FreeLists / si-list / [SI-LIST] Re: Transmission lines reflections again

[Scott McMorrow <scott@xxxxxxxxxxxxx>]

This is basic circuits theory. 
You can use Kirchhoff's laws to solve for the voltage at the end of an 
open transmission line.


Scott McMorrow
Teraspeed Consulting Group LLC
121 North River Drive
Narragansett, RI 02882
(401) 284-1827 Business
(401) 284-1840 Fax

http://www.teraspeed.com

Teraspeed® is the registered service mark of
Teraspeed Consulting Group LLC



Leonard Alexman wrote:

>Hi ,
>
>I am still trying to figure out how in a simple open transmission line the
>voltage gets doubled at the end of the line. I have seen the formulas and
>rope drawings but only found one article that kind of goes into what I what.
>
>The article I read had a battery connected to a serries50 ohm resistor and a
>50 ohm transmission line. The equivelant circuit of the transmission
>linsmission line is a series inductor with a capacitor to the return path to
>the battery
> When the last capacitor in the line is charged, there is no voltage across
>the last inductor and current flow through the last inductor stops. With 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 into
>the last capacitor. Because the direction of current has not changed, the
>capacitor charges in the same direction, thereby increasing the charge in
>the capacitor. Since the energy in the magnetic field equals the energy 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 
>
>1. Since the second to the last cap is charged to 1/2 the battery voltage
>where does the current flow from the left end of the last inductor to 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:
>http://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:     
>               http://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
>  
>
>
>  
>

------------------------------------------------------------------
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:
http://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:     
                http://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