For a pure sinusoid, the effects of an inverter and of a 180 degree phase shift are indistinguishable. I lay the burden upon anyone who maintains that "indistinguishable" means "the same thing" to explain whether the phase shift is positive or negative, and to reconcile the behavior of transients in inverters and diode ring modulators. I apologize to all who may believe that this is a troll. It may be indistinguishable, but it's not the same thing. :-) Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
How does an inverter affect phase?
Started by ●June 15, 2006
Reply by ●June 15, 20062006-06-15
Jerry Avins wrote:> For a pure sinusoid, the effects of an inverter and of a 180 > degree phase shift are indistinguishable. I lay the burden upon > anyone who maintains that "indistinguishable" means "the same > thing" to explain whether the phase shift is positive or > negativeI consider that semantic curiosity an artifact of talking about a toroidal domain, something we don't have native terminology for, in terms of linear intervals.> and to reconcile the behavior of transients in > inverters and diode ring modulators.Doing the same thing on one level needn't make two systems indistinguishable on another ;)> I apologize to all who may believe that this is a troll. It may > be indistinguishable, but it's not the same thing. :-)Can you distinguish whether I'm augmenting this post with a sig or justifying sending the sig with a post? Does it come down to the same thing? Martin -- Sufficiently encapsulated magic is indistinguishable from technology.
Reply by ●June 16, 20062006-06-16
The bit about whether it is + or -180 degrees. Well if you design a positive 180 degrees circuit (that has no amplitude variations). I would use it as a phase advance in every servo in the world. ie if we had a phase margin of -5degrees and we put your circuit in then it would be perfectly stable with a phase margin of +180-5 degrees! The fact that an inverter would make things worse is testament to the fact that it has to be -180 degrees phase shift. M.P "Jerry Avins" <jya@ieee.org> wrote in message news:mMCdnbE7gOsqTQzZnZ2dnUVZ_rKdnZ2d@rcn.net...> For a pure sinusoid, the effects of an inverter and of a 180 degree > phase shift are indistinguishable. I lay the burden upon anyone who > maintains that "indistinguishable" means "the same thing" to explain > whether the phase shift is positive or negative, and to reconcile the > behavior of transients in inverters and diode ring modulators. > > I apologize to all who may believe that this is a troll. It may be > indistinguishable, but it's not the same thing. :-) > > Jerry > -- > Engineering is the art of making what you want from things you can get. > �����������������������������������������������������������������������-- Posted via a free Usenet account from http://www.teranews.com
Reply by ●June 16, 20062006-06-16
Jerry Avins wrote:> For a pure sinusoid, the effects of an inverter and of a 180 degree > phase shift are indistinguishable. I lay the burden upon anyone who > maintains that "indistinguishable" means "the same thing" to explain > whether the phase shift is positive or negative, and to reconcile the > behavior of transients in inverters and diode ring modulators.This reminds me of a hilarious post by Mr. Max Hauser: http://groups.google.com/group/comp.dsp/msg/5580413aa4ebb94f> > I apologize to all who may believe that this is a troll. It may be > indistinguishable, but it's not the same thing. :-)Trolling needn't be a bad thing, I sometimes do it as well. Regards, Andor
Reply by ●June 16, 20062006-06-16
Martin Eisenberg wrote: ...> Martin > > -- > Sufficiently encapsulated magic is > indistinguishable from technology.Neat! Your idea?
Reply by ●June 16, 20062006-06-16
Andor wrote:>> Sufficiently encapsulated magic is >> indistinguishable from technology. > > Neat! Your idea?I wish... Martin -- Quidquid latine scriptum sit, altum viditur.
