This DC generator was built in around 1901 and is based on the 'Lahmeyer principle' of 1887. This device is also called a salient-pole machine, because the field coils project on the outside. This outer element is the stator, the stationary part of the generator. With this new arrangement, very little energy dissipates into the surroundings.
There is a round wheel attached to the shaft on one side which can be driven by a belt. This belt is driven by the power source for the dynamo, such as a steam engine. A copper commutator and carbon brushes are located on the other side. The commutator converts the generated alternating current to direct current. The carbon brushes pick up the current.