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

--

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

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

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
<pcdhSpamMeSenseless@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 yam what I yam - Popeye

jlarkin@highlandsniptechnology.com wrote:
> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
> <pcdhSpamMeSenseless@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

Well, it's $3k, but they have none in stock and the lead time is 22
weeks. That's less than $140 per week on layaway. What's not to like?

(I have some 8-pin TO-3 heat sinks I bought for use with LH0063s and
LH4009s. They'd fit.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
> <pcdhSpamMeSenseless@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
>
>
>
Free shipping though!

--
Marty

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

>On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
><pcdhSpamMeSenseless@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

Joe Gwinn wrote:
> On Wed, 29 Dec 2021 18:54:34 -0800, jlarkin@highlandsniptechnology.com
> wrote:
>
>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>> <pcdhSpamMeSenseless@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

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Thu, 30 Dec 2021 19:39:51 +1100, marty <marty@invalid.net> wrote:

>On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>> <pcdhSpamMeSenseless@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
>>
>>
>>
>Free shipping though!

I'd hate to pay shipping for parts that are out of stock.

I see insane pricing on some parts, factors of 10 and sometimes 100x
reasonable.

--

I yam what I yam - Popeye

On 12/30/2021 18:09, jlarkin@highlandsniptechnology.com wrote:
> On Thu, 30 Dec 2021 19:39:51 +1100, marty <marty@invalid.net> wrote:
>
>> On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
>>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>>> <pcdhSpamMeSenseless@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
>>>
>>>
>>>
>> Free shipping though!
>
> I'd hate to pay shipping for parts that are out of stock.
>
> I see insane pricing on some parts, factors of 10 and sometimes 100x
> reasonable.
>
>
>

The pricing on these opamps may be insane but so are the parts, I never
knew things like that were on offer (2.5kV peak to peak output!).
I have not done more than 200V peak to peak, was some 10 years ago, I
did it with discrete parts though. The project could not have afforded
opamps like these anyway.

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

>Joe Gwinn wrote:
>> On Wed, 29 Dec 2021 18:54:34 -0800, jlarkin@highlandsniptechnology.com
>> wrote:
>>
>>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>>> <pcdhSpamMeSenseless@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

On Thu, 30 Dec 2021 18:47:34 +0200, Dimiter_Popoff <dp@tgi-sci.com>
wrote:

>On 12/30/2021 18:09, jlarkin@highlandsniptechnology.com wrote:
>> On Thu, 30 Dec 2021 19:39:51 +1100, marty <marty@invalid.net> wrote:
>>
>>> On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
>>>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>>>> <pcdhSpamMeSenseless@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
>>>>
>>>>
>>>>
>>> Free shipping though!
>>
>> I'd hate to pay shipping for parts that are out of stock.
>>
>> I see insane pricing on some parts, factors of 10 and sometimes 100x
>> reasonable.
>>
>>
>>
>
>The pricing on these opamps may be insane but so are the parts, I never
>knew things like that were on offer (2.5kV peak to peak output!).
>I have not done more than 200V peak to peak, was some 10 years ago, I
>did it with discrete parts though. The project could not have afforded
>opamps like these anyway.

You can make your own kilovolt-level opamps pretty easily. There are
some nice HV mosfets like IXTY02N120 and 2SK4177 and the IXTT02N450HV.
If you optocouple up into the fets, it avoids all sorts of ugly level
shifting.

--

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

On 12/30/2021 20:28, John Larkin wrote:
> On Thu, 30 Dec 2021 18:47:34 +0200, Dimiter_Popoff <dp@tgi-sci.com>
> wrote:
>
>> On 12/30/2021 18:09, jlarkin@highlandsniptechnology.com wrote:
>>> On Thu, 30 Dec 2021 19:39:51 +1100, marty <marty@invalid.net> wrote:
>>>
>>>> On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
>>>>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>>>>> <pcdhSpamMeSenseless@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
>>>>>
>>>>>
>>>>>
>>>> Free shipping though!
>>>
>>> I'd hate to pay shipping for parts that are out of stock.
>>>
>>> I see insane pricing on some parts, factors of 10 and sometimes 100x
>>> reasonable.
>>>
>>>
>>>
>>
>> The pricing on these opamps may be insane but so are the parts, I never
>> knew things like that were on offer (2.5kV peak to peak output!).
>> I have not done more than 200V peak to peak, was some 10 years ago, I
>> did it with discrete parts though. The project could not have afforded
>> opamps like these anyway.
>
> You can make your own kilovolt-level opamps pretty easily. There are
> some nice HV mosfets like IXTY02N120 and 2SK4177 and the IXTT02N450HV.
> If you optocouple up into the fets, it avoids all sorts of ugly level
> shifting.
>

