CurtPalme.com Home Theater Forum

[tschaeikaei]

Hi, something about the belly fans inside the Marquees.
My projectors (2001 8500 Ultras) have 3 120mm fans inside.

These sit on a aluminium sheet and i think they are accessible from underneath the projector.
There is another sheet of aluminum under the projector. After removing that one, it should be possible to reach the fans
without removing all the boards and tubes.
I will check that later.
I ordered these fans: Enermax magma advance UCMAA12A.http://www.enermaxusa.com/ucmaa12a.php
Should fit...
The original fans are here:http://parts.arrow.com/item/detail/nmb-technologies-corporation/4710nl-05w-b10-p00#gMpz

Regards, Julian

PART INFORMATION
4710NL-05W-B10-P00 PART DETAILS & PARAMETRIC

EU RoHS Supplier Unconfirmed
Voltage Rating (V) 24
Operating Input Voltage Range (V) 10 to 27.6
Power Rating (W) 1.92
Category DC Fan
Nominal Speed (r/min) 1550
Maximum Airflow (CFM) 58.62
Maximum Pressure 20.8Pa
Noise Level (dB) 27
Line Current (A) 0.08
Bearings Ball
Mounting Flange Mount
Fan Rotation Counter Clockwise
Termination Lead Wire
Housing Material Plastic
Maximum Operating Temperature (°C) 70
Minimum Operating Temperature (°C) -10
Shape Square
Size (mm) 119 X 119 X 25.5
Product Length (mm) 119
Product Depth (mm) 119
Product Height (mm) 25.5

[Nashou66]

Static pressure is as if not more important that airflow. the originals put out 20.8 pascals which converts to 2.12 mm-H2O.

So you'll have to run those enermax's in performance mode. But then your moving 30cfm more air than the originals and that can add to Wind noise. so maybe the mid speed mode with a static pressure of 14 mm-H20 might be enough.

Athanasios

[thewolfman]

You don't have to remove anything, unless you go for Silent wings of course, because those require the pins that holds it all together to be put in from the inside, meaning everything has to come off. And I'll say those 1800 rpm:s you are getting now are going to sound just as awful as the original fans do. As far as I'm concerned no more than 1500 rpm should be put there to have them run quite. I promise you will be disappointed with the outcome with rpm @ 1800.

[tschaeikaei]

Yes guys, i know this. i ordered the fans yesterday evening after reading about 50 spec sheets of different fans.
Maybe i was too tired.
The main thing i wanted to say with this post was the specs of the original fans and how
i think they can be accessed.
I did make another failure, too. I compared with the 4710KL-05W-B10 instead of the 4710NL-05W-B10.
They have slightly different specs.
Maybe i will cancel this order and choose other fans.
On the Enermax website, they write about the noise: minimal noise (dBA) 20 (at full speed).
Sounds like they are louder in reality. In my opinion, they would have to write about maximum noise.

The best way to use these Enermax (if i don't cancel the order) would be setting the switch to "performance mode" and undervolt them.
I will have to build a 24-->12V converter anyway, so just use a adjustable voltage regulator instead of a fixed 12V type.

Regards, Julian

[Nashou66]

[thewolfman]

[tschaeikaei]

Thanks für the info, wolfman. But i don't buy things i can build myself. Thats kind of principle for me.
May be easier, but it's so fast and easy to take a piece of perfboard and an LM317 or LM337.
I will wait until the fans are here and see if they are good. Reading and comparing spec sheets is most theoretical.
Let's see how the practical test will be. If they fail, i'll send them back and try others.
Regards, Julian

[redfox001]

One question. I had these fans out and to be sure everything works normal. The fans in the lvps should they blow air or suck air?

[Nashou66]

[redfox001]

Ok. I put the splitter back to its normal position. Seems not a good idea to put a splitter there.

[tschaeikaei]

The Enermax were not quiet. I had them here, tested and sent them back.
I did now find other fans and think they should be ok.

Cougar fans, found them cheap here: Amazon

Here are the specs: Cougar

I had another idea, that may be worth to discuss.
The 3 belly fans cool the HDM and the FGM. Each of those boards has a large heatsink and the boards sit in boxes.
The heatsinks are something about 5mm away from the aluminum boxes. If one would couple the heatsink and the box thermally
(mounting a 5mm aluminum plate in the gap between box and heatsink and screw box and heatsink together), it would massively improve cooling.
The air from the fans travel through the insde of the box.
If one would spraypaint the box and the heatsink black, it would also improve it.

I also thought about problems that could occur if the box and heatsink are electrically coupled.
But, the transistors backplates do not have electrical contact with the heatsinks.
They are mounted on a heat conducting foil, that does not measure as an electrical conductor (above 40MOhm with my DMM).
And: the heatsink is connected to board ground, while the box is screwed to the motherboard and chassis ground.
Do i oversee anything or is this a good and quiet heat dissipation solution?

