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Pol Walrant
Joined: 05 Jul 2007
Posts: 16
Location: Barchon-Belgium
TV/Projector: BarcoGraphics 1209s Iris2
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| Posted: Mon Aug 02, 2010 4:04 pm Post subject: Barco 909 Reality very Noisy |
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A friend of mine bought a 909 reality. the picture is superb, but the noise is much much higher than my 1209s.
After searching around in different forum I got 2 advises.
The first one says to put a 27 ohms resistor acros (in parallel) with the each of the 3 rear fans, and the second says to put a resistor of about 15 ohms in serie with each ot the 3 rear fans.
No technical explanation were given and the 2 approches are absolutely different.
Could anybody let me know which solution (if any) is the good one?
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Sparky015
Joined: 12 May 2009
Posts: 1185
Location: Cleveland / Akron, OH
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| Posted: Mon Aug 02, 2010 4:10 pm Post subject: |
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this isn't a digital, but a high-end CRT. I would ask this in the CRT forum.
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~Paul
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AnalogRocks
Forum Moderator
Joined: 08 Mar 2006
Posts: 26706
Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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| Posted: Mon Aug 02, 2010 4:17 pm Post subject: |
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Moved to the CRT forum ~ Mod
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Tech support for nothing
CRT.
HD done right!
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Pol Walrant
Joined: 05 Jul 2007
Posts: 16
Location: Barchon-Belgium
TV/Projector: BarcoGraphics 1209s Iris2
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| Posted: Tue Aug 03, 2010 7:49 am Post subject: |
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My mistake.
Thanks to have made the location change
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Posted: Tue Aug 03, 2010 2:47 pm Post subject: |
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When resistors are in parallel fans still run as fast and you most likely burn smps. Three times 27 ohm makes about 15W load to fan line.
Series resistors are better way to do it...
If I remember correct 909 have fans temperature control disabled, so fans are running at full voltage all the time. I'd investigate smps if it's possible to make it similar that Cine9 have.
This is how fan speed is controlled in 1209s, don't know if Cine9 use same circuit or not.
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Pol Walrant
Joined: 05 Jul 2007
Posts: 16
Location: Barchon-Belgium
TV/Projector: BarcoGraphics 1209s Iris2
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| Posted: Tue Aug 03, 2010 5:17 pm Post subject: |
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Thanks.
Serie resistor is the best way to go, but is 15 ohms a correct value..?
I did check the projector and found that at start-up both left and right fan go fullspeed (13.5VDC) and the middle fan start later at low speed (6.38VDC) and speed increase following the temperature.
Maybe the best way to go is to put 15ohms in serie with left and right fans and leave the middle fan as it is (as it is temperature controlled).
Any idea............?
The fans are 12VDC, 0.32A then about 40ohms impedance and 15ohms in serie would drop the voltage to about 9VDC. Would that be safe or not..?
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Sparky015
Joined: 12 May 2009
Posts: 1185
Location: Cleveland / Akron, OH
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| Posted: Tue Aug 03, 2010 5:20 pm Post subject: |
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why not replace them with fans that have a lower db rating? I'm not a fan of slowing down fans without knowing what the impact will be on cooling. I would find like-spec fans that are more quiet and sub them in. I'm there is room to play since that projector was designed to run 24-7 in a simulator, but not sure you want to take a chance without doing some thermal measurements on a very rare and expensive projector.
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~Paul
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Sparky015
Joined: 12 May 2009
Posts: 1185
Location: Cleveland / Akron, OH
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| Posted: Tue Aug 03, 2010 5:21 pm Post subject: |
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besides, slow them down too much (below what their voltage rating is), and you could burn them up (essentially starve them to death)
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~Paul
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Mark_A_W
Joined: 15 Mar 2006
Posts: 3068
Location: Sunny Melbourne Australia
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| Posted: Tue Aug 03, 2010 10:30 pm Post subject: |
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| Sparky015 wrote: | | why not replace them with fans that have a lower db rating? I'm not a fan of slowing down fans without knowing what the impact will be on cooling. I would find like-spec fans that are more quiet and sub them in. I'm there is room to play since that projector was designed to run 24-7 in a simulator, but not sure you want to take a chance without doing some thermal measurements on a very rare and expensive projector. |
This is the most dangerous thing you can do.
The best thing to do is to recreate the Cine9 fan control circuit.
The next best thing to do is to slow the fans (I'd use zener diodes) slightly. You know you have room to wiggle as the Cine9 runs the fans slower.
But it wouldn't hurt to add external forced extraction, as well as slowing fans.
Mark
Last edited by Mark_A_W on Wed Aug 04, 2010 2:38 am; edited 1 time in total
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dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
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| Posted: Tue Aug 03, 2010 10:44 pm Post subject: |
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i agree with mark, do not fiddle with the airflow circuit but build a hushbox to lower noise.
