Apex...

[Rich S]

On Thursday, December 30, 2021 at 4:49:54 PM UTC, jla...@highlandsniptechnology.com wrote:

On Thu, 30 Dec 2021 10:44:45 -0500, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

Joe Gwinn wrote:
On Wed, 29 Dec 2021 18:54:34 -0800, jla...@highlandsniptechnology.com
wrote:

On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

John Larkin wrote:
Does anyone use Apex parts?

https://www.mouser.com/c/semiconductors/amplifier-ics/operational-amplifiers-op-amps/?marcom=184808364

The companion heat sink is

https://www.mouser.com/ProductDetail/Apex-Microtechnology/HS11?qs=TiOZkKH1s2RwK46pUwsmlQ%3D%3D



Sure, for one-offs. Last one I used was in about 1989, as the output
stage of a piezo driver for a prototype atomic force microscope. IIRC
it was a PA85, which was a beefier replacement for the Burr-Brown
3584--higher voltage (450V vs 300V) and much faster (1 kV/us vs 150 V/us).

The Apex parts were very noisy, iirc, but since it was the output stage,
I didn\'t care very much.

I really doubt I\'d use one in any design that was going to be replicated
more than 20 times. OTOH the quickish slew rate is worth a fair amount
sometimes.

Cheers

Phil Hobbs

Did you look at the price on that heat sink?

Even boring heat sinks are priced at kilobucks these days.

https://www.mouser.com/ProductDetail/Aavid/602151F00000G?qs=KrMmfw1gsVf%2FvbGzFuwJMg%3D%3D

I\'d read that as Aavid has decided to drop that product, but for $3K,
they will pull the tooling out of storage and make a run. Once going,
they will make many, and sell you the first.

Joe Gwinn



Might well be. Drilling a few more holes in a TO-3 heatsink is pretty
simple--that $3k is more of a stupidity tax.

Distributor prices for heatsinks are pretty high in general. (Not
usually as high as that, of course.)

Cheers

Phil Hobbs
We designed our own box to replace the ugly awkward Hammond things. We
designed a custom extrusion and had a bunch extruded and machined and
anodized, and still saved money.

https://www.dropbox.com/s/rathfqgnng2r7gt/T2box_2.jpg?raw=1

https://www.dropbox.com/s/43gma000fpuocyf/T130_box.jpg?raw=1


Commercial heat sinks cost crazy multiples of the cost of extruding
aluminum.
--

I yam what I yam - Popeye

Not that it explains All the cost, but
heatsinks like these do require the footprint
area to be machined to a certain flatness
and roughness (which then incurs QA work)
So the added labor cost could be major.
cheers, RS

 

[John Larkin]

On Fri, 31 Dec 2021 09:24:38 -0800 (PST), Rich S
<richsulinengineer@gmail.com> wrote:

On Thursday, December 30, 2021 at 4:49:54 PM UTC, jla...@highlandsniptechnology.com wrote:
On Thu, 30 Dec 2021 10:44:45 -0500, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

Joe Gwinn wrote:
On Wed, 29 Dec 2021 18:54:34 -0800, jla...@highlandsniptechnology.com
wrote:

On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

John Larkin wrote:
Does anyone use Apex parts?

https://www.mouser.com/c/semiconductors/amplifier-ics/operational-amplifiers-op-amps/?marcom=184808364

The companion heat sink is

https://www.mouser.com/ProductDetail/Apex-Microtechnology/HS11?qs=TiOZkKH1s2RwK46pUwsmlQ%3D%3D



Sure, for one-offs. Last one I used was in about 1989, as the output
stage of a piezo driver for a prototype atomic force microscope. IIRC
it was a PA85, which was a beefier replacement for the Burr-Brown
3584--higher voltage (450V vs 300V) and much faster (1 kV/us vs 150 V/us).

The Apex parts were very noisy, iirc, but since it was the output stage,
I didn\'t care very much.

I really doubt I\'d use one in any design that was going to be replicated
more than 20 times. OTOH the quickish slew rate is worth a fair amount
sometimes.

Cheers

Phil Hobbs

Did you look at the price on that heat sink?

Even boring heat sinks are priced at kilobucks these days.

https://www.mouser.com/ProductDetail/Aavid/602151F00000G?qs=KrMmfw1gsVf%2FvbGzFuwJMg%3D%3D

I\'d read that as Aavid has decided to drop that product, but for $3K,
they will pull the tooling out of storage and make a run. Once going,
they will make many, and sell you the first.

Joe Gwinn



Might well be. Drilling a few more holes in a TO-3 heatsink is pretty
simple--that $3k is more of a stupidity tax.

Distributor prices for heatsinks are pretty high in general. (Not
usually as high as that, of course.)

Cheers

Phil Hobbs
We designed our own box to replace the ugly awkward Hammond things. We
designed a custom extrusion and had a bunch extruded and machined and
anodized, and still saved money.

https://www.dropbox.com/s/rathfqgnng2r7gt/T2box_2.jpg?raw=1

https://www.dropbox.com/s/43gma000fpuocyf/T130_box.jpg?raw=1


Commercial heat sinks cost crazy multiples of the cost of extruding
aluminum.
--

I yam what I yam - Popeye

Not that it explains All the cost, but
heatsinks like these do require the footprint
area to be machined to a certain flatness
and roughness (which then incurs QA work)
So the added labor cost could be major.
cheers, RS

In my experience, the big heat sink extrusions are not usually very
flat. We often do our own secondary machining to get them flat.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[Rich S]

Commercial heat sinks cost crazy multiples of the cost of extruding
aluminum.
--

I yam what I yam - Popeye

Not that it explains All the cost, but
heatsinks like these do require the footprint
area to be machined to a certain flatness
and roughness (which then incurs QA work)
So the added labor cost could be major.
cheers, RS
In my experience, the big heat sink extrusions are not usually very
flat. We often do our own secondary machining to get them flat.

Sure, I accept that. A former colleague of mine
designed his audio amps to push the limits.
(these were full production commercial units).
the output devices ran as hot as possible, and
to ensure adequate heat removal, he left out the
insulators. Devices were mounted \"metal -on-metal\"
- so flatness mattered. I assume they ordered
the heatsinks already machined as needed.
Yes, the heatsinks were electrified, one at +100V
and the other -100V. Very tricky to work on...

Of course, the flatness need not be too low if we\'re
using a thermal pad or compound to fill the small gaps.

 

[whit3rd]

On Friday, December 31, 2021 at 11:33:53 AM UTC-8, John Larkin wrote:

In my experience, the big heat sink extrusions are not usually very
flat. We often do our own secondary machining to get them flat.

Yeah, you squeeze a toothpaste tube, it\'s not straight. For the aluminum
extrusions, each length is pulled (stretched) by a few percent while it\'s still
hot.

A couple of passes with a flycutter after anodizing is not a hard task.
Any good heatsink manufacturer could/would do that.