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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.





--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On Friday, July 17, 2020 at 9:49:22 AM UTC-7, jla...@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.
Click to expand...

What is your input voltage? I have similar need with 12V to 24V input.
 
On Fri, 17 Jul 2020 09:59:29 -0700 (PDT), edward.ming.lee@gmail.com
wrote:

On Friday, July 17, 2020 at 9:49:22 AM UTC-7, jla...@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.

What is your input voltage? I have similar need with 12V to 24V input.
Click to expand...

Anything I want. I\'ll probably use a MeanWell brick for the main
supply, 24 volts maybe. That would give me a reasonable flyback ratio.

This is a weird custom pulse generator box for a mysterious ultimate
customer. Parts cost isn\'t a big deal, but it would annoy me to spend
a kilobuck per box on little dc/dc things.

I was just looking at ISOW7821, as the gate driver. It has a freebie
5-volt dc/dc built in.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On Fri, 17 Jul 2020 09:59:29 -0700 (PDT), edward.ming.lee@gmail.com
wrote:

On Friday, July 17, 2020 at 9:49:22 AM UTC-7, jla...@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.

What is your input voltage? I have similar need with 12V to 24V input.
Click to expand...

Anything I want. I\'ll probably use a MeanWell brick for the main
supply, 24 volts maybe. That would give me a reasonable flyback ratio.

This is a weird custom pulse generator box for a mysterious ultimate
customer. Parts cost isn\'t a big deal, but it would annoy me to spend
a kilobuck per box on little dc/dc things.

I was just looking at ISOW7821, as the gate driver. It has a freebie
5-volt dc/dc built in.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On Friday, July 17, 2020 at 10:18:57 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Fri, 17 Jul 2020 09:59:29 -0700 (PDT), edward.ming.lee@gmail.com
wrote:

On Friday, July 17, 2020 at 9:49:22 AM UTC-7, jla...@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.

What is your input voltage? I have similar need with 12V to 24V input.

Anything I want. I\'ll probably use a MeanWell brick for the main
supply, 24 volts maybe. That would give me a reasonable flyback ratio.

This is a weird custom pulse generator box for a mysterious ultimate
customer. Parts cost isn\'t a big deal, but it would annoy me to spend
a kilobuck per box on little dc/dc things.

I was just looking at ISOW7821, as the gate driver. It has a freebie
5-volt dc/dc built in.
Click to expand...

12V to 110V AC inverters are cheap and available, but they have a very narrow input range (around 11V). 110V AC to 170V DC regulators are also cheap. So, for my app (4 li bat in serial), i am buck regulating 12V to 16V DC to 12V, 12V DC to 110V AC, then 110V AC to 170V DC. Lots of hardware, but cheap and available.
 
Didn\'t you show some design earlier for a high voltage supply?

Swap your standard caps for the charge pump with y caps. Then it\'s safe wrt approvals and you reuse an earlier design

Cheers

Klaus
 
On 7/17/2020 12:49 PM, 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.
Click to expand...

Even 12 to 24 volt 5 watt isolated converters are relatively expensive
off the shelf, $20-25. Bleh
 
On 7/17/2020 12:49 PM, 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.
Click to expand...

Even 12 to 24 volt 5 watt isolated converters are relatively expensive
off the shelf, $20-25. Bleh
 
On Friday, July 17, 2020 at 9:49:22 AM UTC-7, jla...@highlandsniptechnology.com wrote:
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.
Click to expand...

How about a C-W multiplier driven from an off-the-shelf boost regulator?
In other words, don\'t use use one diode and capacitor, use a string of them.

-- john, KE5FX
 
On Friday, July 17, 2020 at 9:49:22 AM UTC-7, jla...@highlandsniptechnology.com wrote:
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.
Click to expand...

How about a C-W multiplier driven from an off-the-shelf boost regulator?
In other words, don\'t use use one diode and capacitor, use a string of them.

-- john, KE5FX
 
On Fri, 17 Jul 2020 11:00:56 -0700 (PDT), klaus.kragelund@gmail.com
wrote:

Didn\'t you show some design earlier for a high voltage supply?

Swap your standard caps for the charge pump with y caps. Then it\'s safe wrt approvals and you reuse an earlier design

Cheers

Klaus
Click to expand...

But designing new stuff is fun!

I don\'t think this customer cares about approvals.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On Fri, 17 Jul 2020 14:12:32 -0400, bitrex <user@example.net> wrote:

On 7/17/2020 12:49 PM, 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.




Even 12 to 24 volt 5 watt isolated converters are relatively expensive
off the shelf, $20-25. Bleh
Click to expand...

At the 1-watt or 2-watt level, there are lots of nice little
surface-mount dc/dc things for a few dollars. I use them a lot, even
when I don\'t need isolation.





--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On Fri, 17 Jul 2020 14:12:32 -0400, bitrex <user@example.net> wrote:

On 7/17/2020 12:49 PM, 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.




Even 12 to 24 volt 5 watt isolated converters are relatively expensive
off the shelf, $20-25. Bleh
Click to expand...

At the 1-watt or 2-watt level, there are lots of nice little
surface-mount dc/dc things for a few dollars. I use them a lot, even
when I don\'t need isolation.





--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On Friday, July 17, 2020 at 1:05:51 PM UTC-7, jla...@highlandsniptechnology..com wrote:
On Fri, 17 Jul 2020 14:12:32 -0400, bitrex <user@example.net> wrote:

On 7/17/2020 12:49 PM, 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.




