Tuesday, December 31, 2013

DELL 4220 Projector lamp replacement with LED

This is an ongoing project. I am not responsible if you break or otherwise exterminate yourself or your projector using this information :)

I got of ebay a Dell projector with lamps running 2000hrs and above 150$ each. That is quite expensive for my taste especially if one considers that the projector was bought for approximately the same price of a lamp.
So having seen other people modifying their projectors to run on LED light, I started digging.
I sourced in DX.com a supposedly 9000lm, 100W LED light, got the relevant 32-36 volts LED driver and got to work. (After a bit of searching, I found similar items on Ebay but cheaper. I guess I should have searched more.)

Anyway with the help of a cpu heatsink, a battery drill, a threading tool set, and some thermal grease, I produced the following:

A grinder was used to make two groves on the sides of the cooler for the guides on the projector. Also the cooler was cut in a trapezoid of sorts to fit inside the projector opening. Its not very pretty, but I am happy as it turned out. Especially since everything seems to fit nicely!
According to wikipedia the Intel P4 produces between 68.4 and 85 Watts of heat. So the heatsink should be adequate even if a bit maimed for the 100W LED. 

A soldering iron and a few minutes later, the assembled item looks like this:

The cables and plug was sourced from an old air conditioning unit. The screws are standard 3mm computer screws. Although I could cut the long aluminium leads I covered with black nail polish in the hopes that I will avoid any short circuits. Some kapton tape was added for good measure. And the cables were placed together with some heatshrink.

The LED driver was put in a plastic housing. A plug from an old charger was soldered to be able to be used with a common cable, some hot glue was placed in strategic places to keep it steady.

This thing is not going to fit inside the projector, but that is a small problem if you ask me.

The results so far.
This thing is bright! I mean REALLY BRIGHT!!!!!!! I do not have the equipment to measure if it is indeed 9000lm, but seems brighter than the projector lamp which is rated at 4000lm. I should put them side to side for comparison now that the projector still works ;)
The heatsink becomes warm after 1-2 minutes. I didn't want to test it longer without some active cooling.
The positive thing is that the heatsink fins are parallel to the airflow. Will see how that works once I manage to turn the projector on with the LED light source.

Some pics of the space the led and the heatsink must fit. The circular hole is where the light is guided onto the DLP disk colour wheel. While the rectangular white hole on the right is a heat vent to remove the heat from the lap away from the colour wheel.
On the photos above, the fan is located on the lower end of the left photo and the right side of the right photo. The fan blows the hot air out of the projector on the top and left side respectively.
A photo with the heatsink nicely fitted in the slot. I managed (out of pure luck I must say) to make it so that the fit is tight and it is not moving. The fan will blow the hot air parallel to the the heatsink fins.
The heatsink came from a P4 desktop and its dimensions fit nicely into the available space. The think to notice which is not obvious here is that the placement of the LED on the heatsink is not ideal since it is not centered over the color wheel hole. I should make some new holes to position it lower on the heatsink.

 A few photos of the original lamp:

From the design of the lamp I understand that the small piece of glass in front of the lamp is probably acting as a heat shield. To reduce the amount of heat the DLP mechanism of the projector feels from the lamp. At the same design principles, there is a small vent with a grating to channel the heat sideways and into a special opening of the projector which can be seen at the photos above.

I was looking for a used Dell lamp to take apart with no luck. It would be nice to use the heatshield glass on the LED, although I am not sure if it is necessary.
I can safely assume that the heat produced from the 100 Watt LED is lower than the heat produced from the 300W original lamp. Though I cant really measure the difference without an IR thermometer or other equipment.
I will attempt a calculation.
According to wikipedia, typical incandescents convert 5% of electricity into light and the rest to heat. If thats approximately correct for this lamp, then 300-5%*300=285Watts of heat are produced from the original lamp.
The LED in comparison according to wikipedia again, converts 70% into heat which for my 100W LED gives 70Watt of heat, or around 1/4th of the incadescent heat production.

Perhaps I shouldn't be concerned with the heat from the LED. I could cover the black plastic area around the colour wheel hole with a reflective material, aluminium paper or tape comes to mind, to avoid it become heat stressed.
Also from wikipedia it is mentioned that a 5000-20000Volt start up current is used to ignite the metal halide lamps in DLP projectors which would explain why my multimeter stopped working after using it to measure the volt-current from the terminals where the bulb plugs. DAMN!

I am having a hard time getting the projector case open without damaging it. While searching for the service manual, i found the Dell ftp site with lots of things inside ftp://ftp.dell.com/ but not the service manual I was looking for.