Well I have never needed that sort of thing so I never thought of it
really, my HV experiences are by just making HV sources (up to 5kV)
which only need HV diodes at the HV side apart from caps etc. (I got
some really good - fast, small etc. - HV diodes on ebay, can you believe
it).
The opto-level shifting is an interesting idea indeed, one could easily
overlook it and go into that "ugly level shifting", I had not thought of
it. I did "normal" level shifting on that +/- 100V thing back then but
it was not too ugly, getting the thing stable with optocouplers might
have been a challenge (unless one can get decent spice models, never
looked for any). But even without models one can manage it with some
trial and error of course.

Dimiter_Popoff wrote:
> On 12/30/2021 20:28, John Larkin wrote:
>> On Thu, 30 Dec 2021 18:47:34 +0200, Dimiter_Popoff <dp@tgi-sci.com>
>> wrote:
>>
>>> On 12/30/2021 18:09, jlarkin@highlandsniptechnology.com wrote:
>>>> On Thu, 30 Dec 2021 19:39:51 +1100, marty <marty@invalid.net> wrote:
>>>>
>>>>> On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
>>>>>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>>>>>> <pcdhSpamMeSenseless@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
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>> Free shipping though!
>>>>
>>>> I'd hate to pay shipping for parts that are out of stock.
>>>>
>>>> I see insane pricing on some parts, factors of 10 and sometimes 100x
>>>> reasonable.
>>>>
>>>>
>>>>
>>>
>>> The pricing on these opamps may be insane but so are the parts, I never
>>> knew things like that were on offer (2.5kV peak to peak output!).
>>> I have not done more than 200V peak to peak, was some 10 years ago, I
>>> did it with discrete parts though. The project could not have afforded
>>> opamps like these anyway.
>>
>> You can make your own kilovolt-level opamps pretty easily. There are
>> some nice HV mosfets like IXTY02N120 and 2SK4177 and the IXTT02N450HV.
>> If you optocouple up into the fets, it avoids all sorts of ugly level
>> shifting.
>>
>
> Well I have never needed that sort of thing so I never thought of it
> really, my HV experiences are by just making HV sources (up to 5kV)
> which only need HV diodes at the HV side apart from caps etc. (I got
> some really good - fast, small etc. - HV diodes on ebay, can you believe
> it).
> The opto-level shifting is an interesting idea indeed, one could easily
> overlook it and go into that "ugly level shifting", I had not thought of
> it. I did "normal" level shifting on that +/- 100V thing back then but
> it was not too ugly, getting the thing stable with optocouplers might
> have been a challenge (unless one can get decent spice models, never
> looked for any). But even without models one can manage it with some
> trial and error of course.

Slow HV isn't too hard, if you don't mind a few watts' quiescent
dissipation. You can put HV transistors in series, for instance, with a
resistive voltage divider driving the bases.

Fast HV is another thing. Last time I needed to do that, I used an
811A. (It was about 1990.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Thu, 30 Dec 2021 21:11:51 +0200, Dimiter_Popoff <dp@tgi-sci.com>
wrote:

