自动频率控制

Based on the analysis, a new AFC system based on self-optimizing control is proposed with the experience of experts.

本文中简要分析锁相型自动频率控制系统的基本原理及其在实际应用当中遇到的问题，进而提出了一种新型的基于反射波极小值的AFC系统，并对其原理进行了深入的剖析。

A power ultrasonic supply ,which can realize zero phase difference frequency tracing and fixedness of output power,is presented in this paper.

本文介绍了一种具有无相差频率自动跟踪和输出功率恒定功能的功率超声电源，此电源采用集成锁相环来实现无相差自动频率跟踪，采用 PWM方式控制 BUCK电路的斩波，达到恒功率及功率可调的目的。

For this reason, an optimal automatic timing control algorithm is proposed, that can restrain the switching frequency in a certain range to achieve the purpose of high efficiency and energy conservation. Taking such factors as inductive reactance at AC side, switching frequency, harmonic distortion rate and switching loss as well as the interaction among them into consideration, the formulas for inductive reactance and switching frequency are given; then by use of digital signal processor TMS320F2812, a prototype based on the proposed algorithm is implemented, and using this prototype the effectiveness and practicality of the proposed method are verified by experimental research and simulation.

文章提出了自动定时控制的优化算法，将开关频率限定在一定范围内，以达到高效节能的目的；综合考虑交流侧感抗、开关频率、谐波畸变率和开关损耗等指标，提出了主电路电感参数和开关频率的选择公式，并采用TMS320F2812数字信号处理器构造了试验样机，进行仿真和试验研究，其结果证明了该方法的有效性和实用性。

A invariable -angle control circuit of parallel resonance converter which can get high precise control of inverter operating state is designed. Using the technique of phase-lock loop, the circuit implements automatic tracking to inverter operating frequency and constant control of capacitive power factor angle.

论文设计了能在频率自动跟踪的基础上实现高精度的逆变器运行状态控制的并联型逆变器定角控制电路，该电路采用锁相环技术，实现了逆变器工作频率的自动跟踪和容性功率因数角恒定控制。

The interface circuit has five main functions:(1) To processes signals from photo detectors in the 899 laser head and our wavemeter.

自动扫描控制软件主要功能为测量波长、控制自动扫描、在扫描过程中等频率间距采集光谱数据。

Based on the idea of SOC, this receiver merges some function modules in a FPGA, such as digital downconverter, digital matched filter, digital dispreading and demodulation, demodulation and auto frequency control.

基于片上系统的设计思想，该接收机整合了数字下变频器、数字匹配滤波器、数字解调解扩、自动频率控制等功能模块。

In view of these shortcomings, this frequency meter has made the radical innovation in the design, its merit is: Uses the core component is the advanced monolithic special-purpose frequency measurement component -- monolithic frequency meter, the integration rate is high, the volume is small, consumes the electricity province, function, has realized the frequency meter high integration and the microminiaturization; So long as the monolithic frequency meter adds on the crystal oscillator, the measuring range choice, the frequency demonstrated and so on the very few components then constitute DC to the 10MHz miniature basic frequency measurement electric circuit; But the biggest merit was this frequency meter has realized monolithic frequency meter, frequency sampling electric circuit and the monolithic microcomputer three between hardware and the software connection completely, caused the frequency measurement measuring range the choice, the frequency data survey, the sampling as well as the code frontier transformation and the data dump possible monolithic microcomputer software programming automatically to carry on, thus has realized the frequency measurement and the sampling work intellectualizes completely, causes this system already to be possible to constitute a miniature intelligence to measure rate the instrument core electric circuit independently, also might take in the large-scale automatic control or a test system intelligent subsystem.

针对这些缺点，本频率计在设计上作了根本的革新，其优点是：所用核心器件是先进的单片专用测频器件——单片频率计，集成度高，体积小，耗电省，功能强，实现了频率计的高度集成化和微型化；单片频率计只要加上晶振、量程选择、频率显示等很少量的器件即可构成一个DC至10MHz的微型基本测频电路；而最大的优点则是本频率计完全实现了单片频率计、频率采样与单片微机三者之间的硬件与软件接口，使得测频量程的选择、频率数据的测量、采样以及编码的边境转换和数据的转储均可能过单片微机的软件编程自动进行，从而实现了测频与采样工作的完全智能化，使得本系统既可独立构成一个微型智能测率仪器的核心电路，也可作为大型自动控制或测试系统中的一个智能子系统。

