Driving steppers

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Joined Aug 11, 2008
I am going to use this unipolor driver circuit for my CNC steppers, schematic at this link, second page. http://www.kitsrus.com/pdf/k179.pdf
The CMOS devices cost are under a dollar for all of them and the MOSFET IRFZ44 drivers will probably drive the coils at 6 amps or more without a heatsink. The IRFZ44 is rated at 60 volts and a lot of current, with a gate threshold voltage of 2- 4 volts max, which means you can drive them with TTL logic levels if your output current is low enough. Found the IRFZ44’s at $1.00 ea at Mouser Electronics. I have used this same circuit design 10 years ago using TTL logic devices, a 7474 D edge triggered filp-flop driving a Darlington transistor, and something like the 74136 Quad exclusive OR. Can’t remember if the Exclusive OR was a 74136 or a 7486 but it worked great and was cheap.

Since you are using a bipolor motor and you want to use the chopper driver scheme, you may want to look at his DIY KIT 187: STEPPER MOTOR CHOPPER DRIVER. Schematic at http://www.kitsrus.com/pdf/kit187.pdf


60 volt, 50Amps, IRFZ44 datasheet at: http://www.datasheetcatalog.org/datasheets/166/373875_DS.pdf
(nope, fifty amps, did not leave out the decimal point)
100 volt, 5.6Amps, IRF510 data sheet at: http://www.datasheetcatalog.org/datasheet/irf/irf510.pdf
Last edited:


Joined Jul 17, 2007
Nice of you to want to help out, Joe, but the original poster made their inquiry nearly four years ago, and hasn't posted since then.