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PaulB
Joined: 26 Oct 2007
Posts: 359
Location: Bonnie (but rainy) Scotland
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| Posted: Sun Sep 20, 2009 12:22 pm Post subject: |
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| Nashou66 wrote: |
Why do you want to change yours? I thought you have the nocturas or is that someone else I was thinking of?
Athanasios |
Yes, i currently have the Noctua's installed but you got me thinking about static pressure and the more I looked into it the more it made sense, the amount of air moved isn't necessarily the only thing that needs to be taken into account. I think that the Noctua's are probably fine but the Thermaltake's provide an additional level of safety - they won't improve anything as such other than the static pressure but may help avoid any issues that may have arisen if I continued to use the Noctua's.
Like I said I'm pretty sure the Noctua's are fine, I'm just playing cautious with this and its a cheap enough fix. I'll order one up and see how it goes 
_________________
Paul
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Elaine Benes
Joined: 25 Apr 2006
Posts: 1416
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| Posted: Sun Sep 20, 2009 12:38 pm Post subject: |
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| Revox wrote: | Are there information aviable of the NEC cooling Concept.
As i saw the STK screwd at the bottom without a heat sink are a problem.
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Actually, the idea with the STK's attached where they are is to make the entire bottom of the projector act as a heatsink for the STK's which are the things in an NEC which get the hottest. Adding a small fan to the top of them is a good idea, but with a good setup, un-necessary.
NEC's are excellent projectors, I have owned many, many NEC's, all versions, and I can tell you from my own experience that they are capable of producing a better image than the Marquee in stock form. NEC's are sharper, and have better color reproduction than stock Marquee's. Where Marquee's tend to shine is in user friendliness. They are easy to set up well, whereas NEC's are the hardest projector to set up well. Marquee's are easy to work on and parts are plentiful, whereas NEC's are more difficult to work on(partly because there is less knowledge because of fewer common failures), and parts, especially clear tubes, are not easy to find. Color fidelity on an NEC is un-rivaled by any other projector, yet the reference mechanical white balance is the hardest service procedure to do and requires professional calibration and test equipment and a lot of patience and experience to get right. Many NEC's, unfortunately, would benefit from this procedure as they have suffered at the hands of curious previous owners.
Just my two cents...
And personally, I've never found the noise from an NEC PG chassis intrusive...
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Sparky015
Joined: 12 May 2009
Posts: 1185
Location: Cleveland / Akron, OH
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| Posted: Sun Sep 20, 2009 12:54 pm Post subject: |
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Revox,
For what it's worth, I just modified (like last week) my LVPS on my 8500 using the PAPST fans and "fan silencers" by Qualtek. The silencer is basically a rubber boot that seperates the sheet metal from the fan. All I had to do is drill out the 4 original mounting holes for 6.5mm and that's it. Since the PAPST fans are like for like replacements of the originals, no step-down circuitry is needed. I even reused the board connectors on the fans. Just pull off the old wires and slip in the new ones. I now have to be within a foot of the pj to hear the fans when it's off. Big difference. Here is a link to the silencers if interested.
http://www.mouser.com/ProductDetail/Qualtek/QLM-92-40-10/?qs=sGAEpiMZZMuA0nbpbQWbK6j6N%2fRxGa4dQNeFeJYPkus%3d
Paul
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Revox
Joined: 13 Feb 2008
Posts: 158
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| Posted: Sun Sep 20, 2009 1:47 pm Post subject: |
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My AC-Fans are decoupled too, that's the reason i chose them.
My problem as described below, is that i am very sensitive against noise.
I am at "home" now, far away from big loud fast Berlin and it's like a deliverance of noise out here.
But there was a huge difference in noise for me between my old Sony 1271 and the M 8500. The frequency of the LVPS and HVPS is higher than 16000Hz so i cannot hear a very loud fieeep noise. Thats the reason i don't like PAL TV's, i can hear them in the whole flat.
The idea of jusing different speed's for the fan's is very good, i'll mod my 7812 soon!
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David_Web
Joined: 02 May 2007
Posts: 418
Location: Sweden
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| Posted: Sun Sep 20, 2009 5:22 pm Post subject: |
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| Nashou66 wrote: | | David_Web wrote: | Just a question to be clear.
Should the outer two holes under the belly fans be plugged?
