Commutation considered as a switching problem

THE USUAL commutation theories deal with the reversal of the current in the commutating coil and with means for bringing about suet reversal either along a straight line or curve. The principal object in such studies is to accomplish commutation without excessive current densities under the brush. Frequently, however, it is impossible to realize this, and the phenomenon which results is essentially one of switching. With this new concept in mind, factors may be studied which previously have not been considered.