Skin effect, if you will. QED? Bill Hargin > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx=20 > [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Todd=20 > Westerhoff (twesterh) > Sent: Thursday, October 20, 2005 10:56 AM > To: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] Re: Transmission lines reflections again >=20 > You see? >=20 > Good signal integrity =3D3D=3D3D good skin tones. >=20 > Q.E.D. >=20 > Todd ;-) >=20 >=20 > Todd Westerhoff > High Speed Design Group Manager > Cisco Systems > 1414 Massachusetts Ave - Boxboro, MA - 01719 email:twesterh@xxxxxxxxx > ph: 978-936-2149 > = =3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D= 3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3 D=3D3D=3D3D=3D3D=3D3D=3D > = =3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D= 3D=3D3D=3D3D=3D3D=3D3D > =3D20 > "Always do right. > This will gratify some people and astonish the rest." > =3D20 > - Mark Twain >=20 >=20 > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx=20 > [mailto:si-list-bounce@xxxxxxxxxxxxx] > On Behalf Of Tom Biggs > Sent: Wednesday, October 19, 2005 2:50 PM > To: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] Re: Transmission lines reflections again >=20 > Interesting thing is, lots of Olympic pools are designed to=20 > 'impedence match' at the sides (with water-level gutters) to=20 > reduce reflected waves. Also, the racing lanes have floats=20 > that are designed to act as resistances to reduce lane-to-lane waves. >=20 > -tom >=20 > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx=20 > [mailto:si-list-bounce@xxxxxxxxxxxxx] > On Behalf Of Muranyi, Arpad > Sent: Wednesday, October 19, 2005 11:19 AM > To: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] Re: Transmission lines reflections again >=20 >=20 > Leonard, >=20 > This is not a direct answer to your specific question, but I=20 > hope it helps... >=20 > If you are a visual person, you can explain it to yourself by=20 > imagining what happens when you pour water into one end of a=20 > long narrow channel, like a gutter under your roof. >=20 > The water will flow to the other end, and when it hits the=20 > closing wall, it splashes up. Why? > There is nowhere to go. Imagine what happens when the end=20 > wall is missing? It flows straight out with the levels=20 > lowering down to its bottom. > What if the impedance is matched, i.e. you have an identical=20 > channel filled with the same amount of water in it? The=20 > water wave in your first channel will propagate nicely into=20 > the second channel without splashes... >=20 > Arpad Muranyi > Intel Corporation > = =3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D= 3D3D3 D=3D3D3D3D=3D3D=3D > 3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3 > D=3D3D > = 3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3= D=3D3D3D3D > =3D3D3D3D=3D3D3D > = =3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D= 3D3D3 D=3D3D3D3D=3D3D=3D > 3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3 > D=3D3D > = 3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3D=3D3D3D3= D=3D3D3D3D >=20 > =3D3D3D20 >=20 > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx=20 > [mailto:si-list-bounce@xxxxxxxxxxxxx] > =3D3D3D On Behalf Of Leonard Alexman > Sent: Wednesday, October 19, 2005 10:54 AM > To: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] Transmission lines reflections again >=20 >=20 > Hi , >=20 > I am still trying to figure out how in a simple open=20 > transmission line =3D =3D3D =3D3D3D the voltage gets doubled at the=20 > end of the line. I have seen the formulas =3D3D3D and rope=20 > drawings but only found one article that kind of goes into=20 > what I =3D3D3D what. >=20 > The article I read had a battery connected to a serries50 ohm=20 > resistor =3D =3D3D =3D3D3D and a 50 ohm transmission line. The=20 > equivelant circuit of the transmission linsmission line is a=20 > series inductor with a capacitor to the return =3D3D3D path to=20 > the battery When the last capacitor in the =3D line =3D3D is=20 > charged, there is no voltage =3D3D3D across the last inductor=20 > and current =3D3D flow through the last inductor stops. With=20 > =3D3D3D no current =3D flow to maintain =3D3D it, the magnetic=20 > field in the last inductor collapses =3D and forces current to=20 > continue to flow in the same direction =3D3D3D into the last = capacitor. > Because the direction of current has not changed, =3D3D3D the=20 > capacitor charges in the same direction, thereby increasing=20 > the charge =3D3D3D in =3D the capacitor. Since the energy in the=20 > magnetic field equals the energy =3D =3D3D3D =3D3D in the=20 > capacitor, the energy transfer to the capacitor doubles the=20 > voltage across the capacitor. The last capacitor is now=20 > charged to the battery voltage and the current in the last=20 > inductor drops to zero. >=20 > My question is=3D3D3D20 >=20 > 1. Since the second to the last cap is charged to 1/2 the=20 > battery =3D3D3D voltage where does the current flow from the=20 > left end of the last inductor to =3D3D3D the bottom of the last=20 > cap in order to double the =3D3D voltage on the last cap ? >=20 > Can anyone point me to an article that explains the above in detail ? >=20 > Leonard Alexman > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field >=20 > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list >=20 > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >=20 > List FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ >=20 > List technical documents are available at: > http://www.si-list.org >=20 > List archives are viewable at: =3D3D20 > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > =3D3D20 >=20 > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field >=20 > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list >=20 > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >=20 > List FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ >=20 > List technical documents are available at: > http://www.si-list.org >=20 > List archives are viewable at: =3D20 > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > =3D20 > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field >=20 > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list >=20 > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >=20 > List FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ >=20 > List technical documents are available at: > http://www.si-list.org >=20 > List archives are viewable at: =20 > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > =20 >=20 >=20 ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu