Path: utzoo!attcan!uunet!lll-winken!csd4.milw.wisc.edu!uxc!uxc.cso.uiuc.edu!m.cs.uiuc.edu!irwin
From: irwin@m.cs.uiuc.edu
Newsgroups: sci.electronics
Subject: Re: Stepper Motor
Message-ID: <21000031@m.cs.uiuc.edu>
Date: 8 Jun 89 15:27:00 GMT
References: <7137@cbnews.ATT.COM>
Lines: 46
Nf-ID: #R:cbnews.ATT.COM:7137:m.cs.uiuc.edu:21000031:000:1891
Nf-From: m.cs.uiuc.edu!irwin    Jun  8 10:27:00 1989


/* Written 10:11 am  Jun  7, 1989 by byron@pyr.gatech.EDU in m.cs.uiuc.edu:sci.electronics */

>If you have access to an eprom programmer a really quick solution
>comes to mind. Program the eprom with the step sequence and use
>a counter to pick the step. By using a up-down counter it's possible
>to get the motor to rotate in both directions (by presenting the sequence 
>backward). So something like this:

                                                                         
                                                                         
             |---------|--------|---------|-------|---------|------|-------|
             |         |--------|         |-------|         |------|       |
>Step Pulse--| Counter |--------| EPROM   |-------| Drivers |------| Motor |
Fwd/Bkwd-----|         |--------|         |-------|         |------|       |
     ^       |---------|        |---------|       |---------|      |-------|
     |
     |
      -------Add this for forward/reverse, logic looks good.


>Would be a sufficient driver to make it go.

>Does anyone know about drivers for these motors?


If the current required is known, and the voltage, I would think that
power transistors in the T-036 case style could be found to drive it.
A fudge factor could be added to the total wattage so that the transistor
selected was not working at 100% of its power rating. Clamp diodes would
be required across the driver transistors so that "punch through" did
not kill the drivers as the transistor turned off and a reverse voltage
spike got generated by the collapse of the field.

>BAJ
-- 
>Another random extraction from the mental bit stream of...
>Byron A. Jeff
>Georgia Tech, Atlanta GA 30332
>Internet:	byron@pyr.gatech.edu  uucp:	...!gatech!pyr!byron
/* End of text from m.cs.uiuc.edu:sci.electronics */

Al Irwin
Univ of Illinois
Dept of Comp Sci
irwin@m.cs.uiuc.edu