[Gllug] PSU fans

[home at alexhudson.com]

On Fri, Sep 07, 2001 at 02:26:51AM -0700, jackson harry wrote:
> The danger from the power supply is not the residing
> voltage in the capacitors

Resident charge, and yes it is dangerous.

> but the chance that you may damage it and short to the chassis, if no
> earth was apparent and sitting on highly resistive carpet it would create
> a great big 240v live metal thing that the children should avoid.

Not quite. Shorting the supply to the chassis isn't necessarily a problem -
most power supplies are switch-mode, and rely on a grounded chassis to
function. If the chassis isn't grounded (i.e., my PC in France) you get a
nice humming effect when you touch it. 

> The resident voltage in a
> tv is because of the CRT and the fact that some of the
> capacitors are charged to 27000 volts.

I've seen someone reverse polarity on charged TV caps and they blow big :)

> Anything with anything capacitive will have a resident
> charge I am unsure as to how much a 300W one would
> have but I do not think that it will be overly much.

Depends what voltage it spews out - it's the current that kills you, so if
the voltage is low it might be enough. I wouldn't want to try. The wattage
doesn't mean a great deal either - you want the capacitance.

> On a serious note if you are unsure at all do not touch the power supply
> its the one that will kill you and it is also the one that will kill every
> component in your PC you decide which one is more important.

Too true :) One of my collegues had a power supply blow the other day, just
by plugging it into the mains. Took out the whole mobo :(

Cheers,

Alex.

-- 

-- 
Gllug mailing list  -  Gllug at linux.co.uk
http://list.ftech.net/mailman/listinfo/gllug