HV dc/dc...

[Piotr Wyderski]

jlarkin@highlandsniptechnology.com wrote:

> He has huge enthusiasm for designing custom magnetics.

I share his enthusiasm. If you depend on some non-linearities, there is
no other way but to learn the craft.

I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

But why can\'t you have the best of both worlds and use standard parts
wherever possible and custom ones when there is a potential for blowing
the competition out of the water? Custom parts are still manufacturable,
just more expensive.

Best regards, Piotr

 

[server]

On Mon, 20 Jul 2020 00:01:59 +0200, Piotr Wyderski
<peter.pan@neverland.mil> wrote:

jlarkin@highlandsniptechnology.com wrote:

He has huge enthusiasm for designing custom magnetics.

I share his enthusiasm. If you depend on some non-linearities, there is
no other way but to learn the craft.

I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

But why can\'t you have the best of both worlds and use standard parts
wherever possible and custom ones when there is a potential for blowing
the competition out of the water? Custom parts are still manufacturable,
just more expensive.

Best regards, Piotr

Sure I use custom magnetics. I\'ve posted lots of examples here. But
98% of the time, you can use standard parts, available in quantity,
cheap, overnight delivery. Or better yet, use the ones downstairs in
the stockroom.

Custom or home-made is generally needed for transmission-line
transformers, big power transformers, a few things like that. Maybe
flybacks, but if you are clever there are lots of ways to use standard
parts.

I\'ve probably designed 20x as many transformers and inductors as
Sloman. Here are just a few:

https://www.dropbox.com/s/dgno5o0psfzu9we/L_Assy.jpg?dl=0

https://www.dropbox.com/s/0bl6jdkw4ljx4e2/400_Hz_Toroid.JPG?dl=0

https://www.dropbox.com/s/o2hz6oi08agzdy8/T850_Inductor.JPG?dl=0

https://www.dropbox.com/s/4cys3islc9w593v/Xfmrs.JPG?dl=0

https://www.dropbox.com/s/ucfp2fqet5ssy14/Z412_Proto.JPG?dl=0

https://www.dropbox.com/s/15ccw3rppygvr5p/Class-D%20_and_toroid.jpg?dl=0

https://www.dropbox.com/s/2yvttrvcrn9e5rd/XFMR_4.JPG?dl=0

https://www.dropbox.com/s/hoa937c47ir5wwo/T760_Xfmrs.JPG?dl=0

https://www.dropbox.com/s/oam60ys8n0pt8bo/T750_1.JPG?dl=0

https://www.dropbox.com/s/zpu6wpli7pvwuih/TX_1.jpg?dl=0

https://www.dropbox.com/s/vw5oq1g76slzw9l/L500_Xfmr.jpg?dl=0

https://www.dropbox.com/s/cg7lrxnlnnd5rne/PP5.JPG?dl=0


I sometimes design my own resistors and coaxial cables too. When I
have to.







--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[server]

On Mon, 20 Jul 2020 00:01:59 +0200, Piotr Wyderski
<peter.pan@neverland.mil> wrote:

jlarkin@highlandsniptechnology.com wrote:

He has huge enthusiasm for designing custom magnetics.

I share his enthusiasm. If you depend on some non-linearities, there is
no other way but to learn the craft.

I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

But why can\'t you have the best of both worlds and use standard parts
wherever possible and custom ones when there is a potential for blowing
the competition out of the water? Custom parts are still manufacturable,
just more expensive.

Best regards, Piotr

Sure I use custom magnetics. I\'ve posted lots of examples here. But
98% of the time, you can use standard parts, available in quantity,
cheap, overnight delivery. Or better yet, use the ones downstairs in
the stockroom.

Custom or home-made is generally needed for transmission-line
transformers, big power transformers, a few things like that. Maybe
flybacks, but if you are clever there are lots of ways to use standard
parts.

I\'ve probably designed 20x as many transformers and inductors as
Sloman. Here are just a few:

https://www.dropbox.com/s/dgno5o0psfzu9we/L_Assy.jpg?dl=0

https://www.dropbox.com/s/0bl6jdkw4ljx4e2/400_Hz_Toroid.JPG?dl=0

https://www.dropbox.com/s/o2hz6oi08agzdy8/T850_Inductor.JPG?dl=0

https://www.dropbox.com/s/4cys3islc9w593v/Xfmrs.JPG?dl=0

https://www.dropbox.com/s/ucfp2fqet5ssy14/Z412_Proto.JPG?dl=0

https://www.dropbox.com/s/15ccw3rppygvr5p/Class-D%20_and_toroid.jpg?dl=0

https://www.dropbox.com/s/2yvttrvcrn9e5rd/XFMR_4.JPG?dl=0

https://www.dropbox.com/s/hoa937c47ir5wwo/T760_Xfmrs.JPG?dl=0

https://www.dropbox.com/s/oam60ys8n0pt8bo/T750_1.JPG?dl=0

https://www.dropbox.com/s/zpu6wpli7pvwuih/TX_1.jpg?dl=0

https://www.dropbox.com/s/vw5oq1g76slzw9l/L500_Xfmr.jpg?dl=0

https://www.dropbox.com/s/cg7lrxnlnnd5rne/PP5.JPG?dl=0


I sometimes design my own resistors and coaxial cables too. When I
have to.







--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[server]

On Mon, 20 Jul 2020 00:01:59 +0200, Piotr Wyderski
<peter.pan@neverland.mil> wrote:

jlarkin@highlandsniptechnology.com wrote:

He has huge enthusiasm for designing custom magnetics.

I share his enthusiasm. If you depend on some non-linearities, there is
no other way but to learn the craft.

I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

But why can\'t you have the best of both worlds and use standard parts
wherever possible and custom ones when there is a potential for blowing
the competition out of the water? Custom parts are still manufacturable,
just more expensive.

Best regards, Piotr

Sure I use custom magnetics. I\'ve posted lots of examples here. But
98% of the time, you can use standard parts, available in quantity,
cheap, overnight delivery. Or better yet, use the ones downstairs in
the stockroom.

Custom or home-made is generally needed for transmission-line
transformers, big power transformers, a few things like that. Maybe
flybacks, but if you are clever there are lots of ways to use standard
parts.

I\'ve probably designed 20x as many transformers and inductors as
Sloman. Here are just a few:

https://www.dropbox.com/s/dgno5o0psfzu9we/L_Assy.jpg?dl=0

https://www.dropbox.com/s/0bl6jdkw4ljx4e2/400_Hz_Toroid.JPG?dl=0

https://www.dropbox.com/s/o2hz6oi08agzdy8/T850_Inductor.JPG?dl=0

https://www.dropbox.com/s/4cys3islc9w593v/Xfmrs.JPG?dl=0

https://www.dropbox.com/s/ucfp2fqet5ssy14/Z412_Proto.JPG?dl=0

https://www.dropbox.com/s/15ccw3rppygvr5p/Class-D%20_and_toroid.jpg?dl=0

https://www.dropbox.com/s/2yvttrvcrn9e5rd/XFMR_4.JPG?dl=0

https://www.dropbox.com/s/hoa937c47ir5wwo/T760_Xfmrs.JPG?dl=0

https://www.dropbox.com/s/oam60ys8n0pt8bo/T750_1.JPG?dl=0

https://www.dropbox.com/s/zpu6wpli7pvwuih/TX_1.jpg?dl=0

https://www.dropbox.com/s/vw5oq1g76slzw9l/L500_Xfmr.jpg?dl=0

https://www.dropbox.com/s/cg7lrxnlnnd5rne/PP5.JPG?dl=0


I sometimes design my own resistors and coaxial cables too. When I
have to.







--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[Bill Sloman]

On Monday, July 20, 2020 at 1:49:21 AM UTC+10, Lasse Langwadt Christensen wrote:

søndag den 19. juli 2020 kl. 16.33.42 UTC+2 skrev Bill Sloman:
On Sunday, July 19, 2020 at 12:42:42 PM UTC+10, jla...@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 19:31:09 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-18 12:39, jlarkin@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 11:27:16 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-17 09:49, jlarkin@highlandsniptechnology.com wrote:


I need eight isolated 150 volt DC supplies, low current, under 1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high sides..

