This term refers to the typically undesirable property of conventional DC motors to assume a preferred rotor position due to the change in reluctance in the slot wound laminated iron rotor. This means that accurate positioning is simpler and more accurate with a coreless motor and operation is smooth even at low speed.
A condition in which a motor does not rotate smoothly, but "steps" or "jerks" from one position to another during shaft revolution.
The cyclic physical resistance felt in some alternator designs from magnets passing the coils and gaps in the laminates. Detrimental to Start-up.
A condition in which the motor does not rotate smoothly, but steps from position to position while rotating. This may occur at very low speeds when the motor is driven by an adjustable frequency drive.
A term used to describe non-uniform angular velocity. Cogging appears as a jerkiness, especially at low speeds.
Changes in force at low velocity, caused by magnetic “detenting” forces created by relative motion between a motor's permanent magnets and its ferrous core coil windings.
A term used to describe non-uniform angular velocity. It refers to rotation occurring in jerks or increments rather than smooth motion. When an armature coil enters the magnetic field produced by the field coils, it tends to speed up and slow down when leaving it. This effect becomes apparent at low speeds. The fewer the number of coils, the more noticeable it can be.
Non-uniform or erratic rotation of a direct current motor. It usually occurs at low speeds and may be a function of the adjustable speed control or of the motor design.
