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Chuck Williams Fan Mod, WOW!! - Page 2  

post #31 of 231
I'm also very interested, I have a Sony 1252.

patrick@resforum.nu


Patrick J.
post #32 of 231
Count me in for the Sony 1252 mod. My email is jrbrooks@home.com
post #33 of 231
Hey,

I'm interested for my Sony 1271. I'm also confident I can perform the mod myself as I can access all the fans and I can build the likely simple circuits.

Chuck Rulz.

-Brian
post #34 of 231
Chuck
You seem to have quite a following among sony 12XX folks. Guess we are pretty tired of our noisy machines. Anyway, your point about these being industrial units is well taken, but slowing down the fans does make me a bit nervous. Anyone else? This probably comes from a feeling that there is something to be said for headroom/fudge factor. Will the PJ shut down if it gets too hot, and is there a difference in life expectancy over the long hall if the internal temp is say 20 degrees higher than if the fans were at full blast? 10 degrees? 5 degrees? Thanks and please add me to the list of interested people

Colin
cbrietzke@hotmail.com
post #35 of 231
Colin,

Glad you asked about the "increase" in temperature. What's made me really begin to think that this is a dandy idea is what I refer to as the "two finger touch" common sense approach. I've taken a Sony 1252 and essentially slowed the fans to much slower than what they will be with my mod, pumped 720p at max horizontal width into it and let it run for a couple of hours. Then I take two fingers and touch the heat sinks on the deflection board, power supply and video output circuits. They are warm to the touch, but not hot, and not very different from normal. This leads me to believe that the difference in life expectancy between slow, quiet fans and full blast roaring fans is negligible. The noise difference, however, is stunning.

I've also done this on a PG9 over two years ago because the customer wouldn't live with the noise it put out, so it was either make it quiet or loose the sale. Even with full blast fans, the heat sink on the deflection board gets pretty hot and almost fails the two finger test, but this projector has been running just fine for two years now. John Klados's PG 10 (he started this thread) is super quiet, and he doesn't detect any increase in temperature around the projector.

Will it work on an NEC XG/Barco/AmPro? I don't know yet, but I'll bet it will. Can I absolutely guarantee there will be no long term reliability problems? No. Can I guarantee it will run quietly and with reasonable assurance of reliability? Absolutely.

Everyone interested in this mod should please e-mail me at cmwtek@aol.com, and I'll keep you informed as I work out more details.

Chuck
post #36 of 231
Thread Starter 
Allen,

I believe Chuck told me that he was planning on having them available for those in the know who can install it themselves.

Johnboy:)
post #37 of 231
My 1272 must be more sensitive to reducing the fan voltage than others, so I had to settle for the fans running at 1/2 speed instead of 1/3 normal speed as Chuck's original circuit did.

When doing the installation, I started with the fans near the control panel which slowed down with no problem. But when I patched in the fan on the side, the FAN STOP code kicked in when the slowdown engaged. The same thing happened with the fans in the power supply. All the fans ran in the slow mode, they just made the protection circuit kick in. I found that the protection circuit needed between 7.5 and 8V to the power supply fans to not get the error code. Chuck had some suggestions for reducing the sensitivity, but since the power supply is about as easy to remove/install as a car radio in a '67 Camaro, I opted for the higher speed.

To get the mod to work in my 1272, I substituted a 9.1V zener for the 6.1V zener that controls the reduced voltage to the fans. This way the fans startup with -15V and then go to -8. Even at this level the noise reduction is great! The only fans I still hear are the power supply fans and now they sound more like a computer fan instead of an air conditioner.

Thanks Chuck for a great idea!
post #38 of 231
Jerry - Don't suppose you took any temp readings inside the housing pre and post mod did you? Also, what is the length of the delay provided by the 555?
post #39 of 231
The 555 delay is close to 1 second. Sorry, I don't have a temperature probe but nothing appears to be hot when I put my hand on the components with the covers open.
post #40 of 231
Thanks, that's what I'm seeing; one second just seems brief. Here's a calculator I ran across that will allow you to experiment with different resistor and/or capacitor values to see what's necessary to increase the delay should you need to. http://ourworld.compuserve.com/homep...Bowden/555.htm

I took one reading in the rear of the chassis, hood on, for a period of 2 1/2 hours and the temp peaked around 98 degrees before the mod. I'll take another tonight between the boards to establish another baseline.