I don't have the bottom cover on mine but I could install it. |
Those two holes from the FCM and HDM do not have to be pluged and if you look at some covers they have a
rectangular cut out of foam that takes the hot air from those two holes right out of the PJ case, you need the case on to create the pressure for the air flow to move out to the rear heat sink, the air inside the main chassis will swirl around inside and eventually finds its way to the each side of the back of the Projector where it makes its way across the rear outside of the heat sink under the rear cover and through the little holes that are throughout the reap panel. HK Steve though milled off
the entire rear heat sink fins and added his own that I think he bought that fit perfectly, he secured them with thermal glue
and then added a bank of super quiet fans directly to the new rear heat sink. So this way he can run the PJ with the top cover off which keeps the VNB's cooler by not keeping the hot air inside.
Athanasios |
I meant the big holes on the underside that you can see here.
http://www.curtpalme.com/forum/files/pict0006_125.jpg
On a stock Marquee (8000 at least) all but the middle hole (with grille for the hole) is covered by a solid plate.
This is shown in the manual as well with only a hole for vent in the middle.
But on the Marquee I run now the plate is currently missing.
Or are we referring to the same thing only top/bottom reversed?
The only reason I can see is to force some of the air to be sucked though VIM and CLM
But it does this by cutting flow though HDM, FCM and tubes/VNB as the belly fans pushes less airflow to these parts due to the extra load presented by the smaller hole + the even smaller holes for VIM and the rest.
The rear heat sink is convection cooled through all the holes as far as I can see. (although not an optimal one due to wrong orientation of the fins, so only about 75% efficient, not sure how mush with cover on)
The uncooled rear heatsink have bothered me a little so I have been thinking about removing the rear cover and adding some low flow fans. Basically any added airflow should make a huge difference.
You could plug one end of the heatsink, add a plate that covers the rest of the heatsink, then add a big fan that pushes the air though the entire length of the fins and out the other end. Or one that pushes and one that suck if you want it symmetric. Should bring the temperature way down.
You do however rely on forced cooling and it would overheat if a fan fails (if you use only one). But that's no different than any other part.
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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Revox
Joined: 13 Feb 2008
Posts: 158
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| Posted: Mon Sep 21, 2009 9:20 am Post subject: |
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I'd like to know how to cheat on the Fanguard of the NEC PJ.
And Carthage must be destroyed!
I bought the graphics card cooler on ebay for 1€.
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kschmit2
Joined: 09 Mar 2006
Posts: 1141
Location: Heidelberg, Germany
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| Posted: Tue Sep 22, 2009 5:49 pm Post subject: |
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ceterum censeo carthaginem esse delendam 
Kai
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SisterOfMercy
Joined: 31 Oct 2007
Posts: 155
Location: Zwart Nazareth, The Netherlands
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| Posted: Tue Sep 22, 2009 6:06 pm Post subject: |
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| PaulB wrote: | | Yes, i currently have the Noctua's installed but you got me thinking about static pressure and the more I looked into it the more it made sense, the amount of air moved isn't necessarily the only thing that needs to be taken into account. I think that the Noctua's are probably fine but the Thermaltake's provide an additional level of safety - they won't improve anything as such other than the static pressure but may help avoid any issues that may have arisen if I continued to use the Noctua's. |
Thermaltake fans are probably manufactured by some cheapskate taiwanese factory with a weird name 
Just stick with fans that have a datasheet. Papst, NMB, those kind of fans.
I don't know if Noctua has datasheets, but they should. I kind of believe in their products, but their standard fans probably do not deliver enough static pressure. The P-fans (or something like that, the one with the bigger fan blades, designed for cpu coolers with a lot of surface area) are probably better suited for this situation. You could also try to contact Noctua to get some data about their fans, and base your choice on that.
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The kissing and the colour come crashing down
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PaulB
Joined: 26 Oct 2007
Posts: 359
Location: Bonnie (but rainy) Scotland
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| Posted: Wed Sep 23, 2009 8:31 am Post subject: |
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Ok, did a little digging and found the specs for the specific stock NMB Belly fans that I have ( NMB 4710NL-05W-B10 )
http://www.elma.com/StaticPages/BinaryFiles/Common/English/Resources/pdfs/4710NL-05W-B50.pdf
Looking at the pdf, CFM is 59 and static pressure H20 is 0.08 inches - or 2mm in Euro speak. Static Pressure appears to drop off at high CFM - is this correct? 27db.
