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Old April 15th 04, 05:17 PM
VWWall
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Regal wrote:
I read on some website that the capacitors in a PC's PSU can hold a
charge for long after they have been switched off and that the
charge could be fatal.

Is this really so? Surely that is exaggerating?


The capacitors in the input circuit of a PC PSU are charged to
~320 V DC. This can, indeed, be lethal, but they are shunted by
bleeder resistors which will reduce the voltage to a safe value
in a minute or two. By the time you get the unit out of the computer
case and remove it's cover, the voltage is probably safe. To be sure,
wait five minutes after unplugging the PSU before touching anything inside.

A PC monitor uses high voltage, (up to 25,000 V), on the CRT. The tube
glass envelope is used as a capacitor, and can hold a charge for some
time. Because the energy content is quite low, contact with this
very high voltage is usually not deadly, but may result in serious
injury from muscle reaction. Don't remove the housing from a CRT monitor
unless you understand how to safely discharge this voltage!

Virg Wall
--

It is vain to do with more
what can be done with fewer.
William of Occam.