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Old 10th October 2006, 02:12 PM   #31
ssanmor is offline ssanmor  Spain
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Yes, very tight indeed.
No, the fan doesn't disturb. It is very quiet, and its speed is temperature controlled (the BP4078 temperaure sensor probed to be very useful! )
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Old 10th October 2006, 02:28 PM   #32
TOINO is offline TOINO  Portugal
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Quote:
Originally posted by BWRX


Care to share any more info about this module?

Nothing special...

+80V/0/-80V supply in full-bridge. One Cycle Control modulator exactly as in the patent.
I have made it for sub-bass, but works fantastic at full range. Oscillation is about 300Khz.
After some unsuccessful attempts to transform it in BD modulation I decided to leave it as it is now.
My humble opinion is that OCC is a great and simple error correction technique.
Thank you Miss Smedley.
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Old 10th October 2006, 02:58 PM   #33
Javin5 is offline Javin5  Switzerland
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Sander

Thanks a lot for your answer. I didn't know that the medical grade filters are implemented differently (just thought they would use higher quality components). That's quite interesting, I might give this a try.

Regards -- Kurt
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Old 11th October 2006, 10:15 AM   #34
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Default Re: On the way

Quote:
Originally posted by novec
I'll join the gallery too, although I don't have anything yet... This is a four channel NewClassD amp to be driven with an active crossover. It's got 1300VA toroids and separate cap banks for each amp, 15000 uF Jensen 4-pole for the mid/high, and 2x 15000 uF for lows. I'll make the case out of 10 mm aluminium, with 3 mm top and bottom. Haven't desided on front design yet.

With a little luck, I'll have it done by Christmas

Looks like a nice layout. Don't forget to make your top and bottom plate look like a piece of swiss cheese or you're going to have a big problem.
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Old 11th October 2006, 10:53 AM   #35
Puffin is offline Puffin  United Kingdom
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What about this.
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File Type: jpg supersonic.jpg (3.2 KB, 10819 views)
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Old 11th October 2006, 11:40 AM   #36
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Is that a George Foreman Grill? Hard to make out.
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Old 11th October 2006, 12:23 PM   #37
Puffin is offline Puffin  United Kingdom
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I am sorry about the quality of the photo. The photo should be capable of being enlarged but for some reason it did not like being attached. If iit s a G.R grill it sounds bloody good. it has a sink on the chip to keep it cool !

The picture should show 4 S.I carcasses glued back to back and a mirror image for the base. The amp is a a fully working mooded S.I. There is a better picture on the thread "Supersonic T-Amp" (if you are interested)
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Old 11th October 2006, 12:24 PM   #38
novec is offline novec  Norway
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Default Re: Re: On the way

Quote:
Originally posted by classd4sure
Looks like a nice layout. Don't forget to make your top and bottom plate look like a piece of swiss cheese or you're going to have a big problem.
Will do An aluminium case like that will have great heat dissipation, but not for the transformers, which are pretty much thermally disconnected. If I ever were to push them, they'd pump out about 150W of heat. Even when idle, they give off a toasty 20W each.
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Old 11th October 2006, 12:56 PM   #39
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Default Re: Re: Re: On the way

Quote:
Originally posted by Puffin
I am sorry about the quality of the photo. The photo should be capable of being enlarged but for some reason it did not like being attached. If iit s a G.R grill it sounds bloody good. it has a sink on the chip to keep it cool !

The picture should show 4 S.I carcasses glued back to back and a mirror image for the base. The amp is a a fully working mooded S.I. There is a better picture on the thread "Supersonic T-Amp" (if you are interested)
I am interested, if you'd be so kind as to throw me the link


Quote:
Originally posted by novec


Will do An aluminium case like that will have great heat dissipation, but not for the transformers, which are pretty much thermally disconnected. If I ever were to push them, they'd pump out about 150W of heat. Even when idle, they give off a toasty 20W each.

Hi,

The case alone is no where near good enough to dissipate the convected heat. It simply adds alot of thermal mass which helps keep the the mosfets cool via conduction, which means they won't overheat in a matter of seconds or minutes, but you still must ensure there's adequate convection cooling (vents) to keep the ambient temp well within spec. The hotter it is the shorter the lifespan, and if it gets hot enough it could be very short when components start to work (fail) beyond allowed design margins.

Just think of your typical oven with the door closed, same exact thing. In this case it's the filter coils that will act as your heating element. The only other form of cooling they have aside from convection (airflow), is conduction via the pcb traces, and that's hardly worth a mention. You can see now that your smaller compartments, while they may be good for some measure of EMI shielding, will only compound the problem a good deal, and I would imagine critically so if each one is not vented.

What software did you use for working out that layout?
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Old 11th October 2006, 01:05 PM   #40
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Quote:
Originally posted by novec
I know what you mean, but after a lot of thought, I've found this to be the most practical design. This way, I also keep everything AC on one side of the middle divider, shielded from the caps and amp. Also, the wires from the PSU to caps wil be heavy gauge, and only 80-90 mm long. From caps to amp, which is more important, they'll only be 10-20 mm.

I'm not sure what you mean regarding the trafos. I'm running one trafo per channel now, meaning two amps per toroid. I see now that I was a bit unclear on that. They're running off the same bridge (running two bridges on the same secondary is no good), but the high amps are decoupled with 1 ohm resistors, so there's minimal interaction between the two. And like I said, each amp has it's own separate capacitor bank.

Feel free to comment my design, I'm no expert at this

I think I agree with Lucpes here. It's hard to tell by your drawing how you plan on mounting the supplies on that plate, looks like they're kind of integrated. You'd likely be better off isolating them from the divider, flipping the whole thing over, and going with the shortest possible runs for DC to the modules. The bulk storage caps on the modules arent' the biggest, so you really want that path as optimal as possible.

You can still do it and keep all the AC portion shielded from the modules if you work it out right.
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