What a Dynamo!

Dynamo – Electric motor

Henry Sutton invented a continuous current dynamo in 1869, dynamos became one of the most innovative pieces of machinery invented in the 1800’s.

Today dynamos are used only for low voltage items but motors run commercial industry. The dynamo led directly to the first major uses of electricity and revolutionised industry around the world. Domestically motors modernised the world and are used in the home, transport and the workplace.


The dynamo has a long history and was originally invented by Michael Faraday in 1831.

The development of the Dynamo continued and Zenobe Gramme was given the worldwide credit for inventing the first practical dynamo in 1871.

A couple of years before Gramme, 14 year old Henry invented his dynamo and when run in reverse it acted as a motor, a fact Gramme did not discover about his dynamo until 1873.

Henry’s dynamo was an incredible achievement at such a young age it went unnoticed as he did not patent it, history may have been different if he had.

How a dynamo works

A dynamo uses rotating coils of wire and magnetic fields to convert mechanical rotation into a pulsing direct current.

It consists of a stationary structure called the stator, which provides a constant magnetic field. A set of rotating windings called the amature turn within that field.

The motion of the wire within the magnetic field causes the field to push on the electrons in the metal, which creates an electric current in the wire.

The constant magnetic field may be provided by one or more permanent magnets, a commutator is needed to produce a direct current.

A commutator is a rotary switch comprised of a set of contacts mounted on the machine’s shaft.

The commutator reverses the connection of the windings to the external circuit when the potential reverses, so instead of alternating current, a pulsing direct current is produced.