Apex...

J

John Larkin

Guest
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
Click to expand...

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
Click to expand...

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
Click to expand...

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!
Click to expand...

--
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
Click to expand...

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
Click to expand...

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!
Click to expand...

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 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
Click to expand...

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.
Click to expand...

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.
Click to expand...

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.
Click to expand...

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.
Click to expand...

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
Click to expand...

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.
Click to expand...

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?
Click to expand...

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.
Click to expand...

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
Click to expand...

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.
Click to expand...

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.
Click to expand...

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