>On 12/30/2021 20:28, John Larkin wrote:
>> On Thu, 30 Dec 2021 18:47:34 +0200, Dimiter_Popoff <dp@tgi-sci.com>
>> wrote:
>>
>>> On 12/30/2021 18:09, jlarkin@highlandsniptechnology.com wrote:
>>>> On Thu, 30 Dec 2021 19:39:51 +1100, marty <marty@invalid.net> wrote:
>>>>
>>>>> On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
>>>>>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>>>>>> <pcdhSpamMeSenseless@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
>>>>>>
>>>>>>
>>>>>>
>>>>> Free shipping though!
>>>>
>>>> I'd hate to pay shipping for parts that are out of stock.
>>>>
>>>> I see insane pricing on some parts, factors of 10 and sometimes 100x
>>>> reasonable.
>>>>
>>>>
>>>>
>>>
>>> The pricing on these opamps may be insane but so are the parts, I never
>>> knew things like that were on offer (2.5kV peak to peak output!).
>>> I have not done more than 200V peak to peak, was some 10 years ago, I
>>> did it with discrete parts though. The project could not have afforded
>>> opamps like these anyway.
>>
>> You can make your own kilovolt-level opamps pretty easily. There are
>> some nice HV mosfets like IXTY02N120 and 2SK4177 and the IXTT02N450HV.
>> If you optocouple up into the fets, it avoids all sorts of ugly level
>> shifting.
>>
>
>Well I have never needed that sort of thing so I never thought of it
>really, my HV experiences are by just making HV sources (up to 5kV)
>which only need HV diodes at the HV side apart from caps etc. (I got
>some really good - fast, small etc. - HV diodes on ebay, can you believe
>it).
>The opto-level shifting is an interesting idea indeed, one could easily
>overlook it and go into that "ugly level shifting", I had not thought of
>it. I did "normal" level shifting on that +/- 100V thing back then but
>it was not too ugly, getting the thing stable with optocouplers might
>have been a challenge (unless one can get decent spice models, never
>looked for any). But even without models one can manage it with some
>trial and error of course.

Here are some opto-coupled HV things. As Phil says, slow HV isn't
hard.

https://www.dropbox.com/s/w8px8z9mf64wpc9/HVamp.JPG?raw=1

https://www.dropbox.com/s/rmcbw8c0bxcmm1l/T840_1400v_amp.jpg?raw=1

https://www.dropbox.com/s/r6o5krfl5p86cp5/T840_A.JPG?raw=1

--

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

On 12/30/2021 22:17, Phil Hobbs wrote:
> Dimiter_Popoff wrote:
>> On 12/30/2021 20:28, John Larkin wrote:
>>> On Thu, 30 Dec 2021 18:47:34 +0200, Dimiter_Popoff <dp@tgi-sci.com>
>>> wrote:
>>>
>>>> On 12/30/2021 18:09, jlarkin@highlandsniptechnology.com wrote:
>>>>> On Thu, 30 Dec 2021 19:39:51 +1100, marty <marty@invalid.net> wrote:
>>>>>
>>>>>> On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
>>>>>>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>>>>>>> <pcdhSpamMeSenseless@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
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> Free shipping though!
>>>>>
>>>>> I'd hate to pay shipping for parts that are out of stock.
>>>>>
>>>>> I see insane pricing on some parts, factors of 10 and sometimes 100x
>>>>> reasonable.
>>>>>
>>>>>
>>>>>
>>>>
>>>> The pricing on these opamps may be insane but so are the parts, I never
>>>> knew things like that were on offer (2.5kV peak to peak output!).
>>>> I have not done more than 200V peak to peak, was some 10 years ago, I
>>>> did it with discrete parts though. The project could not have afforded
>>>> opamps like these anyway.
>>>
>>> You can make your own kilovolt-level opamps pretty easily. There are
>>> some nice HV mosfets like IXTY02N120 and 2SK4177 and the IXTT02N450HV.
>>> If you optocouple up into the fets, it avoids all sorts of ugly level
>>> shifting.
>>>
>>
>> Well I have never needed that sort of thing so I never thought of it
>> really, my HV experiences are by just making HV sources (up to 5kV)
>> which only need HV diodes at the HV side apart from caps etc. (I got
>> some really good - fast, small etc. - HV diodes on ebay, can you believe
>> it).
>> The opto-level shifting is an interesting idea indeed, one could easily
>> overlook it and go into that "ugly level shifting", I had not thought of
>> it. I did "normal" level shifting on that +/- 100V thing back then but
>> it was not too ugly, getting the thing stable with optocouplers might
>> have been a challenge (unless one can get decent spice models, never
>> looked for any). But even without models one can manage it with some
>> trial and error of course.
>
> Slow HV isn't too hard, if you don't mind a few watts' quiescent
> dissipation.  You can put HV transistors in series, for instance, with a
> resistive voltage divider driving the bases.
>
> Fast HV is another thing.  Last time I needed to do that, I used an
> 811A.  (It was about 1990.)
>
> Cheers
>
> Phil Hobbs
>

Well obviously the slower the easier :-). My 200V p-p output stage (I
think it did up to 100 mA, it was for a one-off thing for a
plasma-physics lab) did something like 2300V/s which is not too fast
for a 200V peak to peak (and it needed much less than that).
They wanted to drive the voltage and monitor the current IIRC.
Then 200V really is not HV, just the highest V I have designed some
driver for.
What is this 811A, is it the valve which I kept finding?

