423 results about "Frequency reduction" patented technology

Entropy coding and decoding techniques are described, which may be implemented separately or in combination. For example, a video encoder uses two-layer run level coding to reduce bitrate for frequency transform coefficients in a quick and efficient manner, and a video decoder uses corresponding two-layer run level decoding. This two-layer coding/decoding can be generalized to more than two layers of run level coding/decoding. The video encoder and decoder exploit common patterns in run level information to reduce code table size and create opportunities for early termination of decoding. Using zoned Huffman code tables helps limit overall table size while still providing a level of adaptivity in encoding and decoding. Using embedded Huffman code tables allows the encoder and decoder to reuse codes for 8×8, 8×4, 4×8, and 4×4 blocks.

The invention discloses a method and device for adjusting the running frequency of an air conditioning compressor as well as an air conditioner. The method comprises the following steps: during the process of frequencyincreasing, determining afrequencyincreasing speed according to the frequencydifferencevalue of the preset target running frequency and the current running frequency, and increasingthe current running frequency at the frequencyincreasing speed; during the process of frequency reduction, judging whether the cause offrequency reduction is protective frequencyreduction or non-protective frequencyreduction, if the cause of the frequency reduction is protective frequencyreduction, running according to the preset frequency reduction speed, if the cause of the frequency reduction is non-protective frequencyreduction, determining a frequency reduction speed according to the temperature difference valueof the set temperature of the compressor and the indoor environment temperature, and reducing the current running frequency at the frequencyreduction speed. By adopting the method and the device provided by theinvention, that the variable-frequency air conditioner is controlled at different speeds according to frequency ranges during the frequency increasingand reduction processes is realized, that the frequency increasing and frequency reduction are performed more stably is ensured, and fluctuation of noises is reduced, therefore, the effect of increasingthe comfortof the air conditioner is achieved.

A jittering frequency control circuit and method for a switching mode power supply enlarge the uttering frequency range of the switching frequency of the switching mode power supply when the switching mode power supplier enters a frequency reduction mode, to improve the electro-magnetic interference of the switching mode power supply operating with the frequency reduction mode.

A cross-coupled differential MOS oscillator having reduced phase noise is applicable to a RF communication device such as a transmitter or receiver. The oscillator having low phase noise is formed of a frequency dependent amplifier to amplify a signal having a fundamental frequency; a frequency dependent feedback device that is connected between an output of the frequency dependent amplifier and an input of the frequency dependent amplifier to feed a portion of an amplified signal having the fundamental frequency to an input of the frequency dependent amplifier to stimulate oscillation; and a attenuating device in communication with the frequency dependent amplifier. The attenuating device reduces the gain of the frequency dependent amplifier for signals having frequencies much, much less than the fundamental frequency to decrease the phase noise.

The invention discloses an online monitoring system and a method for partial discharge of an intelligent switch cabinet based on ultra-high frequency detection. The online monitoring system comprises a sensor unit, a signal conditioning unit, a MCU (Micro Control Unit) unit, a communication unit, a system power supply and an upper machine monitoring unit. The online monitoring method comprises the following steps that: the sensor unit finishes collection of partial discharge signals in the switch cabinet; the signal conditioning unit realizes amplification, filtering, frequency reduction and bias of the signals, thus obtaining signals which can be converted by an ADC (Analog to Digital Converter) module in a DSP (Digital Signal Processor); the MCU unit realizes analysis and procession of the signals; and data are uploaded to an upper machine in a monitoring room through an Ethernet. According to the online monitoring system and the method for the partial discharge of the intelligent switch cabinet based on the ultra-high frequency detection disclosed by the invention, collection and procession of high-frequency signals conducted by the DSP are realized by adopting a frequency spectrum shifting technology; a time-frequency analysis technology and a mode identification theory are applied to the monitoring system, therefore, the monitoring system is functional in fault diagnosis; and in addition, an IEC61850 standard is adopted by the system, consequently, management of various IEDs (Intelligent Electronic Devices) and interconnecting as well as networking of equipment in a transformer substation are convenient.