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marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Posted: Wed Aug 04, 2010 7:26 am Post subject: |
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| Pol Walrant wrote: | | the middle fan start later at low speed (6.38VDC) and speed increase following the temperature. |
Sounds like they used original fan controll only for middle fan.
I'd connect all back end fans to that center fan line and you have same temperature controll that other Barcos. I guess this is how fans are connected in Cine9. Check if there is jumpers in mother board near fan connectors, it's possible that 909/Cine9 use same board and fan controll can be reactivated from jumper.
Convercence tray fan should have own temperature controll like other newer Barcos.
If that is still too noisy for your friend, then it's time to build hushbox.
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Thu Aug 05, 2010 1:45 pm Post subject: |
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It's best to leave the fans in this set as it is. Unlike most of the other CRT projectors that has a lot of space around its boards, the 909 chassis has the boards that are fan cooled in an enclosure. The entire board housing assembly (shown in the picture below) once the cover is closed it is an enclosure. And because there could be up to three boards in there besides the Horizontal board that gets really hot, especially at higher scan rates, having the two outer fans forcing maximum air at all times would be the best for that enclosure.
Actually having that center fan on a fan control circuit was not a good idea. The projector would work better if the fans were all on at full or maybe all on at the same speed but maybe a lower speed, rather than that ridiculous fan control system its designed with.
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Thu Aug 05, 2010 2:07 pm Post subject: |
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The following shot shows the other two fans that are on the front tray. That tray houses the Focus, Stig and Convergence boards along with the control module. All three of them run very HOT and are cooled from those two little fans shown in the shot.
In commercial application the front cover to that tray has small holes for ventilation. Those holes would require maintenance to keep them clear.
Whatever you do, DO NOT lower the speed on those fans...
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Thu Aug 05, 2010 2:26 pm Post subject: |
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| Sparky015 wrote: | | I'm not a fan of slowing down fans |
Can we give the man a RIMSHOT please? 
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dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
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| Posted: Thu Aug 05, 2010 3:09 pm Post subject: |
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does the br909 run hotter then other projectors and if so why does it do that.
just curious.
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1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Posted: Thu Aug 05, 2010 4:31 pm Post subject: |
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| dvh99 wrote: | does the br909 run hotter then other projectors and if so why does it do that.
just curious. |
No with signals we use in HT.
Compared for example to Cine9 max horizontal scanning frequency is 180 vs. 130 KHz, that must be reason why two back end fans run full speed all the time. It's also designed to be used 24/7 and Cine9 is not.
With under 130kHz signals it should work fine with temp control also in those two fans.
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mp20748
Joined: 12 Sep 2006
Posts: 5689
Location: Maryland
TV/Projector: 9500LC Ultra / Super 02 and 03 VIM
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| Posted: Thu Aug 05, 2010 6:35 pm Post subject: |
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| dvh99 wrote: | does the br909 run hotter then other projectors and if so why does it do that.
just curious. |
Yes, for the most part, it does run hotter than any of the other projectors out there. And that explains why there's three fans on the rear for that section of the boards. The Horizontal module unlike what they're doing on some of the projectors, does not have relays and dual horizontal windings on the yoke. It does not switch from low to high band. And it runs VERY HOT, even at low scan rates. That's why a temperature controlled fan on that module was not a good idea. And the higher the scan rate, the hotter it gets.
The other problem with the fan turning on after the temperature reaches a certain level is that it will effect the convergence having that fan switching in and out based on temperature. Because of the critical nature of convergence and what causes it to drift (heat), by not having the horizontal module operating at a non constant temperature, it gives way for convergence drifting.
In a lot of the commercial applications that these projectors were purchased and being used in, they never just like most of the other CRT projectors, never got to go above 130khz. For the applications that they were mainly being used in, there was no need to go that high. The scan ratings listed for the 909 much like the marquee 9500 ultra, Sony G90 and Barco 1209, not one of of them was capable of resolving the bandwidth that's associated at those rates, nor was there anything out there that really required a large screen projector to operate at those rates. The stuff that's at those very high rates were done on Expensive PC monitiors. What they used the projectors to display was the end result, and that was usually 1280x1024 at refresh rates up to 120hz.
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rwallmow
Joined: 19 Jul 2010
Posts: 29
Location: Minneapolis, MN, USA
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| Posted: Sat Aug 14, 2010 3:27 am Post subject: |
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Replace the fans with some good "magnetic bearing" fans, they are near silent, and rarely if ever quit working, search amazon (using the forum links so this site gets credit) for "enlobal" and you will find the "enermax enlobal magnetic bearing fans". These buggers work great for keeping a PC cool and near silent and should work wonders for a projector.
These things are great, they move some serious air and make almost no noise. This would be a lot cheaper than slowing down the stock fans and risk burning out your nice high end CRT projector.
But keep in mind if the stock fans are running higher CFM these may not be the best replacement for you, but generally these projector fans are NOT high CFM and these would be equal or greater than what was there, just please check the current fan specs before replacing them.
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