24V to 500-1000V, 20W floating DC-DC converter

On 7/22/2020 3:35 PM, Matt B wrote:
> On Wednesday, July 22, 2020 at 2:04:25 PM UTC-5, bitrex wrote:
>> On 7/22/2020 3:02 PM, bitrex wrote:
>>> On 7/22/2020 2:26 PM, John Larkin wrote:
>>>> On Wed, 22 Jul 2020 12:52:25 -0400, bitrex <user@example.net> wrote:
>>>>
>>>>> On 7/22/2020 9:43 AM, jlarkin@highlandsniptechnology.com wrote:
>>>>>> On Wed, 22 Jul 2020 06:08:26 -0700 (PDT), Matt B
>>>>>> <m...@gmail.com> wrote:
>>>>>>
>>>>>>> On Tuesday, July 21, 2020 at 10:32:47 PM UTC-5,
>>>>>>> jla...@highlandsniptechnology.com wrote:
>>>>>>>> I you want to design the whole circuit, take a look at LT3803 and its
>>>>>>>> app notes. It just always seems to work.
>>>>>>>>
>>>>>>>> Scribble some circuits and we can talk about them. LT Spice includes
>>>>>>>> the 3803 too. It seems to work just like it simulates.
>>>>>>>
>>>>>>> I generally like to design or at least modify a current design so I
>>>>>>> understand what's going on. This is new territory for me, so I'll
>>>>>>> look into a start some simulations. Thanks for the tip on the LTC3803.
>>>>>>
>>>>>> The pragmatic way to do this, at least for a one-off, is to buy a
>>>>>> dc/dc brick that has a control input, and be done. But as you say, you
>>>>>> wouldn't learn much about HV supplies.
>>>>>>
>>>>>> LTC/ADI has some starting-point simulations for the 3803.
>>>>>>
>>>>>> I'm playing with an isolated flyback right now, probably about 200
>>>>>> volts at very low current, possibly with a voltage regulator on the
>>>>>> high side. When my customer gets un-confused about what he actually
>>>>>> needs, I'll build him a demo.
>>>>>>
>>>>>> Does you piezo move slow or fast? Win Hill has posted some interesting
>>>>>> piezo drive ideas here recently.
>>>>>
>>>>> Says he's got an implied 1000 volt piezo stack with a capacitance
>>>>> of...5uF? that doesn't sound right.
>>>>
>>>> That would lift trucks, or buildings.
>>>>
>>>
>>> Yes, the original flyback in the EDN article has as 0.01uF 1500V cap as
>>> the main output cap and 0.022u 500Vs as the CW boost caps. this is a 4uF
>>> 1000V cap, damn:
>>>
>>> <https://i.ebayimg.com/images/g/LYEAAOSwiONYNMh1/s-l500.jpg>
>>>
>>> the EDN circuit isn't in the right ballpark.
>>>
>>>
>>
>> Hoping he actually meant 5n or something
> 
> The 5uF is the bulk capacitance of the pulser circuit, not the piezo element, to prevent droop during pulses. So the caps are not fully charged and discharged every cycle that would need to fast cap charge capability of the Ultravolt unit. The bulk capacitance will also be "separated" from the power supply with a resistor to slow charge the caps.
> 

Jeepers that's a large bulk capacitance.

If all you really need is an expedient ~1kV supply to charge cap bank 
with that energy that can power up off a 12 or 24 volt supply you could 
use a sine inverter off the shelf and a couple of appropriately-rated 
line transformers like:

<https://www.dropbox.com/s/7byu9dkapx7npcm/p4bBqD70.jpeg?dl=0>

but please don't quote me that I got those dots correct, or actually 
recommended any of this, damn son.

