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DC DC Converter 100V to 10V

Started by panfilero February 7, 2012
On Feb 7, 7:20=A0pm, Tim Wescott <t...@seemywebsite.com> wrote:
> On Tue, 07 Feb 2012 10:35:34 -0800, panfilero wrote: > > can anyone suggest a smps topology or an off the shelf component that > > could convert 100V DC (@ .2A) to 10V DC out? > > > much thanks > > It's an interesting set of assumptions that I'm seeing in the replies to > this. > > Are you doing a onesie hobbyist hack-together, or are you designing a > product? =A0For a onesie hobbyist hack-together, the suggestions about wa=
ll-
> warts (the newer slim-line ones) may be the way to go. > > -- > My liberal friends think I'm a conservative kook. > My conservative friends think I'm a liberal kook. > Why am I not happy that they have found common ground? > > Tim Wescott, Communications, Control, Circuits & Softwarehttp://www.wesco=
ttdesign.com it's a project, a one off type deal but it's gotta be a clean design, there will be no AC involved I only have access to the 100V DC
On Feb 7, 7:20=A0pm, Tim Wescott <t...@seemywebsite.com> wrote:
> On Tue, 07 Feb 2012 10:35:34 -0800, panfilero wrote: > > can anyone suggest a smps topology or an off the shelf component that > > could convert 100V DC (@ .2A) to 10V DC out? > > > much thanks > > It's an interesting set of assumptions that I'm seeing in the replies to > this. > > Are you doing a onesie hobbyist hack-together, or are you designing a > product? =A0For a onesie hobbyist hack-together, the suggestions about wa=
ll-
> warts (the newer slim-line ones) may be the way to go. > > -- > My liberal friends think I'm a conservative kook. > My conservative friends think I'm a liberal kook. > Why am I not happy that they have found common ground? > > Tim Wescott, Communications, Control, Circuits & Softwarehttp://www.wesco=
ttdesign.com I'm currently looking at this chip http://www.linear.com/product/LT3798 seems promising
On Wed, 08 Feb 2012 10:43:13 -0800, panfilero wrote:

> On Feb 7, 7:20&nbsp;pm, Tim Wescott <t...@seemywebsite.com> wrote: >> On Tue, 07 Feb 2012 10:35:34 -0800, panfilero wrote: >> > can anyone suggest a smps topology or an off the shelf component that >> > could convert 100V DC (@ .2A) to 10V DC out? >> >> > much thanks >> >> It's an interesting set of assumptions that I'm seeing in the replies >> to this. >> >> Are you doing a onesie hobbyist hack-together, or are you designing a >> product? &nbsp;For a onesie hobbyist hack-together, the suggestions about >> wall- warts (the newer slim-line ones) may be the way to go. >> >> -- >> My liberal friends think I'm a conservative kook. My conservative >> friends think I'm a liberal kook. Why am I not happy that they have >> found common ground? >> >> Tim Wescott, Communications, Control, Circuits & >> Softwarehttp://www.wescottdesign.com > > I'm currently looking at this chip http://www.linear.com/product/LT3798 > seems promising
It looks to be about the same thing as what I found. The reason I was suggesting a little wall-wart is because that the circuit you see on that web page is -- most likely -- exactly what you'll find inside the wall- wart, and that should work just fine with a DC input. So you can either get the circuit for your one-off by digging through your stash of wall- warts (or Goodwill's), or you can spend much $$ and time designing it yourself. If you want to disguise the "Wall-wartiness" of it, saw the case off of a wall-wart and just use the innards. Or at least the nifty transformer. -- My liberal friends think I'm a conservative kook. My conservative friends think I'm a liberal kook. Why am I not happy that they have found common ground? Tim Wescott, Communications, Control, Circuits & Software http://www.wescottdesign.com
On Feb 8, 1:17=A0pm, Tim Wescott <t...@seemywebsite.com> wrote:
> On Wed, 08 Feb 2012 10:43:13 -0800, panfilero wrote: > > On Feb 7, 7:20=A0pm, Tim Wescott <t...@seemywebsite.com> wrote: > >> On Tue, 07 Feb 2012 10:35:34 -0800, panfilero wrote: > >> > can anyone suggest a smps topology or an off the shelf component tha=
t
> >> > could convert 100V DC (@ .2A) to 10V DC out? > > >> > much thanks > > >> It's an interesting set of assumptions that I'm seeing in the replies > >> to this. > > >> Are you doing a onesie hobbyist hack-together, or are you designing a > >> product? =A0For a onesie hobbyist hack-together, the suggestions about > >> wall- warts (the newer slim-line ones) may be the way to go. > > >> -- > >> My liberal friends think I'm a conservative kook. My conservative > >> friends think I'm a liberal kook. Why am I not happy that they have > >> found common ground? > > >> Tim Wescott, Communications, Control, Circuits & > >> Softwarehttp://www.wescottdesign.com > > > I'm currently looking at this chiphttp://www.linear.com/product/LT3798 > > seems promising > > It looks to be about the same thing as what I found. =A0The reason I was > suggesting a little wall-wart is because that the circuit you see on that > web page is -- most likely -- exactly what you'll find inside the wall- > wart, and that should work just fine with a DC input. =A0So you can eithe=
r
> get the circuit for your one-off by digging through your stash of wall- > warts (or Goodwill's), or you can spend much $$ and time designing it > yourself. > > If you want to disguise the "Wall-wartiness" of it, saw the case off of a > wall-wart and just use the innards. =A0Or at least the nifty transformer. > > -- > My liberal friends think I'm a conservative kook. > My conservative friends think I'm a liberal kook. > Why am I not happy that they have found common ground? > > Tim Wescott, Communications, Control, Circuits & Softwarehttp://www.wesco=
ttdesign.com But since I need this for DC/DC converting, if I try to use a wall wart, wont I have to add an inverter to my circuit ?
On Wed, 08 Feb 2012 11:44:27 -0800, panfilero wrote:

