
Stepping Motor Systems 249
each ministep both currents must be changed in a quite com-
plicated fashion. Despite the difficulties referred to above,
mini-stepping is used extensively, especially in photographic
and printing applications where a high resolution is needed.
Schemes involving between 3 and 10 ministeps for a 1.8° step
motor are numerous, and there are instances where up to 100
ministeps (20000 ministeps/rev) have been successfully
achieved.
So far, we have concentrated on those aspects of behaviour
which depend only on the motor
itself,
i.e. the static per-
formance. The shape of the static torque curve, the holding
torque, and th ...