Panasonic PT-L711U Projector Lamp Hacking.

Hardware related mods, hacks, questions and ideas.
foxmiles
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Re: Panasonic PT-L711U Projector Lamp Hacking.

Post by foxmiles » Sat Dec 03, 2011 8:25 pm

If you want to try that new LED out just replace R1 with a 0.82 ohm Resistor, and short it across a multimeter set to 10A.
Connect your PS Ground to the back lead,
the PS positive (18-20V) to the Vin on the lm350,
red lead to the Iout on the lm350. (put the .5ohm between Lout and the red lead if you're a wimp)
It should read 1.5A. If it does attach a heatsink to the led with thermal paste in between, connect +& - and fire it up. Not for long though, watch how hot the regulator, resistor and led heatsink get. Oh, yea, don't look at the led either.
lm350.jpg
LM-350 Current regulator from datasheet
lm350.jpg (13.11 KiB) Viewed 3063 times
Digging with a spoon will accomplish more than leaning on a shovel.

Jarod
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Re: Panasonic PT-L711U Projector Lamp Hacking.

Post by Jarod » Sat Dec 03, 2011 10:03 pm

I'm going to have to hunt around for a power supply, I don't have anything that puts out enough voltage or current.
I've got a 24v power supply but it'll only put out 200mA which is not nearly enough for anything useful.

I'm going to see if i can find a heatsink and possibly find a power supply sometime before we come up.

I'm also out of thermal compound, mine all hardened up, idk if i can add alcohol or something to thin it or not. I can get some AS5 in town though, so I may have to grab some of that.

Jarod
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Re: Panasonic PT-L711U Projector Lamp Hacking.

Post by Jarod » Sat Jan 07, 2012 6:27 pm

Just a quick update on this project, My brother and I got the LED array installed and I found a power supply to use for powering it.

I was going to remove the ballast and high voltage side of the projector to put this inside but that is all tied together with the power supply that runs everything else, so it has been left alone, and the LED power supply taped to the rear of the projector for testing purposes.

We mounted the array to the heatsink, and then drilled holes in the old housing and ran screws into the heatsink from the side to hold it all in place.

It seems to work fairly well, its a little dimmer than I'd hoped for but still very much so functional and usable.

Here is some photos of the bulb and how we mounted it to the old bulb housing.
Attachments
4.jpeg
Heatsink with holes drilled and tapped for mounting the LED array.
3.jpeg
holes drilled in old bulb housing/mounting frame to mount heatsink to.
2.jpeg
Installed, with reflector and lm350 attached.
1.jpeg
Pre install showing the front of the array

foxmiles
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Re: Panasonic PT-L711U Projector Lamp Hacking.

Post by foxmiles » Sat Jan 14, 2012 11:45 pm

Do you remember which part # you bought? I'm pretty sure it's this one:
http://search.digikey.com/us/en/product ... ND/2331635
We limited it to 1.5A (2000lm), which is the test current, it's rated for 2.5A max. It could be bumped it up to 1.75a (2270lm, 0.68R(roughly)) or 2.0a (not stated probably 2500lm ish, 0.62R) to increase the brightness, 2.5a(0.5R) if we really needed to.
You should check the current it's drawing, if your power supply won't supply the needed voltage (approx 17V under load) the light output drops off. 12V high amperage power supplies are easy to find, 17V could be trickier, some smps units can be modified to bump up the voltage, but I'm not sure how yet.
I'm guessing we can get another 25% out of it if we need it. Just a matter of getting a different resistor for the regulator and a PS that can drive it.
Digging with a spoon will accomplish more than leaning on a shovel.

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