2. Divide the text into logical parts and entitle each part.

3. Answers the questions:

1. Where are feedback controls used?

2. What components does a feedback control system consist of?

3. What term is used to describe this kind of system?

4. What does the input to the system represent?

5. Give an example of the input.

6. Give some examples of the process being controlled.

7. What does the output from the system represent?

8. Give an example of the output.

9. What do the sensing elements represent?

10. Give an example of the sensing element.

11. How does a bimetallic strip function?

12. What is the purpose of the controller and actuating devices?

13. What do the controller and the actuator represent?

14. What devices do these mechanisms consist of?

15. Give an example of the controller and the actuator.

16. How does the switch connected to the bimetallic strip function?

4. Give the characteristics of every component of a feedback control system.

5. Make a short report on the closed-loop feedback control system functioning.

Text 5B

Translate the text in written form using a dictionary:

Process Control

The control of processes in general is a wider extension of the principles used in numerical control of machine tools. Instead of monitoring and controlling solely movement, other parameters such as temperature, time, gas flow, etc. are monitored and controlled. The possibilities are endless, provided suitable transducers exist for the parameters to be controlled. In this case, the more complex the process the more suitable it is for microcomputer control.

Efficient operation of furnaces is an example where energy savings can be substantial when the process is properly controlled. A microprocessor-based system can monitor signals from thermocouples, air flow meters, fuel flow meters and gas analysers, and on the basis of heat loss calculation and furnace efficiency optimize the fuel/air ration.

In an application such as this, it is also possible to collect information of the furnace performance over time. An analysis of this information provides a valuable guide to damage and wear and to establishing the time for appropriate corrective maintenance.

Text 5C

Look through the text and do the tasks below:

Elements of Automation

Automation is the third phase in the development of technology that began with the industrialization of the 18^th century. First came mechanization which created the factory system and separated labour and management in production. Mechanization was a technology based on forms and applications of power. Mass production came next. It was a technology based on principles of production and organization. Automation is a technology based on communication, computation and control.

The truly automated devices must possess one or more of the following elements: system approach, programmability, feedback.

With a system approach, factories which make things by passing them through successive stages of manufacturing without people intervening to transfer lines, which made their debut in car factories before the Second World War, are considered automated systems. These carry components past lines of machine tools which each cuts them automatically. People are not required; the machines clamp the parts out of themselves without a workman being present. Thus transfer lines are different from assembly lines where people are very much in evidence.

With programmability, a system can do more than one kind of job. An industrial robot is an automated machine. It works automatically and an operator can reprogram the computer that controls it to make the machine do different things.

Finally, feedback makes an automatic device vary its routine according to changes that take place around it. An automatic machine tool with feedback would have sensors that detect, for example, if the metal it is cutting is wrongly shaped. If it is, the sensors instruct the machine to vary its routine accordingly. Other examples of devices with feedback are robots with “vision” or other sensors that can “see” or “feel” what they are doing.

1. Translate the title of the text.

2. Formulate the main idea of the text.

3. Choose the main information from every paragraph.

4. Make up the plan of the text.

5. Write down the annotation of the text in Russian.