# Difference between revisions of "Energy in a signal"

From Class Wiki

(→Energy of a Signal) |
(→Energy of a Signal) |
||

Line 17: | Line 17: | ||

This can be written using [http://en.wikipedia.org/wiki/Bra-ket_notation bra-ket] notation as |
This can be written using [http://en.wikipedia.org/wiki/Bra-ket_notation bra-ket] notation as |
||

: <math> <v(t) | v(t)> \!</math> or <math> <v|v> \!</math> |
: <math> <v(t) | v(t)> \!</math> or <math> <v|v> \!</math> |
||

− | |||

+ | By [Rayliegh's Theroem], |
||

+ | : <math> <v|v> = \int_{-\infty}^{\infty} |V(f)|^2\,df </math> |
||

This page is far from complete please feel free to pick up where it has been left off. |
This page is far from complete please feel free to pick up where it has been left off. |

## Revision as of 20:18, 10 October 2006

### Definition of Energy

Energy is the ability or potential for something to create change. Scientifically energy is defined as total work done by a force. Work can be mathematically calculated as the line integral of force per infinatesimal unit distance,

Power represents a change in energy.

This means we can also write energy as

### Energy of a Signal

From circuit analysis we know that the power generated by a voltage source is,

Assuming that R is 1 then the total energy is just,

This can be written using bra-ket notation as

- or

By [Rayliegh's Theroem],

This page is far from complete please feel free to pick up where it has been left off.