2017-12-14
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An (1) (electrical or emergency) power supply is a device that (2) (provides/releases) energy needed by electrical or electronic equipment. Often (3) (electricity/insulation) is directly available only from a source with (4) (appropriate/inappropriate) electrical characteristics – alternating current (AC) instead of direct current (DC). Power (5) (protective/supply) devices commonly change AC into DC, (6)(raise/reduce) the voltage as required. They are also needed to condition power and current to (7) (insensitive/sensitive) devices. A flashlight, for example, does not contain a power supply, but a (8) (digital/analog) camera does. Power supplies often (9) (ensure /prevent) the protection against power source (10) (failures/restorations) that might damage the equipment. They may also provide (11) (conduction/isolation) from the potentially damaging electrical noise that is usually found on commercial power lines.
12. A role play. Make up the dialogues for the following situations:
a) A safety engineer and a worker are discussing how to work safely with electrical equipment at a plant.
d) A trader who sells electrical equipment is speaking on the phone. He is trying to convince his business partners to buy it.
b) The electrical engineers are investigating the cause of an accident which has happened at a plant.
Power supplies were once called battery eliminators. Why was it an apt name? Prove it.
(The answer is: because they made it possible to use less expensive energy from a commercial power line where it is available).
Video
Before you watch the video, discuss the following questions in pairs:
1) Why is working with electricity dangerous for people?
2) What safety measures should electrical engineers take while working with electrical equipment?
ELECTRICAL SAFETY (VIDEO SCRIPT)
This video shows how to follow the correct procedures for working with electricity, so due to engineer colleagues remain safe.
Electricity can kill.
If you work with or close to any life elements it is essential to take precautions. An electric shock occurs when you come into contact with a life element or a conductor such as water or metal which forms a link between you and an electric device. If you receive an electric shock a current of electricity spread throughout your body. A current of 500 million passing through the heart is fatal, but even low-level current can cause severe burns or lead to other dangers.
