[Amps] 3.5 kV 2A REGULATED Power Supply: Schematic ?

[Bill Fuqua]

You know this misconception probably has come from the trig identity 
generally used to expand (Cos A + Cos B)^3.
Which is the same one I use.  However, it could be done with different 
identities. These processes are taking place simultaneously.
It is not that a pair of terms are squared to produce a second harmonic and 
then multiplied  by the fundamental. It is just that in doing the math we 
expand the terms a little bit at a time.

73
Bill wa4lav



At 09:48 PM 1/1/2004 -0500, rfdude at COMCAST.NET,amps at contesting.com wrote:
>You can see from the entire expansion that all three of the effects are 
>there. And one of the most interesting one is the cross modulation term. 
>Here you can see that the amplitude of one signal affects the amplitude of 
>another.
>
>73
>Bill wa4lav
>
>
>At 09:42 PM 1/1/2004 -0500, rfdude at COMCAST.NET wrote:
>>That is incorrect.  If you wish to look over the math you will see the 
>>process that actually produces these products. There are actually 3 
>>effects caused by the odd terms. Harmonics, IMD products and cross 
>>modulation. These are produced simultaneously and if you filter out one 
>>or some it does not affect the others. Frequency Mixing is performed by 
>>the even order terms of the polynomial. You are using simply a binomial 
>>expansion and not a complete Taylor expansion of the non-linear 
>>characteristic curve.
>>
>>73
>>Bill wa4lav
>>
>>
>>At 02:12 AM 1/2/2004 +0000, rfdude at COMCAST.NET wrote:
>>>Bill wrote:
>>>*IMD is caused by the odd order terms of the polynomial ( output
>>>voltage/input voltage) of a device. The harmonics of these can terms ( 3rd,
>>>5th etc harmonics) can easily be filtered but the near by IMD products
>>>cannot since they are KHz or less from each other. Many think IMD is due to
>>>frequency mixing of harmonics but it is not, the additional frequencies are
>>>created in the device with out the aid of harmonics.
>>>......................................................................
>>>
>>>
>>>Just to set the record straight: IMD products ARE the mixing terms of 
>>>the the "harmonics" with the "fundamental(s) (correct for the lowest 
>>>order IMDs)".
>>>
>>>For example for a two tone case, F1 and F2, the first close-in-band IMDs 
>>>are: 3*F2squared-F1 and 3*F1squared-F2, (F2squared is the 2nd harmonic 
>>>of F2, and so on....). Ignoring the amplitude term, this leads to the 
>>>3rd order IMD products: 2F2-F1 and 2F1-F2.
>>>
>>>The harmonics are part of the picture and are generated when the 
>>>fundamentals are raised to the higher power(s) of the binomial expansion.
>>>
>>>The lowest order IMDs are created when the harmonics are mixed with the 
>>>fundament(s). For higher order IMD terms it is the mixing of also the 
>>>harmonics among themselves. These are the cross terms of the binomial 
>>>expansion.
>>>
>>>Only the cross term of the quadratic gives the desired beat products 
>>>because none of the terms are raised to a higher power (n=1) (no 
>>>harmonics are involved). All the other cross terms of the binomial are 
>>>part of the IMD baggage.
>>>
>>>So harmonics are part of the picture in generating IMDs.
>>>
>>>Wonder why we use a "switch" for mixing instead of a true multiplier?
>>>Well that another whole story.
>>>
>>>kb3bf, chris
>>>
>>> > IMD is caused by the odd order terms of the polynomial ( output
>>> > voltage/input voltage) of a device. The harmonics of these can terms 
>>> ( 3rd,
>>> > 5th etc harmonics) can easily be filtered but the near by IMD products
>>> > cannot since they are KHz or less from each other. Many think IMD is 
>>> due to
>>> > frequency mixing of harmonics but it is not, the additional 
>>> frequencies are
>>> > created in the device with out the aid of harmonics. If you are 
>>> interested
>>> > in the math behind IMD and harmonic distortion and frequency mixing (
>>> > algebra and trig.) I can attach to an email notes that one of my 
>>> students
>>> > put together from one of my classes. It is rather large for some reason
>>> > because I could not get it published to PDF without going to total 
>>> bit map.
>>> >
>>> > 73
>>> > Bill wa4lav
>>> >
>>> >
>>> > At 01:12 AM 1/2/2004 +0100, you wrote:
>>> >
>>> > >----- Original Message -----
>>> > >From: "Bill Fuqua" <wlfuqu00 at uky.edu>
>>> > >To: <bill at wjschmidt.com>; "AMPS" <amps at contesting.com>
>>> > >Sent: Friday, January 02, 2004 12:00 AM
>>> > >Subject: Re: [Amps] 3.5 kV 2A REGULATED Power Supply: Schematic ?
>>> > >
>>> > >
>>> > > > At 04:50 PM 1/1/2004 -0600, Dr. William J. Schmidt, II wrote:
>>> > > > >Class A has less little IMD, class B has a lot.  C would be 
>>> really nasty
>>> > > > >if not
>>> > > > >for output filtering (good tank circuit)
>>> > > >
>>> > > > C will have lots of IMD regardless of tank circuit. The tank 
>>> circuit only
>>> > > > eleminates
>>> > > > harmonics.
>>> > >
>>> > >  ** not only eleminates ( most of ) harmonics, when cleaning up up 
>>> the sine
>>> > >( RF ) as a f(Q ) of the tank.
>>> > >      I always believed  IMD was included !  What am I missing Bill ?
>>> > >
>>> > >Hpy 2004 to all.
>>> > >
>>> > >jos on4kj
>>> > >
>>> > >f> 73
>>> > > > Bill wa4lav
>>> > > >
>>> > > >
>>> > > >
>>> > > > _______________________________________________
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>>> > > >
>>> > > >
>>> >
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