LT Spice schmitt oscillator
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From: John Larkin on 10 Oct 2009 19:03 On Sun, 11 Oct 2009 00:18:23 +0200, Fred Bartoli <" "> wrote: >John Larkin a �crit : >> On Sat, 10 Oct 2009 08:54:01 -0400, Phil Hobbs >> <pcdhSpamMeSenseless(a)electrooptical.net> wrote: >> >>> John Larkin wrote: >>>> On Fri, 09 Oct 2009 12:05:31 -0700, Joerg <invalid(a)invalid.invalid> >>>> wrote: >>>> >>>>> John Larkin wrote: >>>>>> On Thu, 08 Oct 2009 15:52:29 -0700, Rich Grise <richgrise(a)example.net> >>>>>> wrote: >>>>>> >>>>>>> On Thu, 08 Oct 2009 14:46:34 -0700, John Larkin wrote: >>>>>>> >>>>>>>> Does anybody have a working LT Spice netlist for a simple schmitt >>>>>>>> inverter/R-C oscillator? I tried one using the library schmitt inverter >>>>>>>> and get obscure sim errors, and I don't understand the HELP stuff. >>>>>>>> >>>>>>>> What's the third pin in the corner for? Ground? >>>>>>>> >>>>>>> We don't do homework. ;-P >>>>>>> >>>>>>> Cheers! >>>>>>> Rich >>>>>> I want to make a low-frequency triangle wave, 1 KHz maybe, to FM >>>>>> spread-spectrum a bunch (namely 5) of switching regulators on this >>>>>> board I'm doing, so that they don't leak into the ADC and show up in >>>>>> the eventual FFTs we're going to do and make birdies in the spectra. >>>>>> >>>>>> Neither the amplitude nor the frequency is very critical. An NC7S14M5 >>>>>> running at 3.3 volts will give me about a 0.9 volt p-p triangle. >>>>>> >>>>> Why so expensive? To spread things nicely you'll probably want five >>>>> individual oscillators all running at different and non-correlating >>>>> frequencies. Why not just use one 74HC14 for all of them and then use >>>>> Schmitt inverter #6 for a blinkenlight or something? >>>> 3.7 cents is expensive? >>>> >>>> I thought about splattering them separately, but don't really see any >>>> advantage. Each switcher has one resistor to set its nominal frequency >>>> and one more to set the FM amount. They should be all over the place. >>>> >>>> John >>>> >>> It'll be a lot easier to test with only one oscillator, too. >>> N-dimensional testing spaces are no fun. >>> >>> Cheers >>> >>> Phil Hobbs >> >> There's a logical fallacy, common in things like cryptography, to the >> effect "If I make it so confusing that I can't understand it myself, >> it must become random." This attitude has, literally, sunk fleets. >> >> If I set the base switcher frequencies different, and FM them from the >> same triangle but with different deviations, I doubt that any of them >> will lock. There may be beats and very brief lock-like intervals as >> all five of them are sweeping here and there, but the fallacy does >> include a bit of hidden truth: none of these interactions should make >> spectral lines anything like what I'd have with five CW oscillators. >> >> Aside: I was recently thinking about N-dimensional optimization in >> general and of of the performance of a very complex scientific >> instrument in particular. The particular instrument I'm working on was >> designed by chemists, and has very bad electronics. Adding EEs >> increases N by adding parameters that the chemists never imagined >> existed, or adds some parameters that didn't matter before because >> their effects were buried in noise. So we show up and, in theory, make >> the sweet spot even more difficuly to find than it was when life was >> simpler... 4 more dimensions at least. >> >> This one isn't too bad. I can bench test the system to verify that >> we've sort of spread the switcher lines and fiddle resistors by >> instinct. Then we can do some real samples with the ss on and off, >> just for fun. That doesn't interact with anything else. >> >> Is *anyone* capable of optimizing, or even mildly improving, something >> as complex as a social system? >> > >Hmmm, you mean like bringing democracy to a foreign country? Well, things, even chaotic systems, move if you apply massive sustained force. Germany, Austria, Italy, Japan became peaceful democracies by force. But it takes a lot of force. Minor tinkering can have unpredictable effects. John
