Input rectifier cap
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From: JosephKK on 13 Jun 2010 21:26 On Thu, 10 Jun 2010 07:48:50 +1000, Grant <omg(a)grrr.id.au> wrote: >On Wed, 09 Jun 2010 12:27:34 -0400, Hammy <spam(a)spam.com> wrote: > >>On Thu, 10 Jun 2010 01:05:03 +1000, Grant <omg(a)grrr.id.au> wrote: >> >> >>>>There's no way that the commercial SMPS's I've looked at are using the >>>>105C rms rateing to select the input cap. Most I've taken apart have >>>>either one cap or two in series for a switch doubler including the >>>>350W SMPS powering my computer. They must be increasing the rms >>>>handling capability of a cap based on a reduced operating temperature >>>>then the 105C specified in the datasheet. >>> >>>A lot of them only want 12 months life -- don't care what happens after >>>warranty expires :( >> >>Mine has been going for 8yrs now. I doubt it could deliver 350W >>continuous power. >> >>I also noticed with mine when cleaning it , it has no Common mode >>choke!! This explained why a TV operating off the same line would get >>snowy when the PC was on simultaneously. Oddly enough it has all these >>regulatory approval stickers and it's a Antec supposedly. >> >>>>Basso's book mentions a multiplier for determining max rms current for >>>>reduced operating temperature. I've looked at several datasheets for >>>>caps and haven't seen one. Is there a rule of thumb? Also is there a >>>>reasonable estimate for including the converters high frequency rms >>>>contribution to the capacitor? >>> >>>Odd you don't have datasheet numbers for this, it was on datasheets >>>I looked at a few weeks ago. Look for a table of multipliers buried >>>in the details, the tables are small, perhaps easy to miss? >> >>Your right it is there. I can double the rms current for 70C ambient. >>I always thought the 105C specification was for core temperature not >>ambient. I have been grossly derateing my caps! Oh well live and >>learn. :-) >> >>>An example. Recently I worked through ripple current adjusted for >>>both temp. and frequency for two different brands of caps and the >>>multipliers are a little different. These are 85'C caps. >>> >>>I built a bank of caps for about 600A ripple current for <45'C, but >>>it's down to about 350A at 85'C (~500A at 60), bank is 20 x 10mF/50 >>>plus 60 x 4700/50. >> >>Christ what's it for an industrial egg friar. ;-) > >A small Splat! (stored energy) welder, only ~25 Ws max. Built for >occasional use with the cheapest caps I could find ;) Yet to make the >power dump switch, I'm thinking 16 x 75A MOSFETs in parallel might >survive the experience, otherwise I could play safe and use a big >stud mounted SCR I got in a box here. > >Grant. <snip> Dunno, that might be in the hockey puck range of SCRs.
From: Grant on 13 Jun 2010 23:38 On Sun, 13 Jun 2010 18:26:15 -0700, "JosephKK"<quiettechblue(a)yahoo.com> wrote: >On Thu, 10 Jun 2010 07:48:50 +1000, Grant <omg(a)grrr.id.au> wrote: > .... >>A small Splat! (stored energy) welder, only ~25 Ws max. Built for >>occasional use with the cheapest caps I could find ;) Yet to make the >>power dump switch, I'm thinking 16 x 75A MOSFETs in parallel might >>survive the experience, otherwise I could play safe and use a big >>stud mounted SCR I got in a box here. >> >>Grant. ><snip> > >Dunno, that might be in the hockey puck range of SCRs. Okay, I hope the friend with the stud SCRs still got some hockey puck ones I didn't imagine ever wanting ;) Grant. -- http://bugs.id.au/
From: Michael A. Terrell on 14 Jun 2010 02:46 JosephKK wrote: > > On Fri, 11 Jun 2010 19:01:23 -0400, Hammy <spam(a)spam.com> wrote: > > >On Fri, 11 Jun 2010 18:27:59 -0400, Hammy <spam(a)spam.com> wrote: > > > >For the record I do have JRE installed and it still doesn't work with > >FF, it does work with IE. > > > >They do recommend using either IE or Netscape for the tool. The site > >does however claim to be compatible with FF. > > Geez, Netscape "died" many years ago. What is in their heads? It did? Then I've not posted anything in many years. -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge.
From: JosephKK on 15 Jun 2010 01:39 On Mon, 14 Jun 2010 02:46:36 -0400, "Michael A. Terrell" <mike.terrell(a)earthlink.net> wrote: > >JosephKK wrote: >> >> On Fri, 11 Jun 2010 19:01:23 -0400, Hammy <spam(a)spam.com> wrote: >> >> >On Fri, 11 Jun 2010 18:27:59 -0400, Hammy <spam(a)spam.com> wrote: >> > >> >For the record I do have JRE installed and it still doesn't work with >> >FF, it does work with IE. >> > >> >They do recommend using either IE or Netscape for the tool. The site >> >does however claim to be compatible with FF. >> >> Geez, Netscape "died" many years ago. What is in their heads? > > > It did? Then I've not posted anything in many years. And i am replying to an imaginary post. It is not so much that people don't keep it running, but that there has been no support for years (other than switching to seamonkey or perhaps firefox & thunderbird).
From: Michael A. Terrell on 15 Jun 2010 10:57
JosephKK wrote: > > On Mon, 14 Jun 2010 02:46:36 -0400, "Michael A. Terrell" > <mike.terrell(a)earthlink.net> wrote: > > > > >JosephKK wrote: > >> > >> On Fri, 11 Jun 2010 19:01:23 -0400, Hammy <spam(a)spam.com> wrote: > >> > >> >On Fri, 11 Jun 2010 18:27:59 -0400, Hammy <spam(a)spam.com> wrote: > >> > > >> >For the record I do have JRE installed and it still doesn't work with > >> >FF, it does work with IE. > >> > > >> >They do recommend using either IE or Netscape for the tool. The site > >> >does however claim to be compatible with FF. > >> > >> Geez, Netscape "died" many years ago. What is in their heads? > > > > > > It did? Then I've not posted anything in many years. > > And i am replying to an imaginary post. > > It is not so much that people don't keep it running, but that there has > been no support for years (other than switching to seamonkey or perhaps > firefox & thunderbird). I have both Firefox and Seamonkey running right now. The only problem with the old Netscape is that it chokes on today's bloated web pages. -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge. |