RE: [CAD_CAM_EDM_DRO] Re: Re: Re: Was Chopper circuit - Now ver 3 .2, G298

I have even seen PIC's with comparators built in!

-----Original Message-----
From: Alan Rothenbush [mailto:beer@...]
Sent: Tuesday, April 09, 2002 9:05 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: Re: Re: Was Chopper circuit - Now ver
3.2, G298

>
> Why bother with a PIC for a L297 replacement, unless you wanted to add

some

> rudimentary microstep capability? Would a PIC be cheaper? The L297 can do
> half-step and full-step, but adding microstepping would require a DAC and
> control logic.

I'm in the middle of a project that uses a PIC to drive a 3776. It uses
simple 2% resistors to generate 1/2 - 1/4 - 1/8 steps. No DAC required.
This would be an add-on for DanM's 5A controller.

Note: I don't expect to get 8 times the resolution over the stock
motor, simply smoother response.

Now, to carry this project further, the only "control" logic required over
and above the PIC to drive the G298 is a comparator.

Hmm ...

Alan

P.S. Yes, suitable PICs ARE cheaper than 297s.

--

Alan Rothenbush | The Spartans do not ask the number of the
Academic Computing Services | enemy, only where they are.
Simon Fraser University |
Burnaby, B.C., Canada | Agix of Sparta

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