Hi, I have purchased a small stepper motor from applied motors. The part number is 5014-842. It says 1 amp / phase. It is labeled 4.3 v, and I was wondering how to power it. My conclusion is that a 2 amp 12v power supply with the easy driver from sparkfun should be sufficient. Can anyone help me figure out if this is right?
I should note that I am concerned I am doing something wrong because on the EasyDriver page it says, "Adjustable current control from 150mA/phase to 700mA/phase", whereas the motor is rated 1amp/ phase, and I belive that would mean I need 2 amps... I presume that there is something I am missing, probably having to do with how the driver works. Any tips?
You could probably get your motor to work with 700mA rather than 1000mA but you would be better using a BigEasydriver or Pololu A4988 that can comfortably supply 1 amp per phase
I don't understand what you think you are missing?
Have a look at stepper motor basics
...R
Thanks! So, do I need a 2a power supply if for big easy driver or the Pololu A4988? My idea is (if this is possible) to use the easydriver with a 2 amp (or whatever is appropriate) 12v power supply, and later buy a larger driver if I am unsatisfied with the power the motor gets. I can't find the amperage rating of the easydriver. On a side note, how should I connect my power? Is the best way just to get a dc barrel type power supply, then buy a jack that you can solder leads to, or one of those larger ones with terminals, like this one?
Having more amps than you need is never a problem. The driver/motor will just take what it needs.
I don't understand your question about connectors or what you are thinking of doing with the barrel jack. I assume you know which wires go where and are just asking about a plug somewhere in the system.
It is very important to ensure there cannot be a deliberate or accidental discconection (even a very brief one) of the wires between the motor and the driver while the system is powered. It is a reliable way to destroy the driver.
...R
Alirghty, thanks again for helping me with my uncertainties! 
Robin2:
I don't understand your question about connectors or what you are thinking of doing with the barrel jack. I assume you know which wires go where and are just asking about a plug somewhere in the system.
What I meant was that I would like to use the driver on a breadboard, and I can't figure out the best type of power supply to use. As I mentioned, I was thinking about using a dc power supply with a barrel, (heck I could even just plug that into the arduino and use the VIN pin now that I think about it; but I'd rather not) and then one of these jacks to connect to a breadboard. I was wondering if there is a better solution.
Edit:I could probably just cut off the barrel jack and tin the wire tips, right?
LBurrito:
then one of these jacks to connect to a breadboard.
That seems to be what it is designed for - but just check the pin spacing. They may mean a PCB rather than a breadboard.
Edit:I could probably just cut off the barrel jack and tin the wire tips, right?
You ask these questions without providing any context that would help make sense of it. I can't read your mind.
I generally just solder some solid core wires to the connector (eg barrel jack) and push the wires into my breadboard. I find a metre or CAT6 solid core cable provides a lot of hook-up wire very cheaply. However do NOT use solid core wire in a long term project as it tends to fracture from bending fatigue.
...R
Sorry for being unclear. I was thinking that maybe the dc power supply with the barrel jack would just have 2 wires for positive and negative if you cut off the connector part. Is that true?
LBurrito:
I was thinking that maybe the dc power supply with the barrel jack would just have 2 wires for positive and negative if you cut off the connector part. Is that true?
That should be correct - but you will have to try it to be certain. You will probably need a multimeter to test which wire is +ve and which is -ve. Getting them the correct way round is essential.
...R
I tried it with an old charger I had. Stripping it revealed one strand of wire coiled around insulation containing another. I just used a simple led circuit to test positive and negative. It worked, but it was a bit impractical. I have found a better solution which is just an adapter from the barrel to two aligator clips. The power supply is on its way, I will let you know how hooking everything up goes :).
Thanks for your help! The stepper is up and running! Is it normal for the easydriver voltage regulator to get a bit more than warm when nothing is connected via the 5v easydriver pin?
LBurrito:
Thanks for your help! The stepper is up and running! Is it normal for the easydriver voltage regulator to get a bit more than warm when nothing is connected via the 5v easydriver pin?
I don't know. You will have to provide a full wiring schematic (a photo of a pencil drawing is good). "Nothing connected to ..." is too easily misunderstood.
The stepper driver chips are designed to work at temperatures that would burn your finger.
...R