If what you need is like that but compact and very efficient and 
infinitely adjustable I'll have to defer. GL

On Wed, 22 Jul 2020 12:24:10 -0400, bitrex <user@example.net> wrote:

>On 7/22/2020 10:21 AM, George Herold wrote:
>> On Tuesday, July 21, 2020 at 6:51:49 PM UTC-4, Matt B wrote:
>>> I need to make a 24V to 500-1000V, 20W adjustable power supply for a pulser. It needs to be a floating or negative converter.
>>>
>>> My specs are:
>>> Input: 24-28V
>>> Output voltage: 500-1000V adjustable via control signal
>>> Output current: 10mA @ 500V (5W), 20mA @ 1000V (20W)
>>>
>>> I've been reading through threads on different HV designs. So far the only one I've come across that is isolated is Figure 50 of LT Application Note 29 (https://www.analog.com/media/en/technical-documentation/application-notes/an29f.pdf). It is specified for 1000V, 5W so not beefy enough. The transformer is also obsolete, but this comment mentions potential replacements. https://groups.google.com/d/msg/sci.electronics.design/F120QpxWWkc/74ljdPZ_BQAJ
>>>
>>> There's also this design (https://www.edn.com/1-kv-power-supply-produces-a-continuous-arc/) that is 1kV, 20W. I just don't know enough about making it adjustable and isolated.
>>>
>>> Thoughts on how to proceed?
>> 
>> If you are going to try building it yourself, then I'd start with the
>> 500V 5 mA one first.  I built my first flyback with the LT3083,
>> 
>> (2018... thread here
>> https://groups.google.com/forum/?fromgroups=&hl=en#!searchin/sci.electronics.design/my$20first$20flyback%7Csort:date/sci.electronics.design/FQAIY1VaYBY/mLvGKJC2AgAJ
>> 
>> Good luck.  Oh buying a ready made HV supply would be a good thing.
>> Gives you something to compare to if/when you have problems putting
>> to whole system together.
>> 
>> George H.
>> 
>
>Yep. OP did not like that I disparaged/was skeptical of his plan to 
>build a 20 watt 1000 volt converter out of the gate but it strikes me as 
>a certain kind of madness as a first project if OP has not designed and 
>built a flyback of any type before.

Just different numbers. Shouldn't be really hard.

