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Red Traffic Cone - new SSTC with conical secondary - full power

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Mates

Wed Oct 14 2009, 09:02AM

Registered Member #1025 Joined: Sun Sept 23 2007, 07:53PM
Location: Czech Rep.
Posts: 566

Red Traffic Cone is a name of a great album made by German band Kraftwerk in 1971 (recommended!) and now it is also a name of my new coil.

I always wanted to experiment with different shapes of the secondaries. It was Tesla by himself who claimed that conical secondary was a breakthrough which shifted his HV experiments up to 100 megavolts range. Here is my first attempt, first test, first sparks at low power and already first big surprise which is related to the wave forms generated by the TC (see the pictures below)

Basic data:

Secondary:
50cm high traffic cone made of PVC
Wire: 0.315mm
Diameter of the base 20cm
Diameter of the top 7cm
Coated by clear acrylic

Primary:
8 turns power cable 16mm (used for high power car amplifiers)

Driver:
Single switch with cap limiter, no interrupter

Driving freq: 185 KHz

Any comments are appreciated, mainly an explanation for the odd wave forms (how the hell is this possible, my previous SSTC with same driver generated only very nice sinus)

Winding was a PITA work. Much more difficult than winding a classical tube

First sparks at low power (30%). Not bad to my standards. I could not get higher becuase an arcing into the primary started

Gate pulses: PW: 1us, Freq: 5,4 us

This are the waves produced by the coil. Have anyone of you ever seen something like this?

Steve Conner

Wed Oct 14 2009, 09:44AM

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

Excellent! :D

The weird display is caused by the magnetic field from the coil deflecting the electron beam in your scope directly. Try moving the scope further away!

brtaman

Wed Oct 14 2009, 10:26AM

Registered Member #2161 Joined: Fri Jun 05 2009, 03:36PM
Location:
Posts: 247

Great conical secondary, how was it to wind?

Hope you don't mind me asking, but where did you get the topload? I have been on a hunt to find a decent topload in Europe, with no luck.

Which IGBT are you using, it seems to be doing the job very well.

Mates

Wed Oct 14 2009, 11:32AM

Registered Member #1025 Joined: Sun Sept 23 2007, 07:53PM
Location: Czech Rep.
Posts: 566

brtaman wrote ...

Great conical secondary, how was it to wind?

Hope you don't mind me asking, but where did you get the topload? I have been on a hunt to find a decent topload in Europe, with no luck.

Which IGBT are you using, it seems to be doing the job very well.

Hi,
Winding the conical shape was horrible. After three unsuccessful attempts I found that the best way how to do it is to secure each finished section by glue tape and/or nail polish to avoid spontaneous unwinding caused by decreasing diameter. Funny thing was that after I successfully finished the coil for the first time a found a crossed wire in the first third of the coil

. So I had to unwind it and do it againâ€¦ But the very last try was a question of 2hours (I had already a lot of experience

)

The top load was originally a thermal stainless coffee mug which I bought in Denmark. It is double layered so the capacitance is higher than it looks.

Regarding the IGBT, it is BUP314 and for the whole driver design you can have a look here:

Cheers Mates

Proud Mary

Wed Oct 14 2009, 12:15PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Really good to see something a bit new, Mates! Well done!

Proud Mary

Wed Oct 14 2009, 12:27PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

brtaman wrote ...

but where did you get the topload? I have been on a hunt to find a decent topload in Europe, with no luck.

Hi Rok,

search for "stainless steel mirror balls" or "Garden ornament mirror balls" or "gazing balls."

Here's one example, but there are plenty of others, sometimes a bit cheaper:

Dr. Dark Current

Wed Oct 14 2009, 04:43PM

Registered Member #152 Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384

Nice idea.
Wouldn't it be easier to start winding from the narrow end?

Mates

Wed Oct 14 2009, 07:59PM

Registered Member #1025 Joined: Sun Sept 23 2007, 07:53PM
Location: Czech Rep.
Posts: 566

Dr. Kilovolt wrote ...

Wouldn't it be easier to start winding from the narrow end?

No, but it is true I tried it as the first option. Problem is that the wire has tendency to slide down.

What is more interesting to me at the moment is to try to place the topload on the other side of the coil (in other words to stand it upside down - on the tip).

Mads Barnkob

Wed Oct 14 2009, 08:11PM

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

Mates wrote ...

Dr. Kilovolt wrote ...

Wouldn't it be easier to start winding from the narrow end?

Super cool that you did this! I have tried once to make a conical secondary too, but gave it up as it was a pain to do and at the moment I thought noone had done it, until I found out Tesla did it :)

That could be interesting to see, that you have the high voltage at the end with lowest Fres, if we talk about a secondary that way.

Coronafix

Thu Oct 15 2009, 05:00AM

Registered Member #160 Joined: Mon Feb 13 2006, 02:07AM
Location: Melbourne, Australia
Posts: 938

Haha!! That's great Mates!! I have often thought about doing the same with a traffic cone but the pain I would have to go through to wind it always put me off. Good on you for persisting!!

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