Reply by ●June 17, 20062006-06-17
Mad Prof wrote:> The bit about whether it is + or -180 degrees. > > Well if you design a positive 180 degrees circuit (that has no amplitude > variations). I would use it as a phase advance in every servo in the world. > ie if we had a phase margin of -5degrees and we put your circuit in then it > would be perfectly stable with a phase margin of +180-5 degrees! The fact > that an inverter would make things worse is testament to the fact that it > has to be -180 degrees phase shift. > > > M.P > > "Jerry Avins" <jya@ieee.org> wrote in message > news:mMCdnbE7gOsqTQzZnZ2dnUVZ_rKdnZ2d@rcn.net... >> For a pure sinusoid, the effects of an inverter and of a 180 degree >> phase shift are indistinguishable. I lay the burden upon anyone who >> maintains that "indistinguishable" means "the same thing" to explain >> whether the phase shift is positive or negative, and to reconcile the >> behavior of transients in inverters and diode ring modulators. >> >> I apologize to all who may believe that this is a troll. It may be >> indistinguishable, but it's not the same thing. :-)How do you know by looking at the waveform? Suppose an otherwise a perfect sinusoid with a blip near the positive peak went into a <name your color> box, and emerged with the blip near the negative peak. Would you guess that there was a phase shifter in the box? My question was intended to provoke the realization that inversion is not a phase shift of any kind, even though it may sometimes be expedient to call it one. Beware: "If a tail ..." Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●June 17, 20062006-06-17
Mad Prof wrote:> The bit about whether it is + or -180 degrees. > > Well if you design a positive 180 degrees circuit (that has no amplitude > variations). I would use it as a phase advance in every servo in the world. > ie if we had a phase margin of -5degrees and we put your circuit in then it > would be perfectly stable with a phase margin of +180-5 degrees! The fact > that an inverter would make things worse is testament to the fact that it > has to be -180 degrees phase shift. > > > M.P > > "Jerry Avins" <jya@ieee.org> wrote in message > news:mMCdnbE7gOsqTQzZnZ2dnUVZ_rKdnZ2d@rcn.net... >> For a pure sinusoid, the effects of an inverter and of a 180 degree >> phase shift are indistinguishable. I lay the burden upon anyone who >> maintains that "indistinguishable" means "the same thing" to explain >> whether the phase shift is positive or negative, and to reconcile the >> behavior of transients in inverters and diode ring modulators. >> >> I apologize to all who may believe that this is a troll. It may be >> indistinguishable, but it's not the same thing. :-)How do you know by looking at the waveform? Suppose an otherwise a perfect sinusoid with a blip near the positive peak went into a <name your color> box, and emerged with the blip near the negative peak. Would you guess that there was a phase shifter in the box? My question was intended to provoke the realization that inversion is not a phase shift of any kind, even though it may sometimes be expedient to call it one. Beware: "If a tail ..." Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●June 17, 20062006-06-17
Mad Prof wrote:> The bit about whether it is + or -180 degrees. > > Well if you design a positive 180 degrees circuit (that has no amplitude > variations). I would use it as a phase advance in every servo in the world. > ie if we had a phase margin of -5degrees and we put your circuit in then it > would be perfectly stable with a phase margin of +180-5 degrees! The fact > that an inverter would make things worse is testament to the fact that it > has to be -180 degrees phase shift. > > > M.P > > "Jerry Avins" <jya@ieee.org> wrote in message > news:mMCdnbE7gOsqTQzZnZ2dnUVZ_rKdnZ2d@rcn.net... >> For a pure sinusoid, the effects of an inverter and of a 180 degree >> phase shift are indistinguishable. I lay the burden upon anyone who >> maintains that "indistinguishable" means "the same thing" to explain >> whether the phase shift is positive or negative, and to reconcile the >> behavior of transients in inverters and diode ring modulators. >> >> I apologize to all who may believe that this is a troll. It may be >> indistinguishable, but it's not the same thing. :-)How do you know by looking at the waveform? Suppose an otherwise a perfect sinusoid with a blip near the positive peak went into a <name your color> box, and emerged with the blip near the negative peak. Would you guess that there was a phase shifter in the box? My question was intended to provoke the realization that inversion is not a phase shift of any kind, even though it may sometimes be expedient to call it one. Beware: "If a tail ..." Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●June 17, 20062006-06-17
Mad Prof wrote:> The bit about whether it is + or -180 degrees. > > Well if you design a positive 180 degrees circuit (that has no amplitude > variations). I would use it as a phase advance in every servo in the world. > ie if we had a phase margin of -5degrees and we put your circuit in then it > would be perfectly stable with a phase margin of +180-5 degrees! The fact > that an inverter would make things worse is testament to the fact that it > has to be -180 degrees phase shift. > > > M.P > > "Jerry Avins" <jya@ieee.org> wrote in message > news:mMCdnbE7gOsqTQzZnZ2dnUVZ_rKdnZ2d@rcn.net... >> For a pure sinusoid, the effects of an inverter and of a 180 degree >> phase shift are indistinguishable. I lay the burden upon anyone who >> maintains that "indistinguishable" means "the same thing" to explain >> whether the phase shift is positive or negative, and to reconcile the >> behavior of transients in inverters and diode ring modulators. >> >> I apologize to all who may believe that this is a troll. It may be >> indistinguishable, but it's not the same thing. :-)How do you know by looking at the waveform? Suppose an otherwise a perfect sinusoid with a blip near the positive peak went into a <name your color> box, and emerged with the blip near the negative peak. Would you guess that there was a phase shifter in the box? My question was intended to provoke the realization that inversion is not a phase shift of any kind, even though it may sometimes be expedient to call it one. Beware: "If a tail ..." Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
