Interesting thing is, lots of Olympic pools are designed to 'impedence match' at the sides (with water-level gutters) to reduce reflected waves. Also, the racing lanes have floats that are designed to act as resistances to reduce lane-to-lane waves. -tom -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [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 Leonard, This is not a direct answer to your specific question, but I hope it helps... If you are a visual person, you can explain it to yourself by imagining what happens when you pour water into one end of a long narrow channel, like a gutter under your roof. The water will flow to the other end, and when it hits the closing wall, it splashes up. Why? There is nowhere to go. Imagine what happens when the end wall is missing? It flows straight out with the levels lowering down to its bottom. What if the impedance is matched, i.e. you have an identical channel filled with the same amount of water in it? The water wave in your first channel will propagate nicely into the second channel without splashes... Arpad Muranyi Intel Corporation =3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D= 3D=3D3D=3D3D=3D3D=3D3D=3D3D=3D3D=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=3D3D=3D3D=3D3D=3D3D=3D3D =3D20 -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] =3D On Behalf Of Leonard Alexman Sent: Wednesday, October 19, 2005 10:54 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Transmission lines reflections again Hi , I am still trying to figure out how in a simple open transmission line = =3D the voltage gets doubled at the end of the line. I have seen the formulas =3D and rope drawings but only found one article that kind of goes into what I =3D what. The article I read had a battery connected to a serries50 ohm resistor = =3D and a 50 ohm transmission line. The equivelant circuit of the transmission linsmission line is a series inductor with a capacitor to the return =3D path to the battery When the last capacitor in the line = is charged, there is no voltage =3D across the last inductor and current = flow through the last inductor stops. With =3D no current flow to maintain = it, the magnetic field in the last inductor collapses and forces current to continue to flow in the same direction =3D into the last capacitor. Because the direction of current has not changed, =3D the capacitor charges in the same direction, thereby increasing the charge =3D in the capacitor. Since the energy in the magnetic field equals the energy =3D = in the capacitor, the energy transfer to the capacitor doubles the voltage across the capacitor. The last capacitor is now charged to the battery voltage and the current in the last inductor drops to zero. My question is=3D20 1. Since the second to the last cap is charged to 1/2 the battery =3D voltage where does the current flow from the left end of the last inductor to =3D the bottom of the last cap in order to double the = voltage on the last cap ? Can anyone point me to an article that explains the above in detail ? Leonard Alexman ------------------------------------------------------------------ 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: =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 ------------------------------------------------------------------ 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