The application is eight isolated high-voltage pulse outputs. My first
idea was to use grounded drivers and final pulse transformers, but the
volt-seconds get huge so the pulse transformer would be awful. Better
to float the entire output circuit.


Mostly I used CCFL inverter transformers for that. Cheap, fairly small.
Even complete modules can be had for a few dollars:

https://www.ebay.com/itm/1Pc-CCFL-inverter-board-for-LCD-screen-with-1CCFL-backlight-LCD-JN/392849295194

$3.33 with free shipping from China. We pay for that.


Yup, they\'ll make the next aircraft carrier :-(


Or course, with everything going LED and OLED these days it\'s only a
matter of years until the available selection starts to thin out.

I won\'t use ebay or Amazon stuff in my gear. Some of my customers care
about part traceability and anti-Chinese stuff.

Some of those things, ebay and Amazon, are OK for breadboards and lab
cables and such.

One customer recently elected to buy a bunch of $40 cables from us,
when Amazon has them for $6.


It was just meant as an example. On most projects where I needed a few
hundred volts I used the bare CCFL transformers and they cost just a few
bucks. Even from US sources they are often produced abroad, sometimes in
China.

Are the CCFL supplies flybacks or Royers or something? What sorts of
open-circuit voltages do they make?

It\'s probably Baxandall Class-D oscillator. Jim Williams seems to have got the circuit from England without getting the literature reference that should have come with it - Baxandall, P.J, Proc I.E.E 106, B, 748 (1959.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

From my web-site.

\"The circuit is probably best known from Jim Williams’ series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61, AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper “Transistors as on-off switches in saturable core circuits” in Electrical Manufacturing.\"

The Baxandall inverter is handy for driving high-turns ratio step-up transformers which tend end up with rather low self-resonant frequencies.

But right, it\'s all LEDs now.

I like ISDN transformers, but they will be gone too.

The little DRQ-type dual inductors are great. The autotransformer
flyback and CW multiplier thing is cool.

The Cockroft-Walton multiplier isn\'t all that cool.

Or you could learn how to design your own special purpose transformers and find a shop that would wind them for you - it isn\'t all that difficult.

There are lots of variables to twiddle in a transformer design, so getting something close enough off the shelf isn\'t easy, even if you get downright sloppy about \"close enough\".


you are kidding right? a few 100mW at 150V for a low volume product and you
want to spend what would quickly be weeks designing/ordering/twiddling a transformer design?

It might take John Larkin weeks. The design is obvious - I could knock up something now, if I felt like it. I\'ve already dealt with the problem that struck me as salient - finding a coil former with enough pins (see earlier post).

http://www.farnell.com/datasheets/1872308.pdf

Finding a transformer winder took me a day or so when I was in Nijmegen. They were in Horst, which was a twenty minute drive away.

https://www.acewikkeltechniek.nl/contact/

John Larkin works in San Francisco, which is a larger town.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, July 20, 2020 at 1:49:21 AM UTC+10, Lasse Langwadt Christensen wrote:

søndag den 19. juli 2020 kl. 16.33.42 UTC+2 skrev Bill Sloman:
On Sunday, July 19, 2020 at 12:42:42 PM UTC+10, jla...@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 19:31:09 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-18 12:39, jlarkin@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 11:27:16 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-17 09:49, jlarkin@highlandsniptechnology.com wrote:


I need eight isolated 150 volt DC supplies, low current, under 1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high sides..

The application is eight isolated high-voltage pulse outputs. My first
idea was to use grounded drivers and final pulse transformers, but the
volt-seconds get huge so the pulse transformer would be awful. Better
to float the entire output circuit.


Mostly I used CCFL inverter transformers for that. Cheap, fairly small.
Even complete modules can be had for a few dollars:

https://www.ebay.com/itm/1Pc-CCFL-inverter-board-for-LCD-screen-with-1CCFL-backlight-LCD-JN/392849295194

$3.33 with free shipping from China. We pay for that.


Yup, they\'ll make the next aircraft carrier :-(


Or course, with everything going LED and OLED these days it\'s only a
matter of years until the available selection starts to thin out.

I won\'t use ebay or Amazon stuff in my gear. Some of my customers care
about part traceability and anti-Chinese stuff.

Some of those things, ebay and Amazon, are OK for breadboards and lab
cables and such.

One customer recently elected to buy a bunch of $40 cables from us,
when Amazon has them for $6.


It was just meant as an example. On most projects where I needed a few
hundred volts I used the bare CCFL transformers and they cost just a few
bucks. Even from US sources they are often produced abroad, sometimes in
China.

Are the CCFL supplies flybacks or Royers or something? What sorts of
open-circuit voltages do they make?

It\'s probably Baxandall Class-D oscillator. Jim Williams seems to have got the circuit from England without getting the literature reference that should have come with it - Baxandall, P.J, Proc I.E.E 106, B, 748 (1959.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

From my web-site.

\"The circuit is probably best known from Jim Williams’ series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61, AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper “Transistors as on-off switches in saturable core circuits” in Electrical Manufacturing.\"

The Baxandall inverter is handy for driving high-turns ratio step-up transformers which tend end up with rather low self-resonant frequencies.

But right, it\'s all LEDs now.

I like ISDN transformers, but they will be gone too.

The little DRQ-type dual inductors are great. The autotransformer
flyback and CW multiplier thing is cool.

The Cockroft-Walton multiplier isn\'t all that cool.

Or you could learn how to design your own special purpose transformers and find a shop that would wind them for you - it isn\'t all that difficult.

There are lots of variables to twiddle in a transformer design, so getting something close enough off the shelf isn\'t easy, even if you get downright sloppy about \"close enough\".


you are kidding right? a few 100mW at 150V for a low volume product and you
want to spend what would quickly be weeks designing/ordering/twiddling a transformer design?

It might take John Larkin weeks. The design is obvious - I could knock up something now, if I felt like it. I\'ve already dealt with the problem that struck me as salient - finding a coil former with enough pins (see earlier post).

http://www.farnell.com/datasheets/1872308.pdf

Finding a transformer winder took me a day or so when I was in Nijmegen. They were in Horst, which was a twenty minute drive away.

https://www.acewikkeltechniek.nl/contact/

John Larkin works in San Francisco, which is a larger town.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, July 20, 2020 at 1:49:21 AM UTC+10, Lasse Langwadt Christensen wrote:

søndag den 19. juli 2020 kl. 16.33.42 UTC+2 skrev Bill Sloman:
On Sunday, July 19, 2020 at 12:42:42 PM UTC+10, jla...@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 19:31:09 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-18 12:39, jlarkin@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 11:27:16 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-17 09:49, jlarkin@highlandsniptechnology.com wrote:


I need eight isolated 150 volt DC supplies, low current, under 1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high sides..

The application is eight isolated high-voltage pulse outputs. My first
idea was to use grounded drivers and final pulse transformers, but the
volt-seconds get huge so the pulse transformer would be awful. Better
to float the entire output circuit.


Mostly I used CCFL inverter transformers for that. Cheap, fairly small.
Even complete modules can be had for a few dollars:

https://www.ebay.com/itm/1Pc-CCFL-inverter-board-for-LCD-screen-with-1CCFL-backlight-LCD-JN/392849295194

$3.33 with free shipping from China. We pay for that.


Yup, they\'ll make the next aircraft carrier :-(


Or course, with everything going LED and OLED these days it\'s only a
matter of years until the available selection starts to thin out.

I won\'t use ebay or Amazon stuff in my gear. Some of my customers care
about part traceability and anti-Chinese stuff.

Some of those things, ebay and Amazon, are OK for breadboards and lab
cables and such.

One customer recently elected to buy a bunch of $40 cables from us,
when Amazon has them for $6.


It was just meant as an example. On most projects where I needed a few
hundred volts I used the bare CCFL transformers and they cost just a few
bucks. Even from US sources they are often produced abroad, sometimes in
China.

Are the CCFL supplies flybacks or Royers or something? What sorts of
open-circuit voltages do they make?

