6.25" Tesla Coil roars to life! / Tesla Coils / Forums

Forums

4hv.org :: Forums :: Tesla Coils

« Previous topic | Next topic »

6.25" Tesla Coil roars to life!

Move Thread

LAN_403

MOT_man

Mon May 19 2008, 02:42AM

Registered Member #1127 Joined: Mon Nov 19 2007, 12:08AM
Location:
Posts: 139

Yep... it works! Rather well I might add...
Using the same power supply as I did with my 3.25" Tesla Coil system, I have run the power supply into a Tesla Coil that has a 6.25" diameter form. The secondary is wound with 27 AWG wire and stands 34" tall. The primary is built from 1/2" copper tubing and is currently tapped at turn 10. The tank cap is LTR at 64.5 nF... input voltage is 12 kV at 2.15 kVA.

Enjoy --- I hope the sound track works ;) ....movie link below!

J. Aaron Holmes

Mon May 19 2008, 04:23AM

Registered Member #477 Joined: Tue Jun 20 2006, 11:51PM
Location: Seattle, WA
Posts: 546

Hey, MOT_man:

Cool!! The 76" (per YouTube details) aligns with Freau for 2kVA.

Now you're playing with NST POWERRRRRR!!!!! (not an oxymoron in this case

)

One of these days I'm going to do a Tesla coil music video. I think I'll use Information Society's "Tell Me What's On Your Mind", except that I'll do the opposite of what they did for the radio edit version: I'll ditch all the "I wanna know what you're thinking" baloney, and just keep the "Pure energy" bit

Maybe somebody's already done that, though...

Cheers,
Aaron, N7OE

MOT_man

Mon May 19 2008, 05:47AM

Registered Member #1127 Joined: Mon Nov 19 2007, 12:08AM
Location:
Posts: 139

I'm sure the sparks could get longer if I used a rotary gap or added a few more turns on the primary I think.... maybe I should ramp up the current a bit more and parallel another 12kV 60mA NST. Should be 2.6 kVA total power ---

I was amazed at just how much extra length I got by adding more inductance on the secondary - or by that I mean using a winder form and using the same gauge of wire. It is really interesting. Also my gap is running much cooler than before. I can hear the difference that the gap makes --- and the voltage in gap is less as well.

Steve Conner

Mon May 19 2008, 09:35AM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

Looks great

I'm not surprised that changing from 3.25" to 6.25" secondary gave a big improvement.

Adding another NST should make even more fun, but you may need to make your tank cap bigger too, so it stays LTR.

GeordieBoy

Mon May 19 2008, 09:57AM

Registered Member #1232 Joined: Wed Jan 16 2008, 10:53PM
Location: Doon tha Toon!
Posts: 881

MOT Man, I observed exactly the same two things when I did a similar secondary replacement on my conventional coil a few years ago. On changing from a 700t sec to a 1200t sec the sparks were brighter & longer, and the RSG was much dimmer & less noisey. I put it down to the increase in primary surge impedance and therefore lower losses. Of course it could also be due to better impedance matching into the streamers! Whatever the explanation the difference was obvious to see.

-Richie,

Alexandre

Mon May 19 2008, 04:39PM

Registered Member #1228 Joined: Tue Jan 15 2008, 01:08AM
Location: Curitiba, Brazil
Posts: 162

Verry good job!!!!

MOT_man

Mon May 19 2008, 11:30PM

Registered Member #1127 Joined: Mon Nov 19 2007, 12:08AM
Location:
Posts: 139

Thanks... well, I found out that by adding one more turn of copper tubing gave me an increase of 5-6" on the streamers. So peaks up to 80" are occuring. Power level suggests I'm still running 2.15 kVA. Odd. I'm getting streamers attaching to the roof and to the metal bookshelf. The ceiling is 12 ft and the fire suppression pipe (steel) is hanging 1 foot from the ceiling. As you can tell by the video - the vast majority of these streamers are snappy and white hot... I got a streamer attached to my forehead and it stung... I was about 85" away from the coil when I got hit. This streamer was also responsible for tripping the surge panel for the electrical room and consequently shut the power off to my power supply.
I'm also noticing a lot of residual charge on isolated objects such as glass and metal. I have too been able to produce some nice static sparks after turning the coil off. The air is rich with ozone and NOx ---
So I did some calculations to see what my output voltage might be - tapped at the end turn I am running 65 times my voltage in gap as my output. My guess is that I am running 16.5 kV peak in gap. The gap is set at a little over 1.5 cm a part. So I guess I must be running peaks of 1 Million Volts AC.

J. Aaron Holmes

Mon May 19 2008, 11:56PM

Registered Member #477 Joined: Tue Jun 20 2006, 11:51PM
Location: Seattle, WA
Posts: 546

MOT_man wrote ...

I got a streamer attached to my forehead and it stung... I was about 85" away from the coil when I got hit. This streamer was also responsible for tripping the surge panel for the electrical room and consequently shut the power off to my power supply.

Yowzers! Glad you're still with us! If you plan to run that sucker indoors, it might be worth investing in a cage or at least some grounded metal to stand behind.

This reminded me of an old post from TCML, which describes how a 15-foot streamer from one of Bill Wysock's coils nailed D.C. Cox right in the head, too. Knocked him on his behind. Moral: If you're not sure, stand back further!

http://www.pupman.com/listarchives/1998/March/msg00073.html

Safe coiling!!
Aaron, N7OE

MOT_man

Tue May 20 2008, 12:56AM

Registered Member #1127 Joined: Mon Nov 19 2007, 12:08AM
Location:
Posts: 139

Let say - It was an electrifying experience... no pun intended. I'm fine... no burns... won't do it again!

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