nano TC - running - dead 2n3055? / Tesla Coils / Forums

Forums

4hv.org :: Forums :: Tesla Coils

« Previous topic | Next topic »

nano TC - running - dead 2n3055?

1 2 next

Move Thread

LAN_403

dingo27

Tue May 13 2008, 06:22PM

Registered Member #890 Joined: Tue Jul 10 2007, 10:06PM
Location: Slovakia
Posts: 180

Hi, i am building another SGTC, what i have now is secondary 4.7cm heigh and 1cm diameter. Right now i am about to wind primary and i am not sure about number of turns. What could you reccomend me ? more/less turns...

the PS i am going to use has 4KV, i need to use diode for DC output, so i was thinking about 3-7 turns with 1mm dia. wire isolated with PVC.

THANKS for responses :)

// i forgot to mention - should be ground end on secondary connected to one end of primary or not? i was always doing that in SGTC, so maybe that was responsible for poor performance.

Andyman

Tue May 13 2008, 09:53PM

Registered Member #1083 Joined: Mon Oct 29 2007, 06:16PM
Location: Upland, California
Posts: 256

For big coils, it's usually recommended to have 800-1200 turns. On a small coil, it's not as easy to get that many turns in such a small place. I would go with 300-600 turns. On my mini coil, I have somewhere between 150 and 250 turns, and it works GREAT. You just have to get it tuned right.
Someone with more experience might be able to give you a more exact amount.

quicksilver

Tue May 13 2008, 09:58PM

Registered Member #1408 Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679

A coil of that size may be a serious challenge.... Did you really mean a centimeter? By using that JAVA-TC page:

You can simply plug in your wire specs and get your answers with a degree of professionalism and accuracy. But what I was wondering from those gentlemen who have made some BEAUTIFUL Tesla Coils is the TECHNIQUE of winding copper tubing (or for that matter ANY heavy copper) in an accurate spiral.....??

Over again I have read of the advantages of using a primary of flat configuration...but how does one wind a spiral with the accuracy I've seen in some examples here?

dingo27

Tue May 13 2008, 10:01PM

Registered Member #890 Joined: Tue Jul 10 2007, 10:06PM
Location: Slovakia
Posts: 180

i mean primary, i.e. the one with less turns...

low photo:
NanoTC

...as i know: primary is the one where the power is connecting, and secondary is where the sparks are coming out. Correct me if i am wrong.

...

Tue May 13 2008, 11:16PM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

The number of primary turns depends on the size of the tank capacitor.

To decide that, you need to decide what break rate and power you want to run at. I would recommend 100bps and the maximum power your supply can put out.

What current can your ps put out? Also, what kind of supply is it?

After you know the current the supply outputs, you use the formulas charge=current*time, charge=capacitance*voltage, and time=1/frequency. With algebra you can solve to get to capacitance=current/(voltage*break rate). Make sure to use SI units when solving.

Then after you know the size of the resonant capacitor you calculate the number of primary turns you need, either using a bunch of nasty formulas or one of the tesla coil softwares (like javatc listed above)

dingo27

Wed May 14 2008, 09:29AM

Registered Member #890 Joined: Tue Jul 10 2007, 10:06PM
Location: Slovakia
Posts: 180

i have no idea what current can my flyback put out... it is flyback with 2n3055 5+3 turnt, and running from 12V10A PS... it is doing 4mm sparks

------------------------------------------ -------------------
well... currently i am not interested in current... i am calculating some "ballast" in java tc calculator... i am putting in it what i know. buti have no idea why the hell it is putting fake numbers where i put there good value once.

so...

Lets talk the zero point (ZP) will be plate i am building that on, something like table or whatewer... i am not running it on earth in grass, so i will not be using that as GROUND.

from image you can see :
gap between ZP and 1st winding is 0.23cm
gap btw. ZP and last winding is 4.9cm

dimater of winding is 1.05cm (i.e radius is 0.525cm) and i am using 0.1 wire (i think... i dont have any precisious tool to find it out exactly.)
the winding is 4.6 cm long. so i think it has appx. 460 turns
-----------

that is what is DONE. now:
for primary (the one where i connect spark gap, capacitors, HV supplu...) i have wire:

0.14 cm bare wire diameter (so 0.07cm radius)
0.28 cm wire thickness with insulation / so insulation is 0.7 thickness

i dont have any idea of number of turns...
BUT i will be using plastic skelet of 1.37 cm diameter (0.685cm radius)
-------------
i have 10x 1nF 2kV, so i can wire it to 2, 4, 6, 8, 10 kV ( i think more will be too much) when i wire it 2x5 , i'll get 0.4nF at 10kV (and i can try different values with crocodile plugs (less and less...)))...

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

TOP LOAD :
i am using that wire at top, it is 0.13cm dia (with same wite i am planning to do primary), it is 5.3cm from ZP and 8.7 cm from ZP, so its length is 3.5 cm. i can use other cylindrical toploads, but only when final testing.

----------------
I was adding this to TC java:

but when i do "calculate" or what, it replace my values with some king of bull****, but only i want to calculate my primary turns and capatitancy...

dingo27

Thu May 15 2008, 10:21AM

Registered Member #890 Joined: Tue Jul 10 2007, 10:06PM
Location: Slovakia
Posts: 180

forget about last post i wrote... the nanoTC is working (well... was working)... the last thing i got was about 1cm sparks...

Then suddenly sparks went gone, and i think i blowed my 2n3055 out. It is gone when B-E has 22(i dont know what, i am trying that with diode multimeter) and the same is E-B ????

Conundrum

Sun May 18 2008, 10:20AM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4061

Hmm. Why are you still using 2N3055's? Most TC'ers moved on from these for everything except coilguns because they don't last long.

A better alternative is MJE13007 or MJE13009, both of which are also excellent for driving flybacks.
Can be acquired from any broken or surplus PC power supply, and with care and heatsinking will outlast a dozen 3055's.

Regards, -A

Mads Barnkob

Sun May 18 2008, 04:59PM

Registered Member #1403 Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968

Are the 2n3055 mounted with a heatsink? And it better be a large one, thats the only way I keep them alive.

dingo27

Sun May 18 2008, 05:23PM

Registered Member #890 Joined: Tue Jul 10 2007, 10:06PM
Location: Slovakia
Posts: 180

heatsinked, cooled with fan,.... and i am running it only from 12V, not 30 or so...

as i manage to reproduce HV PS i-ll post some photos...

1 2 next

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob