nania said:I just thought that I would tell you guys that Nelson puts his mosfets just about at the top of his heatsinks on the X-250 so I guess someone in his production department thinks the thermal differential seems to be the better way...or maybe that was the only place left to stick them because of poor parts planning? Ha!
On my A75 I placed my mosfets also at the very top and it works fine. For my design it was the only way to go if i wanted to have PS at the bottom http://www.passdiy.com/gallery/a75-p7.htm
When I touch heat sink after everything settles down the temperature is even.
R-Theta has a program for thermal behaviour of a sink.
nania said:Coulomb
I think I speak for everyone in this forum when I say that we need to see a bigger pic to help you.
How did you manage to post it? I can't do anything bigger than 900x800.
How did you manage to post it? I can't do anything bigger than 900x800
I just use the img button in the message centre and embed the link to my website.
By the way Peter wht do you think of using this chassis for and Aelph? Maybe the Aelph V as I can reuse my 2x30 VAC Transformer from the A75.
Anthony
Coulomb
That is an appropriate name because you definitely deserved to be flamed for posting it at that size! Next time scan at 72dpi.As fo my chimney, I call it the Towering Inferno.
That is an appropriate name because you definitely deserved to be flamed for posting it at that size! Next time scan at 72dpi
Scanned, only neophytes and cretons scan images. I used a digital camera like the rest of the more advanced homosapiens on this planet.
Don't bother me with etiquette, I am filling posts from work.
Any more constructive comments?
Thanks Peter.
Anthony
Tell me the footprint and hight of the sink, and length of a fin
The base is 13" square the tower is 20' High. it is comprised of 8 Heatsinks 8x10 with .750 fins. The structure is assembled around 4, 1 inch square Aluminum bars which would act as Rails to mount the TO-247 IRFP244 FETs There are 2 or 4 60 MM 12VDC fans running at 6VDC as intakes on the bottom and 1 5.25 12 VDC fan running at 8 VDC on top as an exhaust. All fans run below audible levels.
Coulomb
...and for the record, a digital camera is a scanning device, but nice tryScanned, only neophytes and cretons scan images. I used a digital camera like the rest of the more advanced homosapiens on this planet.
...and for the record, a digital camera is a scanning device, but nice try
Actually it is not, a scanning device by definition scans an image with a reflective light source moving sequentially across a glass plate which has an optic focused on it to return the refracted light to a CCD. The elements of the CCD are not activated until it is passed the scanned light.
In a Digital camera when the "Shutter" opens, (CCD is activated) the incoming light through the optics activates all elements at once. The on board microprocessor reads each pixel sequentially and stores the Data. Although this can be referred to as scanning, it is really a misnomer.
Anthony
When mounting heat sinks, I have always had the fins on the extrusion running vertically and cutting it to length. I have noticed that a common practise employed by DIR'ers on this board is to mount the extrusion with the fins Vertical. This would limit the depth of the chasis to the Extrusion width. The chassis would end up being taller as opposed to longer. Is this due to the belief that convection is improved by the different orientation of the Heatsink Fins?
Anyone care to banter this issue with me?
Anthony
Anyone care to banter this issue with me?
Anthony
I actually made a test with my SOZ at two operating temperatures:
At 102ºC (ouch!) the temp didn't change with the vertical/horizontal configuration.
I tried also with a horizontal configuration with the fins up (the heatsink is horizontal and the fins vertical). this way the temp was 98-99º.
At 50º horizontal fins corresponded a vertical configuration of 48º, so I guess the configuration isn't that important, so I went for the looks
At 102ºC (ouch!) the temp didn't change with the vertical/horizontal configuration.
I tried also with a horizontal configuration with the fins up (the heatsink is horizontal and the fins vertical). this way the temp was 98-99º.
At 50º horizontal fins corresponded a vertical configuration of 48º, so I guess the configuration isn't that important, so I went for the looks
Coulomb said:So if the heatsinks were oriented vertically would 2 times (10 by 12") pecies of R-Theta 65340 be enough for a Mono Aelph II Peter?
65340 comes in 11" width and at 12" lenght 2 pieces should be OK for one channel of Aleph2.
Re: Heatsinks
Here is my completed Chassis for my A75's. I have not sandblasted the heat sinks yet or added the power switch an I/O connections. I will send interior shots in a few weeks when I get back to the project. I have completed the mounting rails for the 48 Transistors, I did not want them mounted to the outside of the heatsink. I have four 60 mm fans on the bottom, one for each 12 Transistors, independantly controlled by a pair of Thermistors in parallel. The exhuast fan will run continuosly, all fans will be "Tuned" to thier lowest operating threshold to minimize noise. The columns are purely architectural and are designed to compliment the angluar lines and tie into to the feet which I machined to match my Audio stand.
I believe that great architectyre can make great art, I hope you can appreciate my A75 for the Art of it's design. That is what drew me to Mr. Pass and his designs in the first place. I beleive Mr. Pass also believes in the appeal of Art in his product.
Here is my completed Chassis for my A75's. I have not sandblasted the heat sinks yet or added the power switch an I/O connections. I will send interior shots in a few weeks when I get back to the project. I have completed the mounting rails for the 48 Transistors, I did not want them mounted to the outside of the heatsink. I have four 60 mm fans on the bottom, one for each 12 Transistors, independantly controlled by a pair of Thermistors in parallel. The exhuast fan will run continuosly, all fans will be "Tuned" to thier lowest operating threshold to minimize noise. The columns are purely architectural and are designed to compliment the angluar lines and tie into to the feet which I machined to match my Audio stand.
I believe that great architectyre can make great art, I hope you can appreciate my A75 for the Art of it's design. That is what drew me to Mr. Pass and his designs in the first place. I beleive Mr. Pass also believes in the appeal of Art in his product.
An externally hosted image should be here but it was not working when we last tested it.
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