Newsgroups: comp.robotics
Path: brunix!uunet!gumby!wupost!micro-heart-of-gold.mit.edu!news.media.mit.edu!fredm
From: fredm@media.mit.edu (Fred G Martin)
Subject: Re: Miniboard question on current capabilites.
Message-ID: <1992Oct20.162818.9394@news.media.mit.edu>
Keywords: Miniboard
Sender: news@news.media.mit.edu (USENET News System)
Organization: MIT Media Laboratory
References: <1992Oct19.214046.267@news.dfrf.nasa.gov>
Date: Tue, 20 Oct 1992 16:28:18 GMT
Lines: 19

In article <1992Oct19.214046.267@news.dfrf.nasa.gov>
disbrow@skipper.dfrf.nasa.gov writes: 

>I need to control two 40-50 Amp motors (from an old electric wheel chair)
>using PWM.  Reading the recent postings on the Miniboard, I notice that 
>it's capable of controlling four DC motors up to only 600 mA of current.
>Does anyone have an idea for a fix, like maybe driving four hexfets in the
>familiar H-pattern?  Any ideas will be appreciated.

You can:

(1) use the Mini Board motor outputs to drive relays large enough to
operate the wheelchair motors; or

(2) build your Mini Board without its motor chips, and wire the
now-available 6811's digital outputs to your own off-board motor
driving circuit (electronic or otherwise).


