Hi,
I bought this high torque stepper motor to use with my arduino. The specs on the internet all say it is a 1.92V motor and I am kind of having problem digesting that. I am expecting that with a high current motor it would need high voltage. I am not sure if there is something I am missing or it actually 1.92V.
Somewhere in another forum was running this same motor with 12V. Can someone demystify the specs for me?
The winding resistance is only 0.8 Ohms, so, to get the rated 2.4 Amps to flow through, takes: Volts = current times resistance = 2.4A * 0.8 Ohms = 1.92V. The motor driver limits the current to 2.4 Amps so the supply voltage only needs to be greater than 1.92V, so 12 or even 24V or more is OK as long as the driver is rated for it. Just be sure you use a chopper type, current adjustable driver.
Also, make sure to get a stepper driver that can comfortably supply 2.4 amps. I would select one that can provide at least 3 amps, and 4 amps would give you a better margin.
Thanks. That helps a lot. Actually I have to confess I did try it with 12V and had no problems. Just wanted to be sure it can handle it. The driver that I have is SN754410NE which I understand is 1Amp so I'll have to find something different.
The SN754410 seems to be a h-bridge driver rather than a specialized stepper driver. Get a specialized stepper driver as they have the ability to limit the current to protect the motor when using a high voltage.
Stepper motors like this are not like other DC motors, they do not have a voltage rating. They are current
driven and thus have a current, resistance and inductance specification.
You can multiply the current rating by the winding resistance to calculate a voltage, but that's not
relevant to driving a stepper. In fact the supply voltage ought to be many times larger than this IR
product, typically 24V or higher is actually employed. Higher supply voltage means higher top speed,
but otherwise makes little difference. The winding inductance is more important to motor performance
than the resistance, BTW, lower inductance is faster.
You need a current-controlling stepper driver to drive a stepper. The driver has to be setup to the correct
output current level. Dont' try to drive low impedance steppers like this one with a DC motor shield, it
will lead to dissappointment and burnt out devices.