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I am using easydriver 4.4 to control stepper motor. Easy driver takes input voltage from 7 to 30V. I fed 20V 3.0A to easydriver, but i got it burnt (easydriver)*. Is 3.0A too much for easydriver ? What is the rated input current for easy driver ?

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    \$\begingroup\$ The page you linked to states "Adjustable current control from 150mA/phase to 750mA/phase", so yes, you've exceeded the rating by about 3x. The driver chip data sheet, linked from that page, also says the same. \$\endgroup\$
    – John U
    Commented Feb 21, 2013 at 9:33

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Looking at the two links you provided the voltage rating of the stepper motor is shown as 12V which you've well exceeded by applying 20V. That may caused it to exceed the 750mA rating of the driver or burnt out the motor, but when operated at 12V the rated current is shown as 330mA so that driver should be OK.

In general 'supplying' 3A shouldn't be a problem, because if operated within spec it won't draw that much current. But I guess you really mean you've attached to a 20V / 3A supply which would have been delivering less current in practice. So yes 3A would be too much, but I doubt it was really drawing that much current unless you also have some other problem, or the motor windings shorted because of the higher than rated voltage.

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  • \$\begingroup\$ Now, i realize that i am real stupid to feed 20V when the stepper is 12V. However, easydriver is capable of taking voltage upto 30V. I am wondering why driver got burnt not the motor ? \$\endgroup\$
    – World
    Commented Feb 21, 2013 at 10:17
  • \$\begingroup\$ At first i tried with 6v battry pack (4xAA battry); both driver and motor worked fine. Later i connected 20V/30A power adapter. It did not show any problem at first, but after sometime the IC started giving smoke. I tried the motor with another driver (powered by 6v battery pack) and it worked fine. \$\endgroup\$
    – World
    Commented Feb 21, 2013 at 11:34
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    \$\begingroup\$ @World Running at almost twice the voltage would have put it close to the current limit, but it may be that only some windings have fused together so it will still operate at 6V. So your motor may stil be generally operational but damaged and only work at the lower voltage. \$\endgroup\$
    – PeterJ
    Commented Feb 21, 2013 at 12:29
  • \$\begingroup\$ One more question. Shouldn't i exceed 750mA input current for Easydriver although it is output current from Easydriver ? \$\endgroup\$
    – World
    Commented Feb 21, 2013 at 13:39
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    \$\begingroup\$ @World, it shouldn't draw more current than it needs for the motor, so while you shouldn't use a motor that needs more than 750mA of current at the operating voltage the amount of current the supply can deliver shouldn't matter. For example if you connect a small 12V motor to a car battery that can probably deliver over 100A all would be fine. \$\endgroup\$
    – PeterJ
    Commented Feb 21, 2013 at 13:50

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