It\'s probably Baxandall Class-D oscillator. Jim Williams seems to have got the circuit from England without getting the literature reference that should have come with it - Baxandall, P.J, Proc I.E.E 106, B, 748 (1959.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

From my web-site.

\"The circuit is probably best known from Jim Williams’ series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61, AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper “Transistors as on-off switches in saturable core circuits” in Electrical Manufacturing.\"

The Baxandall inverter is handy for driving high-turns ratio step-up transformers which tend end up with rather low self-resonant frequencies.

But right, it\'s all LEDs now.

I like ISDN transformers, but they will be gone too.

The little DRQ-type dual inductors are great. The autotransformer
flyback and CW multiplier thing is cool.

The Cockroft-Walton multiplier isn\'t all that cool.

Or you could learn how to design your own special purpose transformers and find a shop that would wind them for you - it isn\'t all that difficult.

There are lots of variables to twiddle in a transformer design, so getting something close enough off the shelf isn\'t easy, even if you get downright sloppy about \"close enough\".


you are kidding right? a few 100mW at 150V for a low volume product and you
want to spend what would quickly be weeks designing/ordering/twiddling a transformer design?

It might take John Larkin weeks. The design is obvious - I could knock up something now, if I felt like it. I\'ve already dealt with the problem that struck me as salient - finding a coil former with enough pins (see earlier post).

http://www.farnell.com/datasheets/1872308.pdf

Finding a transformer winder took me a day or so when I was in Nijmegen. They were in Horst, which was a twenty minute drive away.

https://www.acewikkeltechniek.nl/contact/

John Larkin works in San Francisco, which is a larger town.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, July 20, 2020 at 3:15:04 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Sun, 19 Jul 2020 08:49:16 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

søndag den 19. juli 2020 kl. 16.33.42 UTC+2 skrev Bill Sloman:
On Sunday, July 19, 2020 at 12:42:42 PM UTC+10, jla...@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 19:31:09 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-18 12:39, jlarkin@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 11:27:16 -0700, Joerg <news@analogconsultants..com
wrote:

On 2020-07-17 09:49, jlarkin@highlandsniptechnology.com wrote:


I need eight isolated 150 volt DC supplies, low current, under 1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high sides.

The application is eight isolated high-voltage pulse outputs. My first
idea was to use grounded drivers and final pulse transformers, but the
volt-seconds get huge so the pulse transformer would be awful. Better
to float the entire output circuit.


Mostly I used CCFL inverter transformers for that. Cheap, fairly small.
Even complete modules can be had for a few dollars:

https://www.ebay.com/itm/1Pc-CCFL-inverter-board-for-LCD-screen-with-1CCFL-backlight-LCD-JN/392849295194

$3.33 with free shipping from China. We pay for that.


Yup, they\'ll make the next aircraft carrier :-(


Or course, with everything going LED and OLED these days it\'s only a
matter of years until the available selection starts to thin out..

I won\'t use ebay or Amazon stuff in my gear. Some of my customers care
about part traceability and anti-Chinese stuff.

Some of those things, ebay and Amazon, are OK for breadboards and lab
cables and such.

One customer recently elected to buy a bunch of $40 cables from us,
when Amazon has them for $6.


It was just meant as an example. On most projects where I needed a few
hundred volts I used the bare CCFL transformers and they cost just a few
bucks. Even from US sources they are often produced abroad, sometimes in
China.

Are the CCFL supplies flybacks or Royers or something? What sorts of
open-circuit voltages do they make?

It\'s probably Baxandall Class-D oscillator. Jim Williams seems to have got the circuit from England without getting the literature reference that should have come with it - Baxandall, P.J, Proc I.E.E 106, B, 748 (1959.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

From my web-site.

\"The circuit is probably best known from Jim Williams’ series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61, AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper “Transistors as on-off switches in saturable core circuits” in Electrical Manufacturing.\"

The Baxandall inverter is handy for driving high-turns ratio step-up transformers which tend end up with rather low self-resonant frequencies.

But right, it\'s all LEDs now.

I like ISDN transformers, but they will be gone too.

The little DRQ-type dual inductors are great. The autotransformer
flyback and CW multiplier thing is cool.

The Cockroft-Walton multiplier isn\'t all that cool.

Or you could learn how to design your own special purpose transformers and find a shop that would wind them for you - it isn\'t all that difficult..

There are lots of variables to twiddle in a transformer design, so getting something close enough off the shelf isn\'t easy, even if you get downright sloppy about \"close enough\".


you are kidding right? a few 100mW at 150V for a low volume product and you
want to spend what would quickly be weeks designing/ordering/twiddling a transformer design?




He has huge enthusiasm for designing custom magnetics. I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

http://www.farnell.com/datasheets/1872308.pdf

isn\'t a standard part? Fairly obviously stocked by a major distributor ...

I wonder how his super oscillator is coming along. He ordered a custom
transformer for that, a decade or two ago.

Which confirmed that even a well-gapped core had enough hysteresis to generate harmonics - 95dB below the fundamental. I went over to a variant of the Wien bridge. If I ever find a customer I\'ll build one.

My customer wants a proof-of-principle 150-volt pulser next week, and
I have a 10-layer PCB to release first. Really, he should just trust
us and order the real things.

John Larkin does like it when his customers trust him. He can slap together something for them really quickly. And why is a ten layer PCB supposed to be impressive? The chaotic design process that left him needing that many layers would be.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, July 20, 2020 at 3:15:04 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Sun, 19 Jul 2020 08:49:16 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

søndag den 19. juli 2020 kl. 16.33.42 UTC+2 skrev Bill Sloman:
On Sunday, July 19, 2020 at 12:42:42 PM UTC+10, jla...@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 19:31:09 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-18 12:39, jlarkin@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 11:27:16 -0700, Joerg <news@analogconsultants..com
wrote:

On 2020-07-17 09:49, jlarkin@highlandsniptechnology.com wrote:


I need eight isolated 150 volt DC supplies, low current, under 1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high sides.

The application is eight isolated high-voltage pulse outputs. My first
idea was to use grounded drivers and final pulse transformers, but the
volt-seconds get huge so the pulse transformer would be awful. Better
to float the entire output circuit.


Mostly I used CCFL inverter transformers for that. Cheap, fairly small.
Even complete modules can be had for a few dollars:

https://www.ebay.com/itm/1Pc-CCFL-inverter-board-for-LCD-screen-with-1CCFL-backlight-LCD-JN/392849295194

$3.33 with free shipping from China. We pay for that.


Yup, they\'ll make the next aircraft carrier :-(


Or course, with everything going LED and OLED these days it\'s only a
matter of years until the available selection starts to thin out..

I won\'t use ebay or Amazon stuff in my gear. Some of my customers care
about part traceability and anti-Chinese stuff.

Some of those things, ebay and Amazon, are OK for breadboards and lab
cables and such.

One customer recently elected to buy a bunch of $40 cables from us,
when Amazon has them for $6.


It was just meant as an example. On most projects where I needed a few
hundred volts I used the bare CCFL transformers and they cost just a few
bucks. Even from US sources they are often produced abroad, sometimes in
China.

Are the CCFL supplies flybacks or Royers or something? What sorts of
open-circuit voltages do they make?

It\'s probably Baxandall Class-D oscillator. Jim Williams seems to have got the circuit from England without getting the literature reference that should have come with it - Baxandall, P.J, Proc I.E.E 106, B, 748 (1959.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

From my web-site.

\"The circuit is probably best known from Jim Williams’ series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61, AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper “Transistors as on-off switches in saturable core circuits” in Electrical Manufacturing.\"

The Baxandall inverter is handy for driving high-turns ratio step-up transformers which tend end up with rather low self-resonant frequencies.

But right, it\'s all LEDs now.

I like ISDN transformers, but they will be gone too.

The little DRQ-type dual inductors are great. The autotransformer
flyback and CW multiplier thing is cool.

The Cockroft-Walton multiplier isn\'t all that cool.

Or you could learn how to design your own special purpose transformers and find a shop that would wind them for you - it isn\'t all that difficult..