12/4 - I placed the temp probe under the DC & E boards near the tube cavity and the temp peaked around 105 degrees (Pre-mod). Temp went up roughly 10 degrees after the mod.
post #41 of 231
Randy,

Glad it seems to work for you. One second is all you need to get the fans going, that's the point of the circuit. If you just applied the lower voltage to the fans at turn on, they wouldn't start up reliably. And, 98 degrees is zero problem. How's the fan noise now (as if I didn't know ;))?

Chuck
post #42 of 231
I changed the 12k resistor to something in the 46k range to give me approximately a four second delay. No particular reason, but it's a great reminder of whence we came each time you turn the projector on. In light of Jerry's issues with the 6.1v zener, I went in with the 9.1v as well.

When I powered the projector on, the fans ran full tilt for three or four seconds, then dropped down to roughly half speed. My wife thought the projector turned off! The difference in sound level is very impressive.

Post-mod temp reading under the DC & E boards (right behind the tubes) went from 105 to 115 degrees. I don't believe a 10 degree jump is going to have a material effect on the projector.

At some point, I may install a 7v or 8v zener to see what effect that has on the temp and fan noise.

And yes, the fans on the back of the power supply ARE tougher to deal with than installing a car radio in a '67 Camaro as Jerry suggested. ;)

Thanks again Chuck!
post #43 of 231
Randy,

Which model do you have? I would expect a temperature increase like you describe on a 1270, less on a 1251/1271 and less still on a 1272/1252. I think the heat you're measuring is coming from the video output section (the metal box under the E and DC boards), and the video output section from 1272/1252 runs much cooler than a 1270.

Chuck
post #44 of 231
It's a 1272, or supposed to be :eek:

I'll take a reading from the rear of the chassis tonight. The last reading in this area was 97 degrees or so (pre-mod).

My projector is ceiling mounted, what impact do you think convection has on this? Seems that as heat rises and collects in the top (formerly bottom when floor mounted) of the chassis, the overall temp would rise higher than if it were floor mounted?
post #45 of 231
Chuck any idea if your mod could be done on a VPH-D50QM ?

I would love to have a much quieter projector...

G_ROM
post #46 of 231
How are you guys configuing your 555's and how are you wiring them in? It sounds like a mono-stable configuration. Has anyone tried a pulse-width modulation configuration? I suppose you could even use a temperature sensitive resistor to increase the pulse width when the projector got hotter. I remember from my model railroad days that the DC motors of the trains ran best with pulse-width modulation @ ~40 Hz. Much better than simply lowering the voltage.

I love to know exactly what you guys are doing and see if I can apply some of my old micro-circuit knowledge to play around.

Chuck Anstey
post #47 of 231
Chuck,

Do you know id a Sony D50 would work well at reduced fan speeds. As you probably know, it has three fans only at the back which are easily accessible for modification.

GK
post #48 of 231
The 555 is used solely to actuate the 12V bypass relay. The relay contacts put a short accross the power transistor to get the fans full voltage for a second which overcomes inertia, goo, etc.

The eventual fan voltage is controlled by how much the power transistor is biased ON. So the frequency to the fans is just DC with no pulsing. It would be interesting to see how the protection circuit reacts to a pulsed output to the fans. The high level of the pulse might keep the protection from tripping even at very low speeds, or the low part of the pulse might make it react at any reduction.

Randy - I can see your point about the 4 second delay. The most fun about the mod is hearing the fans go from a roar to a whisper. ;) You might want to check if the power transistor is getting really hot from the longer time it gets shorted this way.
post #49 of 231
Actually, the 2N3055 would remain cool during the period of time that the collector and emitter are shorted, because the current would be flowing through the relay contacts and not the transistor. The 2N3055 passes the current (and hence, heats up), once the bypass relay opens.

Regarding the heat builup of the 2N3055, this is a 115 watt NPN power transistor. If you know how much current is being drawn by all the fans, you can calculate how much power the transistor passes, and hence, what kind of heatsink it needs. If you are concerned that the transistor is operating near its design limit, you can always change to a higher power transistor, or connect two 2N3055's in parallel to increase the power handling capacity. However, for most users, this should not be a problem.