On Wednesday, July 22, 2020 at 3:53:31 PM UTC-5, bitrex wrote:
> On 7/22/2020 3:35 PM, Matt B wrote: 
> > On Wednesday, July 22, 2020 at 2:04:25 PM UTC-5, bitrex wrote: 
> >> On 7/22/2020 3:02 PM, bitrex wrote: 
> >>> On 7/22/2020 2:26 PM, John Larkin wrote: 
> >>>> On Wed, 22 Jul 2020 12:52:25 -0400, bitrex <us...@example.net> wrote: 
> >>>> 
> >>>>> On 7/22/2020 9:43 AM, jla...@highlandsniptechnology.com wrote: 
> >>>>>> On Wed, 22 Jul 2020 06:08:26 -0700 (PDT), Matt B 
> >>>>>> <m...@gmail.com> wrote: 
> >>>>>> 
> >>>>>>> On Tuesday, July 21, 2020 at 10:32:47 PM UTC-5, 
> >>>>>>> jla...@highlandsniptechnology.com wrote: 
> >>>>>>>> I you want to design the whole circuit, take a look at LT3803 and its 
> >>>>>>>> app notes. It just always seems to work. 
> >>>>>>>> 
> >>>>>>>> Scribble some circuits and we can talk about them. LT Spice includes 
> >>>>>>>> the 3803 too. It seems to work just like it simulates. 
> >>>>>>> 
> >>>>>>> I generally like to design or at least modify a current design so I 
> >>>>>>> understand what's going on. This is new territory for me, so I'll 
> >>>>>>> look into a start some simulations. Thanks for the tip on the LTC3803. 
> >>>>>> 
> >>>>>> The pragmatic way to do this, at least for a one-off, is to buy a 
> >>>>>> dc/dc brick that has a control input, and be done. But as you say, you 
> >>>>>> wouldn't learn much about HV supplies. 
> >>>>>> 
> >>>>>> LTC/ADI has some starting-point simulations for the 3803. 
> >>>>>> 
> >>>>>> I'm playing with an isolated flyback right now, probably about 200 
> >>>>>> volts at very low current, possibly with a voltage regulator on the 
> >>>>>> high side. When my customer gets un-confused about what he actually 
> >>>>>> needs, I'll build him a demo. 
> >>>>>> 
> >>>>>> Does you piezo move slow or fast? Win Hill has posted some interesting 
> >>>>>> piezo drive ideas here recently. 
> >>>>> 
> >>>>> Says he's got an implied 1000 volt piezo stack with a capacitance 
> >>>>> of...5uF? that doesn't sound right. 
> >>>> 
> >>>> That would lift trucks, or buildings. 
> >>>> 
> >>> 
> >>> Yes, the original flyback in the EDN article has as 0.01uF 1500V cap as 
> >>> the main output cap and 0.022u 500Vs as the CW boost caps. this is a 4uF 
> >>> 1000V cap, damn: 
> >>> 
> >>> <https://i.ebayimg.com/images/g/LYEAAOSwiONYNMh1/s-l500.jpg> 
> >>> 
> >>> the EDN circuit isn't in the right ballpark. 
> >>> 
> >>> 
> >> 
> >> Hoping he actually meant 5n or something 
> > 
> > The 5uF is the bulk capacitance of the pulser circuit, not the piezo element, to prevent droop during pulses. So the caps are not fully charged and discharged every cycle that would need to fast cap charge capability of the Ultravolt unit. The bulk capacitance will also be "separated" from the power supply with a resistor to slow charge the caps. 
> >
> Jeepers that's a large bulk capacitance. 
> 
> If all you really need is an expedient ~1kV supply to charge cap bank 
> with that energy that can power up off a 12 or 24 volt supply you could 
> use a sine inverter off the shelf and a couple of appropriately-rated 
> line transformers like: 
> 
> <https://www.dropbox.com/s/7byu9dkapx7npcm/p4bBqD70.jpeg?dl=0> 
> 
> but please don't quote me that I got those dots correct, or actually 
> recommended any of this, damn son. 
> 
> If what you need is like that but compact and very efficient and 
> infinitely adjustable I'll have to defer. GL

Yes, it essentially will charge the caps and then keep them topped off once the pulser starts running, so it doesn't matter how long it takes to charge the caps. The max average pulser power is 20W @1000V, so that's the rate the power supply has output to keep the caps topped off. Thanks for the sine inverter suggestion.

After some more digging I found this app note that is modern (parts still in production) and does 15W at 1000V, so it's another design for me to investigate.
https://www.analog.com/media/en/technical-documentation/tech-articles/1000-V-Output-No-Opto-Isolated-Flyback-Converter.pdf

