• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Gb: F5 Pcb

Status
Not open for further replies.
Jump to Latest
#842
Variac said:
Mr Viller was at last year's BA. Came to check out if the area was Ok.
Click to expand...


Yeah I did some recon and decided to go! 😀
I look forward to seeing more of the people from the forum - the community appears to be very strong in SF.

Now I'm reading through craigslist to find a place to stay and a cheap reliable car for camping trips.
 
#844
Christian,
I'd be proud to buy you a beer (import) :drink: at Burning Amp this year as a small way of saying "thank you" for making this Group Buy possible and posting a fine PDF on how to wire up an F5.

I don't drink, but I'll be glad to tip a glass of water with you!


Ron
 
#845
Renron, thanks for the offer - I will definitely take you up on that! 😉

I'm now in SF - found a place in Cole Valley and we have been out shopping for furnitures at garage sales the whole weekend. It is so funny looking at other peoples junk... seems like I'm not the only one accumulating misc junk. 😀

Well my boards will arrive in 3-4 weeks, so I now I'm unable to sell any - I have also decided to give away the rest to diyaudio (for selling at BAF2009). Perhaps I might even have to order more for just that...
 
#852
#855
labjr said:

Anyone know how well an 8 inch piece per channel will work for the stock F5 or do we need more?

I would think you'd need slightly larger piece.
Click to expand...


From the F5 Operation & Service Manual....

{At 1.3 amps per channel, you will see idle heat dissipation of 62 watts. To keep the temperature rise of the heat sink to
20 deg C. above the ambient temperature, you will want a heat sink rated at about .6 deg C./watt for each transistor. An
example of this would be a chunk of fi nned aluminum, with a series of 2” fi ns attached to an 8” by 6” base. You will need
two per channel.}
 
#856
ichiban said:



From the F5 Operation & Service Manual....

{At 1.3 amps per channel, you will see idle heat dissipation of 62 watts. To keep the temperature rise of the heat sink to
20 deg C. above the ambient temperature, you will want a heat sink rated at about .6 deg C./watt for each transistor. An
example of this would be a chunk of fi nned aluminum, with a series of 2” fi ns attached to an 8” by 6” base. You will need
two per channel.}
Click to expand...

Or maybe have him cut a longer piece like 10-12 inches long for each channel that would equal 100 square inches or so.
 
#858
labjr said:


Or maybe have him cut a longer piece like 10-12 inches long for each channel that would equal 100 square inches or so.
Click to expand...


Here's the issue with these heatsinks. First off I like them, but I don't think one per channel will work with an F5 though.

If he cut them longer, they would be taller, NOT wider. (fin direction) After about 6" tall the additional height to thermal efficiency diminishes very quickly. Wider is better at distributing heat. His are 10.125 wide. Not that much more than the 6"X 8" (2 Per channel) that Papa recommends.
IF, big IF, you cut them in 1/2 and placed them next to each other horizontally you might have enough thermal dissipation.
Someone with more mathematical education than I will have to figure that one out.
Just my .02 cents.

Ron
 
#859
double the width and of course double the fins and you get double the dissipation, but only if the whole of the now extra wide backplate is as hot as the smaller backplate.

Double the height with double the area of the fins will dissipate ~sqrt(2) times the smaller one, again if the whole backplate is at the same temperature as the smaller one.

Increasing the width increases the dissipation pro rata.
Increasing the height increases the dissipation by Sqrt(height ratio).

eg. four times the height increases the dissipation by ~double, sqrt(4)=2.
 
Status
Not open for further replies.
Top Bottom