Ignition system

Ignition system in a gasoline engine, means employed for producing an electric spark to ignite the fuel-air mixture; the burning of this mixture in the cylinders produces the motive force.

The basic components in the ignition system are a storage battery, an induction coil, a device to produce timed high-voltage discharges from the induction coil, a distributor, and a set of spark plugs.

The storage battery provides an electric current of low voltage (usually 12 volts) that is converted by the system to high voltage (some 40,000 volts). The distributor routes the successive bursts of high-voltage current to each spark plug in the firing order.

In older automobile ignition systems, the high-voltage pulses are produced by means of breaker points controlled by a revolving distributor cam. When the points are in contact they complete an electrical circuit through the primary winding of the ignition coil. When the points are separated by the cam, the primary circuit is broken, which creates a high-voltage surge in the secondary windings of the induction coil.

Breaker points have been largely replaced by electronic devices in newer automobiles. Most now use a magnetic device, called a reluctor, that is operated by the distributor shaft to produce timed electric signals, which are amplified and used to control the current to the induction coil. These newer ignition systems are more reliable than the old, permit better control of the engine, and produce higher-voltage output to the spark plugs.

During the evolution of solid-state ignition systems, there have been many modifications. Some ignition conversion systems, for example, extend breaker-point life by using transistors, devices in which a small current in the input (the breaker-point circuit) controls a much larger current in the output (the coil primary circuit).

II. Look through the text again and answer the following questions:

1. How do you understand the term “ignition system”? What is it?

2. What are the basic components of the ignition system?

3. What way were the high-voltage pulses in the old automobiles produced?

4. What magnetic device is used in modern automobiles?

5. Why are the new ignition systems more reliable than the old ones?

III. Match the words with their definitions and make up your own sentences with these words:

1. mixture a) a transient, sharp change in voltage, current;

2. to produce b) to act as a barrier between smth.;

3. device c) a constituent part of smth. more complex;

4. pulse d) a small change or adjustment;

5. to separate e) to bring smth. into existence;

6. distributor f) first in importance, degree, rank, etc.;

7. winding g) a substance consisting of two or more substances;

8. component h) a machine or tool used for a specific task;

9. modification i) a curve or bend in a material;

10. primary j) the device that distributes a high-tension voltage;

IV. Find information about the application and function of ignition systems. While looking for information you are free to use the internet sites given below as well as any other online resources.

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