There are lots of variables to twiddle in a transformer design, so getting something close enough off the shelf isn\'t easy, even if you get downright sloppy about \"close enough\".


you are kidding right? a few 100mW at 150V for a low volume product and you
want to spend what would quickly be weeks designing/ordering/twiddling a transformer design?




He has huge enthusiasm for designing custom magnetics. I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

http://www.farnell.com/datasheets/1872308.pdf

isn\'t a standard part? Fairly obviously stocked by a major distributor ...

I wonder how his super oscillator is coming along. He ordered a custom
transformer for that, a decade or two ago.

Which confirmed that even a well-gapped core had enough hysteresis to generate harmonics - 95dB below the fundamental. I went over to a variant of the Wien bridge. If I ever find a customer I\'ll build one.

My customer wants a proof-of-principle 150-volt pulser next week, and
I have a 10-layer PCB to release first. Really, he should just trust
us and order the real things.

John Larkin does like it when his customers trust him. He can slap together something for them really quickly. And why is a ten layer PCB supposed to be impressive? The chaotic design process that left him needing that many layers would be.

--
Bill Sloman, Sydney

 

[John Doe]

\"I am Australian, and this is my netcop badge...\"

--
Bill Sloman <bill.sloman@ieee.org> wrote:

X-Received: by 2002:aed:3023:: with SMTP id 32mr21709639qte.37.1595213964897; Sun, 19 Jul 2020 19:59:24 -0700 (PDT)
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Subject: Re: HV dc/dc
From: Bill Sloman <bill.sloman@ieee.org
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Xref: reader01.eternal-september.org sci.electronics.design:602222

On Monday, July 20, 2020 at 3:15:04 AM UTC+10, jla...@highlandsniptechnology.com wrote:
On Sun, 19 Jul 2020 08:49:16 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

sÇ÷ndag den 19. juli 2020 kl. 16.33.42 UTC+2 skrev Bill Sloman:
On Sunday, July 19, 2020 at 12:42:42 PM UTC+10, jla...@highlandsniptec
hnology.com wrote:
On Sat, 18 Jul 2020 19:31:09 -0700, Joerg <news@analogconsultants.co
m
wrote:

On 2020-07-18 12:39, jlarkin@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 11:27:16 -0700, Joerg <news@analogconsultants
.com
wrote:

On 2020-07-17 09:49, jlarkin@highlandsniptechnology.com wrote:


I need eight isolated 150 volt DC supplies, low current, under
1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/
dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little
flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high side
s.

The application is eight isolated high-voltage pulse outputs. M
y first
idea was to use grounded drivers and final pulse transformers,
but the
volt-seconds get huge so the pulse transformer would be awful.
Better
to float the entire output circuit.


Mostly I used CCFL inverter transformers for that. Cheap, fairly
small.
Even complete modules can be had for a few dollars:

https://www.ebay.com/itm/1Pc-CCFL-inverter-board-for-LCD-screen-
with-1CCFL-backlight-LCD-JN/392849295194

$3.33 with free shipping from China. We pay for that.


Yup, they\'ll make the next aircraft carrier :-(


Or course, with everything going LED and OLED these days it\'s on
ly a
matter of years until the available selection starts to thin out
.

I won\'t use ebay or Amazon stuff in my gear. Some of my customers
care
about part traceability and anti-Chinese stuff.

Some of those things, ebay and Amazon, are OK for breadboards and
lab
cables and such.

One customer recently elected to buy a bunch of $40 cables from u
s,
when Amazon has them for $6.


It was just meant as an example. On most projects where I needed a
few
hundred volts I used the bare CCFL transformers and they cost just
a few
bucks. Even from US sources they are often produced abroad, sometim
es in
China.

Are the CCFL supplies flybacks or Royers or something? What sorts of
open-circuit voltages do they make?

It\'s probably Baxandall Class-D oscillator. Jim Williams seems to have
got the circuit from England without getting the literature reference that should have come with it - Baxandall, P.J, Proc I.E.E 106, B, 748 (1959.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

From my web-site.

\"The circuit is probably best known from Jim Williamsƒ T series
of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61, AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper ƒ oTransistors as on-off switches in saturable core circuitsƒ in Electrical Manufacturing.\"

The Baxandall inverter is handy for driving high-turns ratio step-up t
ransformers which tend end up with rather low self-resonant frequencies.

But right, it\'s all LEDs now.

I like ISDN transformers, but they will be gone too.

The little DRQ-type dual inductors are great. The autotransformer
flyback and CW multiplier thing is cool.

The Cockroft-Walton multiplier isn\'t all that cool.

Or you could learn how to design your own special purpose transformers
and find a shop that would wind them for you - it isn\'t all that difficult.

There are lots of variables to twiddle in a transformer design, so get
ting something close enough off the shelf isn\'t easy, even if you get downright sloppy about \"close enough\".


you are kidding right? a few 100mW at 150V for a low volume product and
you
want to spend what would quickly be weeks designing/ordering/twiddling a
transformer design?




He has huge enthusiasm for designing custom magnetics. I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

http://www.farnell.com/datasheets/1872308.pdf

isn\'t a standard part? Fairly obviously stocked by a major distributor ...

I wonder how his super oscillator is coming along. He ordered a custom
transformer for that, a decade or two ago.

Which confirmed that even a well-gapped core had enough hysteresis to generate harmonics - 95dB below the fundamental. I went over to a variant of the Wien bridge. If I ever find a customer I\'ll build one.

My customer wants a proof-of-principle 150-volt pulser next week, and
I have a 10-layer PCB to release first. Really, he should just trust
us and order the real things.

John Larkin does like it when his customers trust him. He can slap together something for them really quickly. And why is a ten layer PCB supposed to be impressive? The chaotic design process that left him needing that many layers would be.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, July 20, 2020 at 3:15:04 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Sun, 19 Jul 2020 08:49:16 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

søndag den 19. juli 2020 kl. 16.33.42 UTC+2 skrev Bill Sloman:
On Sunday, July 19, 2020 at 12:42:42 PM UTC+10, jla...@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 19:31:09 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-18 12:39, jlarkin@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 11:27:16 -0700, Joerg <news@analogconsultants..com
wrote:

On 2020-07-17 09:49, jlarkin@highlandsniptechnology.com wrote:


I need eight isolated 150 volt DC supplies, low current, under 1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high sides.

The application is eight isolated high-voltage pulse outputs. My first
idea was to use grounded drivers and final pulse transformers, but the
volt-seconds get huge so the pulse transformer would be awful. Better
to float the entire output circuit.


Mostly I used CCFL inverter transformers for that. Cheap, fairly small.
Even complete modules can be had for a few dollars:

https://www.ebay.com/itm/1Pc-CCFL-inverter-board-for-LCD-screen-with-1CCFL-backlight-LCD-JN/392849295194

$3.33 with free shipping from China. We pay for that.


Yup, they\'ll make the next aircraft carrier :-(


Or course, with everything going LED and OLED these days it\'s only a
matter of years until the available selection starts to thin out..

I won\'t use ebay or Amazon stuff in my gear. Some of my customers care
about part traceability and anti-Chinese stuff.

Some of those things, ebay and Amazon, are OK for breadboards and lab
cables and such.

One customer recently elected to buy a bunch of $40 cables from us,
when Amazon has them for $6.


It was just meant as an example. On most projects where I needed a few
hundred volts I used the bare CCFL transformers and they cost just a few
bucks. Even from US sources they are often produced abroad, sometimes in
China.

Are the CCFL supplies flybacks or Royers or something? What sorts of
open-circuit voltages do they make?

It\'s probably Baxandall Class-D oscillator. Jim Williams seems to have got the circuit from England without getting the literature reference that should have come with it - Baxandall, P.J, Proc I.E.E 106, B, 748 (1959.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

From my web-site.

\"The circuit is probably best known from Jim Williams’ series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61, AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper “Transistors as on-off switches in saturable core circuits” in Electrical Manufacturing.\"

The Baxandall inverter is handy for driving high-turns ratio step-up transformers which tend end up with rather low self-resonant frequencies.

But right, it\'s all LEDs now.

I like ISDN transformers, but they will be gone too.

The little DRQ-type dual inductors are great. The autotransformer
flyback and CW multiplier thing is cool.

