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

Coil Update

Quoting SE-CRAWSHAW-at-wpg.uwe.ac.uk:

> Mr. Hull's enthusiasm for his work is evident, with liberal
> sprinklings of exclamation marks and a smattering of irony in
> places. Historical background information is provided, but the
> main body of the work is concerned with the technicalities of
> Tesla's research at CS. I would highly recommend this book to 
> any Tesla freak, it is up there with "Nikola Tesla and his 
> work...." in a list of must haves. 

If what I am seeing is true, we are now honored by the presence 
of the distinguished Mr. Hull on the Tesla-at-grendel.objinc-dot-com
list. I would like to reflect the sentiments of the rest of the
group in welcoming Mr. Hull!

> Well on to my own "research". Following the tips from the
> usa-tesla massive last month on my coil, I have slightly 
> changed the configuration, i.e. gap now across HV trans. 
> instead of cap. Cap is now a single 0.004 mfd mica cap rated at
> 20 amps and 20kvac...  The HV trans knocks out 25KVAC so I can
> only turn it up to 50% on the variac to spare my cap....
> I have three Spark Gaps in series, two of which are 1" diameter
> carbon rods and 1 of which is 1" diameter brass rod. I measured
> the DC resistance of the carbon rods at less than 1 ohm.

> Enough already. Fired it up, gaps too wide, adjusted gaps to a
> total distance of roughly 7mm and fired again at a tapping of
> about 17 turns. Approximately 5" spark :-( Anyway the final max
> tapping was *20 TURNS* This seems pretty big compared to the
> normal 8-12 turns quoted on this list. I assume this is due to
> my relatively small primary cap. I wanted to try a more 
> accurate tune but I was unable to see the spark properly, one 
> of those rare bright days in the UK. I guess this will have to
> wait until i can do a nightime run, as my coil is run outside.
> The final output was maxed out at about 1ft but THIN SPINDLY 
> sparks. I figure this to be due to either a lossy cap, gaps or
> both. I'm limited as to my cap but I could try only 1 gap, 
> maybe just the brass one, what do people think of this 
> strategy?

It seems you've a couple of things going on. You mentioned the
output voltage from the power supply, but you do not mention
the xfmr type or output current rating. This information would 
help. Assuming that your transformer is internally current
limited, then re-working your gaps should help some. 

I have never been impressed with the pulse performance of most
mica caps. The dielectric type and certainly the value are going
to be limiting factors. I would think that a .01 uF or even a bit
larger would work better. A larger cap will reduce the number of
turns required to regain your tune, but it will most likely match
better with your transformer, and will increase the peak power in
your tank circuit assuming your gaps are quenching.

Richard Quick

> I would like to rewire my HV transformer to give say 15kv 
> instead of 25. Can I just rewind the secondary with this ratio
> reduction in turns, beefing up the wire diameter and get the
> proportional boost in current capability? The transformer is of
> open construction, the core comes apart and the windings are on
> bobbins, no epoxy has been used to encapsulate the windings.

Before you go about stripping wire off the windings, have you
looked around for a step-down transformer that you could place
between the variac and the primary of the step-up. The other
option might be to reconnect the variac or use stops to prevent
overvoltage operation.  

> My hand's up for one of those sexy Condenser Products caps 
> if there's another order going in.

Better holler at Scott Myers right away. This order is going to
be placed in a matter of days. Contact Scott at: 

                 scotty-at-wesnet-dot-com

> 7. I have access to a digital camera, I will take some photos
> soon, how do I go about putting them on the FTP server or 
> sending them to the list(s)?

We are UUENCODE compatable on the list. Compress your image
into a JPEG and sent it to the group as an attached file.
There is an upload directory on the FTP server, simply upload
the image(s) there and Kristian can add it to the archives.

> 8. I would like to make the coil generate a double dodecahedron
> rotating merkaba field, so that I can teleport back into time.

You need much more power (and bigger capacitors)... :-)

Richard Quick


... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12