On Fri, 24 Feb 2006 15:21:50 -0800, Padu wrote:> They call me Software Engineer (they call me other names too when they > find bugs in the software, but I doubt you are interested in knowing),Oh, please! Do Tell! Please don't be a tease! ;-P Thanks! Rich -- Elect Me President in 2008! I will: A. Fire the IRS, and abolish the income tax B. Legalize drugs C. Stand down all military actions by the US that don't involve actual military aggression against US territory D. Declare World Peace I.
Closing Control Loops
Started by ●February 24, 2006
Reply by ●February 27, 20062006-02-27
Reply by ●February 27, 20062006-02-27
Tim Wescott wrote:> Paul Carpenter wrote: > >> On Sunday, in article <v5adnZmFqdMffJzZRVn-qA@web-ster.com> >> tim@seemywebsite.com "Tim Wescott" wrote: >> >>> Paul Carpenter wrote: >>> > --snip-- > >>> If you were to write an article about this (beyond "think hard about >>> your problem and deal with sensor failures") I'd be delighted to read >>> it. >> >> >> >> I don't know if I could really class my thoughts and experiences as an >> 'article' (so many different meanings to article as in length and depth >> of content). I could probably summarise a few of the major ones in a >> 'War stories' page sometime. >> >> ..... >> > > War stories would be nice -- particularly of battles won as well as lost. >how about a draw? we recently had a blowup in one of our videoscreens. we use telecomms 48Vdc power supplies, and the one in the burn-in rack failed - the feedback network went open-circuit, it was in the airflow path and not conformally coated, and managed to corrode. Boom, up goes the voltage; it was a 25kW supply. Fortunately they put in a supervisory loop, which shut the power supply down. Unfortunately, it took 10ms to do so. Fortunately I had designed in some kick-ass transient clamping and fusing (nearby lightning strike protection), which protected the circuitry. Unfortunately the over-voltage was such as to limit the current to a value which didnt immediately blow the fuse, and 10ms = eternity as far as junction thermal time constants go, so the TVSs all suicided, thereby snotting the fuses. best not to think about the 16 screws that need to be removed to repair each one.... Fortunately the problem happened in our factory, so the costs associated with removing/dismantling/remantling/replacing all of the modules was minimal. I am now working on a monster clamp, so the same problem doesnt take out a customers $2,000,000 screen :) Cheers Terry
Reply by ●February 27, 20062006-02-27
"Terry Given" <my_name@ieee.org> wrote in message news:1141074304.724496@ftpsrv1...> I am now working on a monster clamp, so the same problem doesnt > take out a customers $2,000,000 screen :)I bet that'd get those shunt-regulating, class-A'ing audiophools drooling. Tim -- Deep Fryer: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms
Reply by ●February 27, 20062006-02-27
On Monday, in article
<MPG.1e6cc8be7a7c6ec798a136@newsgroups.comcast.net>
mborgerson.at.comcast.net "Mark Borgerson" wrote:
>In article <sfp302hpha5kvif9dub3bmj3tsa1tbcnh5@4ax.com>, To-Email-Use-
>The-Envelope-Icon@My-Web-Site.com says...
><<SNIP>>
>> Indeed! Though I don't use the material on any regular basis (*), I
>> had four semesters on non-linear control theory in grad school. Great
>> fun, the real world!
>>
>> (*) Though I recently was involved in a laser beam "wobulator"... a
>> mirror driven by a power amplifier... great fun tuning it up for
>> stability ;-)
>
>Hey, the local paper here (Corvallis Oregon) led me to believe that
>the "wobulator" was a local HP invention to double the resolution
>of their HDTV projection systems. Don't tell me that such a neat
>name actually got applied to more than one system!
I first heard of its use in an article of the early 1970's describing the
BBC Radiophonic Workshop unit's effects box of the late 1960's and early
1970's for distort actors' voices for Dalek characters in the series Dr Who!
--
Paul Carpenter | paul@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/> PC Services
<http://www.gnuh8.org.uk/> GNU H8 & mailing list info
<http://www.badweb.org.uk/> For those web sites you hate
Reply by ●February 27, 20062006-02-27
On Sunday, in article
<SeGdnTmIVPRq95_ZnZ2dnUVZ_tKdnZ2d@centurytel.net>
fmarshallx@remove_the_x.acm.org "Fred Marshall" wrote:
>"Paul Carpenter" <paul$@pcserviceselectronics.co.uk> wrote in message
>
>> "just put a big computer in there that will solve the problem"
>>
>
>I must say that I've had this experience with folks who should have known
>better. When asked: "How are you going to do that?" they would say: "well,
>there will be a computer inside". They had NO idea what they were going to
>do or how they would do it. If the SNR was infinitely low, "well, there
>will be a computer inside".