From: Joerg on 11 Oct 2009 17:11 John Larkin wrote: > On Sun, 11 Oct 2009 00:18:23 +0200, Fred Bartoli <" "> wrote: > >> John Larkin a �crit : >>> On Sat, 10 Oct 2009 08:54:01 -0400, Phil Hobbs >>> <pcdhSpamMeSenseless(a)electrooptical.net> wrote: >>> >>>> John Larkin wrote: >>>>> On Fri, 09 Oct 2009 12:05:31 -0700, Joerg <invalid(a)invalid.invalid> >>>>> wrote: >>>>> >>>>>> John Larkin wrote: >>>>>>> On Thu, 08 Oct 2009 15:52:29 -0700, Rich Grise <richgrise(a)example.net> >>>>>>> wrote: >>>>>>> >>>>>>>> On Thu, 08 Oct 2009 14:46:34 -0700, John Larkin wrote: >>>>>>>> >>>>>>>>> Does anybody have a working LT Spice netlist for a simple schmitt >>>>>>>>> inverter/R-C oscillator? I tried one using the library schmitt inverter >>>>>>>>> and get obscure sim errors, and I don't understand the HELP stuff. >>>>>>>>> >>>>>>>>> What's the third pin in the corner for? Ground? >>>>>>>>> >>>>>>>> We don't do homework. ;-P >>>>>>>> >>>>>>>> Cheers! >>>>>>>> Rich >>>>>>> I want to make a low-frequency triangle wave, 1 KHz maybe, to FM >>>>>>> spread-spectrum a bunch (namely 5) of switching regulators on this >>>>>>> board I'm doing, so that they don't leak into the ADC and show up in >>>>>>> the eventual FFTs we're going to do and make birdies in the spectra. >>>>>>> >>>>>>> Neither the amplitude nor the frequency is very critical. An NC7S14M5 >>>>>>> running at 3.3 volts will give me about a 0.9 volt p-p triangle. >>>>>>> >>>>>> Why so expensive? To spread things nicely you'll probably want five >>>>>> individual oscillators all running at different and non-correlating >>>>>> frequencies. Why not just use one 74HC14 for all of them and then use >>>>>> Schmitt inverter #6 for a blinkenlight or something? >>>>> 3.7 cents is expensive? >>>>> >>>>> I thought about splattering them separately, but don't really see any >>>>> advantage. Each switcher has one resistor to set its nominal frequency >>>>> and one more to set the FM amount. They should be all over the place. >>>>> >>>>> John >>>>> >>>> It'll be a lot easier to test with only one oscillator, too. >>>> N-dimensional testing spaces are no fun. >>>> >>>> Cheers >>>> >>>> Phil Hobbs >>> There's a logical fallacy, common in things like cryptography, to the >>> effect "If I make it so confusing that I can't understand it myself, >>> it must become random." This attitude has, literally, sunk fleets. >>> >>> If I set the base switcher frequencies different, and FM them from the >>> same triangle but with different deviations, I doubt that any of them >>> will lock. There may be beats and very brief lock-like intervals as >>> all five of them are sweeping here and there, but the fallacy does >>> include a bit of hidden truth: none of these interactions should make >>> spectral lines anything like what I'd have with five CW oscillators. >>> >>> Aside: I was recently thinking about N-dimensional optimization in >>> general and of of the performance of a very complex scientific >>> instrument in particular. The particular instrument I'm working on was >>> designed by chemists, and has very bad electronics. Adding EEs >>> increases N by adding parameters that the chemists never imagined >>> existed, or adds some parameters that didn't matter before because >>> their effects were buried in noise. So we show up and, in theory, make >>> the sweet spot even more difficuly to find than it was when life was >>> simpler... 4 more dimensions at least. >>> >>> This one isn't too bad. I can bench test the system to verify that >>> we've sort of spread the switcher lines and fiddle resistors by >>> instinct. Then we can do some real samples with the ss on and off, >>> just for fun. That doesn't interact with anything else. >>> >>> Is *anyone* capable of optimizing, or even mildly improving, something >>> as complex as a social system? >>> >> Hmmm, you mean like bringing democracy to a foreign country? > > Well, things, even chaotic systems, move if you apply massive > sustained force. Germany, Austria, Italy, Japan became peaceful > democracies by force. But it takes a lot of force. Minor tinkering can > have unpredictable effects. > Yep. That's easily forgotten by the younger generation. Had the US not joined the Allieds many Europeans would now probably forced to perform a particular salute on a daily basis. