TESLA COIL ~ First Fire-Up

[Blackbeard]

We built our caps using the salt water/beer bottle trick. When we
fired it up, the bottles started to glow purple.

We never got any streamers. At the toroid, we noticed some slight
sparking between the magnet wire and the connection to to toroid. Out
of curiosity, we place a florescent bulb on top of the toroid. The
bulb glowed on our test....but still no streamers. Since the bulb
glowed, I assume it was getting power to the toroid. But we let the
thing run for at least 30 seconds and never saw lightening.

So we're stymied. Don't have a clue why we have no streamers. We had
approx. 2mm on our spark gap.

Here's how it's built...

Primary coil - 15 turns using 1/4OD Copper tubing
Secondary - 1500 turns using 24-gauge wire
Magnet wire from secondary connect to toroid at the top
Magnet wire from bottom of secondary goes to ground

Capacitors = 6 bottle filled with salt water, wrapped with aluminum
foil all daisy-chained together with wire.
One single wire on the daisy chain connects to the transformer
The second wire on the transformer connects to an aluminum pan that
makes a connection with those bottles where the aluminum makes contact
with the aluminum pan.

Spark Gap - the spark gap doesn't make a whole lot of sense to me. We
pulled a second wire off the two posts from the transformer and the
spark gap was not connected in-line with anything. This is how our
plans show this is supposed to be done.

It sparked at the spark gap
Bottle glowed purple
florescent light lit up
....No streamers.

We have to be close. Doesn't that florescent light glowing suggest I'm
getting power up there?

the toroid is made from a piece of semi-rigid aluminum duct attached
to a 5-gallon paint buck lid to hold it's shape. We connected the
toroid using an a plastic toilet flange connected to that 5-gallon
bucket lid. The tolet flange fits right onto the 4" PVC pipe we used
for the secondary coil.

Any help or suggestions would be appreciated.

 

[Blackbeard]

On Fri, 04 Feb 2005 08:02:15 -0700, Mark Fergerson <nunya@biz.ness>
wrote:

Blackbeard wrote:
We built our caps using the salt water/beer bottle trick. When we
fired it up, the bottles started to glow purple.

That's not a good sign. Is the glass itself glowing, or the air
around them? If the latter, that's just corona (air excited into glowing
visibly, the electrical equivalent of pressure-caused leakage). If the
former, you may be producing x-rays.

It looked like the water was glowing. But I've never seen a tesla coil
fire in real life and I wasn't about to get too damn close. The glass
wasn't glowing. It must have been the air inside.

We never got any streamers. At the toroid, we noticed some slight
sparking between the magnet wire and the connection to to toroid. Out
of curiosity, we place a florescent bulb on top of the toroid. The
bulb glowed on our test....but still no streamers. Since the bulb
glowed, I assume it was getting power to the toroid. But we let the
thing run for at least 30 seconds and never saw lightening.

Good powers of observation! Sparks where the secondary connects to
the toroid indicates a poor electrical connection. Is it soldered,
bolted, duct-taped, what? Did you remember to strip the insulation off
before making that connection? I ask because we've all made these mistakes.

No - I assume when you asked about stripping the insulation, you mean
did we remove the fine film that coats that magnet wire. And no, we
didn't. How do I do that without messing up the wire? It is not
soldered. He used a piece of electrical tape to tape it directly to
the aluminum part of the toroid. Wow...that wire stripping thing could
make a huge different I would think.

The bulb lighting does indeed indicate several things; first, you're
getting some power transfer from primary to secondary, thence to the
bulb, so the thing is _trying_ to work.

As for not getting lightning, likely it isn't tuned properly, among
other things. BTW, try running it in poor lighting (make damn sure you
know where everything is, including the main cutoff switch FIRST).
That'll allow you to look the entire setup over for corona. Corona
anywhere but the toroid is a Bad Thing.

We fired the thing at night. The only visible things we observed were
(or course) the spark gap and the purple glow in the bottle capacitors
and a very faint spark where the connection goes from secondary to
toroid.

Side note; remember that the toroid is one plate of a capacitor whose
value depends partly on its surface area. Once you do get the thing
tuned, putting a fluorescent or anything else on or near the toroid will
detune it somewhat from resonating with the primary.

I gotcha. So as a test, I can use the light to see if we're getting
any power at all. But we have to remove it or we've screwed the
frequency. Makes sense. That didn't occur to us last night.

So we're stymied. Don't have a clue why we have no streamers. We had
approx. 2mm on our spark gap.

Might be too large a gap. Can you tighten it up a bit?

