Newsgroups: comp.robotics
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From: kilian@cray.com (Alan Kilian)
Subject: Re: Motor control
Message-ID: <1995Jan16.105659.11880@driftwood.cray.com>
Lines: 44
Nntp-Posting-Host: poplar021
Organization: Cray Research, Inc.
Date: 16 Jan 95 10:56:59 CST

> From: wernerj@crpl.cedar-rapids.lib.ia.us
>
> ... come up with an off the shelf 
> bidirectional motor control with the folowing charachteristics:
>
> + High Noise Imunity (This is pretty clear)

Use separate batteries, and drive the motor controller with an optoisolator.
Just like what you are using right now.
Keep the motor controller near the motor, and be careful where you run the
controller wires.

Now, I have a sample of a National Semiconductor LMD18245 3A 55V DMOS
Full-Bridge motor driver that ALMOST meets your requirements.

> + Low on-state resistance

About 0.6 Ohms

> + Little effort to connect with logic levels 0-5 ttl/cmos

Has TTL inputs for Direction, Brake, and a 4-bit Current control 

> + Two motor control at 12v and 1-5amps current

Buy two of these. But they are rates 3 A continuous, 6A Peak 55 Volts
so you will have to decide.
 
> + PWM inputs

Actually the LMD18201 might be better for you.
It has direction, Brake and PWM input but does not have the 4-Bit current
control inpputs.

Still 3A 55 Volts though.
 

            -Alan Kilian


-- 
 -Alan Kilian    kilian@cray.com 612.683.5499 (Work)
  "Let us begin by approximating a Cow as a hollow sphere completely filled
   with milk." -A Physicist giving a lecture to the Dairy association.
