This question already has an answer here:

I need to supply +9V to three stepper motors on a breadboard with driver carriers (see parts below). Its too much for my raspberry pi to handle, apparently. I was able to power and control a single driver, so I know my setup is good.

I tried using an arduino power supply to drive them (+9V, 0.664A), but when its under load, the voltage seems to drop below +3V and nothing works.

I need to find a power source (not battery) for this. I'd prefer not ordering anything (short on time). Any suggestions, or tips to get the arduino supply to work properly?

http://www.pololu.com/product/1204 http://www.pololu.com/product/2134


marked as duplicate by JYelton, Passerby, Nick Alexeev, Olin Lathrop, Daniel Grillo Dec 12 '13 at 3:10

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • \$\begingroup\$ What are your motors rated at? Then multiply by 2 (Stall current) and get a wall wart of 9v and that amperage or greater. \$\endgroup\$ – Passerby Dec 11 '13 at 21:53
  • \$\begingroup\$ The motors are rated "0.6 A/Phase", but I see you say I need double that. So, the arduino supply would be insufficient in that regard. \$\endgroup\$ – ronpandolfi Dec 11 '13 at 21:57

If I read the Pololu documentation corrrectly, the motors are 0.6 A per phase, and have two windings, so you will need to allow at least 1.2 amps per motor, or at least 3.6 amps for the three motors. If the "double the stall current" suggestion applies to stepper motors, you'll need 5 - 6 amps.

  • \$\begingroup\$ This might be out of my own ignorance of stepper motors, but wouldn't each phase be on at different times, or atleast only one peaking at any given point? \$\endgroup\$ – Passerby Dec 11 '13 at 23:00
  • \$\begingroup\$ Thanks, I won't need to run all three at once, so something over 2.4 amps (double stall current) sounds right for me then. I just went out and picked up a 5VDC 3.6A supply power supply from radioshack (expensive). I'll see how it works and credit your response if there's no more tips. Thanks. \$\endgroup\$ – ronpandolfi Dec 11 '13 at 23:00
  • \$\begingroup\$ @Passerby, I'm not too familiar with steppers myself, but I believe both phases will be active half the time. Step 1 would be phase A only, step 2 A and B, step 3 B only, step 4 A and B, and repeat (or something like that). \$\endgroup\$ – Peter Bennett Dec 11 '13 at 23:19
  • \$\begingroup\$ @Passerby, Yeah, and with microstepping you'd have both active more often, I think. The 5VDC 3.6A power supply seems to work fine for my project. Thanks all for your guidance. \$\endgroup\$ – ronpandolfi Dec 11 '13 at 23:26

Not the answer you're looking for? Browse other questions tagged or ask your own question.