Electric Machine

Al] dynamoelectric machines or generators are based upon discoveries of Faraday, and Henry contemporaneously in 1832, that if a closed wire or conducting ring is moved acro a magnetic space, a current of electricity is generated in the wire. A dynamo-electric generator is the best apparatus devised for the application of this principle to the production of an electric current. A magnetic space is provided between the poles of two or more powerful magnets, and coils of wire are caused to traverse this magnetic space in such a way as to excite a current in them. The stronger ihe magnetism of the space, the longer the wire and the quicker it is moved, the stronger will be the current excited. The aim of invenit ors, therefore, is to construct their machines with powerful magnets and coils of wire having many turns, and to rapidly rotate these coils through the magnetic “ field’? by mounting them on an axle driven by a steam engine or other mechanical! motor. As each coil or bobbin of wire pa es between the poles of the magnet a transient current is generated in it; but as there are a number of bobbins rapidly following each other, each with its transient current, the joint effect of the whole is a practically continuous current. =