Use a switch mode down convertor. Many single chip solutions exist
for this power level.

Alternatively, one regulator per winding.

The preferred solution is a current sensing stepping motor driver which
would allow you to take advantage of the 12V drive to get fast
acceleration/steps, then automatically current limits the windings to
get lower hold power when you're not moving.
Again many choices. SGS has many (and app notes) in their 'power driver'
databook.

Greg Hastings wrote:
>
> I am making a stepper motor controller driven with a pic.  The motors I have
> are .8A (7.5Ohm), 6V motors.
> I plan to use a 12V SLA battery.
>
> I am using a 7805 V. Regulator to regulate the voltage going into the PIC,
> but in addition to this im going to need 6V to drive the steppers.
>
> Whats a good way to step down the voltage to 6V.  Going through the 7805 is
> probably a bad idea because they are only rated at 1Amp, and there are times
> when multiple coils are going to be on, which will require 1.6Amps.
>
> If my calculations are correct, whatever is stepping down the voltage will
> need to handle about 10W of power.
>
> Any ideas on what component to use?  (The smaller the better)
>
> Greg
>
> _________________________________________________________________________
> Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
>
> Share information about yourself, create your own public profile at
> http://profiles.msn.com.
>
> --
> http://www.piclist.com hint: The list server can filter out subtopics
> (like ads or off topics) for you. See http://www.piclist.com/#topics

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics