Re: [CAD_CAM_EDM_DRO] L297/L298 board concern

I mounted mine on CPU heatsinks with fans mounted on them. Worked very well.
I use Geckos now on my larger router table.
Jim

----- Original Message -----
From: "B Snowden" <bsnowde@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Thursday, November 14, 2002 11:45 PM
Subject: Re: [CAD_CAM_EDM_DRO] L297/L298 board concern


> Gary,
>
> I let the smoke out of one of my L298 also awhile back. Mine had a heat
sink on it. What I have now done, cut angle aluminum to 6.75 in long. I
have three L298's in a row. I connected the aluminum
> to the heat sinks of all three L298's. So what I end up with is a heat
sink attached to the heat sink of the three L298's. When I get the board
installed into a case, I plan to use a fan to draw
> air over the L298's. By adding the extra heat sink, I dropped the temp
from about 230+ F to around 160 - 205 F. I do not know what the temp was
when one of them smoked. The fan should cool it even
> more. I think you can get by without the extra heat sink, but it would
need to be installed in a case where a fan would draw air over the L298's in
a proper way. The extra heat sink allows me to run
> outside a case, and when I do install it, it should allow me more margin,
provided I have proper air flow.
>
> Bruce
>
>
>
> stirlinguy wrote:
>
> > Guys,
> >
> > I have a L297/L298 board that seems to be getting REAL hot. It's
> > basically just the circuit from the L297 datasheet. A friend of mine
> > had the board made up with another order. I built it a few months
> > ago, got a motor spinning (I think I was only using about 12v supply
> > then), then put in on the shelf. I was playing with it today.
> >
> > When I run it, the L298 gets really hot. In fact, I didn't have a
> > heatsink on it and the smoke got let out. After replacing the L298
> > (and adding a heatsink), it seems to work OK, but still gets very
> > hot. I don't want to run it too much for fear more smoke may ruin my
> > day.
> >
> > I am using a 24V power supply, the motor is a size 23 that is rated
> > for 3A, but should work fine with 2. It is stone cold when running
> > at low speed from the driver. The L298 on the other hand could cook
> > dinner.
> >
> > Anybody else have this problem? I'm not sure if there's something
> > else screwy with the board, but the amount of heat I'm getting makes
> > me wonder.
> >
> > Thanks in advance
> >
> > Gary
> >
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> OFF Topic POSTS: General Machining
> If you wish to post on unlimited OT subjects goto:
aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if
you have trouble.
> http://www.metalworking.com/news_servers.html
>
> http://groups.yahoo.com/group/jobshophomeshop I consider this to be a
sister site to the CCED group, as many of the same members are there, for OT
subjects, that are not allowed on the CCED list.
>
> NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
> bill
> List Mom
> List Owner
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
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