Stepper Motor Drives (PWM vs. Little Step U & Power Resistors in Series)
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I'm currently using a BS2P stamp and a Little Step U stepper motor
controller (drive). In order to to increase the stepping speed I need
to decrease the time constant of the motor which is equal to L/R
(inductance/resistance). Since the inductance is fixed I can increase
the resistance of the motor by placing power resisters in series with the
coils (on the center tap). This means that you have to boost the voltage
to the motor and power is being wasted through the resistors. In some of
my projects this is not a good option since the power source is limited
(i.e battery powered).
I've come across another stepper motor controller made by Applied Motion
http://www.applied-motion.com/products/step_drives/2035_O.html. These
controllers use pulse width modulation (PWM), require no "in-series"
power resistors and are able to achieve very high stepping rates.
My question: Are these simply two different forms of technology and the
PWM style is able to somehow lower the inductance thus achieving the
higher step rates? Could the Stamp be used to trigger or PWM out to the
Little Step U and improve speed performance?
Thanks,
Chris Dundorf
________________________________________________________________
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controller (drive). In order to to increase the stepping speed I need
to decrease the time constant of the motor which is equal to L/R
(inductance/resistance). Since the inductance is fixed I can increase
the resistance of the motor by placing power resisters in series with the
coils (on the center tap). This means that you have to boost the voltage
to the motor and power is being wasted through the resistors. In some of
my projects this is not a good option since the power source is limited
(i.e battery powered).
I've come across another stepper motor controller made by Applied Motion
http://www.applied-motion.com/products/step_drives/2035_O.html. These
controllers use pulse width modulation (PWM), require no "in-series"
power resistors and are able to achieve very high stepping rates.
My question: Are these simply two different forms of technology and the
PWM style is able to somehow lower the inductance thus achieving the
higher step rates? Could the Stamp be used to trigger or PWM out to the
Little Step U and improve speed performance?
Thanks,
Chris Dundorf
________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today! For your FREE software, visit:
http://dl.www.juno.com/get/web/.