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From:  Reg Boyle <bandb@n...>
Date:  Sat Apr 6, 2002  12:33 am
Subject:  For Sally.... :)

Dear Sally,
You ask for a reference in relation to my assertion that
there is an absence of even harmonics in a square wave as
derived during one mode of the open and closed functions of
the cords.
I'm sure you are conversant with Fourier Analysis. When this
is applied to any wave shape its sinusoidal components and
their relative amplitudes can be fairly simply derived.

Unfortunately I find it difficult to copy in the appropriate
formulae for you but I'm sure you are in a position to source
these for yourself. Let me try..

Fundamental (F1) = A [1/pi/2]= 2A/pi
(F2) = A [sinpi/pi] = 0
(F3) = A [-1/3pi/2] = 2A/3pi
... and so on. In a practical square wave the 11th harmonic is
seen as the limit.

A is Peak to Peak amplitude. The KEY is that whenever "n" is
an EVEN number, we are taking the sine of a multiple of "pi" or
(180 degrees). The sine of any multiple of "pi" is ZERO.

The Fundamental is about 63%, the second harmonic is ZERO
and the third harmonic is 21% and so on down to the 11th.






  Replies Name/Email Yahoo! ID Date  
18512 Re: For Sally.... :)Lloyd W. Hanson   Sat  4/6/2002  
18513 Re: For Sally.... :)Reg Boyle   Sat  4/6/2002  
18520 Re: For Sally.... :)Reg Boyle   Sat  4/6/2002  
18524 Re: For Sally.... :)Sally Collyer   Sun  4/7/2002  
18530 Re: For Sally.... :)Reg Boyle   Sun  4/7/2002  
18545 Re: For Sally.... :)Lloyd W. Hanson   Sun  4/7/2002  
18557 Re: For Sally.... :)Reg Boyle   Mon  4/8/2002  
18560 Re: For Sally.... :)Reg Boyle   Mon  4/8/2002  
18652 Belting ?bjjocelyn@p...   Wed  4/10/2002  

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