Friday, August 22, 2008

Shock, Horror Gasp! Dept.

I was playing with my Relay Spark Gap Tesla Coil ( RSGTC )
the other day and I noticed something funny was happening,

I was seeing how low a voltage it would run on so I hooked up a 6 volt SLA and when I checked the supply voltage It was higher than when it was at Idle!


Naaah, nah, nah, this is not Right!
I could see the circuit was using power, it was lighting up a flouro!
Must be a flat battery in my D.M.M.,
so I changed the 9 volt and fired it up again.

W.T.F.? again.
ok hook it up to the 12 volt SLA,
no every thing seems kosher here,
voltage dropping slowly Milli volt by Milli volt.

Ok, try the 13.8 volt Motorcycle battery,
same, same,
ok try hooking the wet cell and SLA together to get 24 volt or so,
impressive but nothing unusual here either.

Last resort a 9 volt ni-cad,
nada, everything cool here too.

Hook the 6 volt up
and it's doin' the weird shit again,
what the hell is going on here!

After much Pondering and Brane stretchin' I think I have an answer!

Back E.M.F.!

Yep, I reckon that explains a heap!

I reckon a relationship exists between the freq. it oscillates at when running @ 6 v., and
possibly the relay coil or maybe the physical construction of the SLA or maybe even both!

It's not quite Over Unity, more like Close to Unity!
It took about 3 days to run down to 5.2 volt at which point the relay could no longer sustain itself!
( not bad for a 12 volt relay!)

This compares to about 3.5 hrs. using the 12 volt 1.2 a/h SLA!

Ah, I hear you say, how many a/h is the 6 volt?
The answer is 6.5 a/h!
so taking the discharge rate of the 12 volt into account we come up with <20 hours!

It will take a better Brane than mine to explain it properly and model it Mathematically but,
I will endeavour to some how optimise a cct to take advantage of this anomaly,
you never know,
they say the greatest discoveries started out as mistakes!

Mick. ;-))

Mick's Tesla Coil Endevours!

Hi all again,
Firstly the video didn't load in my last post, I dunno why but I'll get Mark to look into it when he is feeling better. (he has a dose of the flu!).

Right said Fred lets go!

I got an idea to use a relay as a spark gap from a site on You tube,

after watching this vid I freeze framed it to reverse engineer it!
It turned out to comprise only 3 major parts, 4 if you include the battery!

A Relay (configured to be a buzzer),

a capacitor (to Tank the primary),

a battery

and of course a Tesla Coil!

I hooked it up to a Mini Twin Tesla Coil that I was intending to make a solid state driver for!

It's a little pearler
and it worked 1st go too!

I imagine I could get more power out of it if I wound my own buzzer with an adjustable gap!
I did play around with the spring tension in the relay and got some overall improvement!

I got the idea for the twin coil setup from this site!

I seem to be quite lucky when I'm winding coils,
I used a 1" form and wound an arbitary 4" tall pair of Secondaries!
(using the Hair fine wire I got from the printer relay!)
The Primaries were an arbitary job too @ 4.8 turns each!
Oh and the "tank Cap" is 220 pF @ 1kV

well thats another post all done and dusted,

"If you always do what you did,
You'll always get what you got!"

Cheers again,

Mick. ;-))

Mick's Tesla Coil Endevours!

After pressure from the West and East coast (hi Sean and Mark respectively) of my beloved Oz, (Australia of course)
It seems to be time to document my

"Tesla Coil experiences/endeavours"

so here goes for good or ill!

After my Pulse Jet getting shut down 'cause it was too LOUD,
I had to find something quieter to occupy my brane so,
yet again my muse (Mark) stumbles me a site ,

Ulrich Haumann's Plasma Tweeter site.

And yet another childhood dream is embarked upon as,
I realised that it was a Modulated Tesla Coil of sorts!

I went to my Valve (a.k.a. tube) stash to see if I had anything suitable.
Sadly I deemed nothing came close to the Valve that Ulrich was using to
drive the coil.
I've got plenty of 12AX7's and had just scored a blown up telly from my neighbor Marika
to rat out for parts and, it came complete with` a 1500 volt Hitachi 2SD870 power transistor!

So its eBay to the rescue!
Sure enough I find and purchase a pair of Svetlana 6P45S's (you gotta love those Russians!)
from a guy in the Czeck Republic!
But while I was waiting for them to arrive, I continued to surf the net and after I had checked out a number of sites I reckoned I might be able to coax the required power out of a 6V6GT, (of which I have 3!) and so my first Tesla Coil was born!

I basically lifted the circuit straight from Jon's Electronixandmore's site,
(see link below)
because the input voltage Jon was using was well within a 6V6GT's limits!

I wound all the coils by hand (no coil winders for me.......Yet!) to the spec Jon supplied
and just substituted my 6V6GT for his 6146,
the one big difference was I didn't have enough 24 gauge wire to wind the Secondary
so I pulled apart a relay coil out of a printer to get enough wire but it was hair fine more like 35 or 39 gauge!
I continued on anyway and wound the Secondary Coil.
It turned out to be 4" tall instead of 6" but hey it'll work or it wont!

Turns out it did and here it is!

The little power supply you can see in the right if the pic is the very first Valve project I ever made and still puts in great service all these years later!
(full wave @ 330 V aprox. 250 mA.)

As you can see, I could draw a 1/4" Arc to an insulated screwdriver.

I can now assume the title of "Mad Scientist" and I wear it Proudly!

But as it seems to be with all "Coilers" (I love it!) I had to have MORE POWER!
Hmmmm, those other two 6V6GT's were lazily sitting around doin' nuthin' so they got shanghaied into the project, and were quickly paralelled into the circuit!

Hmmmm, not a great difference but it was a little better but, .........need more!
So I wound another 2 plate (a.k.a. anode) chokes and wired them in,
Hmmmm,...... a little better again but not much.

What to do, what to do, what to do?

While pondering this it was well past time to play with my new toy!
And play I did,
I put a Flouro tube near it and i lit up fully,
What next?
A frosted light globe?
It glowed with a nice purplish glow!
Double Kewl!
Hey Mark have you got any clear light globes?
He certainly did and it was quickly pressed into service!
Unbelievably Kewl!
Plasma Globe!
I was in Mad Scientist heaven,

But still no coronas, hmmm, bummer.

What else have I got that I can light up,
what about a Flouro starter?
So the cover was removed along with the capacitor that was inside and,
it too was pressed into service!
Lo and Behold a vast differance was instantly noticeable,
it was forming two little coronas on the end of the starter wires!

Without knowing why I seemed to have gained a lot of extra power,
hmmmmmm, ponder, ponder, ponder?

It would seem that the starter was creating a little bit of extra capacitance the secondary coil needed to tune it in properly!

Here is a short vid of my efforts!

In my next post I'll show you my mini twin coil spark gap Tesla Coil!

Cheers for now,
Mick. ;-))