频率转换

Ultrasonic is a kind of mechanical wave that frequency is upper 20KHz. Ultrasonic may be generated by many ultrasonic transducers.

超声波是频率高于20KHz的机械波，它可由多种能量转换器转变而成。

This dissertation introduces the whole scheme、the hardware electro circuit design and software design, the result of experiment on salinometer is preferred at the end of the dissertation. Salinometer is base on SOPC technology, and use digital technology to design circuit: the excitation source for balance bridge is generated by digital method, its shape、amplitude and frequency can be control by digital signal, the standard branch of bridge is composed of three digital-analog-conversion, and uses the method of successive approximation to regulate the balance of bridge.

盐度计以SOPC技术为基础，通过数字化方式设计测量电路：电桥的激励源由数字化方式产生，激励源的波形、幅值和频率等可由数字量控制；平衡电桥标准支路由3个数模转换器组合实现，测量时以逐次逼近的方式调整电桥的平衡度；检测电桥平衡度的高灵敏度数字检流计同样以数字化方式设计，它的增益由程序控制，将电桥的输出电压数字化，以软件判断电桥平衡度。

TEMCo Frequency Converter Motor Generator Sets are used for converting power frequency, voltage and phase.

坦科变频调速电动机发电机组是用于功率转换的频率，电压和相位。

The system designed to break the traditional model, First of all, the measurement of the resistivity of components using parameters R consisting of 555 timer Multivibrator transformed into a frequency signal f, Then after counting SCM operations of the resistance R calculated, the final delivery of digital display circuit, the implementation of intelligent measurement.

该系统打破传统的设计模式，首先把要测量的电阻元件的参数R利用555定时器构成的多谐振荡器转换成频率信号f，然后用单片机计数后再运算求出R的阻值，最后送数码显示电路，实现了智能化测量。

In order to improve the amplitudes of the rigid Earth nutation series, it become necessary to revise the IAU 1976 value of the general precession in longitude.

非刚体地球章动的转换函数中所采用的简正模频率和常数都直接或间接地依赖地球动力学扁率值。

The application of oscillograph principle in ultrasonic imaging is based on the electronic oscillograph imaging principle.

示波器原理在超声成像中的应用是以电子示波器的成像原理为基础，通过医用超声换能器将以机械波形式存在的超声波转换成同频率的交变的电信号，将该信号以不同的方式输入示波器中，从而形成了不同方式的超声图像。

Since this connection is usually used at very low switching speeds, slew rate is not normally a practical consideration and overcompensation does not reduce accuracy.

鉴于本电路常用于切换频率很低的场合，转换速率一般不是关键指标，因此过补偿不会降低精度。

The transfer function of the LLC resonant converter can be obtained by using the circuit impedance, ratio of resonant inductance, and quality factor. With proper selection of the resonant tank and modulation of the operation switching frequency, the proposed circuit can achieve zero voltage switching, stabilize the output voltage, and then reduce the switching loss.

其后级之半桥LLC谐振式转换器藉由推导电路阻抗、谐振电感比例值与品质因数得到转移函数，以及利用适当的谐振电路的设计与切换频率的调变的方式达到输出电压稳定，并且令功率开关具有零电压切换之功用，以降低功率开关的切换损失。

For instance took when frequency synthesizer, emphasizes is the switching time, the frequency spectrum purity, took when modem emphasizes is the ring circuit band width and so on.

比如作为频率合成器时，强调的是转换时间，频谱纯度，作为调制解调器时强调的是环路带宽等。

In addition to handling the power exchange, this sophisticated HVDC system can stabilize voltages and frequencies on Sardinia.

除了处理电力转换交流，该复杂的 HVDC 系统还可以稳定撒丁岛的电压和频率。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。