摘要 |
Step motor control circuit of the "current chopping" type where, according to the required operative conditions, both the energization current level and the "chopping" frequency is varied. When the current level applied to the motor phases is high, a relatively low chopping frequency is used and, on the contrary, when the current level is low a relatively high chopping frequency is used. Particularly, this allows the use of chopping ultrasonic frequency for the holding operative condition of the motor, where a low energization current level suffices, without causing unacceptable power losses in the current switching components. This has the advantage of eliminating under such condition, the motor noise due to the pulsating electrodynamic actions to which the motor is subjected. |