自动化专业英语教学课件ppt作者徐存善Unit41A1课件.ppt

Unit 4 Operational Amplifier Operational Amplifier Operational Amplifier A basic circuit of a 741 inverting amplifier is shown in Fig 5-3. The input signal is fed to the inverting input of the 741 via R1 and therefore the output is inverted in phase with respect to the input. Operational amplifiers are designed to have a very high input impedance. The input currents of the 741 circuit are therefore very small. As the inverting input is virtually at ground potential，the current which flows through R1 is equal to the input voltage ui divided by R3. Similarly，the current flowing through R3 is –u0 / R3. where u。is the output voltage. These two currents are almost equal，thus the voltage gain of circuit is equal to the resistor values G = 自动化专业英语 一、英语动词、形容词、副词译成汉语名词 1. Telecommunications means so much in modern life that without it our modern life would be impossible. 电信在现代生活中意义重大，没有它就不可能有我们现在的生活。 2. The cutting tools must be strong, tough, hard and wear resistant. 刀具必须有足够的强度，韧性，硬度，而且耐磨。 3. Dynamics is divided into statics and kinetics, the former treating of forces in equilibrium, the latter of the relation of force to motion. 力学分为静力学和动力学：前者研究平衡力，后者研究力和运动的关系。 4. The image must be dimensionally correct. 图形的尺寸必须正确。 二、英语名词、介词、形容词、副词译成汉语动词 1. Substitution of manual finishing is one example of HSM application. 替代手工精加工是高速加工应用的一个例子。 2. Scientists are confident that all matter is indestructible. 科学家们深信一切物质是不灭的。 3. In any machine input work equals output work plus work done against friction. 任何机器的输入功，都等于输出功加上克服摩擦所做的功。 4. Open the valve to let air in. 打开阀门，让空气进入。 自动化专业英语 三、英语的名词、副词和动词译成汉语形容词 1. This wave guide tube is chiefly characterized by its simplicity of structure. 这种波导管的主要特点是结构简单。 2. They said that such knowledge is needed before they can develop a successful early warning system for earthquakes. 他们说，这只是对他们要发明的一种有效的地震早期警报是必要的。 自动化专业