We were told 2mm gap for a total of 12mm by having several gaps. I had
the thought of building a spark gap that was only 1mm and doubling the
length of the gap. I figured that using alligator clips, you could
adjust the gap just by clipping on the desired pieces of copper. So
the gap could be adjusted by 1mm quickly and easily. Is that a
workable solution?

Here's how it's built...

Primary coil - 15 turns using 1/4OD Copper tubing
Secondary - 1500 turns using 24-gauge wire
Magnet wire from secondary connect to toroid at the top
Magnet wire from bottom of secondary goes to ground

Capacitors = 6 bottle filled with salt water, wrapped with aluminum
foil all daisy-chained together with wire.
One single wire on the daisy chain connects to the transformer
The second wire on the transformer connects to an aluminum pan that
makes a connection with those bottles where the aluminum makes contact
with the aluminum pan.

Fine so far.

Spark Gap - the spark gap doesn't make a whole lot of sense to me. We
pulled a second wire off the two posts from the transformer and the
spark gap was not connected in-line with anything. This is how our
plans show this is supposed to be done.

Your post announcing the schematic showed up in the binaries group,
but not the schematic itself. Does your ISP not allow you to send
binaries? I'd _really_ like to see it.

It sparked at the spark gap

Good sign

Bottle glowed purple

bad sign

florescent light lit up

good sign

...No streamers.

I warned you not to be surprised. Tesla coilers proudly (as you're
learning, for good reason) proclaim "first light" when that happens.

The kid was a bit disappointed, but the glowing florescent suggest to
him that he was on the right path. I think he'll pull it off with a
little tweaking.

We have to be close. Doesn't that florescent light glowing suggest I'm
getting power up there?

Yep, just not enough.

the toroid is made from a piece of semi-rigid aluminum duct attached
to a 5-gallon paint buck lid to hold it's shape. We connected the
toroid using an a plastic toilet flange connected to that 5-gallon
bucket lid. The tolet flange fits right onto the 4" PVC pipe we used
for the secondary coil.

Sounds sturdy, which is a good thing.

Any help or suggestions would be appreciated.

Show us the schematic!

I'll have to get the schematic from the kid when he gets home from
school today. I'm trying to keep him in the drivers seat on the
project. I'm pretty excited about it myself. I can imagine that his
excitement is about 100-fold since he built the thing.

I'll get that schematic and post later. We'll try removing the coating
on that magnet wire where it connects to the toroid. Any chance that's
the problem?

I read that "tuning" can be done by adjusting the spark gap and by
moving the connecting wire to different locations on the primary.
Somebody mentioned using some sort of tesla coil math to figure out
the "sweet spot". I don't have the slightest clue where to start on
tuning this thing.

I'll try to get some close-up pictures in addition to the schematics.

thanks for you help
Mike

> Mark L. Fergerson

 

[Mark Fergerson]

Blackbeard wrote:

On Fri, 04 Feb 2005 08:02:15 -0700, Mark Fergerson <nunya@biz.ness
wrote:

Blackbeard wrote:

We built our caps using the salt water/beer bottle trick. When we
fired it up, the bottles started to glow purple.

That's not a good sign. Is the glass itself glowing, or the air
around them? If the latter, that's just corona (air excited into glowing
visibly, the electrical equivalent of pressure-caused leakage). If the
former, you may be producing x-rays.

It looked like the water was glowing. But I've never seen a tesla coil
fire in real life and I wasn't about to get too damn close. The glass
wasn't glowing. It must have been the air inside.

Yep. X-rays is an extreme outside possibility, but I had to ask.
Still, that corona is power wasted instead of going to the secondary.

We never got any streamers. At the toroid, we noticed some slight
sparking between the magnet wire and the connection to to toroid. Out
of curiosity, we place a florescent bulb on top of the toroid. The
bulb glowed on our test....but still no streamers. Since the bulb
glowed, I assume it was getting power to the toroid. But we let the
thing run for at least 30 seconds and never saw lightening.

Good powers of observation! Sparks where the secondary connects to
the toroid indicates a poor electrical connection. Is it soldered,
bolted, duct-taped, what? Did you remember to strip the insulation off
before making that connection? I ask because we've all made these mistakes.

No - I assume when you asked about stripping the insulation, you mean
did we remove the fine film that coats that magnet wire. And no, we
didn't. How do I do that without messing up the wire? It is not
soldered. He used a piece of electrical tape to tape it directly to
the aluminum part of the toroid. Wow...that wire stripping thing could
make a huge different I would think.

