Unit of rotating speed control for direct current motors.

摘要

The invention refers to a unit used to control in steps the rotating speed of direct current motors which, in order to rectify the excitation current, use some reactance coils [L1, L2...] connected to the secondary of an adapter transformer [T] branched to an alternative current network, a switch [S] to short-circuit the reactance coils [L1, L2...] in order to obtain some lower rotating speed steps and a rectifier [U1] for direct current supply to the excitation winding [E] of the direct current motor [M].