phytron 10004904, Руководство пользователя, Страница: 42 / 53

phytron
41 MA 2107-A005 EN
The stepper motor phase current decreases with increasing step frequency caused by the
counter-electromotive force of the motor. The overdrive function compensates the
decrease of current and torque. The phase current is increased by about 40 %. The table
below shows the frequency values for switching on and off the overdrive function with
different step resolutions:
Step resolution Input control pulse frequency
Overdrive on at > Overdrive off at <
1/1 1 kHz 0.9 kHz
1/2 2 kHz 1.8 kHz
1/4 4 kHz 3.6 kHz
1/5 5 kHz 4.5 kHz
1/10 10 kHz 9.0 kHz
1/20 20 kHz 18.0 kHz
A higher torque in the middle and high frequency ranges is effected.
Fig. 23 shows a phase current diagram below and above the Overdrive activation
frequency in Full step- and 1/10-step modes.