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I can't quite wrap my head around the power requirements for a CNC setup i'm building. I'm using 3 x Easydriver 4.4 for driving the Sparkfun Stepper Motors. I previously used a 22 V 800ma Power supply which blew up one of three of the easy drivers. Any explanation as to why ?

will a 12 volt 2A power supply be sufficient to power the entire setup or will it damage it? I'm really new to this and would really appreciate your input.

Edit 1: Added link to the original easydriver page with correct data.

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  • \$\begingroup\$ "the EasyDriver requires a 7 to 20V supply" ... \$\endgroup\$ – Brian Drummond Feb 5 '15 at 21:02
  • \$\begingroup\$ It's actually 7-30 There is a mistake in the product description page at sparkfun. \$\endgroup\$ – Devonic Feb 6 '15 at 14:12
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I have't looked at the datasheet for the driver chip on the Easydriver but Sparkfun website's blurb at the link you posted says that the Easydriver runs from 7 to 20V. That strongly suggests that your 22V supply is too high.

Your 12V 2A supply should work just fine but be aware that you may not get as much stepper speed as is possible.

If you plan to purchase more stepper drivers, I highly recommend TI’s DRV8825 driver chip. This is good for about 1.5A per phase without extra heatsinking and operates with a motor supply up to 45V. Pololu.com has them for a rational price Pololu.

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  • \$\begingroup\$ Easydrivers can in fact handle upto 30V. As for the motor i'm using, it's rated at 12V so shouldn't that be the voltage at which maximum torque and maximum speed is attained? If you go through this post, Schmalzhaus says that the input voltage doesn't matter even for a motor rated at 12 V? Can you brief me on this? \$\endgroup\$ – Devonic Feb 6 '15 at 7:20
  • \$\begingroup\$ I'm replying in a comment, so my space is limited. Given: stepper motors have coils that have inductance -and- the motor moves when different coils are energized and so create a magnetic field that 'moves'. The speed at which the magnetic field changes is directly proportional to how fast the current in the coils can change. Higher voltage means that the current changes faster. The driver limits the current into the coil so as to not damage the motor. \$\endgroup\$ – Dwayne Reid Feb 7 '15 at 0:10
  • \$\begingroup\$ If i understand you correctly you mean to say that, for instance powering the easydriver with 24 V won't affect the motor even though it's rated voltage is lower and that the current will be limited by the easydriver right even if i "supply" it with 2 amps ? \$\endgroup\$ – Devonic Feb 7 '15 at 17:25

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