Re: OLTC update - Poor seconadry Q

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Antonio,

At 10:37 AM 8/31/2002 -0300, you wrote:
.................
>
>Q=36 is not so bad. Most of the input energy is being transferred to
>the secondary. With k=0.2195 (mode 4,5) my calculations show that
>the voltage gain reaches 947, with the ideal maximum being 1089.
>About 76% of the input energy is reaching the secondary capacitance.
>Distributing the secondary capacitance of 36 pF as 18 pF for the
>self-capacitance of the secondary and 18 pF for the terminal,
>38% of the input energy should be immediately available. 

Although, MicroSim is pretty "unverified" for subtle streamer behavior, it
is saying that the instantaneous power to the streamer and to heating the
coil looks like this:

http://hot-streamer-dot-com/temp/OLTC08-31-01.gif

The red is the secondary heating power and the green is the streamer power.

However, if one looks at the voltage across a 3300 ohm series resistor in
the secondary and the streamer voltage, the loss looks small:

http://hot-streamer-dot-com/temp/OLTC08-31-02.gif  

I wander if I initially have the power but there just is not enough there
to keep the streamer going.  The sparks are more brush like too suggesting
that is the case.

Secondary loss, streamer impedance, and....  Is one of those areas that is
not terribly well understood.  Conventional coils seem to have just found
the sweet spot but this coil seems to have found a "bad" spot.  We'll
probably learn a lot before this is over :-))

>
>> > So... I don't k! now if it is the SonoTube, surroundings, proximity 
>effects,
>> > plastic wrap coating... Have to test some things... A small chance it
>> > could be the anti-parallel diodes...
>
>Your coil is performing as expected for a coil with a lot of relatively
>thin wire. I see the same happen in the coil that I used for my 
>transformerless system, with the effective resistance being about 6
>times
>the expected value considering skin depth alone. 

Mine is 6X too and Paul got a Q of 45 for the coil.  Has program can
predict these effects to a reasonable degree.

>I think that proximity 
>effects in the windings are the main reason for the large increase in 
>the effective resistance. I would suspect also of the wrapping, that
>is an "untested technology". Air trapped between the layers may be
>getting ionized, and may be dissipating some energy.

Good point!  I may have made a giant corona machine there.  But I measured
the Q at low power (signal generator) too.  But corona could certainly be a
big factor at the high voltage...

Time to get back into lab to investigate it all ;-))

Cheers,

	Terry

>
>Antonio Carlos M. de Queiroz
>
>