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Date: | Thu, 30 May 2013 11:36:38 -0500 |
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I got a really good blast from a computer monitor that
someone brought in to the shop when I was a technician with
OSU's Audio Visual Center back in the eighties.
The monitor was, for all appearances dead. After all, we
had plugged it in briefly and there was no indication at all
that anything happened.
I opened it up and there was a fuse in the power supply
and I decided to check it.
It was blown but this particular monitor had a rectifier
and 380-UF electrolytic filter capacitor ahead of the fuse. That
is very unusual design. The fuse is usually the first thing so
it protects everything.
In this case, it only protected the electronics after
the rectifier.
There was no bleeder or if there was, it was on the
other side of the rectifier and filter.
One end of the fuse was out there and very easy to get
to and the other end was nestled between a couple of other
components. I had to slide my test lead down the glass body of
the fuse to get to the other end cap. Remember that the fuse was
blown so when I reached that other end cap, I became the fuse.
If you rectify 120 volts, you get about 180 volts peak
across the capacitor and it hit like a freight train. It was
like getting hit in the arm with a hammer.
It really got me but didn't do anything more than hurt
for a while but it could have been lethal. I was in a hurry
and hurry sickness can be fatal.
Martin
Scott Howell writes:
> This thread reminds me of when I was in high school and in electronics =
> class I inadvertently touched this light these guys were working with =
> and I felt like I had just woke up. I was still standing, but it must =
> have been one hell of a shock to make me feel like I lost a minute of my =
> life. grin
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