Re: [CAD_CAM_EDM_DRO] Need 1N4437 bridge rectifier...

Doug,

If it's REALLY old, 30+ years, I wonder if it was a selenium rectifier?
Lotts of plates, stunk like crazy when it failed. The voltage is higher
then before, which is why I suggest it. If it was selenium, I'd suggest
adding a dropping resistor in series with the output. That's what we
did when we replaced them "back then" in TV sets. Limited in inrush
current to the filter caps, as I recall. Might still apply. Mouser and
Newark couldn't find 1N4437.

Alan

dougrasmussen@... wrote:

> Group,
>
> Anyone know a source for this item? Mounts with a 1/4" bolt on the
> back. Metal case. At 110V ac input, ouput is 90V dc. Probably
> about 10 amp rating.
>
> Apparently this was widely used 20-30 years ago. My local sources
> don't even show the number in their listings.
>
> It's for the high/low clutch mechanism in a Hardinge DSMA.
>
> Lacking the exact part number I replaced it with one of those plastic
> cased rectifiers with 30A rating. Output is around 110V dc. Seems
> like the clutch actuating coils are running a little hot, although I
> can't say for sure since I never checked them until now.
>
> Anyway, it'd be nice to get the exact replacement part.
>
> Thanks,
>
> Doug
>