The Noctua's I have NF-S12-1200 are rated at 48cfm but actually tested at 38 CFM ( details given in excellent fan comparison here - http://www.silentpcreview.com/article695-page4.html ). Could not locate Static pressure info.
In trying to track down the static pressure for the Noctua, I came across this site http://aphnetworks.com/reviews/noctua_nf_s12b_flx_nf_s12b_uln which has tested a newer version of the Noctua, the NF-S12B-FLX. It provides some interesting tests of the newer noctua, tests that Nash may recognise. It has a static pressure of 1.31mm h20 and airflow of Airflow: 100.6 m³/h (roughly 60CFM ) and 18db.
The P range of Noctuas, as suggested as a possible alternative by Sister above, the NF-P12 (or NH-U12P SE2 as it is also called - twinpack version) has an airflow of 92.3 m³/h (about 55cfm )and static pressure of 1.68mm H2O, 20db.
Ok, the Thermaltake A2329 have a CFM of 62.2, and static pressure of 2.13mm h2o, 16db (but Nash reckons they are louder than that).
The Papst 4144 (which I think was proposed as an alternative is tested 34cfm and 24db ( http://www.silentpcreview.com/article695-page3.html#papst ), static pressure of about .085 inches (2mm) (which again appears to drop off at higher cfm?) http://img.ebmpapst.com/products/datasheets/4412FML-GER.pdf
Well, where does that leave us? Just a point to note, this is mostly based on rated specs which may well exceed real-life results. All 12v by the way.
The Noctua NF-S12-1200 has too low a measured cfm and probably too low static pressure as well.
The Noctua NF-S12B-FLX looks better but static pressure is too low.
The Noctua NF-P12 comes closer static pressure just doesn't quite get there.
Thermaltake A2329 looks the best of the bunch. Nice find Nash
Papst 4144 too low on cfm but good match on static pressure. Loudest of the lot but quieter than stock.
Of course, thats comparing like for like, things get more complex when installing 4 fans in place of the original 3!
Would this work as a step-down convertor (just need one for all 3 or 4)? http://tiny.cc/Stepdown
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Paul
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Wed Sep 23, 2009 12:35 pm Post subject: |
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Nice investigating Paul, i had all that info once but lost it to a Hard drive crash a few years ago. Glad some one else dug it up!! i like that little variable output regulator. it be perfect for altering the speed of each fan on the belly, even the LVPS if you wanted. I think I'll look for a pot trimmer to add to the regulator design i posted above. Should work fine that way. I think the thermaltakes Silent cats will work , I just never got around to messing with different speeds. I just remember they had a higher pitch frequency than the stock fans ( i also might be sensitive to that frequency) maybe due to the extra air that it can pull trough the side fins on its body. But paul buy a single silent cat and see what you think, they are cheep anyhow. I wish the Enermax Enlobal bearing fan had more CFM, they are the quietest fans i have haven't hear so far
EDIT: Another thing you have to remember guys, the original fans were chosen most likely because the PJ's were to be used in a 24/7 type operation. we maybe keep ours on for one or two movies at a time( if we ever stop moding them ) so even if it has say 5-10 cfm lower I think they would still be ok. Temp readings at certain areas that stay within the limits of the service manual of your PJ would be the best way to determine if the fan is the proper one.
Athanasios
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"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan
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Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
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blue_z
Joined: 27 Apr 2006
Posts: 63
Location: So Calif
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| Posted: Sat Sep 26, 2009 2:10 am Post subject: |
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| PaulB wrote: | | Static Pressure appears to drop off at high CFM - is this correct? |
Hi there
That is an unusual way to describe a fan's characteristic curve.
I've always thought of the airflow versus static pressure (with voltage curves) as plots that indicated how strong (torque) the fan motor was. At one end of the curve, the fan produces max air flow, but the static pressure has to be zero (fan in free air, no enclosure). At the other end of the curve, the fan has pressurized the enclosure to the max, but the air flow is now zero. Each number has limited usefulness since the fan is rarely used in either extreme situation. And one number will be more relevant than the other, depending if you want to move air versus pressurize/inflate something.
Rather than considering static pressure as something that the fan can create, I've treated static pressure as an environmental parameter, like the input voltage. The fan in free air has zero static pressure, and the fan creates its maximum air flow. As the static pressure is increased, it impedes the air flow that the fan can generate. At some point the motor is too weak to generate air flow against the max static pressure. So I usually think of air flow as a function of static pressure (disregarding how it came to be), not the other way 'round as your question: a fan produces more CFM as static pressure is reduced.
