Text b Analog and Digital Circuits

Analog circuits

Most analog electronic devices, such as radio receivers, have combinations of a few types of basic circuits.

There are a great number of different analog circuits, because 'circuits' are very different - from a single component, to systems with thousands of components.

Good examples of analog circuits are vacuum tube and transistor amplifiers, operational amplifiers and oscillators.

Modern circuits are very seldom only analog. Electronic devices usually have analog and digital circuits. In this case they are ‘mixed’ rather than analog or digital.

Digital circuits

Digital circuits are electric circuits with a number of discrete voltage levels.

Digital circuits are the most common physical representation of Boolean algebraand are the basis of all digital computers.

To most engineers, the terms "digital circuit", "digital system" and "logic" are identical in the context of digital circuits. Most digital circuits have two voltage levels: "Low"(0) and "High"(1). Often "Low" will be near zero volts and "High" will be at a higher level.

Not only computers but electronic clocks, andprogrammable logic controllershavedigitalcircuits in their design.

Задания к тексту B:

I. Найдите в тексте английские эквиваленты следующим русским выражениям:

электронные лампы и усилители транзисторов; радиоприемники; программируемые логические контроллеры; сочетание нескольких типов основных схем; ряд дискретных уровней напряжения; аналоговые электронные устройства; цифровые схемы;

II. Сформулируйте в нескольких словах содержание каждого абзаца.

III. Напишите резюме к тексту.

IV. Ответьте на вопросы:

1. Has the analog circuit only one component?

2. What are the examples of analog circuits?

3. Are modern circuits only analog?

1. What are digital circuits?

2. What are the examples of devices with digital circuits?

3. What are the two voltage levels of digital circuits?

V. Перескажите текст, используя в качестве плана вопросы предыдущего упражнения.