You bet it will. 24 gauge is easy to strip if you're careful. Scrape
with an exacto knife or similar tool, just don't scrape copper off if
you can help it. Electrical tape is fine for testing, but it really
should be more firmly attached so that the copper is in direct contact
with the toroid before it goes to school. Copper won't solder to
aluminum without special solder and flux. One way to do it mechanically
is to run a self-tapping sheetmetal screw into the toroid and wind the
stripped part of the wire onto the screw just before tightening it down.

The bulb lighting does indeed indicate several things; first, you're
getting some power transfer from primary to secondary, thence to the
bulb, so the thing is _trying_ to work.

As for not getting lightning, likely it isn't tuned properly, among
other things. BTW, try running it in poor lighting (make damn sure you
know where everything is, including the main cutoff switch FIRST).
That'll allow you to look the entire setup over for corona. Corona
anywhere but the toroid is a Bad Thing.

We fired the thing at night. The only visible things we observed were
(or course) the spark gap and the purple glow in the bottle capacitors
and a very faint spark where the connection goes from secondary to
toroid.

That may change once you get the toroid properly connected and the
primary tuned.

Side note; remember that the toroid is one plate of a capacitor whose
value depends partly on its surface area. Once you do get the thing
tuned, putting a fluorescent or anything else on or near the toroid will
detune it somewhat from resonating with the primary.

I gotcha. So as a test, I can use the light to see if we're getting
any power at all. But we have to remove it or we've screwed the
frequency. Makes sense. That didn't occur to us last night.

Putting the bulb won't screw it up past saving, just detune it enough
to make it work a little harder. Don't expect to get lightning while
you're lighting the tube. FTM you can always retune it to work with the
bulb on it...

So we're stymied. Don't have a clue why we have no streamers. We had
approx. 2mm on our spark gap.

Might be too large a gap. Can you tighten it up a bit?

We were told 2mm gap for a total of 12mm by having several gaps. I had
the thought of building a spark gap that was only 1mm and doubling the
length of the gap. I figured that using alligator clips, you could
adjust the gap just by clipping on the desired pieces of copper. So
the gap could be adjusted by 1mm quickly and easily. Is that a
workable solution?

Yeah, but that changes the amount of energy going into the cap each
cycle. OK, if 12 mm is what the plans say.

<snip>

...No streamers.

I warned you not to be surprised. Tesla coilers proudly (as you're
learning, for good reason) proclaim "first light" when that happens.

The kid was a bit disappointed, but the glowing florescent suggest to
him that he was on the right path. I think he'll pull it off with a
little tweaking.

From your discussion of his previous experience in school, some
encouragement is definitely in order. Even if nobody else praises his
efforts (many will rag him without admitting it's because he did
something they can't) the satisfaction of "first light" will boost his
self-confidence dramatically.

<snip>

I'll have to get the schematic from the kid when he gets home from
school today. I'm trying to keep him in the drivers seat on the
project. I'm pretty excited about it myself. I can imagine that his
excitement is about 100-fold since he built the thing.

Good for both of you. Just riding along can be a thrill, and knowing
that the fruit of your loins can do things like this won't hurt _your_
self-confidence, either! ;&gt

I'll get that schematic and post later. We'll try removing the coating
on that magnet wire where it connects to the toroid. Any chance that's
the problem?

It's certainly _a_ problem.

I read that "tuning" can be done by adjusting the spark gap and by
moving the connecting wire to different locations on the primary.

Yep.

Somebody mentioned using some sort of tesla coil math to figure out
the "sweet spot". I don't have the slightest clue where to start on
tuning this thing.

I could point you to webpages with equations all over the place, but
it's likely a bit beyond your son unless he's in a high-school honors
math program. Save that until after he wants to know how to build a
really big one, then he can work them backwards to discover why you
won't pay for an extra 100 amp power hookup.

The plans you have should suggest where on the primary coil to attach
the connection going to it, and that's a good place to start. Watch for
corona on the toroid as you adjust the tap. The point where you achieve
resonance (and breakout) will be unmistakable.

I'll try to get some close-up pictures in addition to the schematics.

Wouldn't hurt, if for no other reason to make sure you are reading
the diagram properly.

thanks for you help

You're very welcome. I keep thinking back to my youth when I could
have used some pointers.

Mark L. Fergerson

 

[Blackbeard]

I think I may have found a problem with the design. The bottles used
for the bottle capacitor had two wires running down inside the bottle
instead of just one. The idea was to daisy-chain. But having the two
wires down inside each bottle, it looked like there was an arc between
those two wires. He's re-doing the bottle capacitor with only a single
electrode inside each bottle. That should eliminate that arc problem.
And I assume that might have been the source of a major power draw and
possible why the bottles were glowing purple.

