[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Blowing MMC bleed resistors...
Hi Terry,
I was a bit surprised myself. The resistors I have are just normal
carbon film 1/2W units. Nothing special about them. I got them from a
local surplus place before I found out Digikey had a better price. :(
I didn't try ohming them, I'll test them tonight and see if there are
any with the wrong value.
I didn't have any problem with the ones on my 6" coil, and it has more
runtime on it. Those were the last thing I expected to fail on the
coil. There are no metal objects near the MMC that could draw an arc.
And when I watched one go it didn't arc to anything, it just blasted a
hole in the side and spit carbon arround.
Interestingly, it only happened for a while. I replaced them and now
it seems to be OK. I ran the coil quite a bit after that and didn't
blow any more. I suspected that I may have gotten a few bad resistors
or incorrect values in there. I would be interested in trying some of
yours and letting you test the ones I have. I expect it's just bad
resistors. Would be nice to know for sure what's up.
Travis
> Original poster: Terry Fritz <twftesla-at-uswest-dot-net>
>
> Hi Travis,
>
> Wow! This is a new one. I have never heard of a bleed resistor
failing
> and I have done testing on the YAGEO ones which suggest they are
very tough
> indeed. My first thought would be to check them with on ohmmeter to
be
> sure they are not 1.2 Meg or something like that (check all of them
in the
> string). Make sure there are no metal objects near them the draw
arcs.
> Either they are the wrong value are there is something about the
particular
> resistors you have that is not suited for the high voltage. I still
have
> some of the ones I use so I could send you some you could try. I
know the
> YAGEOs work fine. Let me know if you want to try them and maybe
send me
> some of yours to test if you really think the resistors themselves
are the
> problem.