voltage divider calcs
in [Design]
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From: oopere on 21 Apr 2010 05:21 John Larkin wrote: > It's easier to use LT Spice to do a simple resistor string voltage > divider analysis than to use a calculator! Much easier if you want to > futz with values to hit some targets. > > Copying the results from the DC analysis window requires highlighting > and ctrl/c to get the text into the clipboard. There's no obvious > "print" or "copy" or "save" things. > > Interesting that Scad3.exe is only 5.4 megabytes. > > > John > > I once used a spreadsheet to print a table of the voltage divider ratios you get combining _two_ values of a resistor series and use it quite often. There has to be some utility around there to automate this for longer strings! Pere
From: John Larkin on 21 Apr 2010 09:56 On Wed, 21 Apr 2010 11:21:36 +0200, oopere <me(a)somewhere.net> wrote: >John Larkin wrote: >> It's easier to use LT Spice to do a simple resistor string voltage >> divider analysis than to use a calculator! Much easier if you want to >> futz with values to hit some targets. >> >> Copying the results from the DC analysis window requires highlighting >> and ctrl/c to get the text into the clipboard. There's no obvious >> "print" or "copy" or "save" things. >> >> Interesting that Scad3.exe is only 5.4 megabytes. >> >> >> John >> >> > >I once used a spreadsheet to print a table of the voltage divider ratios >you get combining _two_ values of a resistor series and use it quite >often. There has to be some utility around there to automate this for >longer strings! > >Pere I have a PowerBasic program (called RUGRAT) that looks at all the resistors that we have in stock. I can specify if 0603/0805/1206 sizes should be included in any combination, then the target ratio and tolerance and range of Thevenin impedances. It then makes a report listing all pairs that fit, their error, and Thevenin impedance. This program has immensely improved my quality of life. Some day maybe I'll include trimpots in various topologies, to help design trim networks. John
From: krw on 23 Apr 2010 21:10 On Fri, 23 Apr 2010 07:47:31 -0400, Rich Webb <bbew.ar(a)mapson.nozirev.ten> wrote: >On Thu, 22 Apr 2010 19:20:56 -0500, "krw(a)att.bizzzzzzzzzzzz" ><krw(a)att.bizzzzzzzzzzzz> wrote: > > >>We're not *quite* that bad. ;-) It was a P4 with XP. Office '07 killed it, >>so they finally bought me a new system. Why they wanted to go to Office '07, >>I'll never figure out. It sucks. > >They probably upgraded for the same reason most people end up doing so: >somebody in the documentation pool (often, where available, in an >administrative support position) upgrades. Everyone else using those >documents discovers that the between-version interoperability just isn't >quite good enough, or is too slow, or doesn't exist at all. So, they >need to upgrade and then the upgrade push gets into *their* >documentation pool, and so it goes. Could be, but I think IT just needed something to do. When they installed Office '07 I sure gave it to them. ...with both barrels. What a POS. >Not that Microsoft ever intended for that to happen, of course. Of course not.
From: Michael A. Terrell on 23 Apr 2010 21:58 "krw(a)att.bizzzzzzzzzzzz" wrote: > > Michael A. Terrell wrote: > > > >Jim Thompson wrote: > >> > >> Michael A. Terrell wrote: > >> > > >> > You can still upgrade your XP computers with new motherboards RAM and > >> >hard drives, but who knows how long before MS drops all support & > >> >updates? > >> > >> Would that be a loss ?:-) > > > > That depends on whether you need a bug fixed. > > Get real. I didn't say that you would get it, just that you'd need it. :) -- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85. Michael A. Terrell Central Florida http://www.flickr.com/photos/materrell/
From: Sjouke Burry on 23 Apr 2010 23:23
Michael A. Terrell wrote: > "krw(a)att.bizzzzzzzzzzzz" wrote: >> Michael A. Terrell wrote: >>> Jim Thompson wrote: >>>> Michael A. Terrell wrote: >>>>> You can still upgrade your XP computers with new motherboards RAM and >>>>> hard drives, but who knows how long before MS drops all support & >>>>> updates? >>>> Would that be a loss ?:-) >>> That depends on whether you need a bug fixed. >> Get real. > > > I didn't say that you would get it, just that you'd need it. :) > > I am still using WIN3.11 for workgroups, have not needed any bugs fixed by M$. You dont need a new or refurbished OS or computer every 2 years. |