I went to the Allegro site and liked the following chips:
1 - SLA7044M
http://www.allegromicro.com/sf/97042/2 - PG001M
http://www.allegromicro.com/sf/9001/The SLA7044M is capable of driving 3A directly. It also has microstepping
capability, and if desired, can switch modes between microstepping and full
stepping on the fly.
With these two chips and a few discrete components you should be able to
create a pretty simple stepper driver.
I just received some samples that I'm going to try and use to drive my
milling machine.
I also saw a link for:
http://www.futurlec.com/StepperMotorController.htmlwhich are 4A bipolar stepper drivers for only $18 ea. I haven't used them,
so can't comment on their capabilities. You should be able to use your
unipolar motors in a bipolar fashion.
Dave Hylands
> -----Original Message-----
> From: Brian Gracia [mailto:bgracia@...]
> Sent: Tuesday, June 11, 2002 11:05 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: [Homebrew_PCBs] Need help with CNC
>
>
> Hello Everyone,
>
> I need some help starting out with CNC. I am going to build
> a CNC router
> type machine to route pcbs. I need some help with the circuits.
>
> I have 3-60oz in stepper motors I got from HobbyCNC. They are marked
> STH-55D203-02 1.8 deg/step, 5.1V 1A. I believe they are
> unipolar from the
> docs and they have 6 leads coming from them. This is my first
> adventure
> with controlling stepper motors. I have another project for
> CNC when I get
> finished with this one. My mother (I am 34 as of Sunday)
> wants one of
> those embroidery sewing machines that cost $3000+. She
> want's to do some
> sewing designs and monograms on clothes. If I get my CNC
> router/driller
> working, I am going to attempt to build her one with the
> other group of 3
> unipolar stepper motors I have.
>
> I went looking for ICs to control all of the stepper motors I
> have. I have
> a total of 6 motors, 3 being of one make and spec, and the
> other 3 being of
> another make and spec. Each group of 3 motors is the same
> spec, so I do
> not have to worry about trying to control motors of different
> characteristics. I found the UCN5804B to be a good chip, but
> it will not
> meet the power specs of both stepper motor group I have. They have
> different current ratings. One group is 1A, the other 1.44A.
> So, I will
> need some transistors that can interface with the 5804B so
> that no matter
> which motor group I am using, the circuit will power them.
>
> I found the TIP 120 to be able to put out up to 3A, which is
> more than
> enough. Page 5 of this
> doc:http://www.alltronics.com/download/5804.pdf
> shows the circuit I would like to build. I know that I will need the
> diodes as circuit protectors. Can anyone show me how to hook
> up the Tip's.
> I had lots of theory 12 yrs ago in college, but could not
> graduate do to
> not being able to pass calculus. They blocked me from taking
> my Senior
> level classes. So I wasted a lot of money!
>
> I did an extensive search on the net and came across several
> chips, but
> would still need the extra transistors to power the more
> current hungry
> motor. Also, these chips were more expensive. It is not
> that I am being
> cheep, I could purchase a board which many on this group seem
> to sell, it
> is just that I wish to learn more about electronics.
>
> I am looking to purchase the chips this week, so I anyone
> could help me
> out, I would appreciate it.
>
> Thanks,
> Brian G.
>
>
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