Reminds me of a cartoon on a Tshirt web site that has a blackboard and a
professeur wanting more detail on step two, bearing in mind the three
steps of maths on the backboard are:-
1. Complicated maths
2. "By a bit of magic we get to"
3. Less complicated maths
I do not have the URL to hand at present.
--
Paul Carpenter | paul@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/> PC Services
<http://www.gnuh8.org.uk/> GNU H8 & mailing list info
<http://www.badweb.org.uk/> For those web sites you hate
Reply by ●February 27, 20062006-02-27
Tim Williams wrote:> "Terry Given" <my_name@ieee.org> wrote in message > news:1141074304.724496@ftpsrv1... > >>I am now working on a monster clamp, so the same problem doesnt >>take out a customers $2,000,000 screen :) > > > I bet that'd get those shunt-regulating, class-A'ing audiophools drooling. > > Timyep. best I wire it with monster cables.... Cheers Terry
Reply by ●February 27, 20062006-02-27
On Mon, 27 Feb 2006 21:27:14 +0000, Paul Carpenter wrote:> On Sunday, in article > <SeGdnTmIVPRq95_ZnZ2dnUVZ_tKdnZ2d@centurytel.net> > fmarshallx@remove_the_x.acm.org "Fred Marshall" wrote: > >>"Paul Carpenter" <paul$@pcserviceselectronics.co.uk> wrote in message >> >>> "just put a big computer in there that will solve the problem" >>> >> >>I must say that I've had this experience with folks who should have known >>better. When asked: "How are you going to do that?" they would say: "well, >>there will be a computer inside". They had NO idea what they were going to >>do or how they would do it. If the SNR was infinitely low, "well, there >>will be a computer inside". > > Reminds me of a cartoon on a Tshirt web site that has a blackboard and a > professeur wanting more detail on step two, bearing in mind the three > steps of maths on the backboard are:- > > > 1. Complicated maths > > 2. "By a bit of magic we get to" > > 3. Less complicated maths > > I do not have the URL to hand at present.Vaguely reminds me of The Underpants Gnomes, on South Park. They would sneak into your room while you're sleeping, and steal your underpants. Their motivation, it was revealed, was Profit. The kids caught the Underpants Gnomes stealing Tweek's underpants, and followed them to the Underpants Gnome cavern. They had a chart much like that: 1. Steal Underpants. 2. 3. Profit. And when anybody asked what step 2 was, they just stood there and looked confused. And after a beat or two, "But, step 3 is Profit!" "Hooray!" Guess you had to be there. :-/ Thanks, Rich -- Elect Me President in 2008! I will: A. Fire the IRS, and abolish the income tax B. Legalize drugs C. Stand down all military actions by the US that don't involve actual military aggression against US territory D. Declare World Peace I.
Reply by ●March 9, 20062006-03-09
Tim Wescott wrote:> Dougal McDougal of that Elk wrote: > >> "Tim Wescott" <tim@seemywebsite.com> wrote in message >> news:EqmdnWnD9PR-z2LenZ2dnUVZ_s2dnZ2d@web-ster.com... >> >>>So, I've put the finishing touches on my book, and the publisher's >>>marketing department is asking me questions. Some of them I don't have >>>good answers to, because (a) I'm on the fringe of my target audience, >>>and (b) everyone learns differently, and my way is through osmosis and >>>thinking, which doesn't make it easy to cough up a bunch of specific >>>information like conferences and magazines. >>> >>>The book's title is "Applied Control Theory for Embedded Systems", the >>>subject should be self explanatory. >> >> >> I hopr you have lest out Nyquist diagrasm and Root Locus. Never seen >> anybody using them on a real design other than academics. >> >> >> Tam >> >> > You should look over my shoulder some time, then. > > I use root locus when I'm brainstorming controllers, and I have my > spreadsheet program display top & bottom Nyquist & Bode plots when I'm > tuning from measured frequency responses -- I put a circle of diameter > 1/sqrt(2) on the Nyquist plot to indicate the 3dB sensitivity point, and > tune to that. > > I _don't_ spend many pages showing how to construct root locus plots -- > while you do learn something from it there's a gazillion math > applications that will do it for you. >Are any of the root locus solvers free? even really cheap? Not much use for one but if i go back to school i do not want have to repeat controls. -- JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens. --Schiller
