Abstract :
The paper describes a commutatorless alternating-voltage-fed motor which can be used on single- or multiphase supplies. The speed is varied and the motor readily reversed without having to switch high voltage or large current or highly inductive circuits. The machine can be described as an inverted direct-current motor, i.e. the field poles rotate. The reversal of the current in the stationary armature conductors is controlled by silicon controlled rectifiers (s.c.r.s), which, in general, switch off as the alternating current approaches zero. In this experimental motor the application and removal of the gate currents for triggering the s.c.r.s are controlled by a rotating switch mechanically coupled to the motor shaft. The basic parameters of the motor are given, but it must be said that no attempt was made to optimise the design as the motor was built to investigate general operating conditions. Some details of the initial test are presented.
