A permutator is an early, specialized electromechanical machine designed for AC to DC conversion. Unlike standard rotary converters that spin the armature, a permutator keeps the commutator stationary while the brush assembly rotates. The magnetic field is induced directly by the AC supply in a short-circuited core. It was an experimental step in power conversion before solid-state rectifiers made mechanical commutation obsolete.
The museum restored a 1910 permutator to demonstrate early mechanical rectification methods.
Related terms
Rotary converter
An early electromechanical machine used to convert alternating current to direct current.
Commutate
To reverse the direction of electric current in a specific winding or circuit branch.
Commutation
The process of transferring current from one conducting path to another.
Mercury arc rectifier
A historic glass or steel vacuum tube device used to convert high-voltage alternating current into direct current.