On Thu, 30 Dec 2021 15:17:49 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>Dimiter_Popoff wrote:
>> On 12/30/2021 20:28, John Larkin wrote:
>>> On Thu, 30 Dec 2021 18:47:34 +0200, Dimiter_Popoff <dp@tgi-sci.com>
>>> wrote:
>>>
>>>> On 12/30/2021 18:09, jlarkin@highlandsniptechnology.com wrote:
>>>>> On Thu, 30 Dec 2021 19:39:51 +1100, marty <marty@invalid.net> wrote:
>>>>>
>>>>>> On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
>>>>>>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>>>>>>> <pcdhSpamMeSenseless@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
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> Free shipping though!
>>>>>
>>>>> I'd hate to pay shipping for parts that are out of stock.
>>>>>
>>>>> I see insane pricing on some parts, factors of 10 and sometimes 100x
>>>>> reasonable.
>>>>>
>>>>>
>>>>>
>>>>
>>>> The pricing on these opamps may be insane but so are the parts, I never
>>>> knew things like that were on offer (2.5kV peak to peak output!).
>>>> I have not done more than 200V peak to peak, was some 10 years ago, I
>>>> did it with discrete parts though. The project could not have afforded
>>>> opamps like these anyway.
>>>
>>> You can make your own kilovolt-level opamps pretty easily. There are
>>> some nice HV mosfets like IXTY02N120 and 2SK4177 and the IXTT02N450HV.
>>> If you optocouple up into the fets, it avoids all sorts of ugly level
>>> shifting.
>>>
>>
>> Well I have never needed that sort of thing so I never thought of it
>> really, my HV experiences are by just making HV sources (up to 5kV)
>> which only need HV diodes at the HV side apart from caps etc. (I got
>> some really good - fast, small etc. - HV diodes on ebay, can you believe
>> it).
>> The opto-level shifting is an interesting idea indeed, one could easily
>> overlook it and go into that "ugly level shifting", I had not thought of
>> it. I did "normal" level shifting on that +/- 100V thing back then but
>> it was not too ugly, getting the thing stable with optocouplers might
>> have been a challenge (unless one can get decent spice models, never
>> looked for any). But even without models one can manage it with some
>> trial and error of course.
>
>Slow HV isn't too hard, if you don't mind a few watts' quiescent
>dissipation. You can put HV transistors in series, for instance, with a
>resistive voltage divider driving the bases.

Class B has an undeserved bad reputation.