IMPORTANT: Playing with Li-Ion batteries can be dangerous! Make sure you know what you are doing before doing it and be VERY CAUTIOUS. I can't stress it enough. I won't be held liable for the info in this post. You better know what you are doing, or not doit at all.
My father in law got a Ryobi tool case with a variety of Li-Ion battery powered tools. Its mostly a hobby tool case rather than a profesional one, but nevertheless when you buy something you expect it to work out of the box.
Well one of the two included batteries didn't. One worked fine as it should, but the second one would not charge. It would show an error during charging and that would be it.
The shop we bought it from told me to put the battery on a bigger charger and let it for a little time to see if it might fix the issue. After some time I managed to use an 18V charger rather than the 12V it came with and left it charge for a bit. The battery however didn't repair itself. At the time, I didn't have a multimeter to test it, and was left and forgotten on a shelf waiting for someone to call the shop and replace it. Nobody did.
In the mean time I had take apart a few Laptop Li-Ion batteries and with a Li-Ion 18650 charger from DX.com, I managed to salvage quite a few 18650 cells. And then ti dawned me, I could probably repair the RYOBI battery if the fault was within the cells. And I took it apart.
I also got a cheap multimeter, opened the battery and measured each cell.
The first had a healthy (?) 2.9 volts while the other two, had about 0.2 and 0.6volts. HOLLY MOTHER OF GOD a new battery with 2 dead cells. Damn. A close look revealed something that it looked like one of the cells had leaked ?!? (I don't even know if thats possible)

In any case I took it apart, soldered 3 "new" cells and the battery worked like a charm afterwards. Perhaps I shouldnt bother and demand a replacement but it wsa fun to do that. Hopefully we will not suffer any explosive results.

Again be VERY CAREFULL when dealing with Li-Ion batteries. Can be very dangerous when overheated and explode in your face. You have been warned. 

Monday, December 30, 2013

Question to random terrorists

I can't begin to imagine what kind of organisation or person thinks that is a good idea to blow up some train station or some trolei bus. I mean who is going to feel the impact of such actions? The government? High officials? Rich people who disregard everyone and everything when it comes to profit? I would Laugh my Ass off if it wasn't a terrible matter.
The dude, whoever organised such actions and put them in motion is either extremely stupid or has a hidden agenda. Now I do not know how does Russia runs its internal matters, but history and US has shown that for the known terrorist attacks the common people was fucked as a result. Less freedom, more opression, more bullying.

Random terrorist dude I would like to ask you: when you target simple (poor) civilians, all you do is teryfying random poor civilians. Putin doesn't give a shit about them or you, Obama doesn't give two shits about them and you, governments in general doesn't give a shit about them or you., rich people do not give a shit about them or you. So what exactly do you think you have accomplished?

Saturday, December 14, 2013


So here is my experience.
I am a frequent ebay buyer. I mean lots of stuf I need, I can find on Ebay far cheaper than my local market, if I those are available in my local market which is usually not the case.
So OK, I get it, ebay and paypal since they are one company, provide a global marketplace with prices far lower than average and a vast variety of products. However I would like to be a little bit more transparency in how they make their money.
To the point. Ebay provides an "aproximate" price in my currency, in thes care Euro, when the items unde consideration are listed in US dollars or other currency. If you decide to buy the item though, you go to paypal which decides how much you will pay in your currency, and more often than not this price is higher than the "aproximate" price shown in Ebay.
Now I do not know how their websites are structured, but it is reasonable to assume that the exchange rate comes from somwhere and is used for those calculations.
for example:
retrieve exchange rate from www.exchangerate.com, calculate price depending on currency, show price on listing, update every 10 minutes, loop.
I cannot for the love of God understand why would Ebay show a different exchange price from Paypal. Also why all the times I have noticed a discrepancy the price I pay is higher on Paypal than the one shown on Ebay.
Now a couple of pennies, wouldn't constitute a problem for me, but 2-3 euros seems like a robbery in my book when considering the global scale of the business.

Now Ebay makes money from listing fees.
Paypal makes a % of money from sold products.
Both say that they do not charge buyers, although of course buyers are those paying the fees, since the products on ebay tend to sell for a bit higher price than on the sellers personal e-shop websites. And all that is well, as long as it is known to the public.
But when paypal charges more than whats shown in Ebay, doesn't that mean that they make money from currency exchange as well? Which in the end is another fee for the buyer to bear? Last time I read the charging policy of both websites I do not recall anything of the sort.

And unless paypal and ebay want people to belive they rip them off every step of the way, better make that difference in shown and paying prices go away. Assuming of course they do care.

Thursday, December 12, 2013

Ο εφοπλιστής που πήγαν να απαγάγουν είχε Audi q7 άκουσα σε ένα κανάλι.
Μήπως είχε και πινακίδες Μονακό;
Και αν είχε και είναι αυτός που έχω δει πολλές φορές στην Κηφισίας, γιατί έχει αυτοκίνητο με πινακίδες εξωτερικού πάνω από 6 μήνες στη χώρα;

Saturday, December 7, 2013

Club Sandwitch

Συνταγή για Club Sandwitch όπως την ξεσήκωσα από ένα κλαμπάκι, πριν προλάβει να εξαφανιστεί. Τα υλικά αναφέρονται με σειρά από πάνω προς τα κάτω:

ψημένο ψωμί
ψωμί άψητο
βούτυρο με μαγιονέζα
ψημένο ψωμί

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