What case temps (Tc) are you folks seeing with your citizen 1212s?

Got a bunch of CLU048-1212C4 and some $2 95mm cpu fans..

Seeing the following temps using a meter w/thermocouple ambient temps about 80F.

stable 86C after 5 minutes... COB mounted to heatsink/fan, fan OFF, NO thermal compound
stable 46C after 10+ minutes... COB mounted to heatsink/fan, fan ON, NO thermal compound
stable 35C after 10+ minutes.. COB mounter to heatsink/fan, fan ON, w/thermal compound

Seems like I'm in the ballpark, datasheet shows I'm still in the mid 90s as far as Case Temperature vs. Relative Luminous Flux is concerned.

why would you ever not use thermal compound with a COB? are you measuring the cob temp at the anode?

with any CPU fan and a chip in the range we normally use it at (1000-2000 mA), you should be 45-60 Tc in most cases

CobKits said:

why would you ever not use thermal compound with a COB? are you measuring the cob temp at the anode?

with any CPU fan and a chip in the range we normally use it at (1000-2000 mA), you should be 45-60 Tc in most cases

Click to expand...

It's this groundbreaking concept called an "experiment".

but thermal paste is like a few cents per cob to install it per mfr and industry standards

Hairiest_Stamen said:

Got a bunch of CLU048-1212C4 and some $2 95mm cpu fans..

Seeing the following temps using a meter w/thermocouple ambient temps about 80F.

stable 86C after 5 minutes... COB mounted to heatsink/fan, fan OFF, NO thermal compound
stable 46C after 10+ minutes... COB mounted to heatsink/fan, fan ON, NO thermal compound
stable 35C after 10+ minutes.. COB mounter to heatsink/fan, fan ON, w/thermal compound

Seems like I'm in the ballpark, datasheet shows I'm still in the mid 90s as far as Case Temperature vs. Relative Luminous Flux is concerned.

Click to expand...

Good data. And yes, all within the ballpark. The cooler you run them the better the flux will be vs the 85c data sheet numbers and longevity.

My one question is what current/wattage are you running them at in the test?

CobKits said:

but thermal paste is like a few cents per cob to install it per mfr and industry standards

Click to expand...

-Did he offend you by not using TIM?
-Did he not also use thermal paste as a comparison? And provided ACTUAL NUMBERS(not..."it feels hot").
-Did he say that there was no point or that it is too expensive to use?
-Did he not provide numbers that you will most likely spew out later in some other argument when it comes up?
-Did he actually test something that is valid and other just leave to guessing and other people's "professional suggestions"???

Greengenes707 said:

-Did he not provide numbers that you will most likely spew out later in some other argument when it comes up?

Click to expand...

GG dealing out the cheap shots lol

OP, where are you measuring case temp

CobKits said:

GG dealing out the cheap shots lol

OP, where are you measuring case temp

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Great deflection of the truth .So I have your word that you will never reference these numbers. And that if you were to create you own numbers to, they would be all because of this OP's post?

You're the one that jumped in on a thread and acted like he did something wrong. When in reality he did more in the one post that 90% of RIU users in years of being around.

You can call it a cheap shot all you want. Just shows how the truth hurts. Not to mention the other 4 points that were also perfectly valid that you choose to not respond to.

So just be real about it...and call it 5/5 correct.

never seen cxb3590 vs 1825 vs Vero29C in real conditions... it may help a lot of growers... it may really help the community and close a lot of mouths.... I think!!!

Greengenes707 said:

Great deflection of the truth

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truth being what? your speculation that i would cite that post? ill never understand your methodology for picking battles my friend.

Greengenes707 said:

So I have your word that you will never reference these numbers. And that if you were to create you own numbers to, they would be all because of this OP's post?

Click to expand...

i have no desire to do any tests without thermal compound, nor would i recommend that for anybody in any scenario. I see no point for not using ten cents of thermal compound (for COBs)

Greengenes707 said:

So just be real about it...and call it 5/5 correct.

Click to expand...

[ ] Did he offend you by not using TIM?
[X]Did he not also use thermal paste as a comparison? And provided ACTUAL NUMBERS(not..."it feels hot").
[X]Did he say that there was no point or that it is too expensive to use?
[ ] Did he not provide numbers that you will most likely spew out later in some other argument when it comes up?
[ ]Did he actually test something that is valid and other just leave to guessing and other people's "professional suggestions"???

ill give you a half on the last one as yes it was a test but no im not sure how he even measured the temperature so at this point its indeterminate whether the data is useful it is in practice

so youre batting .500, slugger! that could win a batting title though!

CobKits said:

but thermal paste is like a few cents per cob to install it per mfr and industry standards

Click to expand...

