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




Photo: Copyright of www.extremeelectronics.co.uk





Photo: Copyright of www.extremeelectronics.co.uk

I always have a problem getting horizontal streamers from this coil




Photo: Copyright of www.extremeelectronics.co.uk

Video of a 3½ mins        continuous run

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. Its removal was because 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  23/02/10

Click for Video   7-8 Foot Streamers A Slow Motion Version of the above is Here This was held over the last weekend in October 2009 at the Cambridge Museum of Technology. Despite a disappointing performance on the first day, the coil performed very well on the Sunday. This was basically down to the fact that I managed to get the coil tuned properly, and also the loan of a better spark gap. It is possible to get good performance from a pole distribution transformer (pig) using just a static gap, as you can see below. Power is between 5 to 6 KW.
The MMC value is 64nF which with my ballast of 130.8H is very close to resonance at the mains frequency 50Hz (UK). Doing a Spice simulation it shows that the MMC could in theory charge to 94Kv, whereas if the MMC was away from resonance it would only reach approx' 36Kv. In reality the spark gap clamps the voltage so it never reaches sky high proportions.	'Double Strike'
	Fireproof Roof?
	Prior to Tuning
	After Tuning
	After Tuning

It was not all plain sailing at Cambridge however, as early on in the two day event I had a nasty strike to the secondary. It was not untill I got the coil home and checked it over, that I found that the bottom two turns of the secondary were fused together after the strike. However I was very lucky with the location of the damage as the repair was fortunately quiet simple. The original 1400 turns have now simply become 1398.