6 Inch Coil - Log



Date
Entry
8/30/05
There have been different opinions about my primary coil, and it may be alright the way it is. My boss at work (Noguska) saw this site and thought the coil looked pretty neat. So I took it to work and ran it inside for the first time. At first, I was worried that my performance might not be very good because 1) The gaps needed cleaned, 2) The tuning indoors might be way off, 3) My ground connection was 40-50 feet long, with no real clamp to the ground rod, and 4) nothing ever goes right in front of 10 people. Instead, it performed very well, and I got a chance to take some video. I've yet to look at it, but I plan to get some video and still shots up here as soon as I can.

I've also been putting a good deal of time into my SRSG. If you recall, I modified my motor like 100 years ago, but never got around to making the SRSG. Now, I have my base built, the (modified) motor mounted, and my rotor built. The rotor was made from an aerator disc (the top one that protects the motor), and a brass ring. Pics coming soon. I'll let you know when I get the stationary electrode holders made/mounted.
8/10/05
Until recently, my coil has just sat on a shelf out in my shed. A few days ago, however I did get it down again, to play around some more. It still does not have the rest of the Terry Filter installed, as I need to get more MOVs for it (and the time). I have the large power resistors and safety gaps still there though. I realized through a little playing around that this coil has some relatively bad design flaws. 1) Primary Coil - I ran out of Cu tubing during construction, and ended up with just barely 10 turns on the primary. It should have about 12, maybe 13 to be sure. I think I will try to remedy this by getting some more .25" Cu tubing and solder it on to the end of my current coil.   2) Secondary Height - At its lowest, my secondary can only be level with the primary coil. To increase coupling, I could cut a hole in my deck like I mentioned in a previous entry, but I want to keep this as a last resort.   3) Toroid - My torod is 4 x 16 - awfully small especially considering I am a bit shy on the number of primary turns. I think I might try to build a larger toroid out of pizza pans, and 6" ductwork.

I've also realized that there is a bunch of 'broken' stuff on this site and I will begin fixing all that now. Until next time.....
7/8/03
Well, It's certainly been a long time since I've written in here. Coiling gad to take the back-burner to school and other crap. One update is that there are pictures now, here. The audio in the newer photos is weird, It sounds like some sci-fi UFO... Nothing at all like a real coil, must be the compression. Anyways, not much has changed about the coil or anything. I am ordering new MOVs for the filter right now, and I'm making some changes to the website, so some bookmarks might not work... Anyways, have a nice summer.
9-28-02
  Well, over the summer I did a whole lot of nothing. It was nice! But about three weeks ago, I set up just my NST and the tank circuit. Since the primary was not in circuit, the capacitor was out too, so just the NST, filter, and gaps (safety & spark) were in. I set this up so that I could see how many gaps it would take.

  Before when I would run it, the SG wouldn't fire with more than 3 gaps selected.

    3 * .025 = .075" !!!

Thats a firing voltage of

  (.075 * 75,000) ~= 5625 Volts! Terrible!

  So that is why I was running that test. Anyways, while doing it, smoke erupted from the filter board. While examining the burnt-out MOV , I noticed a piece of very thin solder or wire or something stuck under that and an adjacent MOV's leads, shorting them out. With the MOV(s?) shorted out, that lowered the trigger level for which the MOVs should clamp. So they were like a dead short from NST+ to ground. The MOV couldn't take the solid 60 mA, and died. I guess MOVs fail closed, because I killed another MOV before I was done (:-\).

  After that, I just took out the filter board, (which does not include safety gaps or Power Resistors) altogether. Upon testing, I could use all 11 or 12 gaps. Of course, then, I hookedd up the coil, and ran it the next night.

  OH MY GOD! Sold 36" 'ers, and possibly a 40". I admit, even I was a bit scared! :-D Terry Fritz said, "If your coil scares you, its working just right..." Well put Terry! i have no still photos available yet, but there are videos here. Also read the info.txt file with my comments.

  I'll be sure to keep you updated.
6-14-02
YES! School's Finally out!!! Now I might be able to get some work done on revamping my coil...I think I was wrong about the last Journal Entry, because If the coupling were the problem, the coil would tune best at the outermost point. But mine doesn't, It tunes about two turns in. Now I think that the problem may be the Spark Gap. Many people say that static spark gaps like mine do not work very good. So I plan on making some sort of synchronous gap. I have two choices: Rotary Gap, or Triggered Gap. I have the synchronous motor for the RSG, and I have nearly all the components (some assembled) for the TSG. Which should I choose? Tell me what you think. Either way, I think I have to bump my cap up to .034 uF. That means I will have to change a lot of things on my tank circuit board. Well, I will surely post my decision here.
4-17-02
I belive that one reason that my sparks are only half as good as they should be, is coupling. Due to a design flaw, I can't lower my secondary coil. Only raise it. To remedy this, I am going to cut a hole in my primary deck, big enough for the secondary to fit through it. Then I will attatch a metal plate to the bottom of the deck, with the original bolt pattern in it. Then I will be able to lower the secondary to increase coupling. I will still be able to raise it, by placing shims between the secondary and the plate. Confused? Check out this diagram.
3-7-02
Science fair was today. I earned a superior rating! I also got the Governor's Award for Excellence in Energy Research. And what'd you know, I got best of show!!!
3-5-02
Pretty Good! After tuning, I got about 20" sparks to a grounded rod! But, greedy me, I'd still like sparks in the 40's... Pics coming soon
3-03-02
As of 7:30 PM yesterday, The Coil is Completed!!! But it was raining and windy, so it is still unfired... Outside today, It is snowing and blowing... :-( I'll post the results here, and to the TCML as soon as i get them.
1-31-02
Ok, slight change... I'm using the static spark gap for now, and the TSG later, because first of all, I don't have .034uf of caps, and I'm getting close on time for the Science Fair. So, I have the MMC done, the filter done except for the power resistors, and I completed the secondary coil. Turned out very well. 6.25" OD PVC. #20 magnet wire and 6 coats of polyurethane varnish.
1-11-02
Hey, Progress! I got the low voltage components in the triggered gap done. I also have my MMC done! Except for the small burn on my finger, nothing went wrong :-) Stay tuned
12-22-01
Geez, I'm slow!!! No new news, except for the fact that I've decided to build a Triggered Spark Gap instead of a RSG... I have almost all the parts, and will assemble it during Christmas Vacation... Feliz Navidad!
9-15-01
I got all my caps and bleeders, and when I get a chance, I'll put together my MMC...
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