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: >> 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.> > >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. -- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
24V to 500-1000V, 20W floating DC-DC converter
Started by ●July 21, 2020
Reply by ●July 22, 20202020-07-22
Reply by ●July 22, 20202020-07-22
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.
Reply by ●July 22, 20202020-07-22
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. 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>
Reply by ●July 22, 20202020-07-22
On 7/22/2020 9:43 AM, jlarkin@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: >>> 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. the answer to how fast it moves is "slow" if that's really what it is and you've got 20 watts
Reply by ●July 22, 20202020-07-22
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 >> <matt.blessinger@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. the answer to how fast it moves is>"slow" if that's really what it is and you've got 20 watts
Reply by ●July 22, 20202020-07-22
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 >>> <matt.blessinger@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.
Reply by ●July 22, 20202020-07-22
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 >>>> <matt.blessinger@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
Reply by ●July 22, 20202020-07-22
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.> > 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>
Reply by ●July 22, 20202020-07-22
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 somethingThe 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.
Reply by ●July 22, 20202020-07-22
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>> >> 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> >