Simply wanted to see the impact

CobKits said:

GG dealing out the cheap shots lol

OP, where are you measuring case temp

Click to expand...

The Tc measurement point as outlined in the citizen spec.

I've got no problem with some temp readings sans paste, it's interesting... but those low temps are deceiving and it shouldn't be taken to mean it's okay to run without paste. The test point might be in spec but without paste there will be air pockets that are hotter than the test point. It would only be a matter of weeks/months until the cob fails and when it's examined there will be a small area on the LES that's burnt.

Hairiest_Stamen said:

The Tc measurement point as outlined in the citizen spec.

Click to expand...

so the anode? guessing these are soldered as its hard to get a thermocouple on the anode with a holder

Greengenes707 said:

Good data. And yes, all within the ballpark. The cooler you run them the better the flux will be vs the 85c data sheet numbers and longevity.

My one question is what current/wattage are you running them at in the test?



-Did he offend you by not using TIM?
-Did he not also use thermal paste as a comparison? And provided ACTUAL NUMBERS(not..."it feels hot").
-Did he say that there was no point or that it is too expensive to use?
-Did he not provide numbers that you will most likely spew out later in some other argument when it comes up?
-Did he actually test something that is valid and other just leave to guessing and other people's "professional suggestions"???

Click to expand...

Nice post...

Sorry for being a curious person

50w/1400. Got a 1050 floating around here somewhere. Will try that next.

Used to do board level repair of electronics in another life... oscopes, analyzers, meters, counters, data loggers, etc so I like to tear things apart.

Got a handful of dell server heat pipe heat sinks... going to rig one of those up next.

CobKits said:

so the anode? guessing these are soldered as its hard to get a thermocouple on the anode with a holder

Click to expand...

Is it perfect? No...
Is it a worthwhile experiment (to me) to determine a ballpark figure +/- 3c or 5c? Yes...

It's not drainin the oil from a porsche turbo and taking it for a spin.. it's a ~$20 cob...

im not sure i understand your response

Hairiest_Stamen said:

Got a bunch of CLU048-1212C4 and some $2 95mm cpu fans..

Seeing the following temps using a meter w/thermocouple ambient temps about 80F.

stable 86C after 5 minutes... COB mounted to heatsink/fan, fan OFF, NO thermal compound
stable 46C after 10+ minutes... COB mounted to heatsink/fan, fan ON, NO thermal compound
stable 35C after 10+ minutes.. COB mounter to heatsink/fan, fan ON, w/thermal compound

Seems like I'm in the ballpark, datasheet shows I'm still in the mid 90s as far as Case Temperature vs. Relative Luminous Flux is concerned.

Click to expand...

You're blinding me with all your science. I salute you for your inquiring mind and your pioneering ways. Its people like you who used to put men on the moon, goddammit!.

I hate to mention it, but there was one obvious step that was skipped at the start of your experiments. That is, recording the stable temperature with no thermal compound, no fan and no heatsink.

Btw, are those the heatsinks that were on sale at newegg recently? I was wondering how they performed.

Salutations, and good luck in your endeavors.

Rahz said:

I've got no problem with some temp readings sans paste, it's interesting... but those low temps are deceiving and it shouldn't be taken to mean it's okay to run without paste. The test point might be in spec but without paste there will be air pockets that are hotter than the test point. It would only be a matter of weeks/months until the cob fails and when it's examined there will be a small area on the LES that's burnt.

Click to expand...

DrBlaze said:

You're blinding me with all your science. I salute you for your inquiring mind and your pioneering ways. Its people like you who used to put men on the moon, goddammit!.

I hate to mention it, but there was one obvious step that was skipped at the start of your experiments. That is, recording the stable temperature with no thermal compound, no fan and no heatsink.

Btw, are those the heatsinks that were on sale at newegg recently? I was wondering how they performed.

Salutations, and good luck in your endeavors.

Click to expand...

Can do that tonight, ahhah. Yes... $2 at newegg... bought 20, then another 10. Perfect for the 1212s.

Cool, was wondering how they fit, they don't have a large area to mount to. If you get a chance please post a pic of the bottom with the cob mounted.

DrBlaze said:

Cool, was wondering how they fit, they don't have a large area to mount to. If you get a chance please post a pic of the bottom with the cob mounted.

Click to expand...

I shouldn't say perfect. Hopefully acceptable considering the $2 price. You have to rotate the package in order to line up the holder holes so a bit of the package floats over the fins..
But 100% of the area under the leds is flush on solid aluminum though. There's just enough meat there to tap a 3mm. I'll take a few more pics in a bit...

Hairiest_Stamen said:

But 100% of the area under the leds is flush on solid aluminum though.

Click to expand...

That's all that matters.