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Best heat sink compound?

D

DarkMatter

Jan 1, 1970
0
Not if you understand what you're doing.


I'm sorry, but those of use that understand what we are doing do not
design a 200W transistor into a 200 W circuit application.

One should always use a device at an industry accepted full load,
full duty cycle design point. The device IS capable of operating at
the maximum rating, but the headroom is their for reliability reasons,
pulse conditions, etc.

So, yes, understanding what I am doing means that I would use my 30W
IC amp at 10W or so, and use that to pump my large power devices, and
only utilize THOSE at a power level much less than that at which they
are rated. For caps, it can be as high as twice the voltage, for
other components... say power resistors, it is around half. The heat
generated by a 25W resistor AT 25W is far far too high to have it
contained in a rack chassis. Pumping only 12W thru the "25W" device,
however, makes the heat it exhibits much more manageable.
Got clue?

For you not to know that is quite a tell.
 
D

DarkMatter

Jan 1, 1970
0
Even with a perfectly efficient heatsink, if you cant get the heat
into it you can't get rid of the heat that way.

No shit.
 
D

DarkMatter

Jan 1, 1970
0
From your exposition so far, I doubt whether you have the capability of
determining what proper design levels are, other than something like
"Hey, Joe, we just blew out another one. Let's try a fan and see what
happens."

You are a dipshit. You pull this crap often where you act as if you
know someone, or know how much they know, or what they do. You do
not. You are clueless.

We are finishing a 200W, 1500V 0.002% regulated, 10mV ripple
supply. Auto shutoff upon shorts, etc. etc. etc.

I'll bet you couldn't manage that in ten years "try a bigger fan
time" We did it inside a few months.

BTW, the main transformer in this design is huge toroid.
It is a linear design. The ripple cannot be met via switched modules,
nor the voltage regulation.
 
J

John Larkin

Jan 1, 1970
0
I'm sorry, but those of use that understand what we are doing do not
design a 200W transistor into a 200 W circuit application.

You're certainly right there. Sometimes I design a 200 watt part to
dissipate 1000 watts.
One should always use a device at an industry accepted full load,
full duty cycle design point.

Sorry, I don't follow rules, I make rules.
The device IS capable of operating at
the maximum rating, but the headroom is their for reliability reasons,
pulse conditions, etc.

So, yes, understanding what I am doing means that I would use my 30W
IC amp at 10W or so, and use that to pump my large power devices, and
only utilize THOSE at a power level much less than that at which they
are rated. For caps, it can be as high as twice the voltage, for
other components... say power resistors, it is around half. The heat
generated by a 25W resistor AT 25W is far far too high to have it
contained in a rack chassis. Pumping only 12W thru the "25W" device,
however, makes the heat it exhibits much more manageable.
Got clue?

For you not to know that is quite a tell.

Gosh, you almost make me embarassed to cash all those checks people
keep sending us. Almost.

John
 
J

John Fields

Jan 1, 1970
0

---
No shit?

Your:

" The conductivity, and efficiency of the sink to carry off the heat
is far more important. " belies your claim of a grasp of the obvious
before the obvious was presented to you. That is, the conductivity and
efficiency of the heat sink are unimportant if the hot device can't be
coupled to it satisfactorily.

What I think would be interesting would be for you to calculate the
differences in case temperatures between two TO-220 devices dissipating,
say, 10 watts; one sitting on the best SIL-PAD you can find and one
sitting on a patch of anodize about half a mil thick, both on otherwise
identical heatsinks. Then come back and defend the SIL-PAD.
 
J

John Larkin

Jan 1, 1970
0
No? I thought that was what Dark Matter was.

John
 
W

Winfield Hill

Jan 1, 1970
0
DarkMatter wrote...
You are a dipshit. You pull this crap often where you act as if you
know someone, or know how much they know, or what they do. You do
not. You are clueless.

We are finishing a 200W, 1500V 0.002% regulated, 10mV ripple
supply. Auto shutoff upon shorts, etc. etc. etc.

I'll bet you couldn't manage that in ten years "try a bigger fan
time" We did it inside a few months.

BTW, the main transformer in this design is huge toroid.
It is a linear design. The ripple cannot be met via switched modules,
nor the voltage regulation.

Maybe, and best wishes for the success of your interesting project.

I often use Silpads and other such - very convenient. But in the
end the hard reality as stated by the two Johns wins, big time. :>)

Thanks,
- Win

whill_at_picovolt-dot-com
 
D

DarkMatter

Jan 1, 1970
0
No? I thought that was what Dark Matter was.

And all you idiot fucks wonder why I call you retarded.

That was a perfect example of why.
 