On 7/22/2020 5:23 PM, John Larkin wrote:
> On Wed, 22 Jul 2020 12:24:10 -0400, bitrex <user@example.net> wrote:
> 
>> On 7/22/2020 10:21 AM, George Herold wrote:
>>> On Tuesday, July 21, 2020 at 6:51:49 PM UTC-4, Matt B wrote:
>>>> I need to make a 24V to 500-1000V, 20W adjustable power supply for a pulser. It needs to be a floating or negative converter.
>>>>
>>>> My specs are:
>>>> Input: 24-28V
>>>> Output voltage: 500-1000V adjustable via control signal
>>>> Output current: 10mA @ 500V (5W), 20mA @ 1000V (20W)
>>>>
>>>> I've been reading through threads on different HV designs. So far the only one I've come across that is isolated is Figure 50 of LT Application Note 29 (https://www.analog.com/media/en/technical-documentation/application-notes/an29f.pdf). It is specified for 1000V, 5W so not beefy enough. The transformer is also obsolete, but this comment mentions potential replacements. https://groups.google.com/d/msg/sci.electronics.design/F120QpxWWkc/74ljdPZ_BQAJ
>>>>
>>>> There's also this design (https://www.edn.com/1-kv-power-supply-produces-a-continuous-arc/) that is 1kV, 20W. I just don't know enough about making it adjustable and isolated.
>>>>
>>>> Thoughts on how to proceed?
>>>
>>> If you are going to try building it yourself, then I'd start with the
>>> 500V 5 mA one first.  I built my first flyback with the LT3083,
>>>
>>> (2018... thread here
>>> https://groups.google.com/forum/?fromgroups=&hl=en#!searchin/sci.electronics.design/my$20first$20flyback%7Csort:date/sci.electronics.design/FQAIY1VaYBY/mLvGKJC2AgAJ
>>>
>>> Good luck.  Oh buying a ready made HV supply would be a good thing.
>>> Gives you something to compare to if/when you have problems putting
>>> to whole system together.
>>>
>>> George H.
>>>
>>
>> Yep. OP did not like that I disparaged/was skeptical of his plan to
>> build a 20 watt 1000 volt converter out of the gate but it strikes me as
>> a certain kind of madness as a first project if OP has not designed and
>> built a flyback of any type before.
> 
> Just different numbers. Shouldn't be really hard.
> 

The Thor rocket was just sort of a scaled-up kerosene burning V2:

<https://www.youtube.com/watch?v=WYrrVHPur2Y>

On Wednesday, July 22, 2020 at 3:50:46 PM UTC-4, bitrex wrote:
> On 7/22/2020 3:30 PM, George Herold wrote:
> > On Wednesday, July 22, 2020 at 12:24:16 PM UTC-4, bitrex wrote:
> >> On 7/22/2020 10:21 AM, George Herold wrote:
> >>> On Tuesday, July 21, 2020 at 6:51:49 PM UTC-4, Matt B wrote:
> >>>> I need to make a 24V to 500-1000V, 20W adjustable power supply for a pulser. It needs to be a floating or negative converter.
> >>>>
> >>>> My specs are:
> >>>> Input: 24-28V
> >>>> Output voltage: 500-1000V adjustable via control signal
> >>>> Output current: 10mA @ 500V (5W), 20mA @ 1000V (20W)
> >>>>
> >>>> I've been reading through threads on different HV designs. So far the only one I've come across that is isolated is Figure 50 of LT Application Note 29 (https://www.analog.com/media/en/technical-documentation/application-notes/an29f.pdf). It is specified for 1000V, 5W so not beefy enough. The transformer is also obsolete, but this comment mentions potential replacements. https://groups.google.com/d/msg/sci.electronics.design/F120QpxWWkc/74ljdPZ_BQAJ
> >>>>
> >>>> There's also this design (https://www.edn.com/1-kv-power-supply-produces-a-continuous-arc/) that is 1kV, 20W. I just don't know enough about making it adjustable and isolated.
> >>>>
> >>>> Thoughts on how to proceed?
> >>>
> >>> If you are going to try building it yourself, then I'd start with the
> >>> 500V 5 mA one first.  I built my first flyback with the LT3083,
> >>>
> >>> (2018... thread here
> >>> https://groups.google.com/forum/?fromgroups=&hl=en#!searchin/sci.electronics.design/my$20first$20flyback%7Csort:date/sci.electronics.design/FQAIY1VaYBY/mLvGKJC2AgAJ
> >>>
> >>> Good luck.  Oh buying a ready made HV supply would be a good thing.
> >>> Gives you something to compare to if/when you have problems putting
> >>> to whole system together.
> >>>
> >>> George H.
> >>>
> >>
> >> Yep. OP did not like that I disparaged/was skeptical of his plan to
> >> build a 20 watt 1000 volt converter out of the gate but it strikes me as
> >> a certain kind of madness as a first project if OP has not designed and
> >> built a flyback of any type before.
> > 
> > Since you bring it up, it bothered me when you said that too.
> > I assume people mostly know what they are talking about.
> > Why not be nice?
> > 
> > BTW 5 uF for a piezo stack doesn't strike me as impossible.
> > I used this little multilayer stacks (for motion) that were ~0.1 uf
> > (only 150 V.)
> > https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=61
> > 
> > George H.
> 
> Do the math on how much peak current you'd need to slew a 1000 volt 5uF 
> piezo stack full-range to have a sub-ms response time mah dude! with a 
> 20 watt converter it must not be doing anything fast. the V^2 in 
> 0.5*C*V^2 is a bitch

