On Tue, 17 Apr 2018 09:51:16 -0700 (PDT), George Herold <gherold@teachspin.com> wrote:>On Tuesday, April 17, 2018 at 11:29:19 AM UTC-4, John Larkin wrote: >> On Tue, 17 Apr 2018 07:09:07 -0700 (PDT), George Herold >> <gherold@teachspin.com> wrote: >> >> >On Tuesday, April 17, 2018 at 8:58:07 AM UTC-4, bill....@ieee.org wrote: >> >> On Tuesday, April 17, 2018 at 4:01:17 PM UTC+10, Jasen Betts wrote: >> >> > On 2018-04-16, George Herold <gherold@teachspin.com> wrote: >> >> > >> >> > > I started here, (of course) >> >> > > http://www.analog.com/media/en/technical-documentation/application-notes/AN118fb.pdf >> >> > > Figure 13 looked nice. I then priced a pico 32195 transformer. >> >> > > ~$100! Ouch! (maybe I can find a cheaper one.) >> >> > >> >> > that should be possible PC powersupplies have one for stepping about 350V down to >> >> > 5V at about 2-10W as do many wall-warts. these transformers can be run in reverse. >> >> > >> >> > digikey has a bunch of transformwers for a few bucks each >> >> > https://www.digikey.com/products/en/inductors-coils-chokes/arrays-signal-transformers/73 >> >> > dunno why they call them sifnal transformers. the parameters are series >> >> > and parallel incuctance, but if you havce a spice parameters for the part >> >> > you want you can probably find a close match using those numbers. >> >> > >> >> > > Oh over the weekend I was thinking about making a C-W generator, >> >> > > (mostly because I always wanted to.) I was going to make my own >> >> > > oscillator ~10-100 kHz, boost the voltage with a transformer >> >> > > and send it into a CW network. Sounds fun, but a lot of work. >> >> > >> >> > Yeah, for C-W you need a symmetrical output like Baxandall, if you >> >> > just want to step up you can use a flyback converter which is simpler. >> >> >> >> The regular Baxandall circuit always produces a sine wave with a couple of percent of harmonic content. I've got a less efficient version - 50% rather than 95% - where the harmonic content can be a couple of orders of magnitude lower. >> >> >> >> -- >> >> Bill Sloman, Sydney >> > >> >Yeah I've mostly given up the C-W dream for now. At ~300V it looks like >> >a flyback is a cheaper/ easier option. >> > >> >George h. >> >> It would be fun to make a big CW, like a megavolt or something. A >> string of cheap PC boards could do that. >> >I'm not sure what you mean by a string of PC boards. >I've got this guys book, where he makes a 250 kV C-W. >http://www.diyphysics.com/2012/02/09/d-i-y-250-kv-high-voltage-dc-power-supply-with-neat-trick-for-switching-polarity/#more-614 > >I think you need to start worrying about x-rays at those voltages.Make a little PC board like his, 50 KV or so. Then string a bunch in series. Maybe battery power each one... a long pure CW string gets messy because of all the capacitors in series. I want to buy a lot of doorknob capacitors, charge them one at a time to 30 KV, and poke them into a plastic pipe, in series. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
300V power supply.