Regards, Julian

[stridsvognen]

[tschaeikaei]

4 weeks ago, i would even consider painting a heatsink.
But when i tried it and got a surprise.

A friend made LED- Panels for me to lighten my room.
These are 160x100mm circuit boards with 120 SMD LEDs on each.
The circuit boards are screwed to 3mm Aluminum plates on their backsides.
So the Aluminum plates collect the heat from the LEDs and radiate it off to the air.
There is no fan involved.
After mounting the panels in my room they were at 45°C after an hour of use (constant current).
I painted the backside of the aluminum black and there we go: 38°C under the same circumstances.
Same current, same room temperature, same mounting on the ceiling slope as before.
The temperatures were measured directly at the LEDs pins.

I would give the paint a try. If you do make bad experience, just take the box out and clean the paint off
with cellulose thinner (or paint thinner, however the english word is).

The heatsinks on the neckboards could be spraypainted, too.
And this painting thing is not a new idea, i have many heatsinks here, some if not most of them come black from the factory.
But only those, that are meant for passive cooling (without a fan). But could painting harm it if a fan is added? I don't think so.

Regards, Julian

[tschaeikaei]

The cougar fans are here.
And I think I can recommend these. They are really quiet
and the airflow and pressure seem to be approximately the same compared to the original NMB fans.
As far as I can feel that with my hand.
Good idea to order these and thanks to Nashou for the idea.
I would grab these as long as they are so cheap on amazon.
The seller has only 9 pieces left after I ordered.

Regards, Julian

[gjaky]

[tschaeikaei]

Anodizing at home should be doable.
But first I will try to paint one projectors HDM and FGM boxes black.
So it will be easy to measure temperature difference between painted and bare aluminum.
If it does not work, just use paint thinner to remove the paint.
Regards, Julian

[Nashou66]

Julian, what voltage did you choose to run the cougars at?

Athanasios

[tschaeikaei]

I ran one of them at 12V. They are not in the projector yet, I tested with my DC lab power supply.
After they are mounted in the projector, they will be run temperature controlled on an atmega based fan control.
This should be the best and easiest way, because to create 12V out of 24, the max PWM will be set to 50% and thats it.
No voltage regulator needed there.

There is a single mosfet on the HDM board on a single heatsink. I already improved this by mounting a bigger one.
So if the fans do later run at lower speeds, this one won't get too hot. The big heatsink will be screwed to the aluminum box.
The FGM has 3 single LM675, each sitting on its own heatsink, all heatsinks connected to ground.
I will most likely treat them the same way mounting one large heatsink for all of them together.

I think of adapting barclays idea, too. If the projector is ceiling mounted, it would be better to let the fans blow
to the downside of the pj, using the stack effect will surely improve the airflow.

But, what are the goals we want to achieve? It is not the absolute lowest temperature, but a fast reached stable temperature
on all components. This will decrease warming up time for the pj and let convergence set fast to a watchable picture.


And to reach that, it doesn't make sense to use fans that always run at the same rpm. You'll need fans that run at a really low rpm at startup -
let the boards heat to a certain temperature and then keep that temperature stable (spinning faster).
If the room temperature is (let's say) 20°C, it won't make sense to set the target temperature to 25°C,
because of the nessesarity to use many fast spinning fans for something like that.
If the temperature we want to reach is higher (let's say 45°C), the nessesary amount of cooling will be much smaller.
So it's all about delta T.
That target temperature can be determined for each board itself. A lot of work left there.

Connecting the heatsinks on the HDM and FGM to the boxes will increase thermal capacity
(because of the more metal that must heat up before the fans start increasing their rpm).
Thats kind of counterproductive for the mentioned goal, but necessary if they should not get too hot.
Must figure that one out.

Regards, Julian

[tschaeikaei]

Does anyone know how much current those 24V at the fan connectors can deliver?
My cougar bellyfans are rated to 300mA (12V) x3, the 140mm fan for the large heatsink (vertical, astig and convergence board) will be about 150mA
and the 40 or 60mm fans for the neckboards will be about 100mA (x3).
Thats about 1350mA 12V.
The PWM will use the 24V (max PWM on-time 50%), so about 1,5A would be enough.
The original belly fans are rated as 24V 0,08A.
80mA x3 is 240mA. Lots of difference here.

Regards, Julian

[barclay66]

Hi,

No problem with the 24V at the fan connector. I run a total of six 12V fans plus regulator and control circuits on this line since about a year without any issues. Just be aware that the polarity is inversed and we're talking about -24V here. You will have to connect the Marquee Ground line to the positive input connector of the PWM circuit and the Supply line to the Ground input connector. And make sure that Ground of the Marquee and Ground of the PWM and fans are not connected. This would shorten the -24V line...

Regards,
barclay66