Re: How do I check the MOSFET's in my stepper driver

Thanks Jon,

I'll check the transistors. (fuse is a small sealed fast-blow
ceramic, so I don't think I'll get anything by inspection. Any idea
how fast the in-line fuse (external to the drive) should be?

Jeff

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
> turbulatordude wrote:
>
> >
> >
> >
> >>Examin the fuse if it is glass body if the fuse wire has been
totaly
> >>vaperoised look for further faults if it is still there but
broken
> >>
> >>
> >replac
> >
> >
> >>it and continue.
> >>
> >>roger
> >>
> >>
> >
> >
> >Old wives tale or voice of experiance ?
> >
> >
> Especially with slow-blow types, the kind with the spring and wire
wound
> round a thing with solder on it, you can tell the sort of fault.
If it
> was a
> long-term overload, ie. 110 % or rating for 5 minutes, the solder
will
> appear cracked and grainy, and there will be little metal
vaporization.
> If it blew due to a dead short, the solder will be unmelted, but
the wire
> will have turned to a black deposit on the inside of the glass.
When you
> see the granular solder, and you know a motor was jammed or some
other
> reasonable cause for an overload, you free the jammed mechanism and
> replace the fuse. When you see the total vaporization of the fuse
wire,
> it is practically hopeless to just put another fuse in and pray!
>
> Jon