The invention discloses an air conditioner, and a control method and a control device of the air conditioner. The method comprises the following steps: an input voltage effective value and an input current effective value of the air conditioner are acquired; whether the air conditioner is in a power supply voltage dropping state is judged according to the input voltage effective value; if the air conditioner is in a power supply voltage dropping state, then whether the input current effective value is greater than a first current threshold is judged; and if the input current effective value is greater than the first current threshold, target running frequency of a compressor is reduced, and the running frequency of the compressor is controlled to reach reduced target running frequency at a first frequency reduction rate so as to allow the air conditioner to enter a rapid frequency reduction mode, wherein the first frequency reduction rate is greater than a normal frequency reduction rate of the compressor. Thus, when power supply voltage drops, the compressor is controlled to be subjected to rapid frequency reduction to allow a system to continue to operate, and a situation that the user experience is affected due to outage caused by the fact that overcurrent protection is triggered by too high input current resulting from voltage drop is prevented effectively.

The invention discloses a frequency conversion air conditioner and a stop control method and a stop control device for a compressor of the frequency conversion air conditioner. The method comprises the following steps: acquiring current operating frequency of the compressor when a stop instruction is received by the frequency conversion air conditioner; judging a frequency reduction interval to which the current operating frequency of the compressor belongs; and acquiring a corresponding frequency reduction rate according to the frequency reduction interval to which the current operating frequency of the compressor belongs, and reducing the operating frequency of the compressor according to the acquired frequency reduction rate until the operating frequency of the compressor reaches preset stop frequency. The method is capable of performing section-by-section linear frequency reduction on the compressor at a preset frequency reduction rate when the stop instruction is received by the frequency conversion air conditioner, and the compressor stops operating after the operating frequency of the compressor reaches the preset stop frequency, and therefore tubing vibration and stress at the stop moment of the compressor are reduced, danger that tubing is broken is avoided, and system reliability is increased.

The invention belongs to the technical field of air conditioner controlling and provides a frequency-conversion air conditioner operation control method and device. The frequency-conversion air conditioner operation control method includes: acquiring a frequency threshold; judging whether a shutdown instruction is received or not during operation of a compressor, and judging whether current operation frequency of the compressor is larger than the frequency threshold or not when the shutdown instruction is received; if yes, reducing operation frequency of the compressor according to preset frequency reduction rate and continuously judging whether the current operation frequency of the compressor is larger than the frequency threshold or not, if not, controlling an inverter to stop outputting. Therefore, the operation frequency of the compressor can be sustained in the preset frequency threshold during shutdown, problems about voltage overshoot of a direct-current bus and overlarge stress impact upon a system pipeline when the compressor is shut down during high-frequency operation are solved, reliability of the high-frequency-conversion air conditioner can be beneficially improved, and service lives of internal electronic devices and cooling/heating system components of the frequency-conversion air conditioner can be favorably prolonged.

An apparatus for dynamically adjusting power consumption of a CPU in a computer system is described. A current flowing through the limiting resistor is detected and whether or not this current is larger than a predetermined current is determined. A warning signal is issued when the current is larger than this predetermined signal. The warning signal triggers the software framework and the hardware framework of the apparatus to issue an asynchronous operation frequency reduction instruction to the CPU of the computer system.

A signal processing method for performing hierarchical empirical mode decomposition (H-EMD) and an apparatus therefor are provided. In an embodiment, when empirical mode decomposition is performed on an input signal, an artificial assisting signal and the input signal are combined to assist the search for extrema and frequency reduction is performed in each iteration to eliminate the artificial assisting signal and make mode decomposition convergent so as to avoid mode mixing. In addition, in an embodiment, a hierarchical decomposition method is provided to decompose the input signal into a fewer number of fundamental modes. For needs in application, one of the fundamental modes can be further decomposed to produce a number of supplementary modes. In an embodiment, the H-EMD with appropriate frequency reduction can result in modes substantially independent of the form or the way of envelopes and can be applied to decompose multi-dimensional signals.

The invention belongs to the field of communication, and provides a temperature control method of a mobile terminal and a mobile terminal. In the embodiment of the present invention, the surface temperature and the current ambient temperature of the mobile terminal are first obtained, and the running memory ratio of the mobile terminal and the real-time running frequency of the mobile terminal are detected. When it is greater than the preset temperature threshold, the operating frequency of the mobile terminal is reduced according to the design method, and the temperature of the mobile terminal will decrease after the frequency of the mobile terminal is reduced. After the first preset time has passed, the surface temperature of the mobile terminal is detected again. When the re-detected surface temperature is greater than the current ambient temperature, the application program with the largest memory usage is inquired and the user is prompted to close the application program, so that the mobile terminal can further reduce the temperature, avoid scalding the user, and improve the user experience.

