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
Apex
Started by ●December 29, 2021
Reply by ●December 30, 20212021-12-30
Reply by ●December 30, 20212021-12-30
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.
Reply by ●December 30, 20212021-12-30
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
Reply by ●December 30, 20212021-12-30
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
Reply by ●December 30, 20212021-12-30
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?
Reply by ●December 30, 20212021-12-30
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
Reply by ●December 30, 20212021-12-30
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
Reply by ●December 30, 20212021-12-30
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
Reply by ●December 30, 20212021-12-30
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 HobbsI 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
Reply by ●December 31, 20212021-12-31
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 :)
