These N/TT/HO/OO units are designed to give constant speed running on gradients, around curves and through complex pointwork. Suitable for all types of motor except coreless (e.g. Portescap range).
Both the handheld and panel mount versions employ feedback, i.e. the controller senses the change in back EMF* when the train climbs or descends a gradient, crosses pointwork, etc., and automatically adjusts the speed to compensate.
*EMF - Electromotive force, a voltage produced by the motor in opposition to the applied control voltage.