In this manner, at every point, the sets of magnets are compelled to move against their magnetic pull. This explains the dynamo.
Now take up the cycle of the motor, and note in Fig. [124] that the negative magnets D of the armature are closely approaching the positive and negative[p. 179] magnets, on one side; and the positive magnets C are nearing the positive and negatives on the other side. The positives A, therefore, attract the negatives D, and the negative B exert a pull on the positives C at the same time. The result is that the armature is caused to revolve, as shown by the dart G, in a direction opposite to the dart in Fig. [120].
When the pole pieces of the magnets C, D are about to pass magnets A, B, as shown in Fig. [125], it is necessary to change the polarities of the armature magnets C, D; so that by reference to Fig. [126], it will be seen that they are now indicated as C-, and D+, respectively, and have moved to a point midway between the poles A, B (as in Fig. [125]), where the pull on one side, and the push on[p. 180] the other are again the same, and the last Figure 127 shows the cycle nearly completed.
The shaft of the motor armature is now the element which turns the mechanism which is to be operated. To convert electrical impulses into power, as thus shown, results in great loss. The first step is to take the steam boiler, which is the first stage in that source which is the most common and universal, and by means of fuel, converting water into steam. The second is to use the pressure of this steam to drive an engine; the third is to drive the dynamo which generates the electrical impulse; and the fourth is the conversion from the dynamo into a motor shaft. Loss is met with at each step, and the great problem is to eliminate this waste.
The great advantage of electrical power is not in[p. 181] utilizing it for consumption at close ranges, but where it is desired to transmit it for long distances. Such illustrations may be found in electric railways, and where water power can be obtained as the primal source of energy, the cost is not excessive. It is found, however, that even with the most improved forms of mechanism, in electrical construction, the internal combustion engines are far more economical.
Transmission of Energy
One of the great problems has been the transmission of the current to great distances. By using a high voltage it may be sent hundreds of miles, but to use a current of that character in the cars, or shops, or homes, would be exceedingly dangerous.