Home made projector!

[Chernobyl]

well would you believe it!
I was checking why the exhaust temp of the PC has been pretty warm since last night and only just noticed the PSU fan is dead lol.
(yeah yeah you told me )

The PSU was so hot I couldnt touch it but it still functioned flawlessly at that temp all night and day. It hasnt developed any funny smells indicative of stressed components either and it was seriously hot. I expected thermal runaway at that temp!
As bad as this could have been, I am very encouraged by how well this PSU coped with almost zero airflow inside it.
To this end I am getting the same PSU again. I have asked if it is a common mode of failure, in which case I will get something else.

You can argue its more likely to happen to a cheap PSU but my experience of PC fans is I get just as many failures on costly ones as cheap ones.

I'm still hopeful this is a decent cheap power supply.
I'm also glad for good temperature monitoring and good case airflow as this can happen to any PSU (single fan)!
The PC now has a fan blowing onto the PSU as a precaution.
(it costs about £2.00 per year to run the fan 24/7)

My system is now running with the 400W Enermax.
The CPU has been returned to default speeds the graphics card declocked to 500/500 to be safe until I get a replacement.

I have to laugh at the irony

[Favu]

GFX underclocking = overvolting = more heat = bad thing (tm)

I know that underclocking has killed a few people's 6800 series nVidia cards, and in light of that, I wouldn't do it.

I admire you for having the guts to get something after it has died on you once already :|

[Gizmo]

Originally Posted by Chernobyl

As bad as this could have been, I am very encouraged by how well this PSU coped with almost zero airflow inside it.
To this end I am getting the same PSU again. I have asked if it is a common mode of failure, in which case I will get something else.

Why buy a new PSU? Why not just replace the fan? You obviously have the necessary skills?

[Chernobyl]

Originally Posted by Favu

GFX underclocking = overvolting = more heat = bad thing (tm)

I know that underclocking has killed a few people's 6800 series nVidia cards, and in light of that, I wouldn't do it.

I admire you for having the guts to get something after it has died on you once already :|

Interesting point of view!
My own experience has shown different and the theory behind it is pretty sound.
The silicon has specific voltage requirements to remain below a certain temperature and within operational limits for the cooling it has.

My own observation have demonstrated that an increase in clock speed generates more heat and a decrease in clockspeed generates less heat for the same voltage. This makes sense as at higher speeds more gate switching occurs which requires more current.

I wont deny the experience of the 6800 owners but can say with hand on heart that the same problem isnt happening here.
My GPU is operating at 4C less at idle with the lower speeds

[Chernobyl]

Originally Posted by gizmo

Why buy a new PSU? Why not just replace the fan? You obviously have the necessary skills?

hehe the thought did occur.
If something else should fail on the PSU I want to be able to send it back under warranty so decided against it.
The fan it comes with is excellent for the job too (when it works lol).

Here are some piccies of it.

ps it wont cost anything to have the psu replaced.
I dont think I even have to pay for shipping, the last time I had something returned to Ebuyer, they paid for the collection.

Edit:
just got an email from Ebuyer, if postage back to them is more than £5 they will arrange for collection. Nice service still, I havent seen this from any other supplier in the UK.
(It cost one of my clients £35 to send a Surround System back to Komplett, we dont use them any more!)

[Chernobyl]

Originally Posted by Chernobyl

"Favu
GFX underclocking = overvolting = more heat = bad thing (tm)

I know that underclocking has killed a few people's 6800 series nVidia cards, and in light of that, I wouldn't do it.

I admire you for having the guts to get something after it has died on you once already :|"

Interesting point of view!
My own experience has shown different and the theory behind it is pretty sound.
The silicon has specific voltage requirements to remain below a certain temperature and within operational limits for the cooling it has.

My own observation have demonstrated that an increase in clock speed generates more heat and a decrease in clockspeed generates less heat for the same voltage. This makes sense as at higher speeds more gate switching occurs which requires more current.

I wont deny the experience of the 6800 owners but can say with hand on heart that the same problem isnt happening here.
My GPU is operating at 4C less at idle with the lower speeds

After further thinking on this it looks like there is a flaw in some 6800's if what you say is correct.
Power is directly proportional to the square of the voltage used.
Power = V squared / Resistance

So a lower voltage will use less power and generate less heat for the same resistance.
In the case of the damaged 6800's, the only way they could heat up more is if the internal resistance of the GPU's dropped somehow.
This goes against the grain as lower frequency operation (lower switching speed) will increase the internal resistance reducing current flow so something else quite serious is going wrong there.