The Cockroft-Walton multiplier isn\'t all that cool.

Or you could learn how to design your own special purpose transformers and find a shop that would wind them for you - it isn\'t all that difficult..

There are lots of variables to twiddle in a transformer design, so getting something close enough off the shelf isn\'t easy, even if you get downright sloppy about \"close enough\".


you are kidding right? a few 100mW at 150V for a low volume product and you
want to spend what would quickly be weeks designing/ordering/twiddling a transformer design?




He has huge enthusiasm for designing custom magnetics. I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

http://www.farnell.com/datasheets/1872308.pdf

isn\'t a standard part? Fairly obviously stocked by a major distributor ...

I wonder how his super oscillator is coming along. He ordered a custom
transformer for that, a decade or two ago.

Which confirmed that even a well-gapped core had enough hysteresis to generate harmonics - 95dB below the fundamental. I went over to a variant of the Wien bridge. If I ever find a customer I\'ll build one.

My customer wants a proof-of-principle 150-volt pulser next week, and
I have a 10-layer PCB to release first. Really, he should just trust
us and order the real things.

John Larkin does like it when his customers trust him. He can slap together something for them really quickly. And why is a ten layer PCB supposed to be impressive? The chaotic design process that left him needing that many layers would be.

--
Bill Sloman, Sydney

 

[John Doe]

\"I am Australian, and this is my netcop badge...\"

--
Bill Sloman <bill.sloman@ieee.org> wrote:

X-Received: by 2002:aed:3023:: with SMTP id 32mr21709639qte.37.1595213964897; Sun, 19 Jul 2020 19:59:24 -0700 (PDT)
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Message-ID: <30734a55-987f-4a1d-8201-66ebe165c658o@googlegroups.com
Subject: Re: HV dc/dc
From: Bill Sloman <bill.sloman@ieee.org
Injection-Date: Mon, 20 Jul 2020 02:59:24 +0000
Content-Type: text/plain; charset=\"UTF-8\"
Content-Transfer-Encoding: quoted-printable
Xref: reader01.eternal-september.org sci.electronics.design:602222

On Monday, July 20, 2020 at 3:15:04 AM UTC+10, jla...@highlandsniptechnology.com wrote:
On Sun, 19 Jul 2020 08:49:16 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

sÇ÷ndag den 19. juli 2020 kl. 16.33.42 UTC+2 skrev Bill Sloman:
On Sunday, July 19, 2020 at 12:42:42 PM UTC+10, jla...@highlandsniptec
hnology.com wrote:
On Sat, 18 Jul 2020 19:31:09 -0700, Joerg <news@analogconsultants.co
m
wrote:

On 2020-07-18 12:39, jlarkin@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 11:27:16 -0700, Joerg <news@analogconsultants
.com
wrote:

On 2020-07-17 09:49, jlarkin@highlandsniptechnology.com wrote:


I need eight isolated 150 volt DC supplies, low current, under
1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/
dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little
flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high side
s.

The application is eight isolated high-voltage pulse outputs. M
y first
idea was to use grounded drivers and final pulse transformers,
but the
volt-seconds get huge so the pulse transformer would be awful.
Better
to float the entire output circuit.


Mostly I used CCFL inverter transformers for that. Cheap, fairly
small.
Even complete modules can be had for a few dollars:

https://www.ebay.com/itm/1Pc-CCFL-inverter-board-for-LCD-screen-
with-1CCFL-backlight-LCD-JN/392849295194

$3.33 with free shipping from China. We pay for that.


Yup, they\'ll make the next aircraft carrier :-(


Or course, with everything going LED and OLED these days it\'s on
ly a
matter of years until the available selection starts to thin out
.

I won\'t use ebay or Amazon stuff in my gear. Some of my customers
care
about part traceability and anti-Chinese stuff.

Some of those things, ebay and Amazon, are OK for breadboards and
lab
cables and such.

One customer recently elected to buy a bunch of $40 cables from u
s,
when Amazon has them for $6.


It was just meant as an example. On most projects where I needed a
few
hundred volts I used the bare CCFL transformers and they cost just
a few
bucks. Even from US sources they are often produced abroad, sometim
es in
China.

Are the CCFL supplies flybacks or Royers or something? What sorts of
open-circuit voltages do they make?

It\'s probably Baxandall Class-D oscillator. Jim Williams seems to have
got the circuit from England without getting the literature reference that should have come with it - Baxandall, P.J, Proc I.E.E 106, B, 748 (1959.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

From my web-site.

\"The circuit is probably best known from Jim Williamsƒ T series
of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61, AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper ƒ oTransistors as on-off switches in saturable core circuitsƒ in Electrical Manufacturing.\"

The Baxandall inverter is handy for driving high-turns ratio step-up t
ransformers which tend end up with rather low self-resonant frequencies.

But right, it\'s all LEDs now.

I like ISDN transformers, but they will be gone too.

The little DRQ-type dual inductors are great. The autotransformer
flyback and CW multiplier thing is cool.

The Cockroft-Walton multiplier isn\'t all that cool.

Or you could learn how to design your own special purpose transformers
and find a shop that would wind them for you - it isn\'t all that difficult.

There are lots of variables to twiddle in a transformer design, so get
ting something close enough off the shelf isn\'t easy, even if you get downright sloppy about \"close enough\".


you are kidding right? a few 100mW at 150V for a low volume product and
you
want to spend what would quickly be weeks designing/ordering/twiddling a
transformer design?




He has huge enthusiasm for designing custom magnetics. I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

http://www.farnell.com/datasheets/1872308.pdf

isn\'t a standard part? Fairly obviously stocked by a major distributor ...

I wonder how his super oscillator is coming along. He ordered a custom
transformer for that, a decade or two ago.

Which confirmed that even a well-gapped core had enough hysteresis to generate harmonics - 95dB below the fundamental. I went over to a variant of the Wien bridge. If I ever find a customer I\'ll build one.

My customer wants a proof-of-principle 150-volt pulser next week, and
I have a 10-layer PCB to release first. Really, he should just trust
us and order the real things.

John Larkin does like it when his customers trust him. He can slap together something for them really quickly. And why is a ten layer PCB supposed to be impressive? The chaotic design process that left him needing that many layers would be.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, July 20, 2020 at 9:13:55 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Mon, 20 Jul 2020 00:01:59 +0200, Piotr Wyderski
peter.pan@neverland.mil> wrote:

jlarkin@highlandsniptechnology.com wrote:

He has huge enthusiasm for designing custom magnetics.

I share his enthusiasm. If you depend on some non-linearities, there is
no other way but to learn the craft.

I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

But why can\'t you have the best of both worlds and use standard parts
wherever possible and custom ones when there is a potential for blowing
the competition out of the water? Custom parts are still manufacturable,
just more expensive.

Best regards, Piotr

Sure I use custom magnetics. I\'ve posted lots of examples here. But
98% of the time, you can use standard parts, available in quantity,
cheap, overnight delivery. Or better yet, use the ones downstairs in
the stockroom.

Custom or home-made is generally needed for transmission-line
transformers, big power transformers, a few things like that. Maybe
flybacks, but if you are clever there are lots of ways to use standard
parts.

I\'ve probably designed 20x as many transformers and inductors as
Sloman. Here are just a few:

https://www.dropbox.com/s/dgno5o0psfzu9we/L_Assy.jpg?dl=0

Very intellectually demanding design.

I couldn\'t be bothered finding out if the rest were equally impressive.

If you count that as \"design\" you can see why John Larkin thinks he designs electronics. Five turns - one design. Six turns - a second design. The fluency is amazing.

<snip>

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, July 20, 2020 at 9:13:55 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Mon, 20 Jul 2020 00:01:59 +0200, Piotr Wyderski
peter.pan@neverland.mil> wrote:

jlarkin@highlandsniptechnology.com wrote:

He has huge enthusiasm for designing custom magnetics.

I share his enthusiasm. If you depend on some non-linearities, there is
no other way but to learn the craft.

I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

But why can\'t you have the best of both worlds and use standard parts
wherever possible and custom ones when there is a potential for blowing
the competition out of the water? Custom parts are still manufacturable,
just more expensive.

