However, the product of two or more commutators need not be a commutator. Losses also occur in commutation, mechanical commutators spark, and electronic commutators and also dissipate heat. Brushless torque motors are available; elimination of commutators and brushes allows higher speed operation. Witt basis of iterated (braided) commutators. Until the 1960s, automobiles used DC dynamo generators with commutators. This is similar in design to the commutators used in motors and dynamos. Because they are fermions the anti-commutators of the Jordan algebra become commutators. Lacking brushes and commutators, they require less maintenance. However, for fermions the mathematics is different, involving anticommutators instead of commutators. They are also more rugged, requiring no brushes or commutators. A dynamo uses commutators to produce direct current. This is the algebra where all commutators vanish. They have a classical counterpart where the commutators are replaced by Poisson brackets. What is left are the elements that are not expressible as commutators. They form the basis for the idea of commutators.