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Using a big TC on stage? Australia's Got Talent

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LAN_403

Tesladownunder

Sun May 08 2011, 03:48AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

The heats that I appear in will be screened on Australian Channel 7 Tuesday May 10th at 7:30pm. Shortly afterwards they should appear on the AGT website though not sure if these are viewable overseas.

So how did it go? Far from smoothly.
I can say that there were no problems with interference to cameras, mics or audio and no tripping of RCD's, breakers or other such problems that I worried about before.

I will post details with pics and video after it screens.

Here is a pic from my hidden video camera that recorded it all. It shows me with a wooden rod holding CD's that is burning up.

Steve Conner

Sun May 08 2011, 08:10AM

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

Well done TDU!

would you care to share any details of the "far from smoothly"?

Avi

Tue May 10 2011, 10:15AM

Registered Member #580 Joined: Mon Mar 12 2007, 03:17PM
Location: Melbourne, Australia
Posts: 410

Here is the video

Tesladownunder

Fri May 13 2011, 07:51PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Well it has all run on Australian TV on May 10th.
On screen it all went well. See video link same as above.

They did quite a good job of it in the end. Sadly they didn't use the the sound track that my son did.

All videos and YouTubes are on my Tesladownunder.com home page. Including ones accessible outside Australia.

Steve McConner wrote ...

Well done TDU!

would you care to share any details of the "far from smoothly"?

Well, here is the saga that you don't see...

What you didn't get to see was that I took 6 minutes to start the show after the judges OK. As I went to start, There was no power! I had to undo my gear and scamper off stage to turn on the power at the distribution box which had been left off for safety reasons. But when I got there it was dark and I didn't have a torch. I took a stab that these switches were up for on.
Back to the control box and power was lighting up the pilots. Thank God!

2 minutes have now passed but the power is on and the serial gap blower and rotary spark gap are running (apparently).

Back to starting position but again no sparks. WTF.
Undo my gear and head back. I have no idea what is wrong and it takes me 4 minutes to trouble shoot.
Actually I reckon I was fairly cool here. Heck, no-one is dying, I am not going to jail. The worst that will happen is that all my efforts have come to nothing. so no swearing, no embarassment, just acknowledge the crowd and go and fix it.

I eventually realise that my rotary gap motor is not running. I can't tell this as it is hidden under a black cloth skirt and the blower drowns it out.
The reason it is not running is that it runs at about 110V out of it's rating of 240V. Unless it is given a little boost in voltage, it sometimes doesn't start.
I had used voltage isolating transformers with extra voltage drop and in my haste, forgot to give it a boost in voltage. So it sat there with 110 V applied, dead still. It just took a little flick with a finger to get it to start spinning up to speed.

So now 6 minutes have passed, the crowd is restless and talking but once th TC fires, they cheer and the show begins.

Sensibly they edited this out. I didn't really tell anyone what was wrong so they may have put their own safety slant on it. But it didn't detract from the production in the end.

Click to see the 7 second gif of the 2 min show.

magnet18

Fri May 13 2011, 09:12PM

Registered Member #3766 Joined: Sun Mar 20 2011, 05:39AM
Location:

Posts: 624

Avi wrote ...

Here is the video

Well, done, but I really hate those youtube trolls who assume that anything with high voltage is a death sentence and immature >:-(

female judge wrote ...
Is it safe with those wires just hanging there?

YES! LRN!!1!!!!!

Glad you found the problem, trouble shooting last minuet things is always fun...
<insert robot competition story>

Tesladownunder

Sat May 14 2011, 04:48AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

The judge, Dannii Minogue noticed me bump into and loosen a down wire and commented on that. It was only a wire for cosmetic symmetry purposes in that area and I was aware that I might bump it so secured it only with a half twist.

Funny, really, because I brought a 4.5kVA generator with me as an emergency back up, but didn't end up using it and it would have messed things up if I did.

And other things that didn't work?
At the end of the finale there was meant to be a capacitor bank explosion that showered steel wool sparkles over the whole of the TC area. It was setup so this visual flash of the explosion would not affect the judges or the central cameras.
I had originally planned a conservative 5kJ (1/2 power). When I did a test for the producer the bang and echo were huge. It a very resonant room. The producer gave me a thumbs up. The safety officer went pale as decibels flashed past his eyes.
So as requested I arranged to use a smaller power. Since ears have a logarithmic response then to reduce the sound pressure level by half, I would need to reduce this to 1/4 power ie 1.25kJ. This is tiny and I had no idea how much steel wool to use to optimise things.
In the end with all the delays the charge had largely dissipated and there was no bang at all.

The smoke generator was a late addition but had too much condensation in the long corrugated feed and was not visible.

The video that shows the delays and problems is here. Annotated and a bit of a laugh.

Here is a strike towards the judges to a side screen.

1305348326 10 FT107519 Leftscreenstrike1

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