Turning the brushes changes the size relation between winding
No 1 and winding No 2 and thus changes the motor characteristics
for example, the speed at a certain load.
The repulsion motor is used in simple drive systems withvariable
speeds, e.g. small agitators, and shaking machines It is expensive
to purchase and the brushes and commutator become worn quickly
Consequently, it is now often replaced by,for example auniversal
motor with thyristor control.