22
462
R e c o m m e n d e d I M S M o t o r s
IMS stocks the following 1.8° hybrid stepping motors that are recommended
for the IB462H. All IMS motors are CE marked. For more detailed informa-
tion on these motors please see the IMS Full Line Catalog or the IMS web site
at
www.imshome.com.
Maximum Motor Inductance (mH per Phase) =
.4 X Minimum Supply Voltage
As was discussed in the previous section,
Power Supply Requirements,
the
higher the voltage used the faster the current can flow through the motor
windings. This in turn means a higher step rate, or motor speed. Care should
be taken not to exceed the maximum voltage of the driver. Therefore, in
choosing a motor for a system design, the best performance for a specified
torque is a motor with the lowest possible winding inductance used in
conjunction with highest possible driver voltage.
The winding inductance will determine the motor type and wiring configura-
tion best suited for your system. While the equation used to size a motor for
your system is quite simple, several factors fall into play at this point.
The winding inductance of a motor is rated in milliHenrys(mH) per Phase.
The amount of inductance will depend on the wiring configuration of the
motor.
The per phase winding inductance specified may be different than the per
phase inductance seen by your IB462H driver depending on the wiring
configuration used. Your calculations must allow for the actual inductance that
the driver will see based upon the motor’s wiring configuration.
Figure 1.6.1A 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 1.6.1B shows an 8 lead motor wired in parallel. Using this configura-
tion 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
IB462H used with an unregulated power supply with a minimum voltage (+V)
of 18 VDC:
.4 X 18 = 7.2 mH
The maximum per phase winding inductance recommended is 7.2 mH.
NOTE:
In calculating the maximum phase inductance, the
minimum supply output voltage should be used when using an
unregulated supply.