R

Rich Grise

Jan 1, 1970
0
Yeah, speaking of TP. The guy who buys stuff for the shop was
bitching the other day about how we'd gone through 8 rolls of
TP in a week! I wanted to say, "Of courss. Everybody knows
companies are a major source of free stuff!" But I held my
tongue. But I did look at his 12-pack or whatever, and it
was 150 sheets per roll! That's about enough for 6 wipes!
And it's the thick crap, like wiping with a pillow. I like
the industrial-grade cheap stuff too - 1000 sheets/roll,
and it's got a texture, so you know it's wiping, and not
just sliding around feeling comfortable. :)

Cheers!
Rich
 
J

John Larkin

Jan 1, 1970
0
And all you idiot fucks wonder why I call you retarded.

No, I don't wonder about that. What I do wonder about is that, since
you don't like anybody here, and nobody here likes you, and you never
ask questions, and you're always wrong, why are you here?

Really, seriously, why?

John
 
J

jriegle

Jan 1, 1970
0
ROTFLMAO!

all this "wiping" talk!

Long live the bargain brand TP. It doesn't clog up the pot either! (I have
to wipe a lot because I'm so full of sh!t)
 
I

Ian Stirling

Jan 1, 1970
0
In sci.electronics.design John Larkin said:
No, I don't wonder about that. What I do wonder about is that, since
you don't like anybody here, and nobody here likes you, and you never

I dunno, I quite like him, he's funny.
He's simply not up to the class of a decent net.kook though.
Maybe when his subscription to "Wacky invention that will revolutionise
fissiks" comes in he'll get better.
 
D

DarkMatter

Jan 1, 1970
0
and it's got a texture, so you know it's wiping, and not
just sliding around feeling comfortable. :)

Cheers!
Rich


TMI... TMI.... T M I !!!
 
D

DarkMatter

Jan 1, 1970
0
ROTFLMAO!

all this "wiping" talk!

Long live the bargain brand TP. It doesn't clog up the pot either! (I have
to wipe a lot because I'm so full of sh!t)

Now, if only you could get Larkin's lame ass to figure out that he
is full of shit as well, we'll have gotten some work done here besides
just discussing feces. Instead, we discuss the feces that spews the
feces.

Alt.binaries.cd.image look for "Funny Music, and Films" Get
number 4 of 6. Not my posts.
 
D

DarkMatter

Jan 1, 1970
0
Maybe when his subscription to "Wacky invention that will revolutionise
fissiks" comes in he'll get better.


Sorry, dipshit, but I have no such machinery in the works. I am far
above the ilk that has such contrivances as well. They have NO class.
 
D

DarkMatter

Jan 1, 1970
0
The hard anodize *is* the insulator, with a thermal resistance a tiny
fraction of a sil-pad's.


That won't cut it with UL, or CE if isolation is involved. A Hard
Anodized aluminum surface is quite porous to prying, highly energetic
electrical field pressure. I would want a bona-fide barrier there,
and so does the cert labs. I'll bet the hi-pot on such a surface is
quite low for prying electrons, regardless of what some ohm meter and
a simple probe declares.
 
J

John Larkin

Jan 1, 1970
0
That won't cut it with UL, or CE if isolation is involved. A Hard
Anodized aluminum surface is quite porous to prying, highly energetic
electrical field pressure. I would want a bona-fide barrier there,
and so does the cert labs. I'll bet the hi-pot on such a surface is
quite low for prying electrons, regardless of what some ohm meter and
a simple probe declares.


Neat trick, snipping half a paragraph and criticizing what's left.
Who's going to get shocked by touching a grounded heat sink that's
bolted to the chassis?

John
 
D

DarkMatter

Jan 1, 1970
0
Neat trick, snipping half a paragraph and criticizing what's left.
Who's going to get shocked by touching a grounded heat sink that's
bolted to the chassis?

Who said that it was or had to be grounded? Doesn't matter anyway,
they, and any good designer would want any elevated voltage node
isolated, and that better than the isolation provided by some
anodization of some rarely controlled well enough thickness.

Whether it is at ground or not isn't the issue.

The practice is verboten in many circles.

On conduction cooled modules, typically the case is also the heat
sink for one or more devices inside. It needs to be isolated.
Period. I don't care what you say. Plastic devices used in the
design would allow for an exception, but our mil/rugged units don't
use those packages, and it can't be changed to them.
 
D

Daniel L. Belton

Jan 1, 1970
0
Robert said:
The "arctic silver compound" is *bad* stuff.
It migrates all over hell and back, not only making a crappy looking
mess, but also has been reported to do damage to electrical contacts.

Never had that problem here using it for more than 4 years on several
hundred CPU's and chipsets
 
D

Daniel L. Belton

Jan 1, 1970
0
DarkMatter said:
Being an overclocker, you should know better than to give the
multiplied number as in 2.4 GHz OC'd to 2.8, a 400MHz gain.
Bullshit.

That is bullshit. What is the FSB clock change? That is the only
one that REALLY matters.

BTW, if that is not really your valid e-mail, it is illegal to use a
dot gov addy if it isn't legitimate. You could get nailed.

ok... on a PIII rated at 133 mhz FSB, I can run it at a 168 mhz FSB
with Arctic Silver... With the white silicone, I can get no more than
147 mhz...
 
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