Best regards, Piotr

Sure I use custom magnetics. I\'ve posted lots of examples here. But
98% of the time, you can use standard parts, available in quantity,
cheap, overnight delivery. Or better yet, use the ones downstairs in
the stockroom.

Custom or home-made is generally needed for transmission-line
transformers, big power transformers, a few things like that. Maybe
flybacks, but if you are clever there are lots of ways to use standard
parts.

I\'ve probably designed 20x as many transformers and inductors as
Sloman. Here are just a few:

https://www.dropbox.com/s/dgno5o0psfzu9we/L_Assy.jpg?dl=0

Very intellectually demanding design.

I couldn\'t be bothered finding out if the rest were equally impressive.

If you count that as \"design\" you can see why John Larkin thinks he designs electronics. Five turns - one design. Six turns - a second design. The fluency is amazing.

<snip>

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, July 20, 2020 at 9:13:55 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Mon, 20 Jul 2020 00:01:59 +0200, Piotr Wyderski
peter.pan@neverland.mil> wrote:

jlarkin@highlandsniptechnology.com wrote:

He has huge enthusiasm for designing custom magnetics.

I share his enthusiasm. If you depend on some non-linearities, there is
no other way but to learn the craft.

I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

But why can\'t you have the best of both worlds and use standard parts
wherever possible and custom ones when there is a potential for blowing
the competition out of the water? Custom parts are still manufacturable,
just more expensive.

Best regards, Piotr

Sure I use custom magnetics. I\'ve posted lots of examples here. But
98% of the time, you can use standard parts, available in quantity,
cheap, overnight delivery. Or better yet, use the ones downstairs in
the stockroom.

Custom or home-made is generally needed for transmission-line
transformers, big power transformers, a few things like that. Maybe
flybacks, but if you are clever there are lots of ways to use standard
parts.

I\'ve probably designed 20x as many transformers and inductors as
Sloman. Here are just a few:

https://www.dropbox.com/s/dgno5o0psfzu9we/L_Assy.jpg?dl=0

Very intellectually demanding design.

I couldn\'t be bothered finding out if the rest were equally impressive.

If you count that as \"design\" you can see why John Larkin thinks he designs electronics. Five turns - one design. Six turns - a second design. The fluency is amazing.

<snip>

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, July 20, 2020 at 3:42:16 AM UTC+10, piglet wrote:

On 19/07/2020 18:14, jlarkin@highlandsniptechnology.com wrote:
On Sun, 19 Jul 2020 08:49:16 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

søndag den 19. juli 2020 kl. 16.33.42 UTC+2 skrev Bill Sloman:
On Sunday, July 19, 2020 at 12:42:42 PM UTC+10, jla...@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 19:31:09 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-18 12:39, jlarkin@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 11:27:16 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-17 09:49, jlarkin@highlandsniptechnology.com wrote:


I need eight isolated 150 volt DC supplies, low current, under 1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high sides..

The application is eight isolated high-voltage pulse outputs. My first
idea was to use grounded drivers and final pulse transformers, but the
volt-seconds get huge so the pulse transformer would be awful. Better
to float the entire output circuit.


Mostly I used CCFL inverter transformers for that. Cheap, fairly small.
Even complete modules can be had for a few dollars:

https://www.ebay.com/itm/1Pc-CCFL-inverter-board-for-LCD-screen-with-1CCFL-backlight-LCD-JN/392849295194

$3.33 with free shipping from China. We pay for that.


Yup, they\'ll make the next aircraft carrier :-(


Or course, with everything going LED and OLED these days it\'s only a
matter of years until the available selection starts to thin out.

I won\'t use ebay or Amazon stuff in my gear. Some of my customers care
about part traceability and anti-Chinese stuff.

Some of those things, ebay and Amazon, are OK for breadboards and lab
cables and such.

One customer recently elected to buy a bunch of $40 cables from us,
when Amazon has them for $6.


It was just meant as an example. On most projects where I needed a few
hundred volts I used the bare CCFL transformers and they cost just a few
bucks. Even from US sources they are often produced abroad, sometimes in
China.

Are the CCFL supplies flybacks or Royers or something? What sorts of
open-circuit voltages do they make?

It\'s probably Baxandall Class-D oscillator. Jim Williams seems to have got the circuit from England without getting the literature reference that should have come with it - Baxandall, P.J, Proc I.E.E 106, B, 748 (1959.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

From my web-site.

\"The circuit is probably best known from Jim Williams’ series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61, AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper “Transistors as on-off switches in saturable core circuits” in Electrical Manufacturing.\"

The Baxandall inverter is handy for driving high-turns ratio step-up transformers which tend end up with rather low self-resonant frequencies.

But right, it\'s all LEDs now.

I like ISDN transformers, but they will be gone too.

The little DRQ-type dual inductors are great. The autotransformer
flyback and CW multiplier thing is cool.

The Cockroft-Walton multiplier isn\'t all that cool.

Or you could learn how to design your own special purpose transformers and find a shop that would wind them for you - it isn\'t all that difficult.

There are lots of variables to twiddle in a transformer design, so getting something close enough off the shelf isn\'t easy, even if you get downright sloppy about \"close enough\".


you are kidding right? a few 100mW at 150V for a low volume product and you
want to spend what would quickly be weeks designing/ordering/twiddling a transformer design?




He has huge enthusiasm for designing custom magnetics. I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

I wonder how his super oscillator is coming along. He ordered a custom
transformer for that, a decade or two ago.

My customer wants a proof-of-principle 150-volt pulser next week, and
I have a 10-layer PCB to release first. Really, he should just trust
us and order the real things.



You are barely touching the volt-second capability of those
transformers, clearly over-engineered :

But seriously, what\'s the inter-winding capacitance and is that
tolerable in your app?

He wouldn\'t know. He buys in his transformers, and all he knows is whether the circuit works.

You are probably better off thinking in terms of the self-resonant frequency of the transformer (from which you can extract a capacitance).

The problem with step-up transformers is lots of turns on the secondary, which means high inductance and a low self-resonant frequency, which make driving them fast difficult.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

Baxandall seems to have invented his class-D inverter to deal with this, though the paper doesn\'t mention it - I worked for a guy who done his apprenticeship with Baxandall, and that story came from him.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, July 20, 2020 at 3:42:16 AM UTC+10, piglet wrote:

On 19/07/2020 18:14, jlarkin@highlandsniptechnology.com wrote:
On Sun, 19 Jul 2020 08:49:16 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

søndag den 19. juli 2020 kl. 16.33.42 UTC+2 skrev Bill Sloman:
On Sunday, July 19, 2020 at 12:42:42 PM UTC+10, jla...@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 19:31:09 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-18 12:39, jlarkin@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 11:27:16 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-17 09:49, jlarkin@highlandsniptechnology.com wrote:


I need eight isolated 150 volt DC supplies, low current, under 1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high sides..

The application is eight isolated high-voltage pulse outputs. My first
idea was to use grounded drivers and final pulse transformers, but the
volt-seconds get huge so the pulse transformer would be awful. Better
to float the entire output circuit.


Mostly I used CCFL inverter transformers for that. Cheap, fairly small.
Even complete modules can be had for a few dollars:

https://www.ebay.com/itm/1Pc-CCFL-inverter-board-for-LCD-screen-with-1CCFL-backlight-LCD-JN/392849295194

$3.33 with free shipping from China. We pay for that.


Yup, they\'ll make the next aircraft carrier :-(


Or course, with everything going LED and OLED these days it\'s only a
matter of years until the available selection starts to thin out.

I won\'t use ebay or Amazon stuff in my gear. Some of my customers care
about part traceability and anti-Chinese stuff.

Some of those things, ebay and Amazon, are OK for breadboards and lab
cables and such.

One customer recently elected to buy a bunch of $40 cables from us,
when Amazon has them for $6.


It was just meant as an example. On most projects where I needed a few
hundred volts I used the bare CCFL transformers and they cost just a few
bucks. Even from US sources they are often produced abroad, sometimes in
China.

Are the CCFL supplies flybacks or Royers or something? What sorts of
open-circuit voltages do they make?

