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Originally posted by Axle
But these MOSFETS, they are LIVE, am I correct? I mean why else would most sinks be live then?
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It's only a side effect.
There can be 2 reasons:
1 - the backplate of MOSFETs is also the middle pin. Depending on where you take your reference you may end up with mains going through.
2 - EMI. Those components emit strong EM pulses and heatsinks are like big antennas. Basically what you get is a voltage which is the picture of EMI inside your PSU.
It has no real use, but if you plan to remove the original HS you may shunt the holes in which they where connected, to 'emulate' a connection through the HS (just in case they were really used as a big 'wire').
Now make sure you use mica shims behind those MOSFETs to prevent any leakage current through your WB (and watercooling system...).
side note: on thoe 'real' fanless PSUs, the backplate is really at 0V since it's in contact with the PSU frame...
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I basically want to "pull a bladerunner", with some minor differences. Even if anything else is getting hot, I'm going to cut a hole in the PSU box, and then the top of my case, seeing as heat rises. But I realize this may pose some electromegnetic issues, I'm just not sure what.
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No real problem apart from those:
- your neighbours on the next floor will hate you if they're soccer (or generally TV) fans. EMI can be strong and scramble their TV reception
- make sure nothing falls in there.. No liquid no solid nothing. You know what means 'high voltage'...
- if you're near a military base they'll knock at your door with angry looking faces.
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Oh (feel free to laugh-I'm really not an EE), what about replacing the MOSFETS with Active PFCs? Probably around the supidest thing you've ever heard, but I had to ask.
Thankyou sir!
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No problem
Active PFC is actually extra circuitry that controls the switching components, to maximize their efficiency and 'maximize' PF. PFC aka Power Factor Correction modify the global impedance of switching circuitry, to bring the PF as near as 1 as possible. This has for result to 'smooth' current pikes drawn on the mains, and reduce your electrical bill. 'Active' PFC adds active components to control the switch so that it occurs at 0V difference, and other neat features, to eliminate harmonic noise and current spikes (and EMI as a side effect).
In short with active PFC a PSU will handle more smoothly current pikes and quick load variations (which happens a lot in our modern PCs), and produce a cleaner output under load, and be cleaner in your electrical system.
The downside is, it needs more componentry, and is way more expensive...
Mhhh i read my post and i'm not sure i'm clear. Some links:
http://www.national.com/appinfo/power/ -> good basic info
http://www.traceengineering.com/tech...otes/tn11.html -> what's PF
http://www.epanorama.net/links/psu.html -> great links on PSU infos