phytron
31
MA 1303-A007 EN
Motor time constant
R
L
=
applies to the motor´s electrical time constant
The total inductance L
total
is equal to the winding inductance in a parallel circuit, be-
cause of shared inductances.
L
total
=
4 x L applies to a series circuit.
The result is an equal motor time constant
for a serial and a parallel circuit:
Circuit
series
parallel
Resistance R
total
2 x R
2
R
Inductance L
total
4 x L
L
Motor time constant
R
L
x
2
R
x
2
L
x
4
series
R
L
x
2
R/2
L
=
parallel
The values for L and R can be found in the technical data sheet of the connected stepper
motor.
Operation with very low-inductance motor
i
Due to the design of the power stage, operation of the TM StepDrive technology
module with a very low-inductance motor (<2 mH) may not be possible.
In this case, the use of external series inductors can provide a remedy. The inductors
must be suitable for the planned current and for frequencies of several 100 kHz.