[Chernobyl]

Originally Posted by Chernobyl

ps it wont cost anything to have the psu replaced.
I dont think I even have to pay for shipping, the last time I had something returned to Ebuyer, they paid for the collection.

Edit:
just got an email from Ebuyer, if postage back to them is more than £5 they will arrange for collection. Nice service still, I havent seen this from any other supplier in the UK.
(It cost one of my clients £35 to send a Surround System back to Komplett, we dont use them any more!)

Even better, I misread.
They will also refund the postage if the receipt is included in the package!
Brilliant service.

[Chernobyl]

The PSU is going back today so sometime next week I will be able to find out if these PSU's all die early

The 400W PSU is holding up really well at the lower clock speeds.
Playing Oblivion at first was a bit slow. Given that the CPU doesnt sit on the 12V rail, I overclocked it again and the performance is surprisingly excellent with a low clocked x1800xt!
This is a good way to get by if your PSU isnt good enough.

As the brightness is now suffering a little I have ordered another bulb which should be here next week. Mmmm more toys.
I decided not to go with www.aalighting.co.uk (also known as dclighting.co.uk) as mentioned many pages earlier the chap I spoke to didnt quote me for everything I needed and went back on the deal. He has since put the bulb price up 50% when he found they may be in demand!!!
(please note the bulb is the D - Daylight version not NDL or WDL)
He now charges over £38 + delivery for the D bulb and still sells the other versions we dont need for £26 so he wont ever get my recommendation or business.
The site also doesnt tell you anything about the bulbs they sell, you have to research yourself so there isnt any value using his website.
Other suppliers in the UK sell it for a little more than I paid below...

The bulb cost £25 inc delivery from this place in Germany:
http://cgi.ebay.de/ws/eBayISAPI.dll?...tem=4459963741
The shipping costs are wrong for UK as they should be 15 Euros but he honoured the error and is shipping to me at the original price.
The new price would be about £30 delivered.
The bulb is the same or very close specs to the bulb I have and is an Osram, FC2 fittings (double ended), 250W, Daylight (5200 Kelvin), 20000 lumens.
I'm not sure of the bulb life but having read every other spec sheet under the sun, it is between 6,000 and 20,000 hours (between 1 and 3 years continuous use).
The CRI (Colour Rendering Index) will also be a mute point as I havent found any spec sheets for these bulbs with a CRI of less than 85. 85 or above is ideal.
The current bulb is still going and has lasted well over a year so am very happy with it

[Chernobyl]

Woot!
AoaForums is no longer included in the Blocklists.
You are freeeeeeee!

[dsio]

Expensive PSUs dying is a very rare thing really. My Enermax 370 is a 2000 model, and has been running day and night for about 4 years now, without blinking. My Enermax 430 is brilliant. The 470 Noisetaker is flawless.

Replacing the fan is all well and good. But ask yourself why did the fan fail? Was it a bad fan, or was it that the PSU that killed it.

At the end of the day, a good PSU is an insurance policy. It isn't a unit you need to worry about, but it is something that has the potential to destroy the majority of your hardware.

Enermax offer 3 years standard, and both my Noisetaker and my 430W, are covered by a lifetime warranty for an extra $10. They do that, because they simply don't get many returns.

[Gizmo]

Originally Posted by Chernobyl

Woot!
AoaForums is no longer included in the Blocklists.
You are freeeeeeee!

Coolness.

[Chernobyl]

2 bits of good news

After about a week of using the 430W Enermax PSU I have concluded it is absolutely fine to use with the new graphics card.
For a few days I had been playing Oblivion with the x1800xt clocked down to 500/500 and it worked flawlessly.
So a few days ago I decided to try the default clocks of 700/800 while monitoring the 12V rail with a multimeter and have been pleasantly surprised!

At idle the 12V rail sits at 11.93V and full load gfx/cpu it only drops to 11.83V
The ATX specs state that rails must remain with 5% of the rated voltage.
This puts the operating voltage of 12V to be within 11.4V and 12.6V so it is well inside the operating specs.

Really good news for anyone with a 430W Enermax and maybe good news for other old High Power PSU owners who upgrade to a newer Graphics card.
Its worth doing a test with a multimeter firstly when you start under full load. if the voltage rails remain in spec keep going and keep monitoring.
After a few hours if its still within spec you're looking good!
Its worth observing the speed of the fans when you put the system under load. If they drop in speed appreciably, its likely the PSU is being overloaded so you must stop immediately unless you are brave.
(note: I incorrectly stated earlier that the cpu sits on the 5V rail, it also uses the 12V rail)


On Monday the new 250W bulb arrived and the picture is incredibly brighter!
I also spotted something rather embarrassing that was making the bottom of the screen darker. The cardboard shroud surrounding the LCD was a bit too high on the front and was blocking the light from the very bottom of the OHP's mirror. This has been cut away and made quite a difference!

