[Prev][Next][Index][Thread]

FW: Coil Efficiency (was more mini coils)


From: 	John H. Couture[SMTP:couturejh-at-worldnet.att-dot-net]
Sent: 	Tuesday, June 24, 1997 5:19 PM
To: 	Tesla List
Subject: 	Re: Coil Efficiency (was more mini coils)

At 11:52 PM 6/23/97 +0000, you wrote:
>
>From: 	FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
>Sent: 	Monday, June 23, 1997 4:09 AM
>To: 	tesla-at-pupman-dot-com
>Subject: 	Re: Coil Efficiency (was more mini coils)
>
>>    This test can also be done with larger coils using larger lamps or
>> current shunts. It will be found that the efficiencies are much lower with
>> the larger coils. Because small coils are so efficient, magnifiers may
>> provide no additional gain. However, because the efficiencies of large
>coils
>> are so low, magnifiers may show a gain. I have not seen a true comparison
>to
>> prove this conclusion.
> 
>   John Couture
> > >>
>
>John,
>
>Could it be that the larger coils were inefficient due to other factors other
>than "inherent" inefficiency.  For instance the larger coils may have been
>using ballasts that were saturating, transformers that were saturating, gaps
>that were not quenching well, etc. It seems to me that large coils would not
>be inherently less efficient.  True, there will be greater losses in the
>absolute sense, but I wouldn't expect the proportional losses to be higher in
>the large coils.  Do you have an explanation for the lower efficiencies
>you've seen in the large coils?
>
>John Freau
>
>---------------------------------------

  John F.

  I have always thought that the lower efficiency of larger TC's was due to
the higher voltages in the secondary circuit causing proportionally larger
losses. This is contrary to typical engineering where larger means more
efficiency.  However, as you suggested there apparently are increases in
losses due to other conditions.

  For example, larger coils use much larger currents in the pri and sec
circuits. The typical TC does not have proportionally larger wiring. The
losses due to these currents could be reduced by using larger wiring. Maybe
the primary should be one or two turns with extra large conductors and the
secondary with 100 or 200 turns of larger than normal wiring. Resonance at
the proper frequency and coupling would be depended upon for increased sec
voltage.

  I built a small one turn pri coil TC with a large copper cross section and
large capacitor but found no improvement. This was probably because small
coils already have good efficiency. Maybe someone will try a large one or
two turn pri TC. For one thing the pri cap will be larger than normal and
can store more electrical energy. Also, the number of breaks will have to be
increased to handle the extra currents involved.

  John Couture
>
>