heat sink design, pls help

[space2000]

Hi all,

I want to make a heat sink just like this artistic type.

I need to know how much heat will dissipate using like this heat sink?
My ambient temp is 30c. The plate is circled 12inch-dia and ½ inch thickness metal. I will be using aluminum fins, which is each 5inch length X 2 inch to the air. Total fins is 12 pcs.

I don’t know how to calculate this.

Thank you
michael

[AndrewT]

try ESP's calculator

[eeka chu]

There are quite a few manufacturers that already make cylinderical / spherical heatsinks, meaning a flat base with fins that stick up out of them. Could save you a lot of effort.

http://www.digit-life.com/articles/t...orb/index.html

http://www.frostytech.com/permalink.cfm?NewsID=63131

http://www.easycom.com.ua/data/coole...2330/img/4.jpg

http://www.cdrinfo.com/Sections/Revi...rticleId=14499

http://www.xbitlabs.com/articles/coo...-sphere_3.html

[destroyer X]

As amplifiers usually work into average power...you can connect a 250 watts RMS into this heatsink.

But if you put it into the correct position.... horizontal, when your high is 2 inches and no obstructions bellow, or 4 inches cdistance from the heatsink to some solid object.

In my point of view will be good to an AB power amplifiers, pumping 120 watts RMS, continuous sinewave power into 1 Kilohertz.... or a 200 watts of consumption class A amplifier

regards,

Carlos

[space2000]

Hi DX,

waited for such a nice reply. you know what? it is actually for your turbo DX amp, preparing from now on. i will be making for three amps, mooly, aleph-3 (this two already made) and last is huge DX-turbo (waiting for final circuit design)... i am now designing a nice looks heat sink which will be placing on top of the amp and looks beautiful including blue led inside, looks even more beautiful as like you, it will be nice amp "DX turbo"....ha...ha....not prec-1 (ok). i will made own hand craft heat sink. as i know it will be good for 250w dissipate. its enough for one channel. good...news that i don't need to fight with heat sink. as this is the cheapest way to get huge heat sink.

i already bought two heavy circled plate with 1/2 inch thickness and for fins aluminium plate. They cut for me using leath mechine into nice circled.

Can i ask you on more question? if circle dia is 10 inch then how much heat will dissipate base on same design?

For DX-turbo each transistor will dissipate how much heat?

Thank you very,very much for your reply.

best regards
michael

[woody]

I don't think your design will work verry well. First the sink just
isn't big enough, has to few fins and the fins are to thin to disipate much heat. Nothing near enough for an Alph amp.

[space2000]

hi,

update of my heat sink.


i am thinking to use 4 inch height 24 fins on this plate. i will be adding a Fan at center.

pls comments.

thanks.
michael

[nigelwright7557]

Originally posted by space2000
i am thinking to use 4 inch height 24 fins on this plate. just calculated and also center will be a fan.

how about that?

thanks.

I tend to use a heatsink with a reasonable speed fan(s) to help it along. This is why I use PC cases for my amplifiers as they have plenty of fan mountings on them already. I usually rip out the power supply innards and use the mains socket for my amp.

[eeka chu]

Originally posted by nigelwright7557



I tend to use a heatsink with a reasonable speed fan(s) to help it along. This is why I use PC cases for my amplifiers as they have plenty of fan mountings on them already. I usually rip out the power supply innards and use the mains socket for my amp.

Good thinking, they do make mighty handy cases for various things - specially given their availability.

[destroyer X]

properties, cost and weigth... for heat transference (to the air) purposes, the important is the area in contact with the air... how big is the surface in contact with surrounding air to produce the heat changes, the heat transference... when the heat is lost from the heatsink and transfered to the air... the heat loss turns the heatsink more cool.

If you double your heigth, you will double your area... your heatsink will double its capacity to dissipate power.

The thickness causes a delay into the heat transference only... may be good to peaks of power, as it will absorb those surge moments of power in such a way the heat will not appear instantaneously into the heatsink surface...but will appear seconds after that... so...it will fool you... as the heat will not appear into the moment you are touching it, or measuring it to evaluate how hot it is... will be hot seconds after that.... the midnigth bass into your party will heat your heatsink internally and the heat will appear into the surface midnigth and 1 second past...just that.... the thickness does not increase the heatsink performance...just give it better look, a more respectable look, more weigth and strength...just that.

The amplifier is ready to go dear Space.... the pretty schematic not ready, but the schematic provided is the one... was assembled, tested, and it is playing wonderfull.

You need more condensers.... more...much more... electrolitic condensers to your supply, and a transformer that will give you around 70 volts (or more if you want).... a 50 plus 50 volts AC transformer, able to give you 10 plus 10 amperes... condensers to full power may be enormous... 25.000uf each rail minimum, and the best sittuation will be 50.000uf each rail (expensive...very expensive)

The amplifier is able to produce 45 volts of audio man!... a monster!.... this is more than 500 watts undistorted and twice of that distorted!
And using 3 ohms load it can produce much more than that.
It is a power machine... a speaker melter.... the thunderstorm generator... a killer amplifier...good for home demolition.

regards,

Carlos