Development of an electronically commutated motor with laminated brushes

Recent developments in switching by means of thyristors offer possibilities for commutating motors electronically. The method proposed uses a laminated form of brush, and is applicable to existing motors or d.c. generators. Trial equipment was tested over a wide range of speeds in a d.c. motor, and with high current densities in a 200kW d.c. generator, with promising results.