Motors and motoring - Tapa blanda

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 Excerpt: ... but if it becomes dim, then the accumulator is exhausted. This test should always be made at the conclusion of a run, as the accumulator is capable of recovering sufficiently while standing to give a fairly bright light for a few moments, even when almost exhausted. As this is a test of current and voltage, it is very reliable, for a reading with a volt-meter testing an open circuit) will sometimes be almost normal, and a fall of voltage occur as soon as current is withdrawn. GOVERNING AND CONTROLLING. 40. One of the most difficult problems the designer of a petrol engine has to deal with, is the governing of its power and speed. He is called upon to arrange its mechanism in such a way that the engine automatically prevents the production of more power in itself than is actually needed for the propukion of the car at any particular speed. To give practical effect to this condition, designers have exercised their ingenuity in a variety of ways, but they have a more difficult task to deal with in the petrol engine than in either the steam engine or ordinary gas engine, as we shall see directly. It is easy to make arrangements to enable the driver to control1 the engine; and as these arrangements have much in common with those employed in governing, we may proceed to explain that the amount of useful work done by a petrol engine during a cycle can be varied in several ways, the following being the best known. (1) Advancing and retarding the ignition, the charge being constant. (2) Advancing and retarding ignition with fluctuating charge. (3) Varying the amount of charge by throttling, the propor tion of the mixture being constant. (4) By throttling the exhaust. In order to grasp the general principles that underlie the working of the first and second methods,...