Davidson’s motor

Below is shown an imaginary drawing of Robert Davidson's motor, which is considered to have been produced around 1837 and intended for use in the railway. Davidson likely conceived of this arrangement based on the steam locomotive, which was undergoing rapid development at the time and employs a mechanism in which two pistons drive the axle-wheel assembly. The motive power is derived from the attraction between electromagnets and the repulsion between similar magnet poles is not made use of. While Sturgeon's motor employs switches to reverse the current direction, Davidson's motor uses them to simply turn the current on and off. Today, his motor would be called a multi-phase winding motor.