A51 or DIY CXA3070?

mrrager420

mrrager420

Well-Known Member
@AquariusPanta OK cool I'll just use the paste on the heatsink for the 2x 3500k sense I cooked the paste on the arctic 11 i have now. When you say thin strips you put the paste on the heatsink or COB?

@SupraSPL Preciate the info. To my understanding the lower the temp droop the better right? For the fans I took a 5v 750mA cell phone charger and hooked it up. That'll be find for the single vero 29 right? Gonna use another driver to power the other two fans that'll be used for flower. When I get it all together I'll post pics. You're right about drill and tapping. Def looks cleaner and professional but I don't have to have that sense the paste/kapton tape method is safe.
 
AquariusPanta

AquariusPanta

Well-Known Member
mrrager420 said:
@AquariusPanta OK cool I'll just use the paste on the heatsink for the 2x 3500k sense I cooked the paste on the arctic 11 i have now. When you say thin strips you put the paste on the heatsink or COB?

@SupraSPL Preciate the info. To my understanding the lower the temp droop the better right? For the fans I took a 5v 750mA cell phone charger and hooked it up. That'll be find for the single vero 29 right? Gonna use another driver to power the other two fans that'll be used for flower. When I get it all together I'll post pics. You're right about drill and tapping. Def looks cleaner and professional but I don't have to have that sense the paste/kapton tape method is safe.
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I'd advise sticking to one surface or the other. I imagine connecting two surfaces, both with paste, would greatly increase the chances of air bubbles taking place (which can normally be fixed by using Supra's 30-60 second pressing and holding four spots on COB when applying it to heat sink).

I always apply the paste to the heat sink rather than the COB, as I can spread the paste much easier.
 
C

churchhaze

Well-Known Member
I use a flathead screwdriver to apply thermal grease. I don't use it like a paintbrush, but instead like a concrete smoothing tool, using as much surface area on the flat as possible.

Using the flathead, I basically swish and slide the paste around the thermal slug until it's all covered.
 
mrrager420

mrrager420

Well-Known Member
AquariusPanta said:
I'd advise sticking to one surface or the other. I imagine connecting two surfaces, both with paste, would greatly increase the chances of air bubbles taking place (which can normally be fixed by using Supra's 30-60 second pressing and holding four spots on COB when applying it to heat sink).

I always apply the paste to the heat sink rather than the COB, as I can spread the paste much easier.
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Not sure what you thought I meant but I'm gonna use the factory paste on the new gear. The arctic 11 I have now that is gonna be used for veg only will be using a thermal paste sense I cooked the factory paste that was already on it. Thin layer on the heatsink it is.
 
mrrager420

mrrager420

Well-Known Member
churchhaze said:
I use a flathead screwdriver to apply thermal grease. I don't use it like a paintbrush, but instead like a concrete smoothing tool, using as much surface area on the flat as possible.

Using the flathead, I basically swish and slide the paste around the thermal slug until it's all covered.
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How fast does the paste dry?
 
Jeeyah

Jeeyah

Well-Known Member
Quick question. How do I apply the PK3? There's stock adhesive on the heat sink. Remove that stuff, or leave it on?
 
mrrager420

mrrager420

Well-Known Member
@Jeeyah You could use the stock and that would be fine according to some riu members that have experience with those but yeah you'd need to remove the factory paste before applying PK3.
 
SupraSPL

SupraSPL

Well-Known Member
mrrager420 said:
from the info I've read alcohol is a GO for removing the paste. That's what I plan to use on the heatsink I'll be using for veg.
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Yep you can get most of it with a dry paper towel and clean up the residue with alcohol.

mrrager420 said:
@SupraSPL Preciate the info. To my understanding the lower the temp droop the better right? For the fans I took a 5v 750mA cell phone charger and hooked it up. That'll be find for the single vero 29 right?
Click to expand...
Yes the lower temp droop the better. Temp droop is the percentage of light lost as the junction inside the COB warms up from ambient temp to thermally stable temp. So if you are running CXA3070s soft (~25W) with sufficient heatsink/cooling, you can keep temp droop close around .5%. For those who want to run hard, the Vero29 is able to run at 2.45A (95W) with only 2% temp droop ( I was expecting 4%).

Yes that charger should work but if you are just powering one fan it is hard to get fair efficiency from any of them even the high quality adapters. It can be as low as 20% efficient. No biggy but worth mentioning.
 
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mrrager420

mrrager420

Well-Known Member
@SupraSPL OK i see now. Man I tested out the 5000k I got in and wanted to test it out before I got the kapton tape. Held the the two sides you'd screw it into the driver so it wouldn't move. Super bright. And hot! Had to turn it off after a couple seconds.

Good info. So basically if efficiency is what you're aiming at then multiple fans hooked up to one driver running them is the answer.
 
wirat

wirat

Well-Known Member
ballist said:
Its forward volts x current in amps for the device. Vero 29 Vf approx 38 at a current of 2.1 amps
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Thank You! I have been pounding my head for an equation like this as a starting point in order to estimate the approximate HID wattage equivalent for a 200W DIY COB for use in a SCROG micro-cab, approx. 24" X 30" (5 sq. ft.) or less canopy area.

So just to make sure I have it correct; Vf x A = W, and in your example, 38 x 2.1 = 79.8 Watts? This means the COB is driven to 79.8 watts?

Can you or anyone who knows LED electronics please confirm/clarify?
 
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