Mitsumi M42SP-13NK stepper... 12 or 24VDC?

Hello all…

I have a salvaged Mitsumi M42SP-13NK stepper and have a pdf of the maker’s datasheet.

Trouble is, the datasheet (see snippet below) indicates that there are both 12 and 24 VDC versions of this motor, yet there are no voltage indications on the motor itself.

Now, I don’t need this motor to do anything other than run, to experiment with driving it, so I’m not fussed about torque, speed and so on. I have only a 12V supply. I’m guessing if it’s a 24V version, and assuming it actually turns at 12V (I’m yet to test) then it’s ok to use it like that at least for “demo” no-load purposes?

On the other hand, is there any way of telling if this is a 12 or 24V motor? (If I were to apply 24VDC (not that I have a source) and no smoke is released, for example, could I “deduce” it’s a 24V one?)

(As an aside, the datasheet says 4.2 ohm coils; the sticker on mine, and my Fluke, both say 7.5)

Hey Jimbo I just salvaged this stepper as well and googled, got the same question as you Ive actually got two of them but the one is bigger than the other but get the same datasheet.

Did you solve this ?

Thanks M..............

They are bipolar steppers, so current rated, not voltage rated. Notice the datasheet columns headed "12V" and "24V" are for the same motor, driven from chopper drivers at different supply voltages:

The motor is rated at 0.6A and has 4.2 ohm windings - you cannot use this from 12V without a chopper driver

Hi Mark

What is a chopper driver?

If I use this driver Will I have to run it off 24V?


Its a chopper driver that runs off 8 to 45V.

Chopper drivers are current controllers using chopping.

You find something useful in stepper motor basics


Thanks Mark got it and thanks Robin your post are always very helpful.