From: "Terrell W. Fritz"
Date: Sun, 03 Jun 2001 00:01:21 -0600
Subject: [TSSP] Re: Racing arc clues...
Here are som interesting secondary arc photos and some comments I made.... He also mentioned that his older caps may drift in value in longs runs throwing the tuning off. - Terry ============= Hi Robin, You coil is interesting! At one point it seems to resist racing arcs: http://www.geocities.com/rcopini/2ndlighti-1.jpg But at another is seems to race well: http://www.geocities.com/rcopini/2ndlightl-1.jpg From: http://www.geocities.com/rcopini/2ndlight.html We think that higher order harmonics set up on the secondary may create local high voltage gradient areas that promote these arcs. However, the same effect may also cause relatively dead areas along the secondary. These great photos would seem to show both. Still much to be learned in this area but we are getting there. High coupling tends to make higher order harmonics worse. Raising your secondary a little may reduce or eliminate the problem if it is bad enough to worry about. Since it is a high voltage breakdown phenomena, air temperature, humidity, etc. will all have an effect. Cheers, Terry At 02:18 PM 6/2/2001 +0930, you wrote: >Hi Justin. > > I am grateful for the number of people who are interested in my problem >with racing >arcs. However, it is not as common as my post my alludes. Some specs just for >interest sakes. > >Secondary : 10inch form 40 inches close wound with 18g double insulated copper. >Primary : half inch copper pipe, tap point, I don't recall, but suffice to >say in >tune. >Cap : CD 942C16P33K - 0.33 MFD 1600VDC, 630VAC, 33 in series, 7 panels for >0.07mfd. >power source : Pole pig, rated 220in/33Kv out , 15 KVA. Overdriven to >280Vin, 20Kva. >Top Load : 12inch X 36inch, (if I recall correctly), spun aluminum 'psuedo' >toroid, >Fres Sec 92Khz. > >If you want to look, go to > > http://www.geocities.com/rcopini/ > >I run my coil about 1 time per month, or more depending on spectators. My >experience >is high heat levels definitely have a deleterious effect as far as racing >arcs are >concerned. In good conditions, and at full power the coil has produced arcs >in excess >of 4.5 metres. In bad conditions, I can't power up to more than half input >power >without having racing arcs. I would be almost certain it has nothing to do >with my >cap, The longest run at high power levels, (within 10% of full power), was >for almost >7 minutes, (we were trying to destroy a laptop :-) ), the coil never >altered it's >performance levels so a cap variation is fairly remote. I find this problem >very >interesting because the coil itself is never changed, just the running >conditions, so >there, I believe, lies the root of the problem. > >Best Regards > > Robin Copini > >P.S. Chris, tell CD the caps are great! >
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.