--

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

Dimiter_Popoff wrote:
> On 12/30/2021 22:17, Phil Hobbs wrote:
>> Dimiter_Popoff wrote:
>>> On 12/30/2021 20:28, John Larkin wrote:
>>>> On Thu, 30 Dec 2021 18:47:34 +0200, Dimiter_Popoff <dp@tgi-sci.com>
>>>> wrote:
>>>>
>>>>> On 12/30/2021 18:09, jlarkin@highlandsniptechnology.com wrote:
>>>>>> On Thu, 30 Dec 2021 19:39:51 +1100, marty <marty@invalid.net> wrote:
>>>>>>
>>>>>>> On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
>>>>>>>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>>>>>>>> <pcdhSpamMeSenseless@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
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>> Free shipping though!
>>>>>>
>>>>>> I'd hate to pay shipping for parts that are out of stock.
>>>>>>
>>>>>> I see insane pricing on some parts, factors of 10 and sometimes 100x
>>>>>> reasonable.
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> The pricing on these opamps may be insane but so are the parts, I
>>>>> never
>>>>> knew things like that were on offer (2.5kV peak to peak output!).
>>>>> I have not done more than 200V peak to peak, was some 10 years ago, I
>>>>> did it with discrete parts though. The project could not have afforded
>>>>> opamps like these anyway.
>>>>
>>>> You can make your own kilovolt-level opamps pretty easily. There are
>>>> some nice HV mosfets like IXTY02N120 and 2SK4177 and the IXTT02N450HV.
>>>> If you optocouple up into the fets, it avoids all sorts of ugly level
>>>> shifting.
>>>>
>>>
>>> Well I have never needed that sort of thing so I never thought of it
>>> really, my HV experiences are by just making HV sources (up to 5kV)
>>> which only need HV diodes at the HV side apart from caps etc. (I got
>>> some really good - fast, small etc. - HV diodes on ebay, can you believe
>>> it).
>>> The opto-level shifting is an interesting idea indeed, one could easily
>>> overlook it and go into that "ugly level shifting", I had not thought of
>>> it. I did "normal" level shifting on that +/- 100V thing back then but
>>> it was not too ugly, getting the thing stable with optocouplers might
>>> have been a challenge (unless one can get decent spice models, never
>>> looked for any). But even without models one can manage it with some
>>> trial and error of course.
>>
>> Slow HV isn't too hard, if you don't mind a few watts' quiescent
>> dissipation.  You can put HV transistors in series, for instance, with
>> a resistive voltage divider driving the bases.
>>
>> Fast HV is another thing.  Last time I needed to do that, I used an
>> 811A.  (It was about 1990.)
>>
>> Cheers
>>
>> Phil Hobbs
>>
>
> Well obviously the slower the easier :-). My 200V p-p output stage (I
> think it did up to 100 mA, it was for a one-off thing for a
> plasma-physics lab) did something like 2300V/s which is not too fast
> for a 200V peak to peak (and it needed much less than that).
> They wanted to drive the voltage and monitor the current IIRC.
> Then 200V really is not HV, just the highest V I have designed some
> driver for.
> What is this 811A, is it the valve which I kept finding?