Even 12 to 24 volt 5 watt isolated converters are relatively expensive
off the shelf, $20-25. Bleh

At the 1-watt or 2-watt level, there are lots of nice little
surface-mount dc/dc things for a few dollars. I use them a lot, even
when I don\'t need isolation.
Click to expand...

This one is pretty good for $7. It can display input or output voltage as well.
But it does not have output protection, and i blow up the mosfet. I am going to add output protection for cascaded booster.

https://www.ebay.com/itm/FP5139-100W-DC-Boost-Step-up-Adjustable-Voltage-Power-Converter-LED-Voltmeter/142697805000?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649
 
On Friday, July 17, 2020 at 1:05:51 PM UTC-7, jla...@highlandsniptechnology..com wrote:
On Fri, 17 Jul 2020 14:12:32 -0400, bitrex <user@example.net> wrote:

On 7/17/2020 12:49 PM, 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.




Even 12 to 24 volt 5 watt isolated converters are relatively expensive
off the shelf, $20-25. Bleh

At the 1-watt or 2-watt level, there are lots of nice little
surface-mount dc/dc things for a few dollars. I use them a lot, even
when I don\'t need isolation.
Click to expand...

This one is pretty good for $7. It can display input or output voltage as well.
But it does not have output protection, and i blow up the mosfet. I am going to add output protection for cascaded booster.

https://www.ebay.com/itm/FP5139-100W-DC-Boost-Step-up-Adjustable-Voltage-Power-Converter-LED-Voltmeter/142697805000?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649
 
On Fri, 17 Jul 2020 12:40:52 -0700 (PDT), \"John Miles, KE5FX\"
<jmiles@gmail.com> wrote:

On Friday, July 17, 2020 at 9:49:22 AM UTC-7, jla...@highlandsniptechnology.com wrote:
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.


How about a C-W multiplier driven from an off-the-shelf boost regulator?
In other words, don\'t use use one diode and capacitor, use a string of them.

-- john, KE5FX
Click to expand...

Something like this should work.

https://www.dropbox.com/s/5lkbvlwz7b4rb2h/Isol_Pulser_1.jpg?raw=1

Feedback into the LTC chip is interesting.

They want a working demo next week. Gotta warm up the Dremel.







--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On Fri, 17 Jul 2020 12:40:52 -0700 (PDT), \"John Miles, KE5FX\"
<jmiles@gmail.com> wrote:

On Friday, July 17, 2020 at 9:49:22 AM UTC-7, jla...@highlandsniptechnology.com wrote:
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.


How about a C-W multiplier driven from an off-the-shelf boost regulator?
In other words, don\'t use use one diode and capacitor, use a string of them.

-- john, KE5FX
Click to expand...

Something like this should work.

https://www.dropbox.com/s/5lkbvlwz7b4rb2h/Isol_Pulser_1.jpg?raw=1

Feedback into the LTC chip is interesting.

They want a working demo next week. Gotta warm up the Dremel.







--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On Fri, 17 Jul 2020 12:40:52 -0700 (PDT), \"John Miles, KE5FX\"
<jmiles@gmail.com> wrote:

On Friday, July 17, 2020 at 9:49:22 AM UTC-7, jla...@highlandsniptechnology.com wrote:
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.


How about a C-W multiplier driven from an off-the-shelf boost regulator?
In other words, don\'t use use one diode and capacitor, use a string of them.

-- john, KE5FX
Click to expand...

Something like this should work.

https://www.dropbox.com/s/5lkbvlwz7b4rb2h/Isol_Pulser_1.jpg?raw=1

Feedback into the LTC chip is interesting.

They want a working demo next week. Gotta warm up the Dremel.







--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On Friday, July 17, 2020 at 4:30:14 PM UTC-4, jla...@highlandsniptechnology.com wrote:
On Fri, 17 Jul 2020 12:40:52 -0700 (PDT), \"John Miles, KE5FX\"
jmiles@gmail.com> wrote:

On Friday, July 17, 2020 at 9:49:22 AM UTC-7, jla...@highlandsniptechnology.com wrote:
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.


How about a C-W multiplier driven from an off-the-shelf boost regulator?
In other words, don\'t use use one diode and capacitor, use a string of them.

-- john, KE5FX

Something like this should work.

https://www.dropbox.com/s/5lkbvlwz7b4rb2h/Isol_Pulser_1.jpg?raw=1

Feedback into the LTC chip is interesting.

They want a working demo next week. Gotta warm up the Dremel.
Click to expand...
I was going to say I used a LTC3803 design I copied from you...
or someone else here.

George H.
--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
Click to expand...
 
On Friday, July 17, 2020 at 4:30:14 PM UTC-4, jla...@highlandsniptechnology.com wrote:
On Fri, 17 Jul 2020 12:40:52 -0700 (PDT), \"John Miles, KE5FX\"
jmiles@gmail.com> wrote:

On Friday, July 17, 2020 at 9:49:22 AM UTC-7, jla...@highlandsniptechnology.com wrote:
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.


How about a C-W multiplier driven from an off-the-shelf boost regulator?
In other words, don\'t use use one diode and capacitor, use a string of them.

-- john, KE5FX

Something like this should work.

https://www.dropbox.com/s/5lkbvlwz7b4rb2h/Isol_Pulser_1.jpg?raw=1

Feedback into the LTC chip is interesting.

They want a working demo next week. Gotta warm up the Dremel.
Click to expand...
I was going to say I used a LTC3803 design I copied from you...
or someone else here.

George H.
--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
Click to expand...
 
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