I've never taken a Fluids class in Engineering school, so correct me if I'm wrong.
Regards
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Revox
Joined: 13 Feb 2008
Posts: 158
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| Posted: Sat Sep 26, 2009 4:33 pm Post subject: |
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Hi, i moddes something again!
The Bellyfans ran on 10,7 now and i added another fan on the green tube to "squirl" the air thought the PJ (because the airflow of the Bellyfans isn't enought). At 5V it's not audible but you can fell that the PJ is colder now. It's fixed with old Bike tire tubes.
Then i added two very thin small fans on the heat sink in the back. These Small fans @ 5V gave at least 5-10°C less heat sink temperature.
A Question for the NEC users: My PJ is factory color calibrated. Which possibilities do i have in the OSD to calibrate the white balance "better"? Is there a description for the WB aviable in the WWW? Do someone have a Service Manual for me?
I am still waiting for the Arctic Cooling Fan for the NEC.
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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Revox
Joined: 13 Feb 2008
Posts: 158
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| Posted: Sat Sep 26, 2009 5:58 pm Post subject: |
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Sorry, but i think it's voodoo!
Yes of cause it's a rotating magnet field, but on of which dimension?
The permeability of the iron in the rotor is at least 1000 times higher than the permeability of air. So the magnetic field won't go into the air around. The rotating field of the Fan windings isn't big to (and doesn't come out to).
If i ran the fan at 20000V (sorry thats really a bit ironic) the circle currents induced in the iron of the neckcover will be so high that it tourns into red!
I tested something to be shure:
I put a neodym magnet on another Fan, the force is only big in the middle of the Fan (to the axis).
Think about the deflection Cables! Very high currents at high frequency. As higher the frequency as higher the ability to tunnel through the little holes in the Neckboard Cover.
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tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
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| Posted: Sun Sep 27, 2009 12:37 am Post subject: |
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It's not voodoo. Some fans are designed to contain the magnetic field, some are not. It is easy to test, project a crosshatch test pattern and move the fan in question near the tube neck. Some fans will cause the image to move, some won't. One test is worth a thousand opinions.
Scott
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"Were we directed from Washington when to sow and when to reap, we would soon want bread."
Thomas Jefferson
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Revox
Joined: 13 Feb 2008
Posts: 158
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| Posted: Sun Sep 27, 2009 8:40 am Post subject: |
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I've got some problems with the NEC. I changed the deflection and convergenz Cables for desk front projektion and now the convergence on green and blue switches off and on and of and on. I think it will be a bad soldering, because it comes along with shaking the board.
I'll test the fact with the Fan. Sorry for my theory, there must be something my actual electrotechnics and physics study is good for, at least for beeing a wisenheimer.
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Revox
Joined: 13 Feb 2008
Posts: 158
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| Posted: Sun Sep 27, 2009 10:35 am Post subject: |
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I resoldered everything on the board. Nothing.
Then i deform the pins of the stk's to the chip (when i deform the hole pcb to the chip it works too). Now everything is "fine" again.
Is it possible to resoldier the pins of the stk's internally?
Ohhh it is. Lots of work desoldier the stk and at least half of the pins were easy.
Any ideas?
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Revox
Joined: 13 Feb 2008
Posts: 158
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| Posted: Sun Sep 27, 2009 11:33 am Post subject: |
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I opend the chip with a saw! But then i noticed that i must soldier very hot because the heat sink steals the heat from my soldering gun.
Then i noticed that the chip isn't expensive and i ordered one on ebay!
I noticed that one side of the Alu-heatsink of the convergence board was not connected right to the bottom of the chassis. This might be the reason of desoldiering!
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kschmit2
Joined: 09 Mar 2006
Posts: 1141
Location: Heidelberg, Germany
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| Posted: Mon Sep 28, 2009 2:45 pm Post subject: |
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you probably ordered a new stock (or fake) chip on ebay.
Only the old stock chips are of high enough quality to withstand the stress in a PJ with maximized rasters. Those are hard to come by and typically way more expensive though.
Most people would use replacement boards with known good chips on them.
You can ask if you need one, as I can see that you are in Germany as well.
Kai
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