Started by ●April 16, 2018
Reply by ●April 17, 20182018-04-17
Reply by ●April 17, 20182018-04-17
>I want to buy a lot of doorknob capacitors, charge them one at a time >to 30 KV, and poke them into a plastic pipe, in series.Make sure the pipe is full of transformer oil. ;) Cheers Phil Hobbs
Reply by ●April 18, 20182018-04-18
John Larkin wrote: [Snip!]> > Make a little PC board like his, 50 KV or so. Then string a bunch in > series. Maybe battery power each one... a long pure CW string gets > messy because of all the capacitors in series. > > I want to buy a lot of doorknob capacitors, charge them one at a time > to 30 KV, and poke them into a plastic pipe, in series. > >Erwin Otto Marx used to do something like that. Jeroen Belleman
Reply by ●April 18, 20182018-04-18
"Jeroen Belleman" <jeroen@nospam.please> wrote in message news:pb6op4$odr$1@gioia.aioe.org...>> I want to buy a lot of doorknob capacitors, charge them one at a time >> to 30 KV, and poke them into a plastic pipe, in series. >> >> > > Erwin Otto Marx used to do something like that. >Marxist. Shocking. Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: https://www.seventransistorlabs.com/
Reply by ●April 18, 20182018-04-18
On 16/04/2018 18:49, George Herold wrote:> Hi all, So I'd like to make a 300 V supply. I don't really want to start from > the AC line. So I've been looking for a DC-DC converter solution. > > I started here, (of course) > http://www.analog.com/media/en/technical-documentation/application-notes/AN118fb.pdf > Figure 13 looked nice. I then priced a pico 32195 transformer. > ~$100! Ouch! (maybe I can find a cheaper one.) > > I then was trolling Linear Tech/ Analog Dev. What I mostly found was a > line of Xenon lamp charges. > LT3420 > LT3468 > LT3484 > LT3485 > LT3585 > LT3750 > > I haven't delved into the spec sheets, but the LT3420 looks like > it will work. > > Any advice on any of these parts or other ideas is welcome. > > Oh over the weekend I was thinking about making a C-W generator, > (mostly because I always wanted to.) I was going to make my own > oscillator ~10-100 kHz, boost the voltage with a transformer > and send it into a CW network. Sounds fun, but a lot of work. > > Oh finally I can buy DC-DC converters from pico electronics for > ~$100. > https://www.picoelectronics.com/high-voltage-low-power-dc-dc-converters > > TIA > George H. > >If efficiency and board area are not an issue and you are pushed for design time then using mains power transformers "backwards" is an easy option. SMPS flyback types or even plain ol' laminated 50/60Hz. Since your output current need is low I think a voltage doubler rectifier could be useful. Sometimes a low switching frequency is easier to cope with from a noise/EMI p.o.v. piglet
Reply by ●April 18, 20182018-04-18
Tim Williams wrote:> "Jeroen Belleman" <jeroen@nospam.please> wrote in message > news:pb6op4$odr$1@gioia.aioe.org... >>> I want to buy a lot of doorknob capacitors, charge them one at a time >>> to 30 KV, and poke them into a plastic pipe, in series. >>> >>> >> >> Erwin Otto Marx used to do something like that. >> > > Marxist.That was Karl.> > Shocking.Yes. Jeroen Belleman
Reply by ●April 18, 20182018-04-18
On Wed, 18 Apr 2018 08:32:05 +0200, Jeroen Belleman <jeroen@nospam.please> wrote:>John Larkin wrote: > >[Snip!] > >> >> Make a little PC board like his, 50 KV or so. Then string a bunch in >> series. Maybe battery power each one... a long pure CW string gets >> messy because of all the capacitors in series. >> >> I want to buy a lot of doorknob capacitors, charge them one at a time >> to 30 KV, and poke them into a plastic pipe, in series. >> >> > >Erwin Otto Marx used to do something like that. > >Jeroen BellemanI invented one topology that Phil called the Groucho Marx Generator. -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●April 18, 20182018-04-18
On Wednesday, April 18, 2018 at 5:37:27 PM UTC+10, Tim Williams wrote:> "Jeroen Belleman" <jeroen@nospam.please> wrote in message > news:pb6op4$odr$1@gioia.aioe.org... > >> I want to buy a lot of doorknob capacitors, charge them one at a time > >> to 30 KV, and poke them into a plastic pipe, in series. > >> > >> > > > > Erwin Otto Marx used to do something like that. > > > > Marxist. > > Shocking.Je suis Marxiste, tendance Groucho ... from the 1968 student unrest in Paris. Erwin Otto Marx doesn't seem to have member of Karl Marx's family (one of Karl Marx cousins set up Philips Electrical in the Netherlands, though it was the founder's sons who were the famous Philips brothers, so there is an electrical connection there) or related to any of the Marx brothers. You'll have to settle for being electrically rather than politically shocked. -- Bill Sloman, Sydney
Reply by ●April 18, 20182018-04-18
"Jeroen Belleman" <jeroen@nospam.please> wrote in message news:pb7ccq$1phr$1@gioia.aioe.org...> That was Karl. >No, that was Otto. The pun is in making the temporary redefinition. And now I've killed it. I hope you're happy. :^) Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: https://www.seventransistorlabs.com/
Reply by ●April 18, 20182018-04-18
On Wed, 18 Apr 2018 02:36:55 -0500, "Tim Williams" <tiwill@seventransistorlabs.com> wrote:>"Jeroen Belleman" <jeroen@nospam.please> wrote in message >news:pb6op4$odr$1@gioia.aioe.org... >>> I want to buy a lot of doorknob capacitors, charge them one at a time >>> to 30 KV, and poke them into a plastic pipe, in series. >>> >>> >> >> Erwin Otto Marx used to do something like that. >> > >Marxist. > >Shocking.I thought Marxist Generators were colleges and universities.
