What is the optimal voltage for a stepper motor?

[pekpek]

Hello All,

I am a ME student but, I'm trying to teach myself EE. I am testing out a stepper motor. Here are the specs for the motor:

Rated Voltage: 5.7V
Rated Current: 1A per Phase
Resistance per Phase: 5.7V

I am using 15 VDC and want to make sure I don't blow the motor. Using Ohm's Law, V_Input = R * I_Motor, I get 15 = 1(I) which gives me a resistance of 15 ohms.

My Questions:
(1) What is rated voltage? Is that the optimal voltage for the stepper motor?
(2) What happens if I go above the rated voltage?
(3) If I use a 15 Ohm resistor, will this be enough so the motor doesn't blow?

I am clearly missing something here. Any help would be appreciated.

Thanks in Advance.

 

[davenn]

Hi there :)

Rated Voltage: 5.7V
Rated Current: 1A per Phase
Resistance per Phase: 5.7VThink you typo'ed there

resistance isn't measured in V ... is it 5.7 Ohms or something totally different ?

Dave

 

[pekpek]

Yes. Sorry. The Resistance per phase is 5.7 ohms.

 

[pekpek]

Bump. Any help would be appreciated. Thanks!

 

[Windadct]

The V=5.7V and the R=5.7 Ohms? -- There are stepper motor controllers, and a large amount of info on line. If you just want to experiment with the motor - you probably want to get a voltage regulator, V value in the range of the Stepper motor's ratings, or an adjustable one.
If you are looking to actively control the stepper - then the best solution may depend on what you plan to use as a controller. -- the stepper motor is not a fixed resistance - so using a resistor as a voltage divider may not yield the result you are looking for.

 

[jim hardy]

Here's a decent tutorial


that seems to have started with this little TI intro
http://www.ti.com/lsds/ti/apps/motor/stepper_motors/overview.page

(1) What is rated voltage? Is that the optimal voltage for the stepper motor?

That'd be the voltage they expected you to use to make the motor step.
We don't know whether they intended you to reduce current between steps to "hold" it in place.

(2) What happens if I go above the rated voltage?

Overheat and maybe smoke.

(3) If I use a 15 Ohm resistor, will this be enough so the motor doesn't blow?

Probably. That'd give you 15 volts/20.7 ohms = 0.725 amp, which would generate only about half as much heat in the motor as a full amp..You'll need about a ten watt resistor . Maybe an automotive lamp would work.

Is there a part number on that motor?

I don't know a lot about steppers. They come in "unipolar" and "Bipolar", does yours indicate which it is ?
There are lot of educational kits, search on 'hobbyist stepper motor kit'
here's just one...
http://www.electronickits.com/kit/complete/motor/ck1405.htm

Ramsey and Velleman are two familiar names in the kit industry.

Have fun.

old jim