Re: Air cored Tesla coils for high voltage?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

Hi Bob,

On 2 Jul 2005, at 0:04, Tesla list wrote:

> Original poster: Robert Clark <bobbygc2001@xxxxxxxxx>
>
>   In order to have a self-contained power unit for a
> lifter we need a lightweight means of creating high
> voltage in the tens of kilovolts range.
>   To quantify it, a lifter can be made at a thrust to
> power ratio of about 1 gm lifted to 1 watt power
> required.
>   Here's a lithium battery to put out 30V DC:
>
> TP4000-8S2P
>    Amp Hours: 4000 mAh
>    Voltage: 29.6V
>    Balancer connectors
>    Rating: 10-12C continuous, 20C (80A) burst
>    Output: 29.6V Nominal, 4000mAh
>    Dimension: 50mm x 245mm x 28mm
>    Weight: 656 grams
>    Retail: $349.95
> http://www.thunderpower-batteries.com/html/batteries.html
>
>   There are lightweight converters to convert the DC to
> AC for a tesla coil:
>
> DC to AC Inverter with the 555.
> http://www.uoguelph.ca/~antoon/circ/555dcac.html
>
>   However to power the lifter we need say 30,000V. A
> problem with transformers is that their ferrite cores
> make them too heavy for the lifter to raise.
>   So my question could you make the transformers to
> power a tesla coil be air cored?

Yes. I'd suggest a resonant or quasi-resonant converter operating in
the 100's of kHz region to keep the required copper mass and switch
losses low.

>   Then another question is could you make the toroid on
> the tesla coil be lightweight?

I don't see why not. A styrofoam shell covered in cooking foil would
be a start. Perhaps enclosing a balloon filled with He if an
impervious balloon could be found would reduce the total weight of
the terminal to zero.

Malcolm


>
>     Bob Clark
>
>
>
>