Original poster: syd <tesla@xxxxxxxxxxxxxxx>If your burning up the electrodes that fast then there is too much current density in the gaps. You could run at lower power (which you don't want to do), you could use more gaps in series (which I wouldn't recommend because of losses, and four should be ample), you could use forced air (which I think is unnecessarily complex), OR.. the best bet would be to use larger diameter electrodes. You say you're using tungsten; is it pure tungsten? I've used both pure tungsten and oxygen free copper as electrode material, and I must say that I prefer the copper. One would think that because tungsten's melting point is over 3 times that of copper that tungsten would have a much greater longevity in spark gap service. In my experience both the tungsten and the copper are consumed at a remarkably similar rate. I suspect that copper's superior thermal and electrical conductivity may be contributing to the anomaly. One thing is for certain: spark gap electrodes ARE a consumable, and copper is MUCH less expensive.
syd klinge Tesla list wrote:
Original poster: "miles waldron" <mileswaldron@xxxxxxxxxxx> Here is a pic of my friends running coil; it is throwing 10 and 11 foot arcs right now. http://www.gravitymagnet.com/kenmay/images/wn1.JPG We are having the following difficulty and ask your advise. The tungsten rods in the async rotary 6 point 4 pickup spark gap glow red hot after 25 to 30 seconds of use. Maybe less. The tungsten rods then disintegrate. This is bad. How can we improve run time? Do we need another gap? Do we need a different kind of gap? Do we need to quench this gap with an air compressor? Here is a link to a close up of the spark gap: http://gravitymagnet.com/kenmay/images/blueasync.jpg Thanks! Miles & Ken http://www.gravitymagnet.com http://www.kenscoil.com