Forums

300V power supply.

Started by George Herold April 16, 2018
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.  
  
On 04/16/2018 01:49 PM, 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. > >
5 bux chip to charge a 220uF cap to 300 volts in the better part of 4 seconds at not much better than probably 70% efficiency in practice is not exactly setting my world on fire here
On 04/16/2018 02:47 PM, bitrex wrote:
> On 04/16/2018 01:49 PM, 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. >> > > 5 bux chip to charge a 220uF cap to 300 volts in the better part of 4 > seconds at not much better than probably 70% efficiency in practice is > not exactly setting  my world on fire here
The whole circuit could be physically small so there's that, but a 220uF 300 volt photoflash cap is gigantic and will take up most of the board space anyway. LT seems obsessed with everything-in-the-chip solutions but at boost ratios like 5-12 volts to 300-350 the on-die switch just hamstrings the thing IMO
On 04/16/2018 01:49 PM, 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. > >
These work quite well for me, u tried these? <https://www.ebay.com/itm/DC-DC-8-32V-to-45-390V-Step-up-Booster-Module-Power-Voltage-Boost-Converter-ZVS/263052186020?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D44039%26meid%3D80a52905231845a19b5c77e4e1fad3fd%26pid%3D100005%26rk%3D3%26rkt%3D9%26sd%3D152787389030%26itm%3D263052186020&_trksid=p2047675.c100005.m1851> Might want to swap out the eletros for some Nichicon or Panasonics
On Monday, April 16, 2018 at 2:56:46 PM UTC-4, bitrex wrote:
> On 04/16/2018 02:47 PM, bitrex wrote: > > On 04/16/2018 01:49 PM, 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.&nbsp; 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.&nbsp; I then priced a pico 32195 transformer. > >> ~$100!&nbsp; Ouch! (maybe I can find a cheaper one.) > >> > >> I then was trolling Linear Tech/ Analog Dev.&nbsp; 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.)&nbsp; 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. > >> > > > > 5 bux chip to charge a 220uF cap to 300 volts in the better part of 4 > > seconds at not much better than probably 70% efficiency in practice is > > not exactly setting&nbsp; my world on fire here > > The whole circuit could be physically small so there's that, but a 220uF > 300 volt photoflash cap is gigantic and will take up most of the board > space anyway. > > LT seems obsessed with everything-in-the-chip solutions but at boost > ratios like 5-12 volts to 300-350 the on-die switch just hamstrings the > thing IMO
This is to bias a APD, not for a photoflash. The spec sheet says it can be used as a HV supply. I've skimmed to spec sheet, but didn't really find anything telling me what to do if I just want it to hold a voltage. I posted a question to the Analog forum... at least I think I did. The lt3750 is a beefier part. George H.
On Monday, April 16, 2018 at 2:59:40 PM UTC-4, bitrex wrote:
> On 04/16/2018 01:49 PM, 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. > > > > > > These work quite well for me, u tried these? > > <https://www.ebay.com/itm/DC-DC-8-32V-to-45-390V-Step-up-Booster-Module-Power-Voltage-Boost-Converter-ZVS/263052186020?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D44039%26meid%3D80a52905231845a19b5c77e4e1fad3fd%26pid%3D100005%26rk%3D3%26rkt%3D9%26sd%3D152787389030%26itm%3D263052186020&_trksid=p2047675.c100005.m1851> > > Might want to swap out the eletros for some Nichicon or Panasonics
No, I'd be afraid to put that in a product. What's the output ripple look like with ~1-2 mA of load? George H.
On Monday, April 16, 2018 at 2:59:40 PM UTC-4, bitrex wrote:
> On 04/16/2018 01:49 PM, 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. > > > > > > These work quite well for me, u tried these? > > <https://www.ebay.com/itm/DC-DC-8-32V-to-45-390V-Step-up-Booster-Module-Power-Voltage-Boost-Converter-ZVS/263052186020?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D44039%26meid%3D80a52905231845a19b5c77e4e1fad3fd%26pid%3D100005%26rk%3D3%26rkt%3D9%26sd%3D152787389030%26itm%3D263052186020&_trksid=p2047675.c100005.m1851> > > Might want to swap out the eletros for some Nichicon or Panasonics
Oh I found this too... maybe more to your liking. http://www.ti.com/tool/PMP8621#technicaldocuments GH
On 04/16/2018 03:13 PM, George Herold wrote:
> On Monday, April 16, 2018 at 2:59:40 PM UTC-4, bitrex wrote: >> On 04/16/2018 01:49 PM, 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. >>> >>> >> >> These work quite well for me, u tried these? >> >> <https://www.ebay.com/itm/DC-DC-8-32V-to-45-390V-Step-up-Booster-Module-Power-Voltage-Boost-Converter-ZVS/263052186020?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D44039%26meid%3D80a52905231845a19b5c77e4e1fad3fd%26pid%3D100005%26rk%3D3%26rkt%3D9%26sd%3D152787389030%26itm%3D263052186020&_trksid=p2047675.c100005.m1851> >> >> Might want to swap out the eletros for some Nichicon or Panasonics > > No, I'd be afraid to put that in a product. What's the output ripple > look like with ~1-2 mA of load? > > George H. >
I'd be happy to take a look for you when I get a chance, in the meantime yeah you definitely don't need 40 watts. I got some "X-ray vision" pics of it that show all the part numbers and stuff, detailed enough to trace a circuit so you could probably do a "spin off" of the design if you like using significantly smaller diodes/switch/xfrmr. It appears to use a 38438 current-mode PWM controller and a RU7088 MOSFET. <https://www.dropbox.com/s/zv98ajowjklbgkj/2018-4-16%2015-12-47.jpg?dl=0> <https://www.dropbox.com/s/7vq5afom7i6pwqk/2018-4-16%2015-10-56.jpg?dl=0>
On Mon, 16 Apr 2018 10:49:40 -0700 (PDT), George Herold
<gherold@teachspin.com> 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.)
Pico is insane. I don't know why anybody buys their stuff. How much current do you want? The lower section of this will do 300 volts. https://www.dropbox.com/s/e3n5af9sw1a1flh/28S840A_3.pdf?raw=1 Just skip the C-W HV stuff. You could also buy some cheap (like $4) DC/DC converter bricks and put the outputs in series. Stack them on top of whatever power rail you already have. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
bitrex wrote...
> > I got some "X-ray vision" pics
Whoa, how'd you take those pictures?
> ... so you could probably do a "spin off" of the design if > you like using significantly smaller diodes/switch/xfrmr.
Hey, lots of stuff for $7, with free shipping. Not all of the eBay sellers add the parts needed for a bipolar output. The transformer is the most valuable part. -- Thanks, - Win