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TIDA-00293: LED replacement from blue to UV for 3D printing

Part Number: TIDA-00293
Other Parts Discussed in Thread: TPS54620, DLP4500, , DLP3010

Hello,

I intended to modify this projector for 3D printing. I read through all of the documentation on the product page and ordered from the Digi-Key supplier, as linked on the TI site. When following documentation, I expected to be replacing with this LED package. When I took it apart though, I found that I received an older model with this LED. I only found this was an older model after contacting tech support. There was no indication on the TI website, supplier website, or physical package that there was an older model that had a different LED. The manufacturer of the older LED does not have a UV model. Is there any way to swap the old blue LED with UV on this older model?

I should point out, the "newer" model documentation is from 2014. So that must mean that at the very least, the product I received is 6 years old and I didn't even know that there WAS an older model. I can't return it because I took it apart.

  • Hi Simon,

    You may want to fine the replacing LED is electrical compatible to the existing one. Then please note the optical engine has filter to optimize to carry wavelengths of visible wavelength. 420nm can work, if it is deep UV band it may not work, you can look at this explaination https://e2e.ti.com/support/dlp/f/94/t/278008?A-look-inside-the-iView-Engine-in-LightCrafter4500 

    Regards,

    Sanjeev

  • Hi Sanjeev,

    Thank you for your response. I understand that the replacement LED must be electrically compatible. The reason I'm posting this question is asking for help finding that LED. The manufacturer specified in the link that you attached does not make a UV option. I'm wondering it it is possible to replace the LED with a UV wavelength from a different manufacturer.

    Thanks,

    Simon

  • Here is a side-by-side of the LED on the older version LED on the left and the current version on the right recommended for replacement by all of the documentation available online.

  • Hi Simon, Looking at the datasheet of TPS54620, both the LED datasheets and the LCR4500 schematic, it seems both the LEDs are electrically compatible with the circuit. Since the newer LEDs has lesser forword voltages, there shouldn't be an issue driving them at the same current with the existing regulators. Just confirm that TPS54620 is the power converter that has been used on your EVM to drive the LEDs.

    Thanks & Regards,

    Hirak.

  • Hi Hirak,

    Thank you for your response. While the two LEDs may be electrically compatible, it seems like their package is completely different. I am not sure how to physically swap between the two. Please advise if it is physically possible to replace the blue LED with a UV one or if that is only possible on the current version of the LCR4500.

    Thanks,

    Simon

  • Hi Simon, 

    We are currently contacting our Optical & Physical design team to get more information regarding your query and if such an LED exists. Thanks for your patience. Kindly note that even if there exists an UVLED compatible with the footprint on your EVM, it may not be compatible with the optical design. i.e., the actual light output efficiency from the light engine may be quite low, since the optical path is optimized for visible light and not UV light. 
    You can meantime take a look at a modified UV version of LCR4500 from EKB, which comes with UV LEDs and optical path optimized for UV spectrum. Kindly find it here.

    Thanks & Regards,

    Hirak.

  • Hi Hirak,

    Thank you for your attention to this case. If my EVM doesn't work with UV though, I would like to be provided a replacement or refund. There is plenty of documentation online that the EVM I ordered can be modified for UV but I was erroneously given an older model, which it seems may not be able to adapt to UV. I am not going to spend more money after not receiving what I payed for the first time. I understand this was an innocent mistake, but I would like to get this resolved soon without paying more.

    Thanks,

    Simon

  • Hi Simon, 

    I'd like to point out some info regarding your use case:

    • The LCR4500 uses OSRAM Q9 LEDs only. I apologize that you feel you have received an older model, but we think that is not the case.
    • DLP4500 optical engine is designed for visible light and some of the optical components will be damaged with long term exposure to UV light. In fact, the TI reference design uses 420nm Wavelength LED for this reason. You can use use UV for evaluation and experimentation, but you need to conduct your experiments regarding longevity and efficiency before using it as mass market.
    • You can replace a suitable UV LED if it is footprint and electrically compatible. But The LIghtCrafter 4500 contains plastic optics which tend to absorb ≤405nm illumination and get cloudy, leading to very poor performance.
    • If you are considering to build or develop a 3D printer product then we would recommend sourcing an optical engine which is designed for UV light. Another example on that line is this.

    Thanks & Regards,

    Hirak.

  • Hi Hirak,

    This is the product that I ordered. On that page, there is a document titled "TIDA-00293 DLP LightCrafter 4500 Modifications", which details step by step instructions to replace the blue LED with UV for 3D printing. In the document titled "TIDA-00293 BOM" it states to use a Philips Lumileds model LHUV-0420-0650. That LED is the one in the side-by-side picture I attached earlier. The page that you linked earlier for the Q9s is the first document I've seen that lists the mentioned for this product, the rest describe the Lumiled. I've attached a screenshot of my conversation with support where they told me I had an older model.

  • Hi Hirak,

    The forum post that you linked describes the Q9 LEDs. This post was from 2013, whereas the documentation I'm referring to is from 2014.

    Thanks for your continued support,

    Simon

  • Hi Simon, 

    Kindly contact TI Customer & Sales support for more information on replacement of the EVM. We will provide replacement (not refund) of this EVM. However, you are advised to move to the newer DLP3010-LC EVM for 3D printer and UV applications. 

    Thanks & Regards,

    Hirak.

  • Hi Hirak,

    Thank you for your response. What is the advantage of the DLP3010?

    Best,

    Simon

  • Hi Simon, 

    This is newer EVM targeted for 3D Printing and UV applications. This EVM contains optics fully compatible with UV spectrum and is recommended for achieving higher efficiency. 

    Thanks & Regards,

    Hirak.