OK... IDK.  The piezo stack things are pretty slow.  
The OP must be doing something else.  

George H. 
> 
> 
> >>
> >> Even if someone here were able to provide a perfect custom design that
> >> fit the bill the probability of something not working right on a first
> >> prototype is high, and the probability of being able to figure it out
> >> without a real working reference design or experience building more
> >> modest switchers, is low
> >>
> >> <https://thedailywtf.com/articles/plz-email-me-teh-codez>
> >

torsdag den 23. juli 2020 kl. 01.19.00 UTC+2 skrev bitrex:
> On 7/22/2020 5:23 PM, John Larkin wrote:
> > On Wed, 22 Jul 2020 12:24:10 -0400, bitrex <user@example.net> wrote:
> > 
> >> On 7/22/2020 10:21 AM, George Herold wrote:
> >>> On Tuesday, July 21, 2020 at 6:51:49 PM UTC-4, Matt B wrote:
> >>>> I need to make a 24V to 500-1000V, 20W adjustable power supply for a pulser. It needs to be a floating or negative converter.
> >>>>
> >>>> My specs are:
> >>>> Input: 24-28V
> >>>> Output voltage: 500-1000V adjustable via control signal
> >>>> Output current: 10mA @ 500V (5W), 20mA @ 1000V (20W)
> >>>>
> >>>> I've been reading through threads on different HV designs. So far the only one I've come across that is isolated is Figure 50 of LT Application Note 29 (https://www.analog.com/media/en/technical-documentation/application-notes/an29f.pdf). It is specified for 1000V, 5W so not beefy enough. The transformer is also obsolete, but this comment mentions potential replacements. https://groups.google.com/d/msg/sci.electronics.design/F120QpxWWkc/74ljdPZ_BQAJ
> >>>>
> >>>> There's also this design (https://www.edn.com/1-kv-power-supply-produces-a-continuous-arc/) that is 1kV, 20W. I just don't know enough about making it adjustable and isolated.
> >>>>
> >>>> Thoughts on how to proceed?
> >>>
> >>> If you are going to try building it yourself, then I'd start with the
> >>> 500V 5 mA one first.  I built my first flyback with the LT3083,
> >>>
> >>> (2018... thread here
> >>> https://groups.google.com/forum/?fromgroups=&hl=en#!searchin/sci.electronics.design/my$20first$20flyback%7Csort:date/sci.electronics.design/FQAIY1VaYBY/mLvGKJC2AgAJ
> >>>
> >>> Good luck.  Oh buying a ready made HV supply would be a good thing.
> >>> Gives you something to compare to if/when you have problems putting
> >>> to whole system together.
> >>>
> >>> George H.
> >>>
> >>
> >> Yep. OP did not like that I disparaged/was skeptical of his plan to
> >> build a 20 watt 1000 volt converter out of the gate but it strikes me as
> >> a certain kind of madness as a first project if OP has not designed and
> >> built a flyback of any type before.
> > 
> > Just different numbers. Shouldn't be really hard.
> > 
> 
> The Thor rocket was just sort of a scaled-up kerosene burning V2:
> 
> <https://www.youtube.com/watch?v=WYrrVHPur2Y>

hopefully debugging a powersupply doesn't make fireballs like that ;)

