Control circuit for a stepping motor

摘要

The control circuit for a stepping motor comprises a step-driver circuit (21) which varies the rotating-field phase angle of the stepping motor (1) for each clock pulse of a sequence of clock pulses (at 3) by a predetermined angular step in the desired direction. A rotary pulse transmitter (13), which is driven by the stepping motor (1), produces a feedback pulse for each angular step of the stepping motor (1). A control pulse generator produces a sequence of control pulses at a repetition frequency which is greater than the maximum step repetition frequency of the stepping motor (1). The step-driver circuit (21) varies the rotating-field phase angle by a predetermined angular step in the desired direction for each control pulse of the control pulse generator (19). A first difference-counting circuit (11), which counts the clock pulses and feedback pulses, stores the numerical difference between the number of clock pulses and the number of feedback pulses. A second difference-counting circuit (27), which counts the control pulses and the feedback pulses, stores the numerical difference between the number of control pulses and the number of feedback pulses. The sequence of control pulses can be supplied to the step-driver circuit (21) in the desired direction only until the numerical difference which is stored in the first difference-counting circuit (11) deviates from zero and the magnitude of the numerical difference which is stored in the second difference-counting circuit (27) is less than a predetermined number. If this numerical difference is greater or ... Original abstract incomplete. <IMAGE>