It\'s probably Baxandall Class-D oscillator. Jim Williams seems to have got the circuit from England without getting the literature reference that should have come with it - Baxandall, P.J, Proc I.E.E 106, B, 748 (1959.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

From my web-site.

\"The circuit is probably best known from Jim Williams’ series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61, AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper “Transistors as on-off switches in saturable core circuits” in Electrical Manufacturing.\"

The Baxandall inverter is handy for driving high-turns ratio step-up transformers which tend end up with rather low self-resonant frequencies.

But right, it\'s all LEDs now.

I like ISDN transformers, but they will be gone too.

The little DRQ-type dual inductors are great. The autotransformer
flyback and CW multiplier thing is cool.

The Cockroft-Walton multiplier isn\'t all that cool.

Or you could learn how to design your own special purpose transformers and find a shop that would wind them for you - it isn\'t all that difficult.

There are lots of variables to twiddle in a transformer design, so getting something close enough off the shelf isn\'t easy, even if you get downright sloppy about \"close enough\".


you are kidding right? a few 100mW at 150V for a low volume product and you
want to spend what would quickly be weeks designing/ordering/twiddling a transformer design?




He has huge enthusiasm for designing custom magnetics. I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

I wonder how his super oscillator is coming along. He ordered a custom
transformer for that, a decade or two ago.

My customer wants a proof-of-principle 150-volt pulser next week, and
I have a 10-layer PCB to release first. Really, he should just trust
us and order the real things.



You are barely touching the volt-second capability of those
transformers, clearly over-engineered :

But seriously, what\'s the inter-winding capacitance and is that
tolerable in your app?

He wouldn\'t know. He buys in his transformers, and all he knows is whether the circuit works.

You are probably better off thinking in terms of the self-resonant frequency of the transformer (from which you can extract a capacitance).

The problem with step-up transformers is lots of turns on the secondary, which means high inductance and a low self-resonant frequency, which make driving them fast difficult.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

Baxandall seems to have invented his class-D inverter to deal with this, though the paper doesn\'t mention it - I worked for a guy who done his apprenticeship with Baxandall, and that story came from him.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Monday, July 20, 2020 at 3:42:16 AM UTC+10, piglet wrote:

On 19/07/2020 18:14, jlarkin@highlandsniptechnology.com wrote:
On Sun, 19 Jul 2020 08:49:16 -0700 (PDT), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

søndag den 19. juli 2020 kl. 16.33.42 UTC+2 skrev Bill Sloman:
On Sunday, July 19, 2020 at 12:42:42 PM UTC+10, jla...@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 19:31:09 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-18 12:39, jlarkin@highlandsniptechnology.com wrote:
On Sat, 18 Jul 2020 11:27:16 -0700, Joerg <news@analogconsultants.com
wrote:

On 2020-07-17 09:49, jlarkin@highlandsniptechnology.com wrote:


I need eight isolated 150 volt DC supplies, low current, under 1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high sides..

The application is eight isolated high-voltage pulse outputs. My first
idea was to use grounded drivers and final pulse transformers, but the
volt-seconds get huge so the pulse transformer would be awful. Better
to float the entire output circuit.


Mostly I used CCFL inverter transformers for that. Cheap, fairly small.
Even complete modules can be had for a few dollars:

https://www.ebay.com/itm/1Pc-CCFL-inverter-board-for-LCD-screen-with-1CCFL-backlight-LCD-JN/392849295194

$3.33 with free shipping from China. We pay for that.


Yup, they\'ll make the next aircraft carrier :-(


Or course, with everything going LED and OLED these days it\'s only a
matter of years until the available selection starts to thin out.

I won\'t use ebay or Amazon stuff in my gear. Some of my customers care
about part traceability and anti-Chinese stuff.

Some of those things, ebay and Amazon, are OK for breadboards and lab
cables and such.

One customer recently elected to buy a bunch of $40 cables from us,
when Amazon has them for $6.


It was just meant as an example. On most projects where I needed a few
hundred volts I used the bare CCFL transformers and they cost just a few
bucks. Even from US sources they are often produced abroad, sometimes in
China.

Are the CCFL supplies flybacks or Royers or something? What sorts of
open-circuit voltages do they make?

It\'s probably Baxandall Class-D oscillator. Jim Williams seems to have got the circuit from England without getting the literature reference that should have come with it - Baxandall, P.J, Proc I.E.E 106, B, 748 (1959.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

From my web-site.

\"The circuit is probably best known from Jim Williams’ series of application notes for Linear Technology, on high frequency inverters for driving cold cathode back-lights used in laptop computers (application notes AN45, AN49, AN51, AN55, AN61, AN65). Jim Williams describes the inverter as a current driven Royer inverter, referring back to the non-resonant inverter described by Bright, Pittman and George H. Royer in 1954 in a paper “Transistors as on-off switches in saturable core circuits” in Electrical Manufacturing.\"

The Baxandall inverter is handy for driving high-turns ratio step-up transformers which tend end up with rather low self-resonant frequencies.

But right, it\'s all LEDs now.

I like ISDN transformers, but they will be gone too.

The little DRQ-type dual inductors are great. The autotransformer
flyback and CW multiplier thing is cool.

The Cockroft-Walton multiplier isn\'t all that cool.

Or you could learn how to design your own special purpose transformers and find a shop that would wind them for you - it isn\'t all that difficult.

There are lots of variables to twiddle in a transformer design, so getting something close enough off the shelf isn\'t easy, even if you get downright sloppy about \"close enough\".


you are kidding right? a few 100mW at 150V for a low volume product and you
want to spend what would quickly be weeks designing/ordering/twiddling a transformer design?




He has huge enthusiasm for designing custom magnetics. I have huge
enthusiasm for ordering stock parts from Coilcraft or Digikey and
shipping products. He might learn to design with standard parts - it
isn\'t all that difficult.

I wonder how his super oscillator is coming along. He ordered a custom
transformer for that, a decade or two ago.

My customer wants a proof-of-principle 150-volt pulser next week, and
I have a 10-layer PCB to release first. Really, he should just trust
us and order the real things.



You are barely touching the volt-second capability of those
transformers, clearly over-engineered :

But seriously, what\'s the inter-winding capacitance and is that
tolerable in your app?

He wouldn\'t know. He buys in his transformers, and all he knows is whether the circuit works.

You are probably better off thinking in terms of the self-resonant frequency of the transformer (from which you can extract a capacitance).

The problem with step-up transformers is lots of turns on the secondary, which means high inductance and a low self-resonant frequency, which make driving them fast difficult.

http://sophia-elektronica.com/0344_001_Baxandal.pdf

Baxandall seems to have invented his class-D inverter to deal with this, though the paper doesn\'t mention it - I worked for a guy who done his apprenticeship with Baxandall, and that story came from him.

--
Bill Sloman, Sydney

 

[server]

On Fri, 17 Jul 2020 09:49:16 -0700, jlarkin@highlandsniptechnology.com
wrote:

I need eight isolated 150 volt DC supplies, low current, under 1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high sides.

The application is eight isolated high-voltage pulse outputs. My first
idea was to use grounded drivers and final pulse transformers, but the
volt-seconds get huge so the pulse transformer would be awful. Better
to float the entire output circuit.

Here is the companion micropower 150-volt regulator.

I\'ll probably include a voltage-set trimpot, for a couple of reasons.