On 7/22/2020 7:37 PM, George Herold wrote:
> On Wednesday, July 22, 2020 at 3:50:46 PM UTC-4, bitrex wrote:
>> On 7/22/2020 3:30 PM, George Herold wrote:
>>> On Wednesday, July 22, 2020 at 12:24:16 PM UTC-4, bitrex wrote:
>>>> On 7/22/2020 10:21 AM, George Herold wrote:
>>>>> On Tuesday, July 21, 2020 at 6:51:49 PM UTC-4, Matt B wrote:
>>>>>> I need to make a 24V to 500-1000V, 20W adjustable power supply for a pulser. It needs to be a floating or negative converter.
>>>>>>
>>>>>> My specs are:
>>>>>> Input: 24-28V
>>>>>> Output voltage: 500-1000V adjustable via control signal
>>>>>> Output current: 10mA @ 500V (5W), 20mA @ 1000V (20W)
>>>>>>
>>>>>> I've been reading through threads on different HV designs. So far the only one I've come across that is isolated is Figure 50 of LT Application Note 29 (https://www.analog.com/media/en/technical-documentation/application-notes/an29f.pdf). It is specified for 1000V, 5W so not beefy enough. The transformer is also obsolete, but this comment mentions potential replacements. https://groups.google.com/d/msg/sci.electronics.design/F120QpxWWkc/74ljdPZ_BQAJ
>>>>>>
>>>>>> There's also this design (https://www.edn.com/1-kv-power-supply-produces-a-continuous-arc/) that is 1kV, 20W. I just don't know enough about making it adjustable and isolated.
>>>>>>
>>>>>> Thoughts on how to proceed?
>>>>>
>>>>> If you are going to try building it yourself, then I'd start with the
>>>>> 500V 5 mA one first.  I built my first flyback with the LT3083,
>>>>>
>>>>> (2018... thread here
>>>>> https://groups.google.com/forum/?fromgroups=&hl=en#!searchin/sci.electronics.design/my$20first$20flyback%7Csort:date/sci.electronics.design/FQAIY1VaYBY/mLvGKJC2AgAJ
>>>>>
>>>>> Good luck.  Oh buying a ready made HV supply would be a good thing.
>>>>> Gives you something to compare to if/when you have problems putting
>>>>> to whole system together.
>>>>>
>>>>> George H.
>>>>>
>>>>
>>>> Yep. OP did not like that I disparaged/was skeptical of his plan to
>>>> build a 20 watt 1000 volt converter out of the gate but it strikes me as
>>>> a certain kind of madness as a first project if OP has not designed and
>>>> built a flyback of any type before.
>>>
>>> Since you bring it up, it bothered me when you said that too.
>>> I assume people mostly know what they are talking about.
>>> Why not be nice?
>>>
>>> BTW 5 uF for a piezo stack doesn't strike me as impossible.
>>> I used this little multilayer stacks (for motion) that were ~0.1 uf
>>> (only 150 V.)
>>> https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=61
>>>
>>> George H.
>>
>> Do the math on how much peak current you'd need to slew a 1000 volt 5uF
>> piezo stack full-range to have a sub-ms response time mah dude! with a
>> 20 watt converter it must not be doing anything fast. the V^2 in
>> 0.5*C*V^2 is a bitch
> 
> OK... IDK.  The piezo stack things are pretty slow.

Ya, it's just a 5uF 1000 volt filter cap on the out put it seems? That's 
quite a capacitor bank for a piezo driver.

> The OP must be doing something else.

Above my "pay grade", whatever it is.

> George H.

