Hello everyone...
Has anyone ever used one of these:
I purchased 4 last year and modified one so that I could mount an AV800 (Anthony Holton) on each side.
These heatsinks are made by Wakefield Eng. Inc and are MOD. FCA-800, they measure 12 inches (30.5cm) long and all 4 sections are electrically isolated from each other. My aluminum inserts basically split the heatsink into 2 halves electrically.
I was wondering if anyone knew any more information on these, specifically their thermal resistance with a 80cfm fan attached. Any info would be more than I have, here is the actual extrusion from wakefield, but I just don't know how to figure out if what i have done will meet the requirements of the AV800, Anthony specifies .2degrees/watt or .5 degrees/watt with fan cooling. Thanks!
Has anyone ever used one of these:
An externally hosted image should be here but it was not working when we last tested it.
I purchased 4 last year and modified one so that I could mount an AV800 (Anthony Holton) on each side.
An externally hosted image should be here but it was not working when we last tested it.
These heatsinks are made by Wakefield Eng. Inc and are MOD. FCA-800, they measure 12 inches (30.5cm) long and all 4 sections are electrically isolated from each other. My aluminum inserts basically split the heatsink into 2 halves electrically.
I was wondering if anyone knew any more information on these, specifically their thermal resistance with a 80cfm fan attached. Any info would be more than I have, here is the actual extrusion from wakefield, but I just don't know how to figure out if what i have done will meet the requirements of the AV800, Anthony specifies .2degrees/watt or .5 degrees/watt with fan cooling. Thanks!
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Joined 2002
You can find the A-40 article by Nelson Pass at his DIY site. He uses the same heatsinks for his A-40 in the article. He also talks a little about class A heat and heatsinks.
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I found an equation for forced convection thermal resistance:
272.16/(A*h)
Where A is the surface area of the extrusion in sq in (get that from the data sheet.....)
And h is the heat transfer coefficient.
Since you have a 12" long extrusion, and probably not a hurricane blowing across it..........figure h is around 1. That will get you close. The value of h rises to 2 at a flow velocity of 400 ft/min.
Jocko
272.16/(A*h)
Where A is the surface area of the extrusion in sq in (get that from the data sheet.....)
And h is the heat transfer coefficient.
Since you have a 12" long extrusion, and probably not a hurricane blowing across it..........figure h is around 1. That will get you close. The value of h rises to 2 at a flow velocity of 400 ft/min.
Jocko
http://www.fischerelektronik.de/download/download_fr.htm is more - i think - what you are searching for, especially the the D Gruppe.zip under "D".
Using one myself albeit only with a length of 2 units (71 mm.). My fan is spinning only enough to make it start - and then a tad for safety. Two 2N5884/2N5886 on each arm and each running at 0.5 A. /10 V. Works perfectly and without noise from the fan.
Using one myself albeit only with a length of 2 units (71 mm.). My fan is spinning only enough to make it start - and then a tad for safety. Two 2N5884/2N5886 on each arm and each running at 0.5 A. /10 V. Works perfectly and without noise from the fan.
New question.... SAME TOPIC
Has anyone ever mounted a fan at either end of a tunnel and have the second fan come on at a preset temperature.
Does having the first fan running while the second is unpowered reduce the efficiency of the first by a lot?
I was just considering having the first fan on all the time or say come on at 50°C and the second at 65°C and shutdown at 80°C.
Any thoughts?
Thanks again!
Has anyone ever mounted a fan at either end of a tunnel and have the second fan come on at a preset temperature.
Does having the first fan running while the second is unpowered reduce the efficiency of the first by a lot?
I was just considering having the first fan on all the time or say come on at 50°C and the second at 65°C and shutdown at 80°C.
Any thoughts?
Thanks again!
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