Version 4
SHEET 1 1052 680
WIRE -400 -176 -480 -176
WIRE -352 -176 -400 -176
WIRE -160 -176 -272 -176
WIRE 16 -176 -64 -176
WIRE 160 -176 96 -176
WIRE 256 -176 160 -176
WIRE 352 -176 256 -176
WIRE 352 -112 352 -176
WIRE -480 -80 -480 -176
WIRE -80 -48 -80 -128
WIRE 16 -48 -80 -48
WIRE 160 -48 160 -176
WIRE 160 -48 96 -48
WIRE 160 -16 160 -48
WIRE 352 0 352 -48
WIRE -480 32 -480 0
WIRE -80 48 -80 -48
WIRE 160 96 160 64
WIRE 160 96 -16 96
WIRE 160 160 160 96
WIRE -80 192 -80 144
WIRE -80 304 -80 256
WIRE 160 304 160 240
FLAG 160 304 0
FLAG -480 32 0
FLAG -80 304 0
FLAG 352 0 0
FLAG -400 -176 Vin
FLAG 256 -176 Vreg
SYMBOL nmos -160 -128 R270
WINDOW 0 -9 -48 VRight 2
WINDOW 3 -41 -75 VRight 2
SYMATTR InstName M1
SYMATTR Value LND250
SYMBOL res 144 144 R0
WINDOW 0 -67 39 Left 2
WINDOW 3 -86 73 Left 2
SYMATTR InstName R1
SYMATTR Value 450k
SYMBOL voltage -480 -96 R0
WINDOW 0 60 70 Left 2
WINDOW 3 32 109 Left 2
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value PULSE(0 200 1m 20m 0 1)
SYMBOL res 112 -64 R90
WINDOW 0 74 56 VBottom 2
WINDOW 3 82 57 VTop 2
SYMATTR InstName R3
SYMATTR Value 100K
SYMBOL npn -16 48 M0
WINDOW 0 107 21 Left 2
WINDOW 3 82 53 Left 2
SYMATTR InstName Q1
SYMATTR Value 2N5550
SYMBOL res 144 -32 R0
WINDOW 0 66 35 Left 2
WINDOW 3 63 69 Left 2
SYMATTR InstName R4
SYMATTR Value 5e6
SYMBOL cap 336 -112 R0
WINDOW 0 -53 23 Left 2
WINDOW 3 -56 56 Left 2
SYMATTR InstName C1
SYMATTR Value 50n
SYMBOL zener -64 256 R180
WINDOW 0 69 41 Left 2
WINDOW 3 56 6 Left 2
SYMATTR InstName D1
SYMATTR Value BZX84B12VL
SYMBOL res -368 -160 R270
WINDOW 0 -35 56 VTop 2
WINDOW 3 -41 56 VBottom 2
SYMATTR InstName R2
SYMATTR Value 1
SYMBOL res 0 -160 R270
WINDOW 0 -35 56 VTop 2
WINDOW 3 -41 56 VBottom 2
SYMATTR InstName R5
SYMATTR Value 20K
TEXT -462 216 Left 2 !.tran 250m
TEXT -480 128 Left 2 ;150V Regulator
TEXT -480 176 Left 2 ;JL Jul 19 2020
TEXT -184 136 Left 2 ;FCX458
TEXT -216 288 Left 2 ;MAZ3120
TEXT 232 112 Left 2 !.MODEL LND250 NMOS (LEVEL=3 RS=150.00
NSUB=5.0E13 \\n+DELTA=0.1 KAPPA=1.O TPG=1 CGDO=2.1716E-12
\\n+RD=40.0 VTO=-2.0 VMAX=1.0E8 ETA=0.1 \\n+NFS=6.6E10
TOX=1.0E-7 LD=1.698E-9 UO=862.425\\n+XJ=6.4666E-7 THETA=1.0E-5
CGSO=5.09E-10 L=10.0E-6\\n+W=600E-6) \\n.ENDS



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[server]

On Fri, 17 Jul 2020 09:49:16 -0700, jlarkin@highlandsniptechnology.com
wrote:

I need eight isolated 150 volt DC supplies, low current, under 1 mA
average. Commercial dc/dc converters are crazy expensive:

https://www.digikey.com/products/en/power-supplies-board-mount/dc-dc-converters/922?k=&pkeyword=&sv=0&pv183=354808&pv183=354809&pv2211=i1&pv1525=100671&pv1525=114705&pv1525=140848&pv1525=157291&pv1525=182727&sf=1&FV=-8%7C922&quantity=&ColumnSort=0&page=1&pageSize=25

I guess I\'ll have to design it. Coilcraft has some nice little flyback
transformers.

I think I can use one flyback driver circuit and put all eight
primaries in parallel. Maybe regulate a little on the high sides.

The application is eight isolated high-voltage pulse outputs. My first
idea was to use grounded drivers and final pulse transformers, but the
volt-seconds get huge so the pulse transformer would be awful. Better
to float the entire output circuit.

Here is the companion micropower 150-volt regulator.

I\'ll probably include a voltage-set trimpot, for a couple of reasons.

Version 4
SHEET 1 1052 680
WIRE -400 -176 -480 -176
WIRE -352 -176 -400 -176
WIRE -160 -176 -272 -176
WIRE 16 -176 -64 -176
WIRE 160 -176 96 -176
WIRE 256 -176 160 -176
WIRE 352 -176 256 -176
WIRE 352 -112 352 -176
WIRE -480 -80 -480 -176
WIRE -80 -48 -80 -128
WIRE 16 -48 -80 -48
WIRE 160 -48 160 -176
WIRE 160 -48 96 -48
WIRE 160 -16 160 -48
WIRE 352 0 352 -48
WIRE -480 32 -480 0
WIRE -80 48 -80 -48
WIRE 160 96 160 64
WIRE 160 96 -16 96
WIRE 160 160 160 96
WIRE -80 192 -80 144
WIRE -80 304 -80 256
WIRE 160 304 160 240
FLAG 160 304 0
FLAG -480 32 0
FLAG -80 304 0
FLAG 352 0 0
FLAG -400 -176 Vin
FLAG 256 -176 Vreg
SYMBOL nmos -160 -128 R270
WINDOW 0 -9 -48 VRight 2
WINDOW 3 -41 -75 VRight 2
SYMATTR InstName M1
SYMATTR Value LND250
SYMBOL res 144 144 R0
WINDOW 0 -67 39 Left 2
WINDOW 3 -86 73 Left 2
SYMATTR InstName R1
SYMATTR Value 450k
SYMBOL voltage -480 -96 R0
WINDOW 0 60 70 Left 2
WINDOW 3 32 109 Left 2
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value PULSE(0 200 1m 20m 0 1)
SYMBOL res 112 -64 R90
WINDOW 0 74 56 VBottom 2
WINDOW 3 82 57 VTop 2
SYMATTR InstName R3
SYMATTR Value 100K
SYMBOL npn -16 48 M0
WINDOW 0 107 21 Left 2
WINDOW 3 82 53 Left 2
SYMATTR InstName Q1
SYMATTR Value 2N5550
SYMBOL res 144 -32 R0
WINDOW 0 66 35 Left 2
WINDOW 3 63 69 Left 2
SYMATTR InstName R4
SYMATTR Value 5e6
SYMBOL cap 336 -112 R0
WINDOW 0 -53 23 Left 2
WINDOW 3 -56 56 Left 2
SYMATTR InstName C1
SYMATTR Value 50n
SYMBOL zener -64 256 R180
WINDOW 0 69 41 Left 2
WINDOW 3 56 6 Left 2
SYMATTR InstName D1
SYMATTR Value BZX84B12VL
SYMBOL res -368 -160 R270
WINDOW 0 -35 56 VTop 2
WINDOW 3 -41 56 VBottom 2
SYMATTR InstName R2
SYMATTR Value 1
SYMBOL res 0 -160 R270
WINDOW 0 -35 56 VTop 2
WINDOW 3 -41 56 VBottom 2
SYMATTR InstName R5
SYMATTR Value 20K
TEXT -462 216 Left 2 !.tran 250m
TEXT -480 128 Left 2 ;150V Regulator
TEXT -480 176 Left 2 ;JL Jul 19 2020
TEXT -184 136 Left 2 ;FCX458
TEXT -216 288 Left 2 ;MAZ3120
TEXT 232 112 Left 2 !.MODEL LND250 NMOS (LEVEL=3 RS=150.00
NSUB=5.0E13 \\n+DELTA=0.1 KAPPA=1.O TPG=1 CGDO=2.1716E-12
\\n+RD=40.0 VTO=-2.0 VMAX=1.0E8 ETA=0.1 \\n+NFS=6.6E10
TOX=1.0E-7 LD=1.698E-9 UO=862.425\\n+XJ=6.4666E-7 THETA=1.0E-5
CGSO=5.09E-10 L=10.0E-6\\n+W=600E-6) \\n.ENDS



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard