DIY COB LED Calculator

Just so I'm understanding this correctly - If I were to run 3 CXA3070 @ 1.4A, I would need 27in of 3.5 profile heat sink to run active cooling? I wanted to cut blocks of the heat sinks as opposed to bars, but that would mean I need to cut 9 inch sections per chip. Am I understanding this correctly?

HockeyBeard said:

Just so I'm understanding this correctly - If I were to run 3 CXA3070 @ 1.4A, I would need 27in of 3.5 profile heat sink to run active cooling? I wanted to cut blocks of the heat sinks as opposed to bars, but that would mean I need to cut 9 inch sections per chip. Am I understanding this correctly?

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Seems right. I'm not infront of the comp right now. Just do the calculation for 1 cxa3070, whatever shows in the box for active cooling will be the lenght of that hs for 1 cob

Hi @bggrass , Is it possible to use custom input for the load of the cobs, example 900mA?

Best regards!

Flashero said:

Hi @bggrass , Is it possible to use custom input for the load of the cobs, example 900mA?

Best regards!

Click to expand...

I can make an input for custom amps. The problem is, there are no lumens/watt, voltage, efficiency, extracted for that amperage, which in turn won't give you any numbers for par, heat, heatsinks, wattsge.

The amps that are in, are the most often used ones. When you look at Meanwell, they only have the drivers in certain amps.

anyone try using this on OpenOffice Calc? lol....I think that is where I hit a wall.

Downloaded this probably the day you loaded it up, but haven't used it Once yet....

Maybe try on my phone, see if Android works

Thanks for your hard work OP.

@Abiqua Worked for me. Just needed to update Java with the development kit.
http://www.oracle.com/technetwork/java/javase/downloads/index.html

Pretty cool..

I must guesstimate pretty good. Calc put me within 3" inches of the length I used on the last one. I do normally like a little extra just because.

After a few lights you can pretty much picture in your head how cool a light will be just looking at profiles.

Thanks for the calc op..

Abiqua said:

anyone try using this on OpenOffice Calc? lol....I think that is where I hit a wall.

Downloaded this probably the day you loaded it up, but haven't used it Once yet....

Maybe try on my phone, see if Android works

Thanks for your hard work OP.

Click to expand...

@Abiqua I saw your thread on a sticky suggestion. Whether that happens or not, you can send me the links if you'd like and I'll just add them to the calculator. I'm pretty sure the more seasoned guys here have the calculations on excel sheets, but the calculator can be helpful for the newer people that try to figure it out. It can be an all in one reference/resource.

bggrass said:

I can make an input for custom amps. The problem is, there are no lumens/watt, voltage, efficiency, extracted for that amperage, which in turn won't give you any numbers for par, heat, heatsinks, wattsge.

The amps that are in, are the most often used ones. When you look at Meanwell, they only have the drivers in certain amps.

Click to expand...

Thanks for youre response!, Could you just average the values, for the ones that is no data? I have a 900mA driver, for example, and is
between 0,7A and 1.05A

Regards

Positivity said:

@Abiqua Worked for me. Just needed to update Java with the development kit.
http://www.oracle.com/technetwork/java/javase/downloads/index.html

Pretty cool..

I must guesstimate pretty good. Calc put me within 3" inches of the length I used on the last one. I do normally like a little extra just because.

After a few lights you can pretty much picture in your head how cool a light will be just looking at profiles.

Thanks for the calc op..

Click to expand...

@Positivity

thanks Posi!
big ups for that....I need to update and I probably need to search around for the Calc update too....
Glad you got it working too

bggrass said:

@Abiqua I saw your thread on a sticky suggestion. Whether that happens or not, you can send me the links if you'd like and I'll just add them to the calculator. I'm pretty sure the more seasoned guys here have the calculations on excel sheets, but the calculator can be helpful for the newer people that try to figure it out. It can be an all in one reference/resource.

Click to expand...

I will keep you updated...rather than continue being a dick...I have been collecting links on simple Notepad program over the last few days and skpped the bs. That would be great!

and
What's wrong with having 100's of datasheets for every single Kelvin and make out there, for the last 18 moths
@salmonetin might be a worse hoarder than me!

Not sure if I wanna do that. Just do your calculation for 1.05A and subtract 10% from the results. That should give y

Flashero said:

Thanks for youre response!, Could you just average the values, for the ones that is no data? I have a 900mA driver, for example, and is
between 0,7A and 1.05A

Regards

Click to expand...

Not sure if I wanna do that. Just do your calculation for 1.05A and subtract 10% from the results. That should give you an estimate at 0.9A. Even if I do it, it will be the same thing. If you get the exact numbers from Supra or anyone that can do it, I'll add them.

Abiqua said:

@Positivity

thanks Posi!
big ups for that....I need to update and I probably need to search around for the Calc update too....
Glad you got it working too

Click to expand...

There is only one link for the updates and it is in the first post. Trying to keep it simple.

bggrass said:

Not sure if I wanna do that. Just do your calculation for 1.05A and subtract 10% from the results. That should give y

Not sure if I wanna do that. Just do your calculation for 1.05A and subtract 10% from the results. That should give you an estimate at 0.9A. Even if I do it, it will be the same thing. If you get the exact numbers from Supra or anyone that can do it, I'll add them.

Click to expand...

in my opinion, I think also interesting the possibility to calculate the 1.2A result for V29 and CXA/CXB 3070
thank you for your hard work!

bump! i believe this thread should be a sticky. everybody should be using this but it seems like relatively few are.

lovely tool thanks for sharing. would it be possible to add the cxa2540 /cxb2540 6500k? trying to put together a small veg light.

http://www.cree.com/~/media/Files/Cree/LED-Components-and-Modules/XLamp/Data-and-Binning/ds-CXB2540.pdf

jewbag said:

bump! i believe this thread should be a sticky. everybody should be using this but it seems like relatively few are.

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Seriously. I refer people here but they seem to want to ignore it and keep asking people to figure this shit out for them.

Soulblighter said:

lovely tool thanks for sharing. would it be possible to add the cxa2540 /cxb2540 6500k? trying to put together a small veg light.

http://www.cree.com/~/media/Files/Cree/LED-Components-and-Modules/XLamp/Data-and-Binning/ds-CXB2540.pdf

Click to expand...

If you can find a spreadsheet for those cobs, I'll add them. I've never seen one for the cob you asking though. Asking Supra is probably your best option.

I've been thinking on a new, better interface but have been busy. I think I have it mapped out on how to make it export to a plain .txt file so people can print from it. Will update at some point when I get a chance....

bggrass said:

I've been thinking on a new, better interface but have been busy. I think I have it mapped out on how to make it export to a plain .txt file so people can print from it. Will update at some point when I get a chance....

Click to expand...

Thank you! This is a great tool. I have been doing screen prints. A text file would be awesome

bggrass said:

I've been thinking on a new, better interface but have been busy. I think I have it mapped out on how to make it export to a plain .txt file so people can print from it. Will update at some point when I get a chance....

Click to expand...

Thanks mate, one of the most useful threads in the section.

Does anyone know latest Kingbrite cxb3590, cxa/b3070 prices?