(Part 2)

The oil-pressure switch is calibrated to open the contact points above a specific oil pressure. Because oil pressure is largely proportional to engine speed, an idling engine will have normally low pressure, except when used in race cars. The switch is calibrated not to open at idle pressure, which would cause undue concern for the driver. But this characteristic is the major shortcoming of the oil-pressure-lamp system. The difference between normally low idle pressure and dangerously low operating pressure is narrow.

As a result of this narrow margin, many engines have been ruined because a warning lamp didn’t come on until too late. For example, an air-cooled VW engine pump holds less than 3 quarts of oil. If a VW engine develops a gasket leak, all the oil will drain in less than 200 miles of driving. The oil-pressure lamp comes on just in time to announce a completely fried engine!

Of the three primary indicator lamps, this is the only one that operates without a separate switch. When you first start your car, the generator needs an external supply of current to get itself started, this is called excitation. Current, provided by the battery through the ignition switch, flows through the charge-indicator lamp on its way to excite the field windings in the generator. Naturally, with current flowing, the lamp lights, as soon as the generator begins generating current on its own, the voltage regulator allows some of this current back to self-feed the generator to keep it excited. When this happens, the indicator lamp goes out because it now has B+ on both sides, and current can no longer now pass through it.

There’s usually a resistor of about 15 ohms in parallel with the lamp. It carries a large percentage of the current necessary to excite the generator, allowing the lamp to carry a much smaller load. So, if the lamp filament burns out, the 15-ohm resistor is still in the circuit to carry current to the generator.

Size, brightness, and the period of time available for observation are all important considerations when choosing indicator or warning lamps. Lamp colours that most quickly attract attention are: red, green, yellow and white.

In addition to lamp colour, background colour and the amount of ambient light also affect visibility. Obviously, even a red lamp is not going to stand out well against a red instrument panel on a bright, sunny day. So consider these points: for best visibility, choose a lamp colour that contrasts with its background. If the lamp has good contrast with the background, and ambient light is very bright, the warning-lamp color is less important than its relative brightness. When contrast between lamp and back-ground is not strong, follow the colour order just listed above for best delectability.

Exercises Unit 8 (text b)

A malfunction indicator lamp (MIL), also known as a check engine light, is a tell-tale to indicate malfunction of a computerized engine management system. It is found on the instrument panel of most automobiles. When illuminated, it is typically either an amber or red color. On vehicles equipped withOBD-II, the light has two stages: steady (indicating a minor fault such as a loose gas cap or failing oxygen sensor) and flashing (indicating a severe fault, that could potentially damage the catalytic converter if left uncorrected for an extended period). When the MIL is lit, the engine control unit stores a fault code related to the malfunction, which can be retrieved with a scan tool and used for further diagnosis. The malfunction indicator lamp usually bears the legendcheck engine, service engine soon, or a pictogram of an engine. In the United States, specific functions are required of the MIL by EPA regulations.^[1]

The MIL appeared in the early 80s along with computerized engine controls. Even the earliest systems, such as GM's CCC (Computer Command Control) system had self diagnosis functionality. When the computer detected a fault, it illuminated the MIL. Up until OBDII, on most cars the MIL could output codes, when two pins on the ALDL are jumped, the light would flash the codes, for instance (blink) (pause) (blink) (blink) for code 12. Some manufacturers, such as Honda, retained this feature even after OBDII.

Complete the sentences using the suitable word from brakes.

1. ...the general development of new technological methods the foundry industry is rapidly advancing, (in most cases, owing to) 2. ...this general development the quality of castings has greatly improved, (in case, because of) 3. ...castings are produced in sand molds, (owing to, in most cases) 4. ...castings are used as details and component parts of complex machines and mechanisms, (in most cases, because of) 5. ...castings must be machined and finished to specified manufacturing tolerances, (owing to, in this case)

Complete the sentences using the suitable word from brakes.

1. The tyres are made using a basically new casting moldings, which results in weight reduction and 5% fuel ... (economy, accuracy, complexity).

2. This new type of the wheel consists of a ... (wasted, cast, joined) aluminium disk and rim edges.

3. The parts made from polymers give four times weight reduction and require little ... (saving, machining, defining).

4. A typical form of are ... (casting, foundry, furnace) has three electrodes.

5. ... (in most cases, equally, owing to) the ignition, the gas in the cylinder expands.

6. In the ... {lathe, milling machine, turning machine) the tool is fixed and the work is moved to and fro against it.

7. ... (the headstock, the spindle, the saddle) rotates in the bearings.

8. This new method of casting aluminium parts results in dimensional ... (surface, accuracy, linkage) of production.

9. The more complex the functions of... (joining techniques, tolerance, facing), the heavier the demands are met by the operator.

10. A newly designed machine should be tested for... (quality, welding, assembly) in the first place.

Translate into Ukrainian paying attention to the meaning of which.

1. Every Volkswagen had а network of sensors leading to one central socket which can report the operating condition of parts in your VW directly to you. 2. The KAMAZ is incorporating six specialized enterprises which are known to the industrialized world. 3. The engineers design, build and test cars, which makes every new car durable and reliable. 4. All of the car equipment will be checked for operation in a short test run after which the car will return to the plant to undergo finishing operations. 5. Titanium is light, strong and corrosion resistant which makes it one of the most useful structural materials. 6. In testing grounds there are many stretches of roads which are built on the principle “the worse the better”. 7. Science Weeks are usually held simultaneously with student scientific and technical conferences during which students are presented diplomas and prizes.

Match two parts to make up a sentence.

1. Most automotive engines operate...

2. This cycle comprises: ...

3. The first stroke starts with the piston...

4. The fuel mixture in the cylinder is compressed and ignited...

5. The piston is pushed downwards...

6. The crankshaft rotates...

7. Thus power...

8. The burnt gases are expelled...

9. The flow of gases into and out of the cylinder is controlled by two valves:...

a) through 180°.

b) the inlet valve and the exhaust valve.

c) from the cylinder,

d) on the four-stroke cycle.

e) is produced,

f) at t.d.c.

g) by the burnt gases.

h) by the spark plug.

i) the induction stroke, the compression stroke, the power stroke and the exhaust stroke.

Make up the questions of all types to the text.

State the forms and functions of the Participles; translate the following sentences into Ukrainian.

1. The experiment being made at our laboratory shows the action of catalysts. 2. The temperature used depended upon the substances entering the reaction. 3. The figures following show the dependence of the rate of reaction on temperature. 4. Efforts being made in the development of chemical industry meet with great success. 5. The success achieved in the development of industry resulted in a considerable growth of the well-being of the people. This does not mean, however, that we can be satisfied with the results obtained. 6. Science has opened out possibilities for the conquest of nature hardly dreamed of a few years ago. 7. The experiments referred to in our article demonstrate the action of catalysts in chemical reactions. 8. The substance acted upon by heat changed its composition. 9. The molecules of a substance affected by a catalyst are changed more easily. 10. This reaction, when completed, will give us a new proof of the use of catalysts in living systems.

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