Heatsink, just don't drop it on concrete

[Tim Williams]

<krw@notreal.com> wrote in message
news:7g7rgepernjf6r0u94p5r6l79a8qr3v2b8@4ax.com...

Other than pulse ratings, no, conductivity of the cement doesn't matter
much, considering the pitiful conductivity of the air surrounding it.

Right, so why would one think that material is great for heatsinking
semiconductor devices?

Compared to what? Great how?

Aluminum metal is so much more conductive than needed, it doesn't really
matter, in terms of board-level heatsinks.

Alumina is perfectly traditional in many products. Must be good for
something.

Tim

--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/

 

[John Larkin]

On Fri, 21 Jun 2019 23:19:11 -0400, krw@notreal.com wrote:

On Fri, 21 Jun 2019 12:21:01 -0500, "Tim Williams"
tiwill@seventransistorlabs.com> wrote:

krw@notreal.com> wrote in message
news:ub1qgetodft4e52nf6o1n1sq3fi59cs7pq@4ax.com...
Does the thermal resistance of a power resistor coating matter all
that much (within reason)? At least for a resistor that isn't
intended to be connected to a heat sink. Power resistors run at much
higher temperatures than the normal semiconductor parts and the area
of the case is larger than the element. Thermal conductivity helps
moving heat. It doesn't help dissipate it.

Other than pulse ratings, no, conductivity of the cement doesn't matter
much, considering the pitiful conductivity of the air surrounding it.

Right, so why would one think that material is great for heatsinking
semiconductor devices?

Because it looks cool? Because it makes things sound better?


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

On Sat, 22 Jun 2019 02:04:32 -0500, "Tim Williams"
<tiwill@seventransistorlabs.com> wrote:

krw@notreal.com> wrote in message
news:7g7rgepernjf6r0u94p5r6l79a8qr3v2b8@4ax.com...
Other than pulse ratings, no, conductivity of the cement doesn't matter
much, considering the pitiful conductivity of the air surrounding it.

Right, so why would one think that material is great for heatsinking
semiconductor devices?


Compared to what? Great how?

AlN, Al, or any of the usual suspects.

Aluminum metal is so much more conductive than needed, it doesn't really
matter, in terms of board-level heatsinks.

Huh?

Alumina is perfectly traditional in many products. Must be good for
something.

We were discussing ceramics.

 

On Sat, 22 Jun 2019 09:43:50 -0700, John Larkin
<jjlarkin@highland_snip_technology.com> wrote:

On Fri, 21 Jun 2019 23:19:11 -0400, krw@notreal.com wrote:

On Fri, 21 Jun 2019 12:21:01 -0500, "Tim Williams"
tiwill@seventransistorlabs.com> wrote:

krw@notreal.com> wrote in message
news:ub1qgetodft4e52nf6o1n1sq3fi59cs7pq@4ax.com...
Does the thermal resistance of a power resistor coating matter all
that much (within reason)? At least for a resistor that isn't
intended to be connected to a heat sink. Power resistors run at much
higher temperatures than the normal semiconductor parts and the area
of the case is larger than the element. Thermal conductivity helps
moving heat. It doesn't help dissipate it.

Other than pulse ratings, no, conductivity of the cement doesn't matter
much, considering the pitiful conductivity of the air surrounding it.

Right, so why would one think that material is great for heatsinking
semiconductor devices?

Because it looks cool? Because it makes things sound better?

Sound? Like breaking glass?

 

[John Larkin]

On Sat, 22 Jun 2019 22:00:13 -0400, krw@notreal.com wrote:

On Sat, 22 Jun 2019 09:43:50 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Fri, 21 Jun 2019 23:19:11 -0400, krw@notreal.com wrote:

On Fri, 21 Jun 2019 12:21:01 -0500, "Tim Williams"
tiwill@seventransistorlabs.com> wrote:

krw@notreal.com> wrote in message
news:ub1qgetodft4e52nf6o1n1sq3fi59cs7pq@4ax.com...
Does the thermal resistance of a power resistor coating matter all
that much (within reason)? At least for a resistor that isn't
intended to be connected to a heat sink. Power resistors run at much
higher temperatures than the normal semiconductor parts and the area
of the case is larger than the element. Thermal conductivity helps
moving heat. It doesn't help dissipate it.

