Anybody checked temps on the Obi chips? I cracked mine open as soon as I got it, and the 12/3.3 Volt DC/DC chip is the hottest I have ever seen in any ATA I've looked at! By far...
My little infrared thermometer was saying 70 deg C, PCB by itself, wide open!!! And the chip itself must be quite a bit warmer as the "beam" of my themometer is way too wide to cover the chip alone.
Anyrate: I already cut a piece of 486 CPU heatsink and epoxied it in place. Did the same to the main CPU as well, while at it. Also cut big openings in the SIDES of the plastic case, and covered with mosquito screening...
Oh yea: also soldered a Anderson pigtail for best "lead acid"-style 12 Volt DC uninterruptible power supply. (I like my telephones to be direct "lead-acid" power, NOT AC...)
Chriswlan
Real interesting improvements! Please keep us posted.
Quote from: Chriswlan on September 25, 2012, 12:18:06 PM
My little infrared thermometer was saying 70 deg C, PCB by itself, wide open!!!
70 deg C <-- Are you sure about that, the boiling point of water is 100°C. (70 deg C = 158 deg F)
Various melting points of different types of plastic:
http://answers.yahoo.com/question/index?qid=20090813112027AASM7YC
The melting point of HDPE (High Density Polyethelyne) is about 130 ºC
The melting point of LDPE (Low Density Polyethelyne) is about 110 ºC
The melting point of PET (Polyethylene terphthalate) is about 250—260 ºC
The melting point of PP (Polypropylene) is about 160—170 ºC
The melting point of PS (Polystyrene) is about 70—115 ºC
The melting point of PVC (Polyvinyl Chloride) is about 75—90 ºC
You cannot hold in your bare hand anything 70C hot. I did not have the impression Obi would run hot, as a matter of fact less than my other devices. ???
Quote from: QBZappy on September 25, 2012, 02:19:03 PM
Various melting points of different types of plastic:
::) Where do you find the time?!! ;D
Quote from: GregoryZ on September 26, 2012, 01:03:25 PM
::) Where do you find the time?!! ;D
Google is my friend.
BTW you never told us your dog's name. It looks well fed. :)
Quote from: QBZappy on September 26, 2012, 01:10:35 PM
BTW you never told us your dog's name. It looks well fed. :)
Her name is Kasey. Thanks for asking.
She is 5yrs old now, and about 70lbs. Choc. Lab/Pit Mix. And the Love of My Life!
Now back to the regularly scheduled Postings.... :)
-G
70C on an IC probably isn't a problem but lets look at this from an engineering standpoint. I don't know what the ICs are that are running hot so unless you want to list them here, I will make some assumptions. Let's assume the junction temperature (the die itself) will run 10C hotter then the case which you are measuring. Many ICs have junction temperature ratings of 85C, 100C and 125C maximum. Let's assume these ICs can operate to 125C. If they could only operate to 85C, there would be a lot of complaints about Obi failures after a few years. A little math; 80/125=0.64 or 64% of maximum junction temperature. That isn't a bad derating. 70C is hot to the touch but the ICs will operate just fine at that temperature.
But if the max junction is 100C, then 85% is a bit high. If there are owners out there who see failures after 3 to 5 years, then yes, the ICs are running too warm.
Your adding the heatsinks will increase the life of the ICs in any case.