Secondary Problems Need Help / Tesla Coils / Forums

Forums

4hv.org :: Forums :: Tesla Coils

« Previous topic | Next topic »

Secondary Problems Need Help

previous 1 2 3 4 next last

Move Thread

LAN_403

teravolt

Wed Aug 19 2009, 02:07PM

Registered Member #195 Joined: Fri Feb 17 2006, 08:27PM
Location: Berkeley, ca.
Posts: 1111

you could use a conical primary like steve wards on Steve Ward's page or maby your tesla is out of tune and you have high voltage nodes in the midle of your tesla secondary

Austin

Wed Aug 19 2009, 02:31PM

Registered Member #1169 Joined: Wed Dec 12 2007, 09:16AM
Location: Portland OR
Posts: 251

yup, it should take you like 5 minutes to figure out if its the coupling.... I only suggested it because he saw sparks at the bottom. I don't think most people "know" for sure its only arcing to the secondary itself.

Although Jonathan did mention knots and sharp edges in his secondary. that could just be corona. if you have knots and the windings are overlapping each other the secondary is going to perform poorly in any scenario.

HV Enthusiast

Wed Aug 19 2009, 02:54PM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068

Sparks at the bottom are usually indicative of poor grounding.

Jonathan Dennis

Wed Aug 19 2009, 06:25PM

Registered Member #2153 Joined: Wed Jun 03 2009, 03:19PM
Location:
Posts: 69

I will try changing the coupling, and I'll check the ground again to make sure it's good. Is there a way to post a video on here? A picture's worth a thousand words but a video is worth a million. I will make a video tomorrow.

J. Aaron Holmes

Wed Aug 19 2009, 06:42PM

Registered Member #477 Joined: Tue Jun 20 2006, 11:51PM
Location: Seattle, WA
Posts: 546

YouTube?

Yep, a vid would be great.

Cheers,
Aaron, N7OE

Herr Zapp

Thu Aug 20 2009, 04:33AM

Registered Member #480 Joined: Thu Jul 06 2006, 07:08PM
Location: North America
Posts: 644

JD -

You wrote: "A picture's worth a thousand words but a video is worth a million. I will make a video tomorrow."

Wrong, at least for this type of troubleshooting. No one is debating that some sort of arcing is occurring; you don't have to "prove" it with a video.

What we need is a series of well-illuminated, good resolution, well-focused macro photos (no blurry cell-phone shots) showing the following:

1. The bottom of the secondary where the arcing is occurring;
2. The bottom of the secondary showing the attachment of your ground connection;
3. The bottom of the secondary and the innermost turn of the primary, at whatever point wherever the clearance between the two is at a minimum;
4. The top of your ground rod, showing how your ground wire is attached;
5. An extreme close-up (if possible) showing one of the areas where the insulation on the secondary wire is "burned off";
6. An extreme close-up (if possible) showing the "black spots" on the secondary wire;

After you have taken the time to set up and capture these photos (you will probably need to use some auxilliary lighting, and a tripod or other means to support the camera), then go ahead and create a video if you feel that it will provide some additional information.

Also, you wrote: "I'm not ABSOLUTELY SURE that my secondary is grounded because my voltmeter will not reach from the coil itself to the ground, it's too far away."

Obviously, you will need to add a piece of extension wire to one of your voltmeter probes to reach your ground rod. If this ISN'T obvious, you may want to get some additional education in basic electrical circuits before trying to tune and optimize this coil.

Regards,
Herr Zapp

Myke

Thu Aug 20 2009, 06:13AM

Registered Member #540 Joined: Mon Feb 19 2007, 07:49PM
Location: MIT
Posts: 969

Jonathan Dennis wrote ...

The wire I used for secondary had several kinks and sharp bends in the spool, and I am considering contacting the company with a complaint as I feel this might be the original cause of the problem.

Seems like everyone is saying the same things over and over and no one has addressed this detail... Maybe the insulation was damaged/weakened when you undid the kinks (which I assume you did). And yes, as said before, coating the secondary with polyurethane wouldn't always solve the problem. If the polyurethane didn't get into the place it was arcing for some reason, all that happened is that the gap where the spark occurs is just covered in polyurethane.

Jonathan Dennis wrote ...

I'm not ABSOLUTELY SURE that my secondary is grounded because my voltmeter will not reach from the coil itself to the ground, it's too far away.

You meter probes not reaching doesn't confirm that the tesla coil is grounded. Either way, it needs to be a good RF ground. It can't just be a rod in some gravel. What sort of soil/ground do you have where you stuck the ground rod? If I recall correctly, other people have had similar problems where there were sparks between turns because of poor grounding. Grounding makes the node of the waveform at the bottom of the coil and the anti-node at the top. Without proper grounding, the node could be anywhere along your secondary.

And again, tuning the coil helps the performance a lot. There are multiple calculators and instructions on how to tune your tesla coil.

Hope you get this problem fixed soon. I'd like to see pics when you get it working.

Jonathan Dennis

Thu Aug 20 2009, 02:27PM

Registered Member #2153 Joined: Wed Jun 03 2009, 03:19PM
Location:
Posts: 69

I'm going to take the pictures and post them. Also, I'm not that incompetent, there are numerous ways I could of gone about checking my ground, but I was under time constraints and I wanted to turn it on b4 I had to go out of town, to see if it worked. I'll add an extension to my voltmeter to test the ground. The ground, is gravel on the surface, and thick mud with more gravel mixed in most of the way beyond that. It's in about 3 feet (and the ground was soaked). I expect that this IS in fact a combination of problems b/tween grounding and/or tuning. In a few hours I will be home and will take some close ups for everyone to examine.

Thanks,
Jonathan

Jonathan Dennis

Thu Aug 20 2009, 05:37PM

Registered Member #2153 Joined: Wed Jun 03 2009, 03:19PM
Location:
Posts: 69

Ok, Pictures! Video will be on youtube shortly and I'll post a link.

Here is the link for youtube video. It shows more than I could capture with the pictures.

Also, I could not get continuity with my volt meter from the toroid to the ground. I fear the worst. :(

Herr Zapp

Thu Aug 20 2009, 06:51PM

Registered Member #480 Joined: Thu Jul 06 2006, 07:08PM
Location: North America
Posts: 644

JD -

Unfortunately, the photos of your secondary are not well enough illuminted, or taken close enough to be of much use.

Most importantly, there is no photo showing how the bottom turn of your secondary wire is connected to your ground wire.
I'm emplasizing this because I STILL suspect that your secondary is not properly grounded. Can you clearly describe how you have connected your secondary wire to your ground wire?

Also, it appears that there may be numerous pinholes or other defects in the insulation of your secondary wire. This may be a non-repairable condition, but get confirmation that your ground is properly connected first.

Once again, take your multimeter and make sure that there is electrical continuity from your topload to your ground rod. You're wasting time and effort looking at other areas if you do not first verify that your ground path is intact.

(You previously mentioned "the base of the secondary(where the windings start) is almost level with the primary". Have you now changed the relationship of the primary to secondary? The photo shows the first turn of the secondary at least 1-1.5 inches ABOVE the level of the primary. With every 1/4" of height difference hetween the primary and secondary having a significant effect on coupling, there's a big difference between "almost level with the primary" and 1 - 1.5" higher than the primary. Again, accurately describing your setup is important.)

Regards,
Herr Zapp

previous 1 2 3 4 next last

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob