did I do this COB build right?

[ILoveYouSweetLeaf]

I started the last message about 1 hour after turning on the lights. I had the potentiometer only about 1/3 of the way up. temps stayed at about 55F.
then about 30 minutes ago I turned the potentiometer all the way up and have seen the temps rise slowly. they are at about 100F. now. what is too hot ?

 

[VegasWinner]

anything hotter than touch is too hot. Use a fan to blow across the heatsinks to circulate cooler air for better temp controls. At 50w that should work for most pin heat sinks.

 

[ILoveYouSweetLeaf]

anything hotter than touch is too hot. Use a fan to blow across the heatsinks to circulate cooler air for better temp controls. At 50w that should work for most pin heat sinks.

thanks for answering.
they seem to even out at 100F at full amps. that's using auto infrared thermometer and putting the laser thru the pins to where the back of the chip should sit (in cold basement with no air circulation). to me this is not hot. what temps F or C should I be concerned about. never done DIY light, so I'm not sure if this is normal temps. I'm using a heatsink that says 75watts dissipation for passive. at full amps I should be running 50.5watts a cob. should I be seeing 100F at the heatsink?
"anything hotter than touch is too hot" is to vague for me to feel confident I'm doing this right. could you tell me in degrees what Is a good range of temps. I gotta sleep near this thing.

I wanted to make this a passive build because it eliminates failure points. every fan I put up requires more power (tiny), and most importantly is another device that can fail.
the grow room also has an exhaust can fan which this area does not.

 

[ILoveYouSweetLeaf]

anyone know in Fahrenheit what Is acceptable heat on a passive heat sink ?

 

[GBAUTO]

My 80W Vero's run at ~125 degF in a 80 degF room on the same 140mm sinks. Just room fans provide cooling.

 

[Olive Drab Green]

My 80W Vero's run at ~125 degF in a 80 degF room on the same 140mm sinks. Just room fans provide cooling.

That probably shouldn’t be that hot.

 

[nfhiggs]

thanks for answering.
they seem to even out at 100F at full amps. that's using auto infrared thermometer and putting the laser thru the pins to where the back of the chip should sit (in cold basement with no air circulation). to me this is not hot. what temps F or C should I be concerned about. never done DIY light, so I'm not sure if this is normal temps. I'm using a heatsink that says 75watts dissipation for passive. at full amps I should be running 50.5watts a cob. should I be seeing 100F at the heatsink?
"anything hotter than touch is too hot" is to vague for me to feel confident I'm doing this right. could you tell me in degrees what Is a good range of temps. I gotta sleep near this thing.

I wanted to make this a passive build because it eliminates failure points. every fan I put up requires more power (tiny), and most importantly is another device that can fail.
the grow room also has an exhaust can fan which this area does not.

I would try to stay 135F or lower. 140 is hot enough to cause a mild 1st degree burn in 5 seconds or so.

 

[GBAUTO]

That probably shouldn’t be that hot.

...and why not?

 

[ILoveYouSweetLeaf]

anyone willing to take temperature readings on their running lights and post em ?

mine run at up to 114 degrees F at near 50w/per cob.
I'm a diy led noob and I cant seem to find anywhere on the web what I should expect to see for actual temps at the heatsink. All I can seem to find is discussions on how many watts they are dissipating. Unless I'm missing some info, that doesn't tell me a noob, when I'm running my first lights, what are normal temps I should expect to see. not watts.

what temps should I start to worry I'm burn out my cobs etc.

 

[HydoDan]

anyone willing to take temperature readings on their running lights and post em ?

mine run at up to 114 degrees F at near 50w/per cob.
I'm a diy led noob and I cant seem to find anywhere on the web what I should expect to see for actual temps at the heatsink. All I can seem to find is discussions on how many watts they are dissipating. Unless I'm missing some info, that doesn't tell me a noob, when I'm running my first lights, what are normal temps I should expect to see. not watts.

what temps should I start to worry I'm burn out my cobs etc.

Just tested mine.. @ 40 watts per cob I'm running at 103*... I'm sure you're fine..

 

[GBAUTO]

I know that during veg when mine are @ 40w/cob they are barely above room temps-they only get hot when they are at max power.

 

[nfhiggs]

anyone willing to take temperature readings on their running lights and post em ?

mine run at up to 114 degrees F at near 50w/per cob.
I'm a diy led noob and I cant seem to find anywhere on the web what I should expect to see for actual temps at the heatsink. All I can seem to find is discussions on how many watts they are dissipating. Unless I'm missing some info, that doesn't tell me a noob, when I'm running my first lights, what are normal temps I should expect to see. not watts.

what temps should I start to worry I'm burn out my cobs etc.

Your hand is the best gauge, TBH. If you can keep your hand on them for more than a few seconds you're fine.