The picture size has been maxed vertically on the new screen leaving a little border on the sides and it is fantastic. The picture is 2.85 metres diagonal. It isnt restricted by the screen size but the max height I can have unless the screen can be raised nearer the ceiling. Also the OHP is almost as far back as it can go so I cant get much bigger anyway. Its a massive picture and I dont want for more so I'll leave it as it is.
I want to post some piccies but my camera cant seem to produce a decent picture, I hope its not faulty.
I'm gonna try and find another way to get some decent pictures.

It is proven that a 250W (metal halide) LCD OHP projector can give you an almost 3 metre diagonal screen with brilliant results for Windows, TV, Movies and gaming
Pretty cheaply too.

Phenomenal!

[Chernobyl]

I dug up the best looking photos for you

The first one is the difference between the old and new bulbs.
The old one is at the bottom and shows a browning on the inside of the glass which dimmed the image.
It has been in constant use for 1 and 1/3 years (rated for 1 year) so I will probably be replacing this bulb after 1 year to keep brightness up.

Next is Oblivion with a 15" monitor at the bottom right of the picture to compare the size.
The last is watching the Grand Prix on the TV card.

It looks a lot brighter here, its GREAT

[Chernobyl]

"So a few days ago I decided to try the default clocks of 700/800 while monitoring the 12V rail with a multimeter and have been pleasantly surprised!"

oops, default clocks are 600/700 and is what I used.

[metehanefe]

Hi guys, I'm quite new at this subject but I have decided to build a homemade projector. I have a few concerns and questions:
1.is it possible to make it with those portable projectors which perhaps many of you have seen it. They don't have this bottom part and there is just a slim place to put the stuff to reflect. It is very light but I have no idea if it is appropriate for this project. I don't know if they work with the same mechanism with other big and heavy ones.
2.For experienced people, what is the limitations for significat parts such as the ansi lumen value limitation. Can you say 1800 ansi lumen is just wasting money? or maybe it could be about the lcd panel.


thats all for now...if someone replies I will be pleased..

[dsio]

Perhaps a picture or link to one of these portable projectors would help?

[metehanefe]

yes I am sending a few pics of the slim projector. In addition I guess for these kind of projectors, the light comes from above. I mean from the under of reflector mirrors and lens towards to bottom plate(circular reflector).

It sounded pretty good for me. there will be no problem to lighten the lcd panel from bottom but still I have no certain idea if it could be a problem.

http://www.hipernex.com/im/pr/m/3021...le%202523T.jpg
http://www.ofislink.com/images/urunl.../OL-330002.jpg

[Chernobyl]

Soz for taking a while to respond, the forum didnt notify me of new posts.

You can get a decent result from using some portable OHP's but there are drawbacks.

It is widely considered that 4000 lumens is the minimum brightness OHP you should use with an LCD panel. You can get away with less if you get a high gain screen and dont need to go much larger than a 2 metre screen.
Its worth looking at how long the bulbs last and how much a replacement costs. Also make sure they are easy to buy if they dont last long.

Depending on the type of light bulb used, the light spectrum will differ.
If the bulb is a filament type it will have a colour temp of around 3600 Kelvin, Blues dont look so good and white looks a bit yellow.
The result is still amazing but ultimately with the lack of decent blue and if you compare white with a TV/monitor, it will bug you.
Flourescent bulbs are quite likely to have a decent light spectrum (but arent usually bright enough) and metal halides come in all flavours. Beware these bulbs also come in spectrums which are like a filament bulb so its wise to check out the colour temp.
Daylight colour temp is about 5700K, my Metal Halide bulb is 5200K, I'm very happy with it.

The LCD doesnt need to fit 100% on the OHP. The larger the OHP bed the better but you can compensate...
My LCD has a function to shrink the screen left/right which works really great. I also use Powerstrip to adjust it a little further so that I get 100% of the screen displayed.

[Dan_B]

i have been looking at doing this for about a year i only recently found this forum i like what you have done Chernobyl i will definately have to try this with an ohp i have built a very low resolution lcd projector using a slide projector and a 2.52" lcd the projector has a 300w bulb
the resolution is exedingly low as expected but it is very bright
it is not that usefull but is fun.
i hope to find a ohp at a good price soon a have a couple of 15" unbranded lcd displays that were given to me becouse they were dead (both have same fault the internal 12v power supply has died) posibly design flaw other than that there is nothing rong with them.

[Chernobyl]

cool, I'm interested to see what happens.
Hopefully you can resurrect one of the LCD's.