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

Re: 50%



At 05:25 AM 10/31/96 +0000, you wrote:
>> Subject: Re: 50%
>> >Subject: 50%
>
>From hullr-at-whitlock-dot-comWed Oct 30 21:46:37 1996
>Date: Wed, 30 Oct 1996 12:56:35 -0800
>From: Richard Hull <hullr-at-whitlock-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: 50%
>
>Tesla List wrote:
>> 
>> >From couturejh-at-worldnet.att-dot-netTue Oct 29 22:52:39 1996
>> Date: Tue, 29 Oct 1996 22:14:10 +0000
>> From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
>> To: tesla-at-pupman-dot-com
>> Subject: Re: 50%
>> 
>> At 05:25 AM 10/29/96 +0000, you wrote:
>> >From hullr-at-whitlock-dot-comMon Oct 28 21:48:14 1996
>> >Date: Mon, 28 Oct 1996 12:43:40 -0800
>> >From: Richard Hull <hullr-at-whitlock-dot-com>
>> >To: tesla-at-pupman-dot-com
>> >Subject: 50%
>> >

  Richard -

I agree with your comment about differences in spark energy for sparks of
the same length. This is a weakness in the watts per foot of spark rating.
However, I have not heard of an easier way to rate Tesla coils. The
controlled spark length avoids some of these differences.

JHC

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

>> >Tesla List wrote:

> >In theory,  We should never be more than 50% efficient in energy transfer
>> >from one capacitor to another!  i.e. the Cprimary to the Csecondary
>> >Usually the resonator load capacitance plus Ion cloud loading.  This
>> >assumes 100% coupling and zero other losses!  If fact, we are much lower
>> >than that with the finest system in operation.
>> >
>
>Richard Hull, TCBOR

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

Richard -

The replies from coilers including mine regarding your 50% subject can be
misleading. The difficulty is due to the misunderstanding of what you are
talking about.

You mentioned transfer of energy from one capacitor to another and you also
mentioned Cprimary to the Csecondary. These are two completely different
electrical phenomena.  The first has to do with capacitor connections in
general and has little to do with Tesla coils. The second I took to mean
energy transfer between the primary and secondary coils of Tesla coils and
the 50% is not correct.

Part of the energy transfer in Tesla coils involves 3 conditions. First is
the flow of energy to the primary capacitor Cprimary which is continually
being fed energy by a source such as the power transformer. Second is the
energy transfer between the primary and secondary coils. Third is the energy
in the secondary circuit which includes the Csecondary. 

My previous reply only covered the second condition, the transfer of energy
between the primary and secondary coils. This transfer can be considered as
100%, not 50% of energy transfer, that is 100% efficient, and no losses! I
base some these considerations on Michael Faraday's discovery (pure genius)
and Hugh Skilling's excellent treatise "Transient Electric Currents".
Studying these sources of information are truly revealing.

Skilling writes for two coupled RCL circuits (Tesla coils) "It is
approximately true that complete transfer of energy from one circuit to the
other occurs if the natural frequencies of the two individual circuits are
equal". To me this means almost 100% of the energy is transfered if the
Tesla coil is in tune. This also means there are  no losses in the transfer.
The reason is that the transfer is by electrical induction of the reactive
parts of the two circuits. As I have mentioned before there are never
reactive energy losses at any time. However, there are always resistive
energy losses in the circuits.

Skilling also writes that the COUPLING takes NO part in the energy transfer
but "close coupling permits a faster transfer of energy". This means that
the coupling of Tesla coils should be coordinated with the GAP BREAK "ON"
TIME SO THE TIMING IS OPTIMUM FOR ENERGY TRANSFER. This has to do with the
10% cycle time that the JHCTES program shows in the outputs. An insufficient
"On" time (such as too many breaks) means there will not be enough time
(which varies with the coupling) to transfer all of the energy from the
primary coil to the secondary coil. That is, not enough time to transfer all
of those "10% cycles".

I have never heard of anyone who has ever adjusted their gap break "On time"
to get the 100% energy transfer. This definitely would affect the spark
length. In one of my books I say that the break rate should be coordinated
with the available input wattage but other conditions are obviously
required. Some day I hope to add to the JHCTES program the design conditions
for these additional requirements of the gap break system.

It is apparent that the Tesla coil is not the simple electrical device we
sometimes presume it to be.

Jack C.