Other than pulse ratings, no, conductivity of the cement doesn't matter
much, considering the pitiful conductivity of the air surrounding it.

Right, so why would one think that material is great for heatsinking
semiconductor devices?

Because it looks cool? Because it makes things sound better?

Sound? Like breaking glass?

I was thinking about inner microdynamics, or crisp granularity, or
holographic sound staging, one of those technical audio terms.

I have a list somewhere.


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

On Mon, 24 Jun 2019 10:58:27 -0700, John Larkin
<jjlarkin@highland_snip_technology.com> wrote:

On Sat, 22 Jun 2019 22:00:13 -0400, krw@notreal.com wrote:

On Sat, 22 Jun 2019 09:43:50 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Fri, 21 Jun 2019 23:19:11 -0400, krw@notreal.com wrote:

On Fri, 21 Jun 2019 12:21:01 -0500, "Tim Williams"
tiwill@seventransistorlabs.com> wrote:

krw@notreal.com> wrote in message
news:ub1qgetodft4e52nf6o1n1sq3fi59cs7pq@4ax.com...
Does the thermal resistance of a power resistor coating matter all
that much (within reason)? At least for a resistor that isn't
intended to be connected to a heat sink. Power resistors run at much
higher temperatures than the normal semiconductor parts and the area
of the case is larger than the element. Thermal conductivity helps
moving heat. It doesn't help dissipate it.

Other than pulse ratings, no, conductivity of the cement doesn't matter
much, considering the pitiful conductivity of the air surrounding it.

Right, so why would one think that material is great for heatsinking
semiconductor devices?

Because it looks cool? Because it makes things sound better?

Sound? Like breaking glass?

I was thinking about inner microdynamics, or crisp granularity, or
holographic sound staging, one of those technical audio terms.

Ah, "sound" as in the audiophoolery arena.

>I have a list somewhere.

If you dig it out, I could use it. ;-)

 

[John Larkin]

On Mon, 24 Jun 2019 22:54:50 -0400, krw@notreal.com wrote:

On Mon, 24 Jun 2019 10:58:27 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Sat, 22 Jun 2019 22:00:13 -0400, krw@notreal.com wrote:

On Sat, 22 Jun 2019 09:43:50 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Fri, 21 Jun 2019 23:19:11 -0400, krw@notreal.com wrote:

On Fri, 21 Jun 2019 12:21:01 -0500, "Tim Williams"
tiwill@seventransistorlabs.com> wrote:

krw@notreal.com> wrote in message
news:ub1qgetodft4e52nf6o1n1sq3fi59cs7pq@4ax.com...
Does the thermal resistance of a power resistor coating matter all
that much (within reason)? At least for a resistor that isn't
intended to be connected to a heat sink. Power resistors run at much
higher temperatures than the normal semiconductor parts and the area
of the case is larger than the element. Thermal conductivity helps
moving heat. It doesn't help dissipate it.

Other than pulse ratings, no, conductivity of the cement doesn't matter
much, considering the pitiful conductivity of the air surrounding it.

Right, so why would one think that material is great for heatsinking
semiconductor devices?

Because it looks cool? Because it makes things sound better?

Sound? Like breaking glass?

I was thinking about inner microdynamics, or crisp granularity, or
holographic sound staging, one of those technical audio terms.

Ah, "sound" as in the audiophoolery arena.

I have a list somewhere.

If you dig it out, I could use it. ;-)

https://www.dropbox.com/s/4dqdt9magblxk5g/audio.txt?dl=0

From actual audio reviews. Additions are welcome.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

tabbypurr@gmail.com wrote in
news:7ef098c2-8b9c-4b87-8657-bfb9a720835f@googlegroups.com:

On Tuesday, 25 June 2019 04:07:27 UTC+1, John Larkin wrote:
On Mon, 24 Jun 2019 22:54:50 -0400, krw@notreal.com wrote:
On Mon, 24 Jun 2019 10:58:27 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

I was thinking about inner microdynamics, or crisp granularity,
or holographic sound staging, one of those technical audio
terms.

