The object, therefore, is to change the battery pressure on the one hand, and to produce the most effective action on the other hand, at the motor, and to do so make both battery and motor more efficient.
The Controller.—The device which performs this operation, at the will of the operator, is called the Controller, which changes the wiring connection from series to multiple, or the reverse.
The Controller is, in all probability, the most complicated piece of mechanism in the entire electric car. It must make an entire series of changes for each of the different speeds, of which there are frequently six.
The fields of the motor are also connected in series, or both series and multiple, so as to give a still greater efficiency. By this means the terminal points of the Controller may be turned, (1), so they will connect the batteries in multiple and the field windings in series; or, (2), the batteries in multiple and the fields in series multiple; or, (3), the batteries in series and the fields in series; or, (4), the batteries in series and the fields in multiple.
The figures in parentheses indicate the first, second, third and fourth speeds, respectively, and in such an arrangement two battery units are used, and also two motors.
The same rule as to efficiency applies with one motor, and two or more battery units. The battery unit may be of any desired number of cells, as stated.
The General Equipment.—Cars for pleasure purposes are of different types, such as runabouts, roadsters, victorias, coupés, broughams, and the like, provided with batteries which will permit runs of at least 100 miles on each charge.
Speeds.—The Controller will permit of speeds ranging from five to thirty miles an hour. The number of cells vary with different makes, from twenty to forty, and the number of plates in each cell average about fifteen.
It will thus be seen that the operating limit is wide enough to permit considerable latitude; but recharging stations are now found everywhere, particularly in the cities, and in the large towns.
Accessories.—A fully-equipped electric, designed for the greatest luxury and comfort, has two head lamps, two side, and a tail lamp, and one in the interior, a lighting switch to control all the lights, a ventilator, voltammeter, shaft odometer, for showing speed and distance traveled, complete outfit of tools, novelty toilet set and case, cut glass flower vase, eight day clock and mirrors suitably arranged within the body.