You may wish to consider adding a fuse before the voltage regulator input to protect the source from which you are drawing the 15 volts, as a safety precaution. Should, for example, the voltage regulator short out, the possibilty exists that the circuit supplying the 15 volts to the fan speed reduction circuit (such as, for example, the deflection board) could be damaged.

steve
post #50 of 231
Quote:
Originally posted by Chuck Williams


The problem with that is these fans in these projectors have a sensor output to tell the computer that the fan is running. If the computer doesn't see this signal, it shuts down.

Also, you can't just lower the drive voltage to the fans because to get them reasonably quiet with a lower voltage they won't start up upon power up. What I'm working on is a small circuit that applies full power to the fans at power up, then applies the lower running voltage once they're going.

Chuck
The computer fans I speak of are those that have a 3rd sensor wire. This wire is for connection to a motherboard, and looks the same on my 1272Q. The purpose of this 3rd wire is to read the speed of the fan, thereby controlling it at startup and when things get hot. I picked up one from my local computer store for $5. Cdn.
Thought this might help.

Alan
post #51 of 231
Quote:
Originally posted by Jerry Arseneau
The most fun about the mod is hearing the fans go from a roar to a whisper. ;)
That is very cool, isn't it :cool: ?

Steve,

Did you get the addendum I sent? I suggested shunting the 2955 regulator with a 50 Ohm 3 watt resistor to share the current and make the transistor run cooler, plus adding fuses for safety.

Alan

These fans have sensor wires, also, but they only tell the micro that the fan is running, not how fast they run.

Chuck
post #52 of 231
Hi Chuck,
what is the addendum? Anything I could need for my 1270?
Thanks,
Roland
post #53 of 231
hi chuck or anyone who has the info,

could someone please send me the mod for a sony 1272? my email is kuzu_ryu_sen@hotmail.com .


thanks a lot in advance,

hiko
post #54 of 231
Hiko and Roland,

I'm out of town today, but when I get back I'll get you the info.

George and G Rom,

I'm sot sure doing this mod to a D50 is a good idea. These don't seem to be built to anywhere near the degree of toughness as these other units. A D50 will overheat and burn up some components on its deflection board if the chassis is opened up and the unit is running for more than about 15 minutes. Also, I've never had a D50 to experiment on.

Chuck
post #55 of 231
chuck:

No, I did not get the addendum. Could you please send it to me.

BTW, by "2955 regulator", are you referring to the 2N3055 power transistor, or the 78l05 voltage regulator? I don't think you would want to shunt the voltage regulator, and it most likely is not needed for the power transistor. The less circuitry, the better.

Steve
post #56 of 231
Quote:
Originally posted by Chuck Williams


That is very cool, isn't it :cool: ?

Steve,

Did you get the addendum I sent? I suggested shunting the 2955 regulator with a 50 Ohm 3 watt resistor to share the current and make the transistor run cooler, plus adding fuses for safety.

Alan

These fans have sensor wires, also, but they only tell the micro that the fan is running, not how fast they run.

Chuck
Chuck:

On my 1272, on the left rear corner, I noticed a hole where a fan may have been. Do you know if there should be one there? On the right side there is a fan, and the cable connects to a plug about 8" forward, but I cannot locate a cable connection or plug location on the circuit board.

Have you worked out a fan mod for the 1272?

Alan
post #57 of 231
Quote:
Originally posted by alared
On my 1272, on the left rear corner, I noticed a hole where a fan may have been. Do you know if there should be one there? On the right side there is a fan, and the cable connects to a plug about 8" forward, but I cannot locate a cable connection or plug location on the circuit board.
There shouldn't be any fan on that spot in 1272. The 1270's have it though.
post #58 of 231
Quote:
Have you worked out a fan mod for the 1272?
The fan mod mentioned will work for any 12xx series.
post #59 of 231
One thing to remember here, when you are getting a 10 degree increase in temp inside the tube cavity, the actually heat producing items are getting somewhat hotter than that.
I'm hoping to try Chuck's mod on my XG110, along with my hush box. I"ve decided no matter how quite it is, I'm keeping the Hbox, first because it will disperse more hot air than the pj's fans can, and that will possibly keep my internal temps where they are now, and second because all the air that reaches the pj is being filtered, and that's a nice idea.
post #60 of 231
Chuck,

Can you send me a copy of the 1272 instructions too? My address is bryan@loudcloud.com

Thanks!
Bryan
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