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Re: TC Critical Coupling


  Malcolm, All -

  I agree that critical coupling MAY not produce an optimized coil.

  What is your definition of an optimized coil?
 
  My difinition of an optimized coil is the coil with the maximum percent
efficiency for the input energy. I show a percent efficiency test in one of
my books. Note that magnifiers may not work because they have additional
parts that cause losses.

  How would you test to determine if the coil is optimaized? You can forget
about the random extra long spark because that doesn't make engineering
sense. The true input and output energies (volts, amps, dt's) of that random
spark, of many sparks, cannot be determined. The one shot test also is
useless, or is it?

  You misunderstood my explanation about raising the coil. If the critically
coupled coil does not have to be raised because it is properly designed at
the start the critically coupled coil MAY produce an optimized coil. Only
building and properly testing a lot of coils can solve this problem.

  John Couture

---------------------------------

At 10:46 PM 5/9/99 -0600, you wrote:
>Original Poster: "Malcolm Watts" <MALCOLM-at-directorate.wnp.ac.nz> 
>
>> Original Poster: "John H. Couture" <COUTUREJH-at-worldnet.att-dot-net> 
> 
><snip>
>
>>   Raising the secondary can be used to find the critical coupling point but
>> this is self defeating because it reduces the magnetic flux linkages which
>> reduces the TC output. 
>
>Therefore, one can do better than critical coupling. Therefore, 
>critical coupling does not produce an optimized coil.
>QED.
>
>Malcolm
>
>
>
>> For optimal power output the TC must be designed
>> correctly from the start in order that the secondary does not have to be
>> raised to make it work at all, usually to prevent sparkovers.  
>> 
>>   The 830 primary amps and the 32.4 secondary amps are instantaneous peak
>> amps. In my TC Notebook I show how the primary amps are found.
>> 
>>    Ip = Vp sqrt(Cp/Lp)
>>  
>>   These instantaneous amps are high and the reason the primary wiring must
>> be large. Note that the magnetic flux from the primary coil is dependent on
>> the turns times the amps. Using more turns as some coilers recommend would
>> not help if the primary wiring was large enough for the current. In fact the
>> added resistance of more turns would reduce the magnetic flux and the TC
>> output.
>> 
>>   Thank you again for replying to my post.
>> 
>>   John Couture