Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: George221 on January 30, 2013, 05:25:53 PM
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i got few stepper motor from robotshop : 12V 0.68A 125oz-in Unipolar Stepper Motor
(http://www.robotshop.com/ca/rbsoy14-soyo-unipolar-stepper-motor.html (http://www.robotshop.com/ca/rbsoy14-soyo-unipolar-stepper-motor.html))
Question: i wanna control it that it can move both direction, so i tried to use darlington array uln2004A
but the collector-current rating is 500 mA. will this burn when driving 0.68A stepper.
is there another darlington array with higher current rating ? or other way to drive this stepper in both directions.
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You can use discrete MOSFET, Bipolar or Darlington transistor instead of an array. An arry is not needed for bi-directional control of a uni-polar stepper motor.
Try googling 'uni-polar stepper drive' for lots of circuit examples.
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Pretty much all motor drivers these days use MOSFET transistors.
Because your motor is unipolar, you need four transistors. Four N-channel MOSFETs will work just fine, and you can buy power MOSFETs with logic-level I/O for about $1 each from places like Digi-Key. Adafruit also sells them.
You could also get a dedicated unipolar motor driver circuit, but I don't think you'd get anything out of that that you wont' get out of just discrete MOSFETs.