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: krw on 11 Oct 2009 17:44 On Sun, 11 Oct 2009 14:11:46 -0700, Joerg <invalid(a)invalid.invalid> wrote: >John Larkin wrote: >> On Sun, 11 Oct 2009 00:18:23 +0200, Fred Bartoli <" "> wrote: >> >>> John Larkin a �crit : >>>> On Sat, 10 Oct 2009 08:54:01 -0400, Phil Hobbs >>>> <pcdhSpamMeSenseless(a)electrooptical.net> wrote: >>>> >>>>> John Larkin wrote: >>>>>> On Fri, 09 Oct 2009 12:05:31 -0700, Joerg <invalid(a)invalid.invalid> >>>>>> wrote: >>>>>> >>>>>>> John Larkin wrote: >>>>>>>> On Thu, 08 Oct 2009 15:52:29 -0700, Rich Grise <richgrise(a)example.net> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> On Thu, 08 Oct 2009 14:46:34 -0700, John Larkin wrote: >>>>>>>>> >>>>>>>>>> Does anybody have a working LT Spice netlist for a simple schmitt >>>>>>>>>> inverter/R-C oscillator? I tried one using the library schmitt inverter >>>>>>>>>> and get obscure sim errors, and I don't understand the HELP stuff. >>>>>>>>>> >>>>>>>>>> What's the third pin in the corner for? Ground? >>>>>>>>>> >>>>>>>>> We don't do homework. ;-P >>>>>>>>> >>>>>>>>> Cheers! >>>>>>>>> Rich >>>>>>>> I want to make a low-frequency triangle wave, 1 KHz maybe, to FM >>>>>>>> spread-spectrum a bunch (namely 5) of switching regulators on this >>>>>>>> board I'm doing, so that they don't leak into the ADC and show up in >>>>>>>> the eventual FFTs we're going to do and make birdies in the spectra. >>>>>>>> >>>>>>>> Neither the amplitude nor the frequency is very critical. An NC7S14M5 >>>>>>>> running at 3.3 volts will give me about a 0.9 volt p-p triangle. >>>>>>>> >>>>>>> Why so expensive? To spread things nicely you'll probably want five >>>>>>> individual oscillators all running at different and non-correlating >>>>>>> frequencies. Why not just use one 74HC14 for all of them and then use >>>>>>> Schmitt inverter #6 for a blinkenlight or something? >>>>>> 3.7 cents is expensive? >>>>>> >>>>>> I thought about splattering them separately, but don't really see any >>>>>> advantage. Each switcher has one resistor to set its nominal frequency >>>>>> and one more to set the FM amount. They should be all over the place. >>>>>> >>>>>> John >>>>>> >>>>> It'll be a lot easier to test with only one oscillator, too. >>>>> N-dimensional testing spaces are no fun. >>>>> >>>>> Cheers >>>>> >>>>> Phil Hobbs >>>> There's a logical fallacy, common in things like cryptography, to the >>>> effect "If I make it so confusing that I can't understand it myself, >>>> it must become random." This attitude has, literally, sunk fleets. >>>> >>>> If I set the base switcher frequencies different, and FM them from the >>>> same triangle but with different deviations, I doubt that any of them >>>> will lock. There may be beats and very brief lock-like intervals as >>>> all five of them are sweeping here and there, but the fallacy does >>>> include a bit of hidden truth: none of these interactions should make >>>> spectral lines anything like what I'd have with five CW oscillators. >>>> >>>> Aside: I was recently thinking about N-dimensional optimization in >>>> general and of of the performance of a very complex scientific >>>> instrument in particular. The particular instrument I'm working on was >>>> designed by chemists, and has very bad electronics. Adding EEs >>>> increases N by adding parameters that the chemists never imagined >>>> existed, or adds some parameters that didn't matter before because >>>> their effects were buried in noise. So we show up and, in theory, make >>>> the sweet spot even more difficuly to find than it was when life was >>>> simpler... 4 more dimensions at least. >>>> >>>> This one isn't too bad. I can bench test the system to verify that >>>> we've sort of spread the switcher lines and fiddle resistors by >>>> instinct. Then we can do some real samples with the ss on and off, >>>> just for fun. That doesn't interact with anything else. >>>> >>>> Is *anyone* capable of optimizing, or even mildly improving, something >>>> as complex as a social system? >>>> >>> Hmmm, you mean like bringing democracy to a foreign country? >> >> Well, things, even chaotic systems, move if you apply massive >> sustained force. Germany, Austria, Italy, Japan became peaceful >> democracies by force. But it takes a lot of force. Minor tinkering can >> have unpredictable effects. >> > >Yep. That's easily forgotten by the younger generation. Had the US not >joined the Allieds many Europeans would now probably forced to perform a >particular salute on a daily basis. Stalin wouldn't have been a fun time either.
From: Michael A. Terrell on 12 Oct 2009 01:44
Joerg wrote: > > Yep. That's easily forgotten by the younger generation. Had the US not > joined the Allieds many Europeans would now probably forced to perform a > particular salute on a daily basis. Tell them that on new:aus.electronics -- The movie 'Deliverance' isn't a documentary! |