FloEFD LED module - RC ladder data

cattewell · March 16, 2018, 06:58

Hi there,

I currently use Mentor graphics FloEFD to thermally simulate automotive LED lamps. We have the LED module but don't find it very useful because the few Pre-defined LED's in the database we don't use therefore we have to use the two resistor function. (very inaccurate)
Does anybody know where I can get the RC ladder data for LED's?
The current LED I am simulating is a Cree XHP-50.

If you have any questions or need further information please let me know.

Many thanks

Cameron

Boris_M · March 28, 2018, 07:30

Hi Cameron,

Most of the RC Ladder model data can be extracted in some way from datasheets. The only thing you usually don't get in detail is the RC ladder itself as this only comes from measurements as the vendors don't supply such depth.
You might get a single value such as the Rth also for the Cth from the vendor but usually not as a curve, but you can use only a single value from junction to board.
The other data such as luminous flux is often in dependency defined in the datasheet in some way or another, that's often dependent on the vendor.

If you need the information in detail but don't have a T3Ster TeraLED to measure it, Mentor also offers such measurements.
The 4 LEDs that are included are only examples as it is simply impossible for Mentor to provide that data for all possible LEDs on the market. You might only be interested in 2-3 but another company is interested in 3-4 other LEDs than you are plus than the next generation that comes out in a year or differences in the binning etc.

The LED "module" is more than just the LED "model". The LED model, especially the RC ladder model, has been introduced because there is also such measurement equipment offered by Mentor and some companies use it for that. The key features in the LED module are the Monte Carlo radiation model with all its capabilities and the condensation/evaporation and icing model. Those are the actual core of the LED module, besides some other features that come along with it.

Regards,
Boris

cattewell · April 3, 2018, 04:00

Hi Boris,

Thank you for your reply. So am I right in saying that my options are as follows if I want to accurately simulate a lamp using a Cree XHP-50 is to either buy the T3Ster and do this testing in-house or get Mentor to test this LED for us?
Would you know what the costs are involved with these options and who I would need to contact?
Finally regarding the binning of the LED; would the figures be diferent depending on which binning we used?

Many thanks

Cameron

Boris_M · April 3, 2018, 04:15

Hi Cameron,

Partially, it depends if you need the details of the RC Ladder, if you are ok with just a single value rather than multiple layers, then the Rth can be found mostly in the datasheets already. The Cth, however, is often not mentioned in the datasheets but you might get it from the supplier.
But if you want detailed models then yes, either buying the T3Ster and TeraLED or getting Mentor to measure it for you. For a contact information, I would need to know where you are based, you can send me a PM with your location or your contact details so I can forward them or send you the contact details of a person you can contact.

I know of companies that take these experiments serious and test also different binnings as slight changes can appear due to manufacturing processes etc.
As for the prices, I wouldn't be the right person to ask and it depends on the system requirements which depends on the LED performance regarding current requirements and the corresponding cooling performance etc.

Regards,
Boris

March 28, 2018, 07:30		#2
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 23	Hi Cameron, Most of the RC Ladder model data can be extracted in some way from datasheets. The only thing you usually don't get in detail is the RC ladder itself as this only comes from measurements as the vendors don't supply such depth. You might get a single value such as the Rth also for the Cth from the vendor but usually not as a curve, but you can use only a single value from junction to board. The other data such as luminous flux is often in dependency defined in the datasheet in some way or another, that's often dependent on the vendor. If you need the information in detail but don't have a T3Ster TeraLED to measure it, Mentor also offers such measurements. The 4 LEDs that are included are only examples as it is simply impossible for Mentor to provide that data for all possible LEDs on the market. You might only be interested in 2-3 but another company is interested in 3-4 other LEDs than you are plus than the next generation that comes out in a year or differences in the binning etc. The LED "module" is more than just the LED "model". The LED model, especially the RC ladder model, has been introduced because there is also such measurement equipment offered by Mentor and some companies use it for that. The key features in the LED module are the Monte Carlo radiation model with all its capabilities and the condensation/evaporation and icing model. Those are the actual core of the LED module, besides some other features that come along with it. Regards, Boris cattewell likes this.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
[OpenFOAM] How to get the coordinates of velocity data at all cells and at all times	vidyadhar	ParaView	9	May 20, 2020 20:06
CFD by anderson, chp 10.... supersonic flow over flat plate	varunjain89	Main CFD Forum	18	May 11, 2018 07:31
[OpenFOAM] Paraview doesn't seem to be picking up data generated by icofoam	MikeHersee	ParaView	2	January 6, 2015 08:27
Data Produced From Fine Marine Cant Match with The Experimental Data	PeiSan	Fidelity CFD	4	August 23, 2014 05:33
Problem running in parralel	Val	OpenFOAM Running, Solving & CFD	1	June 12, 2014 02:47

April 3, 2018, 04:00		#3
cattewell New Member Cameron Join Date: Mar 2018 Posts: 11 Rep Power: 8	Hi Boris, Thank you for your reply. So am I right in saying that my options are as follows if I want to accurately simulate a lamp using a Cree XHP-50 is to either buy the T3Ster and do this testing in-house or get Mentor to test this LED for us? Would you know what the costs are involved with these options and who I would need to contact? Finally regarding the binning of the LED; would the figures be diferent depending on which binning we used? Many thanks Cameron

April 3, 2018, 04:15		#4
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 23	Hi Cameron, Partially, it depends if you need the details of the RC Ladder, if you are ok with just a single value rather than multiple layers, then the Rth can be found mostly in the datasheets already. The Cth, however, is often not mentioned in the datasheets but you might get it from the supplier. But if you want detailed models then yes, either buying the T3Ster and TeraLED or getting Mentor to measure it for you. For a contact information, I would need to know where you are based, you can send me a PM with your location or your contact details so I can forward them or send you the contact details of a person you can contact. I know of companies that take these experiments serious and test also different binnings as slight changes can appear due to manufacturing processes etc. As for the prices, I wouldn't be the right person to ask and it depends on the system requirements which depends on the LED performance regarding current requirements and the corresponding cooling performance etc. Regards, Boris