Pages: [1]   Go Down
Author Topic: Power usage for Stepper Motor  (Read 1336 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 3
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Hi

I'm controlling a 28BYJ-48-5v Bi-Polar stepper motor from an Arduino Ethernet. I'm trying to work out what I need to power this motor. This link seems to have the most information on it:

http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=170703720133&clk_rvr_id=288195647094

Suggests it's 50ohm, I make that 100ma but from searching around I don't think it's that simple, but I don't entirely understand enough to be sure I'm right :-) From other things I've read I'm lead to believe the ULN2003 can't take more than around 500ma anyway which would suggest that's what the motor is likely to pull if that's what they're providing with it

I was wondering if I would be able to run this from the Arduino regulator's 5v Vout when powering it from a >7v external PSU. I've seen both 200ma and 1A given for the onboard regulator which is also a little confusing.

So my question is, can I run that stepper motor from the 5v Vout on an Arduino Ethernet board? I'd also be interested to know if I would be able to run 2 motors in the same way. If not I guess I'll need a 5v PSU with enough ampage or a >5v PSU that I can regulate to 5v for the motors.

Any advice greatly appreciated,

John
Logged

Manchester (England England)
Offline Offline
Brattain Member
*****
Karma: 602
Posts: 33362
Solder is electric glue
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Only two coils will be on at any one time so that is 200mA per motor so yes you can get two to run from the arduino's on board regulator.
http://www.thebox.myzen.co.uk/Workshop/Motors_3.html
and
http://www.thebox.myzen.co.uk/Workshop/Motors_4.html

Quote
I've seen both 200ma and 1A given for the on board regulator which is also a little confusing.
The 1A is the limit for the regulator component itself but that is not the limit, the limit is set by the power dissipation.
http://www.thebox.myzen.co.uk/Tutorial/Power_Examples.html
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 3
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Thanks Mike, I'd read the Power Examples page which is what led me to believe that I'd be better off not running more than ~200ma through the Arduino regulator. In that case are you saying that I *can* run two motors through the Arduino's regulator but perhaps shouldn't?
Logged

Manchester (England England)
Offline Offline
Brattain Member
*****
Karma: 602
Posts: 33362
Solder is electric glue
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

It depends on the voltage input, with 12V probably not but if you can drop that to just under 8V then yes.
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 3
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Ah yes, i get you, thanks very much.
Logged

Pages: [1]   Go Up
Jump to: