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DLPDLCR3010EVM-G2: Thermal output data required for optical module

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Replies: 8

Views: 110

Part Number: DLPDLCR3010EVM-G2

Hello Forum! I wonder if anyone can help.

I'm trying to passively cool the optical module of the 3010EVM-G2 but I can't find anywhere the thermal output for the RGB LEDs. I emailed AnhuaOE (aka eprotech) but they haven't responded yet. I've also searched the forum and couldn't find it anywhere although there's a chance I'm not using the right terminology.

Does anyone have this information that can share? Has anyone tried to add passive cooling to this EVM?

My assumption is that the OM in the 3010EVM-G2 is the H6 in AnhuaOE's website http://www.anhuaoe.com/en/product_detail/id/208 but the tech specs do not specify anything other than the power (draw?) to generate the lumens. I've also tried searching on the OSRAM website but I'm not finding anything that makes much sense to me at least.

Your expert advice will be much appreciated! Many thanks in advance

A

  • Hi A, 

    Welcome to TI E2E Forums! Our expert will look at your query and get back soon. 

    Thanks & Regards,

    Hirak.

  • In reply to Hirak Biswas:

    Hello,

    The optical engine in DLP3010EVM-G2 uses Osram Q8WP LED's.. You can refer to Osram LED datasheet and calculate the thermal load (heat generated) by the LEDs are various current.

    You can control power consumption by LEDs by changing the current. The max LED power with passive cooling will depend on the your system and surface for thermal dissipation.

    Are you planning to use the EVM as it is with fan or will modify to fit into another system?

    regards,

    Vivek

  • In reply to Vivek Thakur:

    Hi A,

    Keynote Photonics LC3010 projector uses the same optical engine as TI's DLP3010EVM-LC so we have some familiarity with the engine's thermal behavior. The optical engine manufacturer recommends the LED copper PCB temperature be kept to 50C or lower in order to maximize LED lifetime. Structured light applications vary tremendously in operational duty cycle and LED current requirements so most often we recommend that customers actually try operating the projector in their use case and measure the temperature directly to see if any adjustments need to made to their thermal management.

    The red LED on the optical engine has a 100K NTC thermistor embedded so it's possible to use the existing hardware to measure the red LED temperature directly. On the Keynote LC3010 this is connected and readable through the GUI. It is not connected on the DLP3010EVM-LC but the pins are accessible on the LED connector so you can use a multimeter to check the thermistor resistance and calculate the temperature based on that. The LED connector is a Molex PicoBlade series and you can purchase precrimped wires (Molex p/n 797580006 or similar) to insert in the connector housing for access to the thermistor pins.

    The blue and green LEDs do not have embedded thermistors so to measure them you will need an external temperature sensor.

    - Layne

    Layne Jenkins
    Applications Engineer
    Keynote Photonics

     

  • In reply to Vivek Thakur:

    Hello Vivek - thank you very much for your reply. I'll dig out details from the OSRAM website!

    I intend to use the EVM without a fan. The idea is to replace the current cooling arrangement with a passive solution. Space is not a constraint, which means I have plenty of room to add custom copper plate + heatpipe + large heatsink elsewhere.

    Why do you ask? Are there any other considerations I should take into account? To my knowledge, it should not be a problem as long as the passive cooling solution dissipates the required heat from the LEDs. Any additional thoughts are welcomed.

    Best regards

    Alex

  • In reply to Layne Jenkins:

    Hi Layne,

    Thank you so much for the detailed info! I visited your website and noticed your H6 concept shows a picture with heatsinks attached to the LED copper PCB. What usage do you cover with that solution? what operating temperature range does that cover you for? If the room temp is higher have you modelled using larger heatsinks? I'd love your thoughts on whether heatsinks would be enough or do I need to consider heatpipes to allow larger heatsinks + any other consideration you could share.

    I intend to use mine as media projection (i.e. like a consumer projector) which means it could have extended use for a few hours if I watch a movie or two. I don't expect the LEDs to have to work at full capacity so I will also play with the voltage like Vivek mentioned in a previous reply to strike a balance.

    Great info re measuring temp on the LEDs, thanks again!

    Alex

  • In reply to A Cordi:

    Hello Alex,

    With large surface to dissipate  heat , you should be able to drive this engine at relatively higher brightness with passive cooling. As Layne mentioned, try to keep solder point temperature for ledS below 50C  especially RED. You can estimate the LED junction temperature from " Electrical  thermal resistance junction / solder point" specification from LED datasheet.

    Key issue for passive cooling will efficient transfer heat from LED contact to  cooling plate. You may want  to consider using high thermal conductor material like graphite sheet.

    regards,

    Vivek

  • In reply to Vivek Thakur:

    Hello Vivek and thanks again for your great input.

    I think I now have a working design in my mind as follows:

    2 x copper plates 1mm thick cut to the same size of the ones that ship with the 3010EVM to make contact with the LED back plates. Will use graphite sheet in-between them

    2 x 6MM diameter, 150mm long sintered heatpipes soldered to the copper plates to take the heat away from the LEDs (I've slightly over-spec'd one them on purpose to have some leeway)

    The heatpipes will be soldered on the other end to a 100mm x 50mm aluminium extruded heatsink with wide spacing between fins to allow good convection

    I presume it's impossible to judge at a distance, but does this sound reasonable to you at a very high level at least?

    Regards

    Alex

  • In reply to A Cordi:

    Hi Alex,

    It will definitely help in thermal management. I can not guess to what LED power level you may be able ot drive. You have to run your own experiment and measure.

    All the best.

    Please let us know how it goes.

    Regards,

    Vivek