NTNUJAVA Virtual Physics Laboratory
Enjoy the fun of physics with simulations!
Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/
December 12, 2017, 11:54:41 am *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
 
   Home   Help Search Login Register  
Life well spent is long. ..."da Vinci (1452-1519, Italian artist, sculptor, painter, architect, engineer and scientist) "
Google Bookmarks Yahoo My Web MSN Live Netscape Del.icio.us FURL Stumble Upon Delirious Ask FaceBook

Pages: [1]   Go Down
  Print  
Author Topic: request for applet /board:26-100-  (Read 9573 times)
0 Members and 1 Guest are viewing this topic. Click to toggle author information(expand message area).
peacenlove
Newbie
*
Offline Offline

Posts: 9


«
Embed this message
on: November 18, 2009, 05:18:06 am » posted from:,,New Zealand

hi
thank you so much for your amazing work here

you will have to excuse me as i don't posses a great knowledge of physics

i,m wondering if you could build us an applet in which one could enter a frequency
and it would show the major harmonics

eg Tesla and royal rife used 11.78 million Hz for treating cancer
so if i enter 11.78 into an applet it would give me the lower harmonics say down to under 10,000Hz and also a picture of the wave form as in sine wave and square wave etc

is this possible please
Logged
Fu-Kwun Hwang
Administrator
Hero Member
*****
Offline Offline

Posts: 3080



WWW
«
Embed this message
Reply #1 on: November 18, 2009, 07:28:51 am » posted from:Taipei,T'ai-pei,Taiwan

You need to indicate that what is the waveform of your signal.
If the signal is a sine wave, then the frequency f of the sine wave is the lowest harmonic,
the other harmonic might be 2f,3f,...

If you are talking about the possible resonance with a system, then it will depend on what kind of system you are talking about. Each system has it's own characteristic frequency pattern.
Logged
peacenlove
Newbie
*
Offline Offline

Posts: 9


«
Embed this message
Reply #2 on: November 19, 2009, 06:47:05 am » posted from:,,New Zealand

hi thank you for answering Smiley

the wave used is a square wave

there is this we use often http://www.csgnetwork.com/harmonicscalc.html

but it lacks the visual that your so clever at producing

it would be great to be able to choose a frequency and see its harmonics in values and its wave form kinda like you have produced here http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1073.0
but where you have cos and sine it shows the harmonics and the wave form as is

i hope i,m making sence Wink
Logged
Fu-Kwun Hwang
Administrator
Hero Member
*****
Offline Offline

Posts: 3080



WWW
«
Embed this message
Reply #3 on: November 19, 2009, 12:22:57 pm » posted from:Taipei,T'ai-pei,Taiwan

The square is a superposition from infinite sine wave.
The Fourier series is f(t)=\frac{4}{\pi} \sum_{n=1,3,5,...}^\infty \frac{1}{n}\sin(\frac{n\pi t}{T}).
where L is the full length of the square wave.
You can check out http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=17.msg114#msg114 to find it's 1-15th components.

You can use the above equation to find out the relative intensity (1/n) of each component (harmonic).
Logged
peacenlove
Newbie
*
Offline Offline

Posts: 9


«
Embed this message
Reply #4 on: November 20, 2009, 03:58:36 am » posted from:,,New Zealand

hi
thank you,,, Sad
its a very comlex applet for sick people to try to use
i could not get the base frequency tone to change
and the results ment nothing
Logged
Fu-Kwun Hwang
Administrator
Hero Member
*****
Offline Offline

Posts: 3080



WWW
«
Embed this message
Reply #5 on: November 20, 2009, 09:35:11 am » posted from:Taipei,T\'ai-pei,Taiwan

You need to HIT ENTER after you change the number in the text box.
And you will be able to hear it when you click play.

You can also find all the value for those components, from the table just below the simulation.
Click button label as "get" to get values for all the components. You can change the value in the table and click "set" to change it in the simulation.
Code:
its a very comlex applet for sick people to try to use
Sorry! If you can provide me suggestion: how to make it better, I will try to improve it.
Logged
peacenlove
Newbie
*
Offline Offline

Posts: 9


«
Embed this message
Reply #6 on: November 26, 2009, 04:04:04 am » posted from:,,New Zealand

hi THANKS Smiley

COULD YOU DO AN Applet that shows two waves (frequencies) the same
and allows people to adjust and hear those frequencies from say 100 to 11,700hz

then allows them to phase shift by 90 or 180 and plays the result
Logged
Fu-Kwun Hwang
Administrator
Hero Member
*****
Offline Offline

Posts: 3080



WWW
«
Embed this message
Reply #7 on: November 26, 2009, 03:58:51 pm » posted from:Taipei,T\'ai-pei,Taiwan

For two waves with the same frequency \omega and amplitude, but only different by phase shift \psi
The result is f=A \sin\omega t +A (\sin\omega t+\psi)= A \sin\omega t +A \sin\omega t \cos\psi+A\cos\omega t \sin\psi
so f= A(1+\cos\psi) \sin\omega t + A \sin\psi \cos\omega t=A\sqrt{(1+\cos\psi)^2+\sin\psi^2} \sin(\omega+\delta)=A\sqrt{2(1+\cos\psi)} \sin(\omega+\delta)
where \tan\delta=\frac{\sin\psi}{1+\cos\psi}
So the result is a wave with the same frequency but different amplitude.
For special case, where \psi=\pi, the wave will cancel with each other, otherwise, you will not hear any different in sound frequence except sound level difference.

You can use EJS version of Fourier Synthesis (You can hear the sound,too!) to hear sound at different frequence.

Please check out Superposition of two waves to view the sum of two waves (with phase difference)
Logged
peacenlove
Newbie
*
Offline Offline

Posts: 9


«
Embed this message
Reply #8 on: December 31, 2009, 06:02:43 am » posted from:,,New Zealand

HI
THANK YOU
Logged
Pages: [1]   Go Up
  Print  
Life well spent is long. ..."da Vinci (1452-1519, Italian artist, sculptor, painter, architect, engineer and scientist) "
 
Jump to:  


Related Topics
Subject Started by Replies Views Last post
request
Optics
amada 1 7553 Last post October 19, 2007, 09:11:06 am
by Fu-Kwun Hwang
Request for new simulation
Request for physics Simulations
aveek 1 7746 Last post January 21, 2009, 01:59:01 pm
by Fu-Kwun Hwang
Induced voltage by shaking a magnet through a solenoid applet request
Request for physics Simulations
entomopter 9 14835 Last post June 09, 2008, 11:43:59 pm
by Fu-Kwun Hwang
How make applet run one time only/board:23-100-
Question related to Physics or physics related simulation
ahmedibrahim 4 4502 Last post July 17, 2010, 12:35:45 am
by ahmedelshfie
Request: Cavitation phenomena/board:26-100-
Question related to Physics or physics related simulation
Ice9 2 2607 Last post November 27, 2013, 12:11:13 pm
by Cancerbero_29
Powered by MySQL Powered by PHP Powered by SMF 1.1.13 | SMF © 2006-2011, Simple Machines LLC Valid XHTML 1.0! Valid CSS!
Page created in 0.579 seconds with 22 queries.since 2011/06/15