UV DLP projector retrofit

[Matthew Caron]

Throwing this out there. Tear it apart, opine, etc.

Okay, so let's review what we know:

1. LED projectors can be retrofit with UV LEDs, but the UV breaks down the LCD panel and badness ensues. So, you need a DLP projector.
2. UV DLP projectors are costly ($1500 for the TI eval kit) and not mass produced.
3. Non-UV DLP projectors will die eventually, because the UV degrades the micromirror array.
4. But, we get the same problem when removing the hot mirror. So, we've accepted this risk.
5. Bulbs are expensive, die pretty quickly, and are sensitive to orientation.
6. LEDs are cheap, last a long time (like 10X) and are not sensitive to orientation.

Proposed BOM (Note: 100W LED may be overkill, not sure. I also need to check dimensions to see what will fit.):

• 100W UV LED - $25
  
• Heat Sink and fan - $10
  
• LED Driver Circuit - $36
  

So, this puts my cost under $100. What would need to be done is:

1. Make sure it will physically fit.
2. Defeat the bulb detection circuit so the projector stays on.
3. Power the LED circuit (likely by tapping in to the mains feed to the power supply)
4. Power the heatsink fan circuit or, just get rid of the fan, if the other fan is blowing directly on the heatsink)
5. (Optional, may not be necessary) Focus the light better (reflector, light pipe, etc.)

Any thoughts on this? Has anyone investigated this? It seems pretty obvious, so I'm surprised no one is offering conversion kits.

[Matthew Caron]

Also, adding:

 6. (Optional) Remove color wheel

[Matthew Caron]

• Collimator and Lens - $7
  
• (Alternative) Larger heat sink and lens - $17
  

Lenses are 60 degree, which is the tightest I can find.

[Matthew Caron]

• Kit with 10k lumen visible spectrum light, driver, heat sink, lens, etc. - $47 - They info in the listing suggests that they can substitute different LEDs. I wonder if they can sub a UV LED array in.
  

[Hellenicopter]

Matthew,

As far as I have searched, point 2 is the hardest as most of the projectors use the UART protocol that can only be bypassed by a specific circuit that fakes response signals and sends them to the main board. It can be done by reverse engineering (programming an Arduino to do the job for example) but each vendor has it's own setup.

On top of that, if someone sells such a "solution" for faking the lamp circuit I am not sure that would not have legal implications (vendors rely a lot on the market of bulb assemblies).

[Matthew Caron]

I'm curious how they do that; there are only 2 wires going to the bulb... Are you thinking they piggyback a digital signal on top of the high voltage and it just talks to itself through the bulb?

But yes, I agree that this is the most difficult problem to solve.

But, I'm essentially at an impasse. I am not spending $250 for a new bulb every 1000 hours. I simply refuse. In that case, the printer is going to sit in a corner of my shop until I can get a UV LED projector for sub $500. My max acceptable cost for the bulb is $100, and I blame myself for assuming that the third party bulbs would work when evaluating the TCO.

[Hellenicopter]

It is basically a very accurate monitoring of the filament's resistance which is translated to digital signals. If the resistance at certain operation points and moments (startup for example) is not within the specs then the system goes off.

[Matthew Caron]

Yeah, but I'm not sure that would use a UART. You could do that by checking impedance/current/etc.

[Elliot McAllister]

This is a great discussion guys,  I've seen this as well from instructables:

http://www.instructables.com/id/Convert-A-Projector-To-An-LED-Light-Source/

http://www.instructables.com/id/Projector-led-lamp-100w/

http://www.instructables.com/id/LED-Projector-Lamp-v10/

(there is also a v 2.0 from the same contributor.)

[Matthew Caron]

I don't have time to do all the research and do all this up, but if anyone were to make conversion kits of reasonable complexity with good instructions, I'd be up for it (I'm looking at you mUVe).

Quite frankly, if the LCD dies after 5000 hours, but the whole unit costs $100, I don't care.

[Matthew Caron]

So, uhm, I replied to this and got an email that a G3DSupport ticket has been created, and the domain is this guy: https://www.g3dsys.com/

Anyone know anything about this?