Yup.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

John Larkin wrote:
> On Thu, 30 Dec 2021 15:17:49 -0500, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>> Dimiter_Popoff wrote:
>>> On 12/30/2021 20:28, John Larkin wrote:
>>>> On Thu, 30 Dec 2021 18:47:34 +0200, Dimiter_Popoff <dp@tgi-sci.com>
>>>> wrote:
>>>>
>>>>> On 12/30/2021 18:09, jlarkin@highlandsniptechnology.com wrote:
>>>>>> On Thu, 30 Dec 2021 19:39:51 +1100, marty <marty@invalid.net> wrote:
>>>>>>
>>>>>>> On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
>>>>>>>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>>>>>>>> <pcdhSpamMeSenseless@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
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>> Free shipping though!
>>>>>>
>>>>>> I'd hate to pay shipping for parts that are out of stock.
>>>>>>
>>>>>> I see insane pricing on some parts, factors of 10 and sometimes 100x
>>>>>> reasonable.
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> The pricing on these opamps may be insane but so are the parts, I never
>>>>> knew things like that were on offer (2.5kV peak to peak output!).
>>>>> I have not done more than 200V peak to peak, was some 10 years ago, I
>>>>> did it with discrete parts though. The project could not have afforded
>>>>> opamps like these anyway.
>>>>
>>>> You can make your own kilovolt-level opamps pretty easily. There are
>>>> some nice HV mosfets like IXTY02N120 and 2SK4177 and the IXTT02N450HV.
>>>> If you optocouple up into the fets, it avoids all sorts of ugly level
>>>> shifting.
>>>>
>>>
>>> Well I have never needed that sort of thing so I never thought of it
>>> really, my HV experiences are by just making HV sources (up to 5kV)
>>> which only need HV diodes at the HV side apart from caps etc. (I got
>>> some really good - fast, small etc. - HV diodes on ebay, can you believe
>>> it).
>>> The opto-level shifting is an interesting idea indeed, one could easily
>>> overlook it and go into that "ugly level shifting", I had not thought of
>>> it. I did "normal" level shifting on that +/- 100V thing back then but
>>> it was not too ugly, getting the thing stable with optocouplers might
>>> have been a challenge (unless one can get decent spice models, never
>>> looked for any). But even without models one can manage it with some
>>> trial and error of course.
>>
>> Slow HV isn't too hard, if you don't mind a few watts' quiescent
>> dissipation. You can put HV transistors in series, for instance, with a
>> resistive voltage divider driving the bases.
>
> Class B has an undeserved bad reputation.
>
It can be done well, for sure, but usually isn't IME.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Thu, 30 Dec 2021 18:26:39 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>Dimiter_Popoff wrote:
>> On 12/30/2021 22:17, Phil Hobbs wrote:
>>> Dimiter_Popoff wrote:
>>>> On 12/30/2021 20:28, John Larkin wrote:
>>>>> On Thu, 30 Dec 2021 18:47:34 +0200, Dimiter_Popoff <dp@tgi-sci.com>
>>>>> wrote:
>>>>>
>>>>>> On 12/30/2021 18:09, jlarkin@highlandsniptechnology.com wrote:
>>>>>>> On Thu, 30 Dec 2021 19:39:51 +1100, marty <marty@invalid.net> wrote:
>>>>>>>
>>>>>>>> On 30/12/21 13:54, jlarkin@highlandsniptechnology.com wrote:
>>>>>>>>> On Wed, 29 Dec 2021 21:16:34 -0500, Phil Hobbs
>>>>>>>>> <pcdhSpamMeSenseless@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
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>> Free shipping though!
>>>>>>>
>>>>>>> I'd hate to pay shipping for parts that are out of stock.
>>>>>>>
>>>>>>> I see insane pricing on some parts, factors of 10 and sometimes 100x
>>>>>>> reasonable.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> The pricing on these opamps may be insane but so are the parts, I
>>>>>> never
>>>>>> knew things like that were on offer (2.5kV peak to peak output!).
>>>>>> I have not done more than 200V peak to peak, was some 10 years ago, I
>>>>>> did it with discrete parts though. The project could not have afforded
>>>>>> opamps like these anyway.
>>>>>
>>>>> You can make your own kilovolt-level opamps pretty easily. There are
>>>>> some nice HV mosfets like IXTY02N120 and 2SK4177 and the IXTT02N450HV.
>>>>> If you optocouple up into the fets, it avoids all sorts of ugly level
>>>>> shifting.
>>>>>
>>>>
>>>> Well I have never needed that sort of thing so I never thought of it
>>>> really, my HV experiences are by just making HV sources (up to 5kV)
>>>> which only need HV diodes at the HV side apart from caps etc. (I got
>>>> some really good - fast, small etc. - HV diodes on ebay, can you believe
>>>> it).
>>>> The opto-level shifting is an interesting idea indeed, one could easily
>>>> overlook it and go into that "ugly level shifting", I had not thought of
>>>> it. I did "normal" level shifting on that +/- 100V thing back then but
>>>> it was not too ugly, getting the thing stable with optocouplers might
>>>> have been a challenge (unless one can get decent spice models, never
>>>> looked for any). But even without models one can manage it with some
>>>> trial and error of course.
>>>
>>> Slow HV isn't too hard, if you don't mind a few watts' quiescent
>>> dissipation.  You can put HV transistors in series, for instance, with
>>> a resistive voltage divider driving the bases.
>>>
>>> Fast HV is another thing.  Last time I needed to do that, I used an
>>> 811A.  (It was about 1990.)
>>>
>>> Cheers
>>>
>>> Phil Hobbs
>>>
>>
>> Well obviously the slower the easier :-). My 200V p-p output stage (I
>> think it did up to 100 mA, it was for a one-off thing for a
>> plasma-physics lab) did something like 2300V/s which is not too fast
>> for a 200V peak to peak (and it needed much less than that).
>> They wanted to drive the voltage and monitor the current IIRC.
>> Then 200V really is not HV, just the highest V I have designed some
>> driver for.
>> What is this 811A, is it the valve which I kept finding?
>
>Yup.
>
>Cheers
>
>Phil Hobbs

I did some fun stuff with a TV HV rectifier tube, 1B3 I think, as an
amplifier, with the input going into the filament. Voltage gain around
50K, bandwidth not so good.

It's amazing that I survived childhood.

--

I yam what I yam - Popeye

On 31/12/21 03:04, jlarkin@highlandsniptechnology.com wrote:

> I did some fun stuff with a TV HV rectifier tube, 1B3 I think, as an
> amplifier, with the input going into the filament. Voltage gain around
> 50K, bandwidth not so good.
>
> It's amazing that I survived childhood.

