs to the technical field of the THz laser. According to the method, an opto-acoustic detector is added on the basis of the THz laser; an opto-acoustic signal generated by operation material absorbing pumping lasers is detected by the added opto-acoustic detector; according to opto-acoustic signal changing conditions, a computer feedback control system is used for controlling a pump laser and piezoelectric ceramics arranged in a cavity of the THz laser, a pump laser source and the cavity length of the resonant cavity of the THz laser are convenient to adjust, the laser outputting stabilization of the pump laser source is achieved, and therefore the power outputting stabilization and the frequency outputting stabilization of the THz laser are achieved. By means of the method and system, the accuracy of frequency stabilization of outputting power and frequency can be higher, the responding speed can be higher, and the method and system are suitable for an optical pump gas THz laser system particularly.

An oscillator and the control method thereof. The oscillator includes an oscillation unit to receive a first current and to generate an oscillating signal according to the first current, a frequency-to-voltage converter to receive the oscillating signal and to generate a converted voltage according to a frequency of the oscillating signal, and a voltage-to-current converter to receive the converted voltage and to generate the first current according to the converted voltage, wherein the first current is modulated from a first value to a second value after the initiation of the oscillation unit.

A temperature-controlled crystal oscillating unit and oscillator are provided, which can stabilize an output frequency thereof, have firmness against shock of falling etc., and are suitable for miniaturization and mass production. A crystal blank for the temperature-controlled crystal oscillating unit is formed by an inner region which is an oscillating plate; an outer region which surrounds the periphery of the inner region; and a connection portion which connects the inner region with the outer region. Electrodes are formed on two surfaces of the inner region, and a heater and a temperature sensor are disposed to surround the periphery of the electrode on one surface of the inner region where the electrode is formed thereon. The electrodes, the heater and the temperature sensor are respectively connected with terminals on the outer region by leads. A contact area between the temperature sensor and a crystal is increased.

The invention discloses a high precision numerical control annular oscillator adopting laminated current tubes. The high precision numerical control annular oscillator includes a fine modulation array including a plurality of array units. Each array unit includes a plurality of array MOS tubes in a consistent direction. The array units are connected in series according to the width W direction of the array MOS tubes and are connected in parallel in the length L direction of the array MOS tubes. The high precision numerical control annular oscillator also includes a fixed current circuit connected in parallel with the fine modulation array. According to the invention, higher frequency precision can be achieved under the limited minimum current. Through the optimization of the array units of the fine modulation array, the current change rate is increased, namely, the time period starting from current control code input to output current change implementation is short, so that the high precision numerical control annular oscillator can meet requirements for working at high rates.

The invention provides an oscillator, including a resistor, at least one first reverser, at least one second reverser and a capacitor bank. The at least one first reverser is connected with the resistor in parallel, and has an input end and an output end. The at least one second reverser has an input end and an output end, the input end of the at least one second reverser is connected to the output end of the at least one first reverser. The capacitor bank is connected with the input end of the at least one reverser and the output end of the at least one second reverser, and includes a first capacitor and a second capacitor, the first capacitor has a negative voltage coefficient, and the second capacitor has a positive voltage coefficient. By utilization of mutual compensation of the first capacitor and the second capacitor, the oscillator can be free of influence of voltage variation, so as to maintain stable output frequency.

The invention relates to a signal generator. A portable signal generation device is composed of a single-chip microcomputer, a display module, a USB communication module, a button module, a power supply circuit and a signal processing module. The signal processing module is composed of a DDS module, a signal processing circuit and a signal amplification circuit which are successively connected. The portable signal generation device provided by the invention can generate any waveform, and has the advantages of simple software and hardware design, low power consumption, convenient debugging and stable output frequency.

The invention relates to a magnetic resonance compatible microwave ablation instrument, which is characterized in that the microwave ablation instrument comprises a shielding chassis made of heat conduction non-magnetic material, a power supply module, a microwave generation module and a main control module arranged in the shielding chassis. The power supply module is electrically connected with the microwave generation module and the main control module to supply power to the microwave generation module and the main control module. The main control module is electrically connected with the microwave generation module for controlling the power of the microwave generation module. The microwave generating module adopts transistor microwave solid-state source. A heat sink made of thermally conductive non-magnetic material is fixedly arranged on the outside of the shielding chassis. In accordance with that prior art. The invention has the advantages that the microwave generation module adopts the transistor microwave solid-state source, the non-magnetron mode, the output frequency is stable, the power is constant, the magnetic compatibility and the electromagnetic compatibility are better than the magnetron mode, the heat is dissipated through the shielding chassis, and the whole microwave ablation instrument is made of the magnetism-free device, so as to prevent the influence on the field uniformity of the magnetic resonance.

The invention discloses an emergency power supply for outdoor operation of the electrical power system. The emergency power supply comprises solar cell panels, an electric generator, an air operated machine, a brake, a top cover, a wind-gathering cover, a controller and an accumulator. According to the emergency power supply, the air operated machine is provided with an adjustor for adjusting angles of wind approach of blades, and matched with the control effects of the brake and magnetic valves on the wind-gathering cover, so that the beneficial effects of ensuring stable rotating speed and output frequency of a motor are achieved. The problem of electricity utilization of engineering constructors in a remote area is solved.

