UK Teslathons


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Cambridge 2009

Cambridge 2010


As early March is a bit cold for any outdoor tesla coiling, any chance to give it a run inside in the warm is quite welcome. The coil performed well after some early issues  with secondary strikes, but this was soon rectified, resulting in the ceiling of the venue taking a bit of a beating from streamers.

The following pictures were kindly taken for me by Derek of www.extremeelectronics.co.uk
Big tesla coil arc to pole

A very young Phoenix in action



The coil has undergone quite a few changes since this image was captured.
The main improvements have been a new ballast, more capacitance and better heat sinking of the SRSG.
A new addition I recently made, (June 2015) but currently untried, is off-set terminals on the SRSG rotor, as advocated on Richie Burnnett's webpage.
Tesla coil hitting pole




I always have a problem getting horizontal streamers from this tesla coil. They are either hitting the floor, or more often than not hitting the ceiling.

tesla coil running

This secondary has suffered several incidents of damage, either from primary arcing or streamer hits (see below for Cambridge damage)   This may be because I no longer have a strike ring as on previous coils.
The removal was because rather than protect, it seemed to attract streamers even more, I will however soon be adding an earthed wire around the periphery on the underside of the Acrylic sheet that protects the primary.

After the damage above had occurred, I repaired the secondary by loosing a few more turns, which takes it down now to about 1394 turns from the original 1400.
I also raised the secondary to reduce the coupling and give more clearance between the inner turn of the primary and the secondary.  The topload was also lowered by an inch to provide more shielding.
The effect of both these moves has resulted in no more secondary damage even after a few protracted runs.

For More Photos of Nottingham Gaussfest 2010:     

Goto the organisers site

YouTube video Tesla Coil at Cambridge


youtube video of tesla coil running
My eight inch coil running on my PDT (Pig)

Cambridge 2009: 6kW~

This was running with a blown static gap. Shortly after this I changed to a 200 bps synchronous rotary.

youtube video of tesla coil running

youtube video of tesla coil running
A Slow Motion Version of the above.

Phoenix tesla coil

The Cambridge (UK) 2009 Teslathon was held over the last weekend in October at the Cambridge Museum of Technology.

Despite a disappointing performance on the first day, the coil performed very well on the Sunday.
The improvement was basically down to the fact that I managed to get the coil tuned properly overnight, and also the loan of a better static spark gap, (thanks Phillip).
It is possible to get good performance from a pole distribution transformer (PDT) even when just using a static gap rather than the normal RSG (be it an ARSG or SRSG variety).

Power is between 5 to 6 KW.

The MMC value is 64nF which with my ballast of 130.8H (secondary side equivalent value) is very close to resonance at the mains frequency 50Hz (UK).

Phoenix tesla coil in action
Phoenix tesla coil again
Phoenix tesla coil hitting ceiling
the Phoenix tesla coil
The Phoenix tesla coil hitting a pole
Phoenix tesla coil in action again
secondary damage

It was not all plain sailing at Cambridge however, as on the first day I had a rather nasty strike to the secondary, but it was not until I got the coil home that I discovered it. I found that the bottom two turns of the secondary had become fused together after the strike. However I was very lucky with the location of the damage as the repair was fortunately quite simple. The original 1400 turns have now simply become 1398.