In view of these shortcomings this frequency meter has made the radical innovation in the design its merit is: Uses the core component is the advanced monolithic special-purpose frequency measurement component -- monolithic frequency meter the integration rate is high the volume is small consumes the electricity province function has realized the frequency meter high integration and the microminiaturization; So long as the monolithic frequency meter adds on the crystal oscillator the measuring range choice the frequency demonstrated and so on the very few components then constitute DC to the 10MHz miniature basic frequency measurement electric circuit; But the biggest merit was this frequency meter has realized monolithic frequency meter frequency sampling electric circuit and the monolithic microcomputer three between hardware and the software connection completely caused the frequency measurement measuring range the choice the frequency data survey the sampling as well as the code frontier transformation and the data dump possible monolithic microcomputer software programming automatically to carry on thus has realized the frequency measurement and the sampling work intellectualizes completely causes this system already to be possible to constitute a miniature intelligence to measure rate the instrument core electric circuit independently also might take in the large-scale automatic control or a test system intelligent subsystem.

摘要传统的测频仪器体积很大，耗能量大，主要靠手工操作，而最大的缺点是不可编程，其量程转换、数据测量、采样控制和处理等均不能通过程序指令来进行控制，无法作为一个微型智能子系统与某一大型自动控制或测试系统进行接口。针对这些缺点，本频率计再设计上作了根本的革新，其优点是：所用核心器件是先进的单片专用测频器件——单片频率计，集成度高，体积小，耗电省，功能强，实现了频率计的高度集成化和微型化；单片频率计只要加上晶振、量程选择、频率显示等很晌慰的器件即可构成一个DC至10MHz的微型基本测频电路；而最大的优点则是本频率计完全实现了单片频率计、频率采样与单片微机三者之间的硬件与软件接口，使得测频量程的选择、频率数据的测量、采样以及编码的边境转换和数据的转储均可能过单片微机的软件编程自动进行，从而实现了测频与采样工作的完全智能化，使得本系统既可独立构成一个微型智能测率仪器的核心电路，也可作为大型自动控制或测试系统中的一个智能子系统。关键词高度集成化，单片机，频率计，电路

Telephone Features: 5.8 GHz, 40 Channel AutoScan, 40 Name/Number Personal Directory, Compander Circuitry Filtered Sound, Digital Security Code, Handset Volume Control, In Use Indicator, Battery Low Indicator, Out of Range Indicator, Automatic Standby, Paging From Base to Handset, Flash, Last Number Redial/Pause, Tone/Pulse Switchable, Hearing Aid Compatible, Ringer On/Off Switch, Headset Jack, Removable Belt Clip, Desk/Wall Mountable.

厂商：爱默生描述/特点：电话特点：5.8千兆赫，40频道自动频率，40名/若干个人电话簿 compander声过滤电路、数字安全码，手机体积控制，使用指标，电池低标志，出于各种指标，自动待命，从基地到手机的寻呼、闪电、数量上径向/稍停，语调/脉冲切换，助听器兼容，对林格/转客，杰克耳机、皮带夹撤职、书桌/墙mountable。

Based on these design guides, the analysis and design of a low phase noise and low power dissipation, with 0. 18μm CMOS process, integrated Colpitts crystal oscillator with automatic gain controlled feedback loop as the amplitude-limiting technique, low dropout voltage regulation with band gap reference voltage and frequency tuning monotonicity guaranteed by digitally controlled variable capacitor array is performed to revise influence caused by process, voltage and temperature conditions for. handset. The oscillation with very stable amplitude value and frequency value is achieved.

它利用对工作温度、电源电压和制造工艺不敏感的带隙基准源和在集成电路中元件特性之间匹配好的优点产生了一个不随温度、电源和工艺改变而且可以跟踪工艺变化的参考基准电压，同时通过自动频率控制环路利用数字电路控制可变电容阵列控制瞬态频率稳定度，校正温度、电源和工艺改变对频率的影响，从而可以在很宽的电源电压范围(2.7v—3.7v)和温度范围(-40℃—125℃)以及CMOS工艺参数变化(TT、FF、SS、SF、FS)的条件下提供幅度稳定、频率稳定的振荡输出信号。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。