Ah, "sound" as in the audiophoolery arena.

I have a list somewhere.

If you dig it out, I could use it. ;-)

https://www.dropbox.com/s/4dqdt9magblxk5g/audio.txt?dl=0

From actual audio reviews. Additions are welcome.


One does make sense, bass transient response. Some ported speakers
were terrible on this point.


NT

I absolutely loved my Acoustic Suspension, sealed cabinet, Scott
speakers from 1972. Quite responsive across the range. Had them
for decades. The pair ended up as my center channel, before it was
all stolen.

 

On Tuesday, 25 June 2019 04:07:27 UTC+1, John Larkin wrote:

On Mon, 24 Jun 2019 22:54:50 -0400, krw@notreal.com wrote:
On Mon, 24 Jun 2019 10:58:27 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

I was thinking about inner microdynamics, or crisp granularity, or
holographic sound staging, one of those technical audio terms.

Ah, "sound" as in the audiophoolery arena.

I have a list somewhere.

If you dig it out, I could use it. ;-)

https://www.dropbox.com/s/4dqdt9magblxk5g/audio.txt?dl=0

From actual audio reviews. Additions are welcome.

One does make sense, bass transient response. Some ported speakers were terrible on this point.


NT

 

On Mon, 24 Jun 2019 20:07:19 -0700, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

On Mon, 24 Jun 2019 22:54:50 -0400, krw@notreal.com wrote:

On Mon, 24 Jun 2019 10:58:27 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Sat, 22 Jun 2019 22:00:13 -0400, krw@notreal.com wrote:

On Sat, 22 Jun 2019 09:43:50 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

On Fri, 21 Jun 2019 23:19:11 -0400, krw@notreal.com wrote:

On Fri, 21 Jun 2019 12:21:01 -0500, "Tim Williams"
tiwill@seventransistorlabs.com> wrote:

krw@notreal.com> wrote in message
news:ub1qgetodft4e52nf6o1n1sq3fi59cs7pq@4ax.com...
Does the thermal resistance of a power resistor coating matter all
that much (within reason)? At least for a resistor that isn't
intended to be connected to a heat sink. Power resistors run at much
higher temperatures than the normal semiconductor parts and the area
of the case is larger than the element. Thermal conductivity helps
moving heat. It doesn't help dissipate it.

Other than pulse ratings, no, conductivity of the cement doesn't matter
much, considering the pitiful conductivity of the air surrounding it.

Right, so why would one think that material is great for heatsinking
semiconductor devices?

Because it looks cool? Because it makes things sound better?

Sound? Like breaking glass?

I was thinking about inner microdynamics, or crisp granularity, or
holographic sound staging, one of those technical audio terms.

Ah, "sound" as in the audiophoolery arena.

I have a list somewhere.

If you dig it out, I could use it. ;-)

https://www.dropbox.com/s/4dqdt9magblxk5g/audio.txt?dl=0

From actual audio reviews. Additions are welcome.

It'll be put to good use. Thanks!

 

On Tuesday, 25 June 2019 14:45:25 UTC+1, tabby wrote:

On Tuesday, 25 June 2019 04:07:27 UTC+1, John Larkin wrote:
On Mon, 24 Jun 2019 22:54:50 -0400, krw@notreal.com wrote:
On Mon, 24 Jun 2019 10:58:27 -0700, John Larkin
jjlarkin@highland_snip_technology.com> wrote:

I was thinking about inner microdynamics, or crisp granularity, or
holographic sound staging, one of those technical audio terms.

Ah, "sound" as in the audiophoolery arena.

I have a list somewhere.

If you dig it out, I could use it. ;-)

https://www.dropbox.com/s/4dqdt9magblxk5g/audio.txt?dl=0

From actual audio reviews. Additions are welcome.


One does make sense, bass transient response. Some ported speakers were terrible on this point.

to clarify they had the amplitude of response at the port frequency, but the rate at which the resonance changed amplitude was excessively slow.


NT