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| Thread ID: 47268 | 2004-07-21 06:07:00 | what is the power suppily fan do?? | robsonde (120) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 254017 | 2004-07-21 06:07:00 | I know it sounds like a dumb question but . . . . . . . . . . I have an old system that i need to make super quite . is the power suppily fan for keeping the suppily cool or is it more just to give good case air flow with the side affect of cooling the suppily that might get warm if it is pushed a bit . the suppily is a 200W job and is only need to give abotu 100W or less . would it a the end of the power suppily if i removed the fan?? |
robsonde (120) | ||
| 254018 | 2004-07-21 06:23:00 | It is to keep the supply cool Derek, so remove the fan at your peril. Cheers Billy 8-{) |
Billy T (70) | ||
| 254019 | 2004-07-21 08:34:00 | The fan's main job is to save you buying new power supplies on a regular basis. :) R2 |
R2x1 (4628) | ||
| 254020 | 2004-07-21 08:44:00 | There are heatsinks in there that do nothing if the hot air around them in not removed . I suggest that you don't . But if you do, you can shove it next to your router (like I did), and half the cut out rate! |
Growly (6) | ||
| 254021 | 2004-07-21 08:55:00 | If you are keen, & Iike to live dangerously(cause opening a psu can KILL you) you can add a 5w resistor of about 22 to 47 ohms in series with the fan to slow it down a bit. You want about 9-10v to run it, down from 12v. This makes a huge difference to the noise level while keeping a fair amount of air moving. Remember the capacitors in a psu can hold a LETHAL charge for days......... Be very carefull!!!!!!!!!!. |
rmcb (164) | ||
| 254022 | 2004-07-21 11:44:00 | If you can just replace the current PSU with one that has a temp controlled fan. 2nd hand ones aren't expensive. I got a 2nd hand 250W AT for $10. I have come across a couple of systems where the PSU fan had stopped. They got a really nice shimmering/wavey effect on the screen and crashed after a couple of hours. And were probably a big fire risk. |
bmason (508) | ||
| 254023 | 2004-07-21 11:47:00 | What part of the PSU kills you? Don't say mains cause that just gave me a fright :D Does the PSU store at higher voltages? |
Growly (6) | ||
| 254024 | 2004-07-21 11:50:00 | if your really keen have a look at the passive cooled psu's. you might be able to mod an existing one to work similar. check out zfz.com/ or http: however just replaceing the fan with a varible speed one is proberly the easiest. | tweak'e (174) | ||
| 254025 | 2004-07-21 12:24:00 | now that looks like the sort of stuff i need...... | robsonde (120) | ||
| 254026 | 2004-07-21 20:36:00 | > What part of the PSU kills you? > > Don't say mains cause that just gave me a fright :D > > Does the PSU store at higher voltages? The incoming mains is rectified and stored in large capacitors at approximately 325 volts . These caps should have bleeder resistors across them to discharge the stored energy after switch-off but that is not a given, in fact it is a safe bet that cheaper supplies don't bother . In the days when caps were of lower quality the charge would dissipate quite rapidy through internal leakage, but now they can hold up for several hours (not days) at levels that would make you jump if you got across the terminals . The concept of days actually stems from the HV charge stored in the CRT of the monitor, and that can stay for several days in conditions of very low humidity . The greatest risk with PSUs is the first 10-15 minutes after switch-off when there may be enough charge to deliver a shock current of several milliamps . If you get that shock from hand-to-hand the effect is similar to a heart defibrillator only it is a one-hit wonder that can stop your heart dead in its tracks . CRTs can deliver such a shock for a lot longer . The risk is not great as the shock has to occur at the right point in the heart's electrical cycle but I wouldn't risk it as the odds are still quite bad . You buy lottery tickets with less chance of winning! If not trained, you play with open power supplies at your peril . I wouldn't play with the fan either . Running it slow may make it quieter but then it will not cope with the temperature increase at full load demand . Only a thermostatically controlled fan can do that . Just buy a better, quieter PSU if noise matters that much . Cheers Billy 8-{) |
Billy T (70) | ||
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