A universal motor can be driven both by single-phase and direct current voltage. Both assembly and circuitry correspond to direct current series motors.
1 Direct current
Because of the low power and subsequent minimal incidence of commutator sparking, universal motor stators dispense with interpole and compensation windings.
Figure 121 shows the lamella section of a universal motor. The exciter windings, also known as pole or field coils, have been positioned on the pole core.
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