One of the instructors[1] that taught my 15yo to fly gliders
flew pointy nosed jets in the 1950s. He once told me, w.r.t. my
daughter, that "you expect to lose a few". I just grinned.

[1] her favourite, since he let her continue when other
instructors would have taken control :)

On Friday, 31 December 2021 at 03:04:48 UTC, jla...@highlandsniptechnology.com wrote:
> On Thu, 30 Dec 2021 18:26:39 -0500, Phil Hobbs
> <pcdhSpamM...@electrooptical.net> wrote:
>
> >Dimiter_Popoff wrote:
> >> On 12/30/2021 22:17, Phil Hobbs wrote:
> >>> Dimiter_Popoff wrote:
> >>>> On 12/30/2021 20:28, John Larkin wrote:
> >>>>> On Thu, 30 Dec 2021 18:47:34 +0200, Dimiter_Popoff <d...@tgi-sci.com>
> >>>>> wrote:
> >>>>>
> >>>>>> On 12/30/2021 18:09, jla...@highlandsniptechnology.com wrote:
> >>>>>>> On Thu, 30 Dec 2021 19:39:51 +1100, marty <ma...@invalid.net> wrote:
> >>>>>>>
> >>>>>>>> On 30/12/21 13:54, 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
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>> Free shipping though!
> >>>>>>>
> >>>>>>> I'd hate to pay shipping for parts that are out of stock.
> >>>>>>>
> >>>>>>> I see insane pricing on some parts, factors of 10 and sometimes 100x
> >>>>>>> reasonable.
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>
> >>>>>> The pricing on these opamps may be insane but so are the parts, I
> >>>>>> never
> >>>>>> knew things like that were on offer (2.5kV peak to peak output!).
> >>>>>> I have not done more than 200V peak to peak, was some 10 years ago, I
> >>>>>> did it with discrete parts though. The project could not have afforded
> >>>>>> opamps like these anyway.
> >>>>>
> >>>>> You can make your own kilovolt-level opamps pretty easily. There are
> >>>>> some nice HV mosfets like IXTY02N120 and 2SK4177 and the IXTT02N450HV.
> >>>>> If you optocouple up into the fets, it avoids all sorts of ugly level
> >>>>> shifting.
> >>>>>
> >>>>
> >>>> Well I have never needed that sort of thing so I never thought of it
> >>>> really, my HV experiences are by just making HV sources (up to 5kV)
> >>>> which only need HV diodes at the HV side apart from caps etc. (I got
> >>>> some really good - fast, small etc. - HV diodes on ebay, can you believe
> >>>> it).
> >>>> The opto-level shifting is an interesting idea indeed, one could easily
> >>>> overlook it and go into that "ugly level shifting", I had not thought of
> >>>> it. I did "normal" level shifting on that +/- 100V thing back then but
> >>>> it was not too ugly, getting the thing stable with optocouplers might
> >>>> have been a challenge (unless one can get decent spice models, never
> >>>> looked for any). But even without models one can manage it with some
> >>>> trial and error of course.
> >>>
> >>> Slow HV isn't too hard, if you don't mind a few watts' quiescent
> >>> dissipation. You can put HV transistors in series, for instance, with
> >>> a resistive voltage divider driving the bases.
> >>>
> >>> Fast HV is another thing. Last time I needed to do that, I used an
> >>> 811A. (It was about 1990.)
> >>>
> >>> Cheers
> >>>
> >>> Phil Hobbs
> >>>
> >>
> >> Well obviously the slower the easier :-). My 200V p-p output stage (I
> >> think it did up to 100 mA, it was for a one-off thing for a
> >> plasma-physics lab) did something like 2300V/s which is not too fast
> >> for a 200V peak to peak (and it needed much less than that).
> >> They wanted to drive the voltage and monitor the current IIRC.
> >> Then 200V really is not HV, just the highest V I have designed some
> >> driver for.
> >> What is this 811A, is it the valve which I kept finding?
> >
> >Yup.
> >
> >Cheers
> >
> >Phil Hobbs
> I did some fun stuff with a TV HV rectifier tube, 1B3 I think, as an
> amplifier, with the input going into the filament. Voltage gain around
> 50K, bandwidth not so good.
>
> It's amazing that I survived childhood.

Yes, a rectifier diode operated like that would make a good X-ray source.
John

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

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

> >>
> >> 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.

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.