In order to design as inexpensively as possible a control device for DC motors
which are provided with a commutator for feeding their motor windings which has
at least four sliding contacts, this device comprising a modulation stage which
generates at least one control signal modulated as to pulse width with a clock
frequency substantially above the motor speed and a control circuit which is controlled
by the at least one control signal and has at least one load branch which feeds
the commutator and is provided with an electronic switch controlled by the control
signal modulated as to pulse width, it is suggested that the sliding contacts be
combined to form at least two control groups, that the sliding contacts be combined
within each control group to form pairs of sliding contacts and that each control
group have its own load branch associated with it.