Safe PSU removal

  • Thread starter Thread starter kony
  • Start date Start date
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kony

Ok guys I need to actually remove the circuitry from my PSU casing. I am
gonna media blast it, my question is, is there a way to discharge the PSU
before removal or is there some set way to do this?

TIA
-Chris
Click to expand...

"Media blast it?"

If that's like turning on a camcorder and filming yourself taking out your
frustrations with a hammer, just choose a hammer with wooden handle.

Generally a power supply will discharge almost immediately, at least
within a couple minutes unless there's something physically wrong with it.

If you have doubts then measure voltage of primary (largest) capacitors
and/or anything else before you "touch" it. Unless you're really in a
rush just leave it sitting for a day, or two or longer... not really
necessary but even in a worst case scenario it'd have the least charge at
that point.

If you were able to remove the circuit board, AFTERWARDS you'd have access
to the large capacitors' leads and could drain that point to ground, or
from the top side it'd be easiest to do so with a probe attached to the
output of the bridge rectifier (since they generally sit up off the pcb a
bit so the metal is exposed), but if you didn't know that there's probably
no point in being informed of it, better to just wait longer period of
time.
 
Chris Stolworthy said:
Ok guys I need to actually remove the circuitry from my
PSU casing. I am gonna media blast it,
Click to expand...

Media blasting also refers to shooting something with fine plastic BBs
to clean it off.
my question is, is there a way to discharge the PSU before
removal or is there some set way to do this?
Click to expand...

The capacitors normally discharge in well under 60 seconds from the
load applied by the supply's own circuitry, but if the supply failed
it's possible for the capacitors to stay charged up for weeks or even
months, so if that happened, either toss it or have a person who knows
electronics look at it.

Be careful when reassembling the supply because you don't want the
high voltage section, except for its ground connections, to touch
anything else. There may be plastic or fish paper (very stiff thin
cardboard) insulators between the bottom of the circuit board and the
case and between certain components and the sides of the case, and
these should be reinstalled to prevent electric shock (high voltage
coils have wiring insulated only by thin varnish, and those coils may
be located right next to the case). Also replace the screws in
exactly their original positions because if they're too long or the
head is too large they could touch high voltage metal or pierce
insulation.
 
Ok guys I need to actually remove the circuitry from my PSU casing. I am
gonna media blast it, my question is, is there a way to discharge the PSU
before removal or is there some set way to do this?

TIA
-Chris
 
Chris Stolworthy schreef:
Ok guys I need to actually remove the circuitry from my PSU casing. I am
gonna media blast it, my question is, is there a way to discharge the PSU
before removal or is there some set way to do this?

TIA
-Chris
Click to expand...

Now days all the PSU are discharged when powering down. In case of a
defect in the PSU some charge may be left. Boot from floppy (tiny square
thinge you can put data om :) ) and when in dospromt pull the power
plug. This way the working system will drain the PSU.

Succes
Also Chris
 
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