how to measuring heat

Hello everyone

wan't to ask how to measuring heat? I'm worried that , there is too much heat



which one is right ? what can I do?

It's not measuring heat persay. It's measuring case/junction temps. Heat into the enviorment will be constant of whatever wattage you're running. Improving the cobs mounting will help the COB operating temps, not the enviorment.

But to answer you question: which point of measurement... neither.

The correct way is to use a thermocouple on the Tc measuring point...the little copper dot that nothing is attached to in the pic.

I build this and measuring like photo

I think it's just too much heat

Does anybody know what I should do ?

mrtt said:

Does anybody know what I should do ?

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Yes be more detailed on what you are doing. Please explain what you need help on

When it comes to junction temp in the LED, it ultimately translates into temp droop

It looks like you are running Vero18s at 1400mA? (42W ea). On cpu coolers with active cooling, I would expect 1-2% temp droop, case temp 30-35C, junction temp 35-40C.

SupraSPL said:

When it comes to junction temp in the LED, it ultimately translates into temp droop

It looks like you are running Vero18s at 1400mA? (42W ea). On cpu coolers with active cooling, I would expect 2% temp droop or a junction temp of 50C.

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Since his HS is already 50-55°C the Tj can hardly be 50°C.

Maybe he was testing without a fan. In my testing CPU cooler temps between the fins can be as low as 7C above ambient.

The first pic he posted was just a generic example, not his actual temps. Actually that is a pic I posted a long time ago of a CXA3070 3K Z2 but I don't recall where those temps came from I think someone else added that in.

SupraSPL said:

Maybe he was testing without a fan. In my testing CPU cooler temps between the fins can be as low as 7C above ambient

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Might be. Typical CPU cooler should be able to cool Vero18 @1.4A quite easily, shouldn't it?

Yes definitely. I was able to cool a CXB3590 running at 100W with a CPU cooler and fan running at 5V (.5W) Temp droop was 2.75%. When I increased fan speed to 12V (3.5W) temp droop was 1.92%

ran the test again to double check

wow

please guys open university I'm begging you I'll be your first student!

@SupraSPL you are my hero you know that

I order 8 cxb3070 but I use now only 4 and drive with 185h-c1400ma (A)bin mw.

my question really simple ;

I use before hps (600w) in summer and heat really melted everything , now I trying to use cob literally like the same situation again and I scared this

when I hold my hand under the light my fingers burned. is it normal ?

normal circumstances what should be degree ?

@alesh thankyou

O gotcha I see now you used the plastic holders. Did they work OK, very good price on those.

Regarding the 600HPS, you should be able to get the same job done with 300W of COBs. Sounds like you are starting off with 200W and you are running at 48% efficiency, so your yield will probably be close and 1/3 the total heat in the system, awesome

Driven at 50W ea your COBs are emitting 25W of pure radiant energy into a very small surface area. 25W of photons will easily scorch flesh or ignite combustion if an object is placed very close to the LES, perfectly normal. Very important to keep safety in mind so they must be hung very securely and with a smoke detector and fire extinguisher nearby, as with any grow. Good luck!