A method and circuit is disclosed for soft-commutation of a direct current (DC) motor. An attenuation circuit is connected through auxiliary brushes A, A', B and B' to the commutator (16) to drain circuit from successive armature coils (15) before the main brushes (27, 28) disconnects from each of the coils (15). This prevents the spark generation that normally occurs in conventional DC motors. The attenuation circuit may also be connected before energization of the coil (15) for a soft turning on operation.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
This invention was made with Government support under Contract No. DE-AC05-96OR22464 awarded by the U.S. Dept. of Energy. The Government has certain rights in the invention.