On Wed, 22 Jul 2020 19:18:54 -0400, bitrex <user@example.net> wrote:

>On 7/22/2020 5:23 PM, John Larkin wrote:
>> On Wed, 22 Jul 2020 12:24:10 -0400, bitrex <user@example.net> wrote:
>> 
>>> On 7/22/2020 10:21 AM, George Herold wrote:
>>>> On Tuesday, July 21, 2020 at 6:51:49 PM UTC-4, Matt B wrote:
>>>>> I need to make a 24V to 500-1000V, 20W adjustable power supply for a pulser. It needs to be a floating or negative converter.
>>>>>
>>>>> My specs are:
>>>>> Input: 24-28V
>>>>> Output voltage: 500-1000V adjustable via control signal
>>>>> Output current: 10mA @ 500V (5W), 20mA @ 1000V (20W)
>>>>>
>>>>> I've been reading through threads on different HV designs. So far the only one I've come across that is isolated is Figure 50 of LT Application Note 29 (https://www.analog.com/media/en/technical-documentation/application-notes/an29f.pdf). It is specified for 1000V, 5W so not beefy enough. The transformer is also obsolete, but this comment mentions potential replacements. https://groups.google.com/d/msg/sci.electronics.design/F120QpxWWkc/74ljdPZ_BQAJ
>>>>>
>>>>> There's also this design (https://www.edn.com/1-kv-power-supply-produces-a-continuous-arc/) that is 1kV, 20W. I just don't know enough about making it adjustable and isolated.
>>>>>
>>>>> Thoughts on how to proceed?
>>>>
>>>> If you are going to try building it yourself, then I'd start with the
>>>> 500V 5 mA one first.  I built my first flyback with the LT3083,
>>>>
>>>> (2018... thread here
>>>> https://groups.google.com/forum/?fromgroups=&hl=en#!searchin/sci.electronics.design/my$20first$20flyback%7Csort:date/sci.electronics.design/FQAIY1VaYBY/mLvGKJC2AgAJ
>>>>
>>>> Good luck.  Oh buying a ready made HV supply would be a good thing.
>>>> Gives you something to compare to if/when you have problems putting
>>>> to whole system together.
>>>>
>>>> George H.
>>>>
>>>
>>> Yep. OP did not like that I disparaged/was skeptical of his plan to
>>> build a 20 watt 1000 volt converter out of the gate but it strikes me as
>>> a certain kind of madness as a first project if OP has not designed and
>>> built a flyback of any type before.
>> 
>> Just different numbers. Shouldn't be really hard.
>> 
>
>The Thor rocket was just sort of a scaled-up kerosene burning V2:
>
><https://www.youtube.com/watch?v=WYrrVHPur2Y>


OK, my bad. It would be really hard for you.



-- 

John Larkin         Highland Technology, Inc

Science teaches us to doubt.

  Claude Bernard
  

On Wednesday, July 22, 2020 at 11:43:32 PM UTC+10, jla...@highlandsniptechnology.com wrote:
> On Wed, 22 Jul 2020 06:08:26 -0700 (PDT), Matt B
> <matt.blessinger@gmail.com> wrote:
> 
> >On Tuesday, July 21, 2020 at 10:32:47 PM UTC-5, jla...@highlandsniptechnology.com wrote:

<snip>

> >On Tuesday, July 21, 2020 at 10:40:31 PM UTC-5, Bill Sloman wrote:
> >> http://www.sophia-electronica.com/Baxandall_parallel-resonant_Class-D_oscillator1.htm 
> >> 
> >> has a circuit for a high-voltage output inverter at the bottom of the page, which relies on pulse with modulation to adjust the output voltage. 
> >> 
> >> It's strictly an LTSpice simulation, the output voltage goes higher than you need, and the power levels are for biasing a photomultiplier tube and lower than you want. 
> >> 
> >> A bigger transformer, with room for thicker wire would fix most of that - you would also need a higher voltage MOSFET switch - 24V into the centre tap of a Baxanadall class oscillator produces a 75.4V peak half-sine across the MOSFET that is off, and the AP9465GEM is only good for 40V. 
> >> 
> >> The NXP BUK9Y72-80E might do. 
> >> 
> >> http://www.farnell.com/datasheets/1705544.pdf 
> >
> >I'll simulate this one as well and read up on Baxandall oscillators more. Interesting that this design was never built; I'm sure I would find a way to produce some fireworks.
> 
> Oh, Bill doesn't ever build things. He's only here to manufacture
> insults.

