Balanced F5 question

[Luke]

No one will be exempted from import tax & VAT.

Patrick

Doesnt that depend on the country? For example in NZ I would not pay VAT and may or may not pay GST to our customs people?

 

[Horio]

Patrick,
What about these HS for builders in the US. Seller will cut them to any height.
They are 10" wide and could be used for a tower. Claimed as °C/W/3" Approximately: 0.80, so 0.2 for 12" height? One per channel?

Barrredboss

http://cgi.ebay.com/Heatsink-Aluminum-Extrusion-10-080-Wide-x-12-Long-/170555438990?pt=LH_DefaultDomain_0&hash=item27b5e5778e

Those heatsinks look like the same one Heatsink USA offers (a forum sponsor).

Heatsink USA - 10.080 inch profile

 

[neb001]

That's because barrredboss is Heatsink USA

 

[EUVL]

If you wish to build the case yourself and use those heatsinks, you could use 4x of those 6~8 inch length and build it like Hifi2000.
Details you can see in the Hifi2000 download drawing.

For a large tower, probably 4x 19" length, depending on design. Will surely take 100W Class A, e.g. Aleph-JX 100.


Patrick

 

[EUVL]

> Will surely take 100W Class A, e.g. Aleph-JX 100.

Monoblock (single channel), of course.

Patrick

 

[AudioSan]

Patrick,
What about these HS for builders in the US. Seller will cut them to any height.
They are 10" wide and could be used for a tower. Claimed as °C/W/3" Approximately: 0.80, so 0.2 for 12" height? One per channel?

Barrredboss

http://cgi.ebay.com/Heatsink-Aluminum-Extrusion-10-080-Wide-x-12-Long-/170555438990?pt=LH_DefaultDomain_0&hash=item27b5e5778e

12" hight will give you about 0.45-0.5C/W
dobbel hight DO NOT disepate twice the watts.
more like 40-50% more.

 

[EUVL]

I know, but post #261 was specifically asking for a tower.
Then the heatsink becomes part of the housing.

Patrick


For illustration purposes only, here is the Rth vs length of a Fischer heatsink.

 

[ichiban]

For a large tower, probably 4x 19" length, depending on design. Will surely take 100W Class A, e.g. Aleph-JX 100.
Patrick

Thanks

 

[EUVL]

This one has the closest fin geometry to the Conrad MF35-151.
As you can see, practically no gain after 150mm.

You can roughly scale the Rth according to the inverse of the width (160/350) to get an estimate for the Conrad.
The Rth values here assumes 80°C temperature rise, and hence you need to apply the correction factor for 35~40°C rise.

So the Conrad would come to Rth of about 0.3 (for 40°C rise), and thus can take 120W for a sink temperature of 40°C above ambient.
It does need some help.

The SK88 and SK49, I leave you to search at the Fischer website :

http://www.fischerelektronik.de/index.php/download-heatsinks-fcool/?&L=1


Patrick

.

 

[tinitus]

Doing a "tower" design doesnt mean there have to be heatsink all the way from bottom to top
Might then not be a tower design tho

 

[EUVL]

This I consider as Tower :

http://www.diyaudio.com/forums/atta...urce-follower-configurations-hp_amp_front.jpg


Patrick

 

[qusp]

Doesnt that depend on the country? For example in NZ I would not pay VAT and may or may not pay GST to our customs people?

same here, australia has import tax, but you do not pay any until the value is over 1000AUD, so I would certainly hope to avoid paying VAT for no reason

 

[EUVL]

It was a general statement. Of course laws of individual countries apply.

Patrick

 

[samoloko]

thinking of possible heatsinks what about of toroid for this project
GB - custom purchase from Plitron ?

 

[Luke]

same here, australia has import tax, but you do not pay any until the value is over 1000AUD, so I would certainly hope to avoid paying VAT for no reason

Its the same here, if there were vat and gst that would add 35% to the price, it starts to get costly.

 

[Luke]

thinking of possible heatsinks what about of toroid for this project
GB - custom purchase from Plitron ?

I used antek for my current project, and although its not quite finished, they seem like good quality and I dont know how they ship for the price they do. Im happy with them thus far.

http://www.antekinc.com/gview.php?d[]=0

 

[EUVL]

You already know how much space you have inside the case for Tx ?
(Of course you are not obliged to use the case designed for DIYA.)




Patrick

 

[Bksabath]

Samoloko

I had same trafos made they are 1000 VA with twin sec at 24 V with tap at 20 V.

Already discussed before but my response was.

We could get those made at decent price once agreed to voltagges and such.

As on other items on this tread once decided those will be avvaliable trough the forum.
See atachment picture


Al

 

[Bksabath]

And for heath sink asking for 0.06 C/W I have found tose.

Again if ok with board or to order for different project

Minimum 10 each at £120 and £300

Al

 

[EUVL]

In post #256, I mentioned that the total width is 350mm.
Take off 100mm for 2 heatsinks, we are left with 250mm.

Allow another 50m per PCB (and some gap), the maximum dia. for the Tx is 150mm.
No problem fitting 2x 500VA.
1x 1000VA might be tricky, depending on from which manufacturer ......

But then again, you could use the case from hifi2000 .......


Patrick