A pipe flow direct-drive power generating device comprises a generator shell. The two ends of the generator shell are respectively and fixedly connected with a shrinkable pipe and a wake flow pipe. At least two stages of rotatable blades are arranged in the generator shell, the shrinkable pipe and the wake flow pipe are communicated in space, and a first rotor installation ring, a guide blade installation seat and a second rotor installation ring are sequentially arranged between the shrinkable pipe and the wake flow pipe. The inner wall of the first rotor installation ring is fixedly connected with a first-stage rotating blade, the inner wall of the second rotor installation ring is fixedly connected with a second-stage rotating blade, the first-stage rotating blade and the second-stage rotating blade are fixed on a supporting shaft, the two ends of the supporting shaft can be rotationally supported on the inner wall of the communicated space, the inner wall of the guide blade installation seat is fixedly connected with guide blades, the guide blade installation seat is fixed on the generator shell, permanent magnets are arranged on both the periphery of the first rotor installation ring and the periphery of the second rotor installation ring, a stator coil is arranged in the generator shell, the stator coil and the permanent magnets are opposite, and gaps are left among the stator coil and the permanent magnets. According to the pipe flow direct-drive power generating device, a power transmission link of a transmission shaft is eliminated, energy loss in a shaft transmission link is avoided, and the utilization rate of power is improved.

The invention provides a plasma processing method. The plasma processing method comprises that a first frequency is obtained in advance, and the first frequency is the output frequency of a frequency-variable power source when the frequency-variable power source matches the impedance of a reaction chamber in the first plasma processing process; a second frequency is obtained in advance, and the second frequency is the output frequency of the frequency-variable power source when the frequency-variable power source matches the impedance of the reaction chamber in the second plasma processing process; first plasma processing is carried out on a substrate to be processed, and at the same time, an external control unit sets the output frequency of the frequency-variable power source as the first frequency so that the frequency-variable power source matches the impedance of the reaction chamber; and second plasma processing is carried out on the substrate to be processed, and at the same time, the external control unit sets the output frequency of the frequency-variable power source as the second frequency so that the frequency-variable power source matches the impedance of the reaction chamber. The plasma processing method can keep plasma stable and avoid plasma from quenching.

PROBLEM TO BE SOLVED: To provide a crystal oscillator with a thermostatic bath capable of further stabilizing an output frequency by reducing thermal influence from the outside. SOLUTION: Disclosed is a crystal oscillator with a thermostatic bath in which a substrate 11 is fixed onto a base 16. This oscillator includes: an oscillation circuit 12 mounted on the substrate 11; a heater resistance 13; a power transistor 14; pins 15 for fixing the substrate 11 onto the base 16 with a predetermined interval; metallic cover 17 covering the oscillation circuit 12, the heater resistance 13, and the power transistor 14; and a resin-made cover 18 covering the outside of the metallic cover 17. An air layer is provided between the metallic cover 17 and the resin-made cover 18.

A high resolution biosensing system for detecting and identifying a biochemical material to be tested by using proportional relationship between frequency variation of oscillation and mass of the biochemical material to be tested comprises a biosensor: all oscillator for generating oscillation based on the sensed result, a phase-lock loop circuit receiving the oscillation of the oscillator and generating pulse signals; an ultra-high frequency counter for counting the Bulb; signals; and a microprocessor for storing and displaying output from the ultra-high frequency counter and for controlling the oscillator. The phase-lock loop circuit generates the pulse signals of a frequency, which is n times the frequency of the oscillator and with a constant phase difference therebetween to trigger the ultra-high frequency counter. Accordingly, the resolution can be raised up to n times.

The invention relates to a laser regeneration amplifier switch, comprising a first photoelectric switch, a second photoelectric switch, an isolator, a first polarizer, a second polarizer, a 1/2 wave plate and a first reflector. The first photoelectric switch is located in an optical channel between the first polarizer and the second polarizer, and the second photoelectric switch is located in an optical channel between the second polarizer and the first reflector. In the invention, the position of the first photoelectric switch in the optical channel is changed to remove one photoelectric switch in comparison with that in the prior art, thereby the amount of the photoelectric switches in the optical channel is reduced and the system stability is improved under conditions that the laser output pulse is ensured to be a single pulse and the laser with stable frequency and high contrast is output.

The invention discloses an RC oscillator with stable frequency, which is an RC oscillator with low temperature drift and high power supply rejection ratio, has the characteristics of simple structure, small influence by temperature and power supply voltage and stable frequency, and comprises a reference generation circuit used for generating fixed bias current and bias voltage, and the bias voltage is generated by the bias current flowing through a bias resistor; an oscillation generating circuit is used for generating a periodic signal of which the frequency is only related to the resistance and the capacitance by utilizing the reference of the reference generating circuit; a feedback adjustment circuit is used for adjusting the comparison reference voltage of the comparator according to the time delay change of the comparator in the oscillation generation circuit and eliminating the influence of the time delay of the comparator; a logic circuit is used for receiving a signal of the oscillation generation circuit and controlling switching of a switch in the oscillation generation circuit to generate a periodic clock signal; a reference generation circuit is connected with the oscillation generation circuit, the oscillation generation circuit is connected with the logic circuit, and the feedback adjustment circuit is connected with the oscillation generation circuit.

The invention relates to the field of micro-grids, and in particular relates to a voltage source inverter control method applied to the grid connection mode of a micro-grid system. The micro-grid system comprises a number of power generating units. Each power generating unit uses a voltage source inverter, and is connected with a public grid through a fixed connection impedance. The method comprises the steps that the reference angular frequency omega r.k of the k-th control period is calculated during the k-th control period; the angular frequency omega o.k and the effective value Vo.k of theoutput voltage in the k-th control period are calculated; according to the angular frequency omega o.k and the effective value Vo.k, the reference voltage Vref of an inverter is calculated; the output voltage of the voltage source inverter is controlled according to the reference voltage Vref, so as to control the output active power Po and reactive power Qo of the voltage source inverter; and the output active power Po of the voltage source inverter is equal to the active power Pref of the reference output of the voltage source inverter, and the output reactive power Qo of the voltage sourceinverter is equal to the reactive power Qref of the reference output of the voltage source inverter.