A method for tracking GPS signal carrier wave with high sensitivity includes enabling to eliminate phase estimation error caused by data modulation when carrier wave loop is quickly restrained by making selection on frequency-lock ring frequency detection algorithm in carrier wave tracking loop and phase-lock loop phase detection algorithm, enabling to raise sensitivity of receiver and to decrease tracking error of low frequency by utilizing software to carry out FIFO buffer treatment on output value of correlator in each stage of carrier-wave track.

The invention relates to a chemical washing method of reverse osmosis, which belongs to industrial wastewater processing technologies. The method which comprises four links of pickling, coarse alkali washing, fine alkali washing, and sterilization washing is characterized in that: a pickling washing agent added in the pickling link is citric acid with the weight of 120kg; an alkali washing agent added in the coarse alkali washing link is a mixture containing 60kg of sodium hydroxide and 6kg of sodium dodecanesulphonate, or a mixture containing 60kg of disodium ethylenediaminetetraacetate and 6kg of sodium dodecanesulphonate; and an alkali washing agent added in the fine alkali washing link is a mixture containing 50kg of MCT511, 30kg of disodium ethylenediaminetetraacetate, and 6kg of sodium dodecanesulphonate. The method of the present invention which allows organic pollutants and biomembrane scale deposits to be effectively washed has the advantages of system operation cost reduction, reverse osmosis membrane replacing frequency reduction, and resource saving.

The invention discloses a temperature control method of an intelligent power module and a frequency conversion device. The method comprises the steps that the inner temperature Tc of the intelligent power module is detected; when the temperature Tc approaches a set safety threshold Tmax, the output frequency of the intelligent power module is controlled to descend or the current frequency is maintained, so that the rise of the temperature of the intelligent power module is limited. According to the temperature control method of the intelligent power module, frequency rise limitation motion or frequency reduction motion is conducted before the inner temperature of the intelligent power module reaches the protecting detection temperature, so that the temperature of the intelligent power module is controlled in a safe range all the time without protecting detection, the intelligent power module is operated stably at the safe and reliable temperature, meanwhile, the consistency of system operation is guaranteed, and the use comfort of frequency conversion household appliance users is improved.

There is provided an apparatus for measuring the characteristics of an optical fiber in which a frequency difference between first and second coherent light respectively generated by first and second light sources can be accurately set and wherein preferable coherent detection can be carried out in accordance with frequency components of returned light. First coherent light at a frequency f1 is converted into a pulse light which is output to the optical fiber to be measured. The characteristics of the optical fiber are measured by multiplexing returned light from the optical fiber to be measured and second coherent light at a frequency f2 and by detecting the multiplexed light. A component |f1-f2| is detected from an optical signal obtained by the multiplexed light and is mixed with a signal at a frequency fr to decrease the frequency. An electric signal at a voltage level corresponding to a differential frequency |f1-f2|-fr included in the mixed signal is generated, and a predetermined voltage level is generated which corresponds to a set value for an optical frequency difference between the first and second coherent light. The second light source is driven based on the difference between the two voltage levels to correct the frequency of the second coherent light.

The invention discloses a processor and the frequency reducing device and method. And the frequency reducing device comprises a multi-bit state converter, a multichannel selector, a frequency reduction coefficient register, and a gated clock circuit, where the frequency reducing device receives original clock and real-timely reads value of the frequency reduction coefficient register, and gates the original clock, so as to complete a function of reducing frequency of original clock. And it can implement a function of dynamically reducing frequency of processor kernel by simple digital logic circuit and at very low cost and the frequency reduction has features of small spacing granularity and high real-timeness, thus completely applying to various universal processors, embedded processors and SOC to achieve the purpose of reducing average operating power consumption of processors and saving electric energy.

The invention relates to an adaptive inertia damping comprehensive control method for a virtual synchronous generator. The frequency fluctuation cycle after the traditional virtual synchronous generator is disturbed is segmented to four intervals, and adaptive inertia damping comprehensive control based on the segmentation is realized. The virtual inertia is increased adaptively within the first interval and the third interval with frequency disturbance, and in the rest intervals, the initial virtual inertia values are kept unchanged; and the virtual damping is increased adaptively within thesecond interval and the fourth interval, and in the rest intervals, the initial virtual damping values are kept unchanged. Compared with the prior art, the method of the invention realizes interleaving control on the virtual rotating inertia and the virtual damping, the problem of frequency stability after disturbance of the virtual synchronous generator grid-connected system can be effectively improved, and the frequency adjustment time is shortened while the frequency overshoot is reduced.