Intelligent Motion Systems IM805 Operating Instructions Manual page 28

Actual Inductance
Seen By the Driver
Specified Per Phase
Inductance
The per phase winding inductance specified may be different than the
per phase inductance seen by your IM805 driver depending on the wiring
configuration used. Your calculations must allow for the actual inductance
that the driver will see based upon the wiring configuration.
Figure 6.1A shows a stepper motor in a series configuration. In this
configuration, the per phase inductance will be 4 times that specified.
For example: a stepping motor has a specified per phase inductance of
1.47mH. In this configuration the driver will see 5.88 mH per phase.
Figure 6.1B shows an 8 lead motor wired in parallel. Using this configu-
ration the per phase inductance seen by the driver will be as specified.
Using the following equation we will show an example of sizing a motor
for a IM805 used with an unregulated power supply with a minimum
voltage (+V) of 18 VDC:
.2 X 18 = 3.6 mH
The recommended per phase winding inductance we can use is 3.6 mH.
26 IM805 Operating Instructions Revision R032306
PHASE A
PHASE A
PHASE B
PHASE B
8 Lead Stepping Motor
Series Configuration
(Note: This example also
applies to the 6 lead motor
full copper configuration and
to 4 lead stepping motors)
A
Figure 6.1 A & B: Per Phase Winding Inductance
Maximum Motor Inductance (mH per Phase) =
.2 X Minimum Supply Voltage
NOTE: In calculating the maximum phase inductance, the
minimum supply output voltage should be used when using an
unregulated supply.
Actual Inductance
Seen By the Driver
Specified Per Phase
Inductance
PHASE A
PHASE A
PHASE B
PHASE B
8 Lead Stepping Motor
Parallel Configuration
(Note: This example also
applies to the 6 lead motor
half copper configuration)
B