Not strictly true. I don't flatter John Larkin with the enthusiasm that John Larkin feels he deserves, but that isn't - of itself - insulting.

I haven't built anything recently, but I haven't been able to find people who needed stuff built. I've certainly posted LTSpice simulations that probably would have worked if they had been built, but John Larkin doesn't count them.

-- 
Bill Sloman, Sydney

On 7/22/2020 10:01 PM, jlarkin@highlandsniptechnology.com wrote:
> On Wed, 22 Jul 2020 19:18:54 -0400, bitrex <user@example.net> wrote:
> 
>> On 7/22/2020 5:23 PM, John Larkin wrote:
>>> On Wed, 22 Jul 2020 12:24:10 -0400, bitrex <user@example.net> wrote:
>>>
>>>> On 7/22/2020 10:21 AM, George Herold wrote:
>>>>> On Tuesday, July 21, 2020 at 6:51:49 PM UTC-4, Matt B wrote:
>>>>>> I need to make a 24V to 500-1000V, 20W adjustable power supply for a pulser. It needs to be a floating or negative converter.
>>>>>>
>>>>>> My specs are:
>>>>>> Input: 24-28V
>>>>>> Output voltage: 500-1000V adjustable via control signal
>>>>>> Output current: 10mA @ 500V (5W), 20mA @ 1000V (20W)
>>>>>>
>>>>>> I've been reading through threads on different HV designs. So far the only one I've come across that is isolated is Figure 50 of LT Application Note 29 (https://www.analog.com/media/en/technical-documentation/application-notes/an29f.pdf). It is specified for 1000V, 5W so not beefy enough. The transformer is also obsolete, but this comment mentions potential replacements. https://groups.google.com/d/msg/sci.electronics.design/F120QpxWWkc/74ljdPZ_BQAJ
>>>>>>
>>>>>> There's also this design (https://www.edn.com/1-kv-power-supply-produces-a-continuous-arc/) that is 1kV, 20W. I just don't know enough about making it adjustable and isolated.
>>>>>>
>>>>>> Thoughts on how to proceed?
>>>>>
>>>>> If you are going to try building it yourself, then I'd start with the
>>>>> 500V 5 mA one first.  I built my first flyback with the LT3083,
>>>>>
>>>>> (2018... thread here
>>>>> https://groups.google.com/forum/?fromgroups=&hl=en#!searchin/sci.electronics.design/my$20first$20flyback%7Csort:date/sci.electronics.design/FQAIY1VaYBY/mLvGKJC2AgAJ
>>>>>
>>>>> Good luck.  Oh buying a ready made HV supply would be a good thing.
>>>>> Gives you something to compare to if/when you have problems putting
>>>>> to whole system together.
>>>>>
>>>>> George H.
>>>>>
>>>>
>>>> Yep. OP did not like that I disparaged/was skeptical of his plan to
>>>> build a 20 watt 1000 volt converter out of the gate but it strikes me as
>>>> a certain kind of madness as a first project if OP has not designed and
>>>> built a flyback of any type before.
>>>
>>> Just different numbers. Shouldn't be really hard.
>>>
>>
>> The Thor rocket was just sort of a scaled-up kerosene burning V2:
>>
>> <https://www.youtube.com/watch?v=WYrrVHPur2Y>
> 
> 
> OK, my bad. It would be really hard for you.
> 
> 
> 

Mooom, Mr. Larkin's trying to peer pressure me again. He say he's bad!

<https://youtu.be/Sd4SJVsTulc?t=516>