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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