> On Feb 8, 1:17&nbsp;pm, Tim Wescott <t...@seemywebsite.com> wrote: >> On Wed, 08 Feb 2012 10:43:13 -0800, panfilero wrote: >> > On Feb 7, 7:20&nbsp;pm, Tim Wescott <t...@seemywebsite.com> wrote: >> >> On Tue, 07 Feb 2012 10:35:34 -0800, panfilero wrote: >> >> > can anyone suggest a smps topology or an off the shelf component >> >> > that could convert 100V DC (@ .2A) to 10V DC out? >> >> >> > much thanks >> >> >> It's an interesting set of assumptions that I'm seeing in the >> >> replies to this. >> >> >> Are you doing a onesie hobbyist hack-together, or are you designing >> >> a product? &nbsp;For a onesie hobbyist hack-together, the suggestions >> >> about wall- warts (the newer slim-line ones) may be the way to go. >> >> >> -- >> >> My liberal friends think I'm a conservative kook. My conservative >> >> friends think I'm a liberal kook. Why am I not happy that they have >> >> found common ground? >> >> >> Tim Wescott, Communications, Control, Circuits & >> >> Softwarehttp://www.wescottdesign.com >> >> > I'm currently looking at this >> > chiphttp://www.linear.com/product/LT3798 seems promising >> >> It looks to be about the same thing as what I found. &nbsp;The reason I was >> suggesting a little wall-wart is because that the circuit you see on >> that web page is -- most likely -- exactly what you'll find inside the >> wall- wart, and that should work just fine with a DC input. &nbsp;So you can >> either get the circuit for your one-off by digging through your stash >> of wall- warts (or Goodwill's), or you can spend much $$ and time >> designing it yourself. >> >> If you want to disguise the "Wall-wartiness" of it, saw the case off of >> a wall-wart and just use the innards. &nbsp;Or at least the nifty >> transformer. >> >> -- >> My liberal friends think I'm a conservative kook. My conservative >> friends think I'm a liberal kook. Why am I not happy that they have >> found common ground? >> >> Tim Wescott, Communications, Control, Circuits & >> Softwarehttp://www.wescottdesign.com > > But since I need this for DC/DC converting, if I try to use a wall wart, > wont I have to add an inverter to my circuit ?
Look at that transformerless bridge rectifier in the circuit on the page you referenced, and ask yourself "what would happen if I applied a DC voltage to that?". -- My liberal friends think I'm a conservative kook. My conservative friends think I'm a liberal kook. Why am I not happy that they have found common ground? Tim Wescott, Communications, Control, Circuits & Software http://www.wescottdesign.com
"panfilero" <panfilero@gmail.com> wrote in message 
news:ac4b9a0f-aeec-42d6-937c-93660db04dcb@f5g2000yqm.googlegroups.com...
On Feb 8, 1:17 pm, Tim Wescott <t...@seemywebsite.com> wrote:
> On Wed, 08 Feb 2012 10:43:13 -0800, panfilero wrote: > > On Feb 7, 7:20 pm, Tim Wescott <t...@seemywebsite.com> wrote: > >> On Tue, 07 Feb 2012 10:35:34 -0800, panfilero wrote: > >> > can anyone suggest a smps topology or an off the shelf component that > >> > could convert 100V DC (@ .2A) to 10V DC out? > > >> > much thanks > > >> It's an interesting set of assumptions that I'm seeing in the replies > >> to this. > > >> Are you doing a onesie hobbyist hack-together, or are you designing a > >> product? For a onesie hobbyist hack-together, the suggestions about > >> wall- warts (the newer slim-line ones) may be the way to go. > > >> -- > >> My liberal friends think I'm a conservative kook. My conservative > >> friends think I'm a liberal kook. Why am I not happy that they have > >> found common ground? > > >> Tim Wescott, Communications, Control, Circuits & > >> Softwarehttp://www.wescottdesign.com > > > I'm currently looking at this chiphttp://www.linear.com/product/LT3798 > > seems promising > > It looks to be about the same thing as what I found. The reason I was > suggesting a little wall-wart is because that the circuit you see on that > web page is -- most likely -- exactly what you'll find inside the wall- > wart, and that should work just fine with a DC input. So you can either > get the circuit for your one-off by digging through your stash of wall- > warts (or Goodwill's), or you can spend much $$ and time designing it > yourself. > > If you want to disguise the "Wall-wartiness" of it, saw the case off of a > wall-wart and just use the innards. Or at least the nifty transformer. > > -- > My liberal friends think I'm a conservative kook. > My conservative friends think I'm a liberal kook. > Why am I not happy that they have found common ground? > > Tim Wescott, Communications, Control, Circuits & > Softwarehttp://www.wescottdesign.com
But since I need this for DC/DC converting, if I try to use a wall wart, wont I have to add an inverter to my circuit ? vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv Everything after the rectifier/reservoir is DC-DC converter - which is what you want. There are a couple of potential gotcha's though. Firstly if the wall-wart spec says 85 - 260VRMS, the DC-DC converter will be expecting at least 120VDC (multiply 85 by 1.414). Secondly older switchers originally designed for 230VRMS had a voltage doubling arrangement for 110VRMS operation, either a voltage sensing chip + triac or a manually applied link shorts one AC arm of the bridge to the middle connection of a series connected pair of reservoir electrolytics - the voltage doubler won't double DC.