Re: L298 goes boom

Hoyt,
It normally takes a lot to get me stirred up but you managed it.
There is easily enough EMF generated when the magnetic field
collapses to jump the gap as the contacts are disconnected. This
forum is for "helping" people - not generating bad info that will be
expensive and discouraging to the people on it. May as well not have
a forum if information like this gets disseminated.

Eric

--- In CAD_CAM_EDM_DRO@y..., bjammin@i... wrote:
> At 10:57 AM 8/4/02 -0400, RichD wrote:
> >You are quite wrong. Any inductance carrying current will generate
large
> >voltages when disconnected as the flux field collapses.
>
> Not back EMF, by definition. Also, it's not able to affect drivers,
as it
> doesn't occur until disconnected from them. BUT, if you take power
off
> steppers when connected, there *will* be a magnetic field collapse
that
> puts voltage on the drivers ... and nobody even you has cautioned us
> against that! Therefore, you need to think these things thru a bit
more
> before writing.
>
> Regards, Hoyt McKagen
>
>
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