Thankyou for the ideas. According to the ATI site, their 7500 supports DVI-out up to 1600x1200 but I've not seen a fanless one so far. The XFree-86 site says it supports those cards fully, including the dual-display capability (though only one of that card's outputs is DVI). If I can find a fanless ...

Found them at €15,99 from
www.silentpcshop.nl/CaseFan.asp#waterwheel
but I don't know about delivery & taxes etc. because I didn't want the trouble of registering with them in order to find out. They deliver to a lot of different countries.

Where to buy them in the UK, though...

Very tempting if it's as quiet as claimed. They don't publish it, but with that kind of design the pressure (the P-Q curve) must be much better than "ordinary" fans with comparable noise levels and maximum flow rate. Put one of these on a good heatsink with a suitable duct and the performance would ...

I know, I know, it's not strictly a silence-related thread, but I'm hoping that one or two of you will spare a minute to make a suggestion that'll save me a lot of hours of reading elsewhere. I'm wanting to choose a decent card but it needn't be too special or expensive: it's not for gaming. Needs t...

I am very impressed! Jones_Rush, how did you cool the power supply? Not many water-cooled PSUs about. A word of caution: the modern faster processor might generate heat at a similar rate to the old one, but the die size is smaller, the power per unit area greater, so it's more of a challenge. Don't ...

Am I right in thinking that at present the software on the microcontroller allows for monitoring of temperatures and fans speeds, and for sending new numbers from the computer to the ADM1027, and that's all? Update: confirmed, that's right. Any chance of having a way to update the software on the mi...

Place the pump inside a box or cage with small thick soft foam feet on all sides of the pump, then bolt the box or cage to your case rigidly.

So the same pump was louder submerged than in-line? I had guessed it would probably be the other way.

Sorry about the motherboard.
Perhaps it's worth planning for small leaks and arranging things so that drips will flow away from the circuitry.

This watercooling thread might be useful. A few posts back, someone was writing about corrosion. Certainly corrosion can be a problem, but I'm not convinced that the mixed-metal issue is all that important. Anyway, here is by far the best article I've seen on the subject: http://www.watercool.de/wis...

That's right, BillyBuerger. Mr_Smartepants, you have everything backwards. The power supply is a well regulated voltage source. The fan switches its coils on and off sharply, so the current it draws changes sharply. If there is a resistor in series with the fan then the current through the resistor ...

That's not the same thing at all. joesgarage11 was concerned about height (head) differences. Resistance (from friction) matters of course. It causes back-pressure in response to flow, and this is sometimes called "head loss" because pressure is sometimes measured in terms of the head that would giv...

I wonder if something like this could be achieved using a currently available fan with a tachometer wire. Feed suitably shaped pulses into the power lines, synchronised with the tachometer signal. Tricky, but it might work. Ultimately, I think the best solution would have the control circuitry in th...

A big fat chimney leading from the case outlet up to say a foot below the ceiling would give a useful increase in airflow from convection. It would work even better if you put some sort of heater inside the chimney just above the PC, but that would be a dreadful waste of power. Of course, the other ...

The head is irrelevant. That's why siphons work: all that matters is the difference in height between one end and the other, and for you there aren't any ends: it's a closed system.

Thankyou again. That is a bit disheartening. Essentially, you seem to be saying that for most fans, below 5V the tachometer signal just does not contain the information we want. That leaves three options: Never go below 5V. At least below 5V, don't bother trying to measure and control fan speed in r...

It would be the same.

supastar, no-one is suggesting that the PFC causes noise. Rather, the PFC model of this unit is noisier than the corresponding non-PFC model. I remember reading (I think it was somewhere in this huge thread) that it's because they have different fans. Perhaps the PFC version has some cheaper compone...

It might be worth a try on the Papsts as well. Do you have the parts to see how it is with, say, a 7V supply with a 10 ohm resistor to give about 6V across the fan? It would be useful to know how much "softening" of the voltage is necessary to make the clicking go away. In one way this is annoying t...

Thankyou! Very useful details. The fans won't necessarily be run at as much as 5V though: this is to be part of a circuit that should adjust the voltage automatically so as to keep the fan at some target speed which might be very slow. Still, if the speed sensor inside the fan is part of the coil sw...

That design looks as though the idea should work, but evidently it doesn't, or not as shown. Perhaps a smaller C2 and/or R4 and R5 would help, or perhaps the filtering makes the spikes smaller and shorter and something like this would help: 1------||------[ R ]----3 where 1 and 3 are the pins on the...

That helps, thankyou. Also I found some information elsewhere. I followed a link from cpemma's site to a page by Maxim about using their fan-control chips. Here is a section from it: Both EBM/Papst and NMB, along with other manufactures, offer fans with speed sensors that give a digital output whose...

I suppose they might think, "What's the problem? A faster drive than you ordered, for the same price."

Legally, if they send something wrong or broken then they must pay for the post and packing involved in replacing it.

A fan controller with a switch could switch the light on and off. On the other hand, you could just buy a switch. As for dimming, I suppose it would work so long as the light doesn't draw a higher current than the controller can handle, and so long as the light responds well to reduced voltage witho...

What does the signal from a fan's tachometer wire look like on an oscilloscope? Is it positive-going pulses?
Like that? If so, how high are they, and are they from zero?
Is there one pulse per revolution of the fan, or is it four or however many poles the fan has?

Quite a few people have used air filters meant for car engines etc. See other threads on these forums, and a couple of articles at overclockers.com You might also consider tumble-dryer filters (clog relatively quickly perhaps, but very quick and easy to clean), car passenger-cabin air filters, or va...

Active power factor correction, rather than passive. It's explained elsewhere on the site.

I think "Silenx" PSUs are available with at least that much power these days, from exoticpc.com or silenx.com. I would expect that the Fortron-branded one you mention would not be especially quiet, but would be stoutly made with big heatsinks so you could modify it for lower airflow without harming ...

Scalar, you mis-typed: the electrons come from the hot cathode, not from an anode. That's about right, SometimesWarrior. In a CRT, the phosphor starts glowing when the electron beam hits it, then dims gradually until it's not glowing at all, unless the bean hits it again. Therefore if the beam keeps...

I think you'd want a thin radiator/heater. A motorcycle radiator might be a good choice. Car radiators tend to have a lot of thin flat tubes with fins around them. For something like this, the same idea but with far fewer fins or none at all might be better: poorer performance for a given air flow r...