We did shave the coating off the magnet wire. At this point, the only
problem that was noticable was the arc problem inside the bottle
capacitors. And I'm not sure my "best guess" on that is correct. But I
guess we'll see.

It feels like we're getting closer. Might have streamers before the
weekend is out. Any other ideas?


On Fri, 04 Feb 2005 14:22:26 -0700, Mark Fergerson <nunya@biz.ness>
wrote:

Blackbeard wrote:
On Fri, 04 Feb 2005 08:02:15 -0700, Mark Fergerson <nunya@biz.ness
wrote:

Blackbeard wrote:

We built our caps using the salt water/beer bottle trick. When we
fired it up, the bottles started to glow purple.

That's not a good sign. Is the glass itself glowing, or the air
around them? If the latter, that's just corona (air excited into glowing
visibly, the electrical equivalent of pressure-caused leakage). If the
former, you may be producing x-rays.

It looked like the water was glowing. But I've never seen a tesla coil
fire in real life and I wasn't about to get too damn close. The glass
wasn't glowing. It must have been the air inside.

Yep. X-rays is an extreme outside possibility, but I had to ask.
Still, that corona is power wasted instead of going to the secondary.

We never got any streamers. At the toroid, we noticed some slight
sparking between the magnet wire and the connection to to toroid. Out
of curiosity, we place a florescent bulb on top of the toroid. The
bulb glowed on our test....but still no streamers. Since the bulb
glowed, I assume it was getting power to the toroid. But we let the
thing run for at least 30 seconds and never saw lightening.

Good powers of observation! Sparks where the secondary connects to
the toroid indicates a poor electrical connection. Is it soldered,
bolted, duct-taped, what? Did you remember to strip the insulation off
before making that connection? I ask because we've all made these mistakes.

No - I assume when you asked about stripping the insulation, you mean
did we remove the fine film that coats that magnet wire. And no, we
didn't. How do I do that without messing up the wire? It is not
soldered. He used a piece of electrical tape to tape it directly to
the aluminum part of the toroid. Wow...that wire stripping thing could
make a huge different I would think.

You bet it will. 24 gauge is easy to strip if you're careful. Scrape
with an exacto knife or similar tool, just don't scrape copper off if
you can help it. Electrical tape is fine for testing, but it really
should be more firmly attached so that the copper is in direct contact
with the toroid before it goes to school. Copper won't solder to
aluminum without special solder and flux. One way to do it mechanically
is to run a self-tapping sheetmetal screw into the toroid and wind the
stripped part of the wire onto the screw just before tightening it down.

The bulb lighting does indeed indicate several things; first, you're
getting some power transfer from primary to secondary, thence to the
bulb, so the thing is _trying_ to work.

As for not getting lightning, likely it isn't tuned properly, among
other things. BTW, try running it in poor lighting (make damn sure you
know where everything is, including the main cutoff switch FIRST).
That'll allow you to look the entire setup over for corona. Corona
anywhere but the toroid is a Bad Thing.

We fired the thing at night. The only visible things we observed were
(or course) the spark gap and the purple glow in the bottle capacitors
and a very faint spark where the connection goes from secondary to
toroid.

That may change once you get the toroid properly connected and the
primary tuned.

Side note; remember that the toroid is one plate of a capacitor whose
value depends partly on its surface area. Once you do get the thing
tuned, putting a fluorescent or anything else on or near the toroid will
detune it somewhat from resonating with the primary.

I gotcha. So as a test, I can use the light to see if we're getting
any power at all. But we have to remove it or we've screwed the
frequency. Makes sense. That didn't occur to us last night.

Putting the bulb won't screw it up past saving, just detune it enough
to make it work a little harder. Don't expect to get lightning while
you're lighting the tube. FTM you can always retune it to work with the
bulb on it...

So we're stymied. Don't have a clue why we have no streamers. We had
approx. 2mm on our spark gap.

Might be too large a gap. Can you tighten it up a bit?

We were told 2mm gap for a total of 12mm by having several gaps. I had
the thought of building a spark gap that was only 1mm and doubling the
length of the gap. I figured that using alligator clips, you could
adjust the gap just by clipping on the desired pieces of copper. So
the gap could be adjusted by 1mm quickly and easily. Is that a
workable solution?

Yeah, but that changes the amount of energy going into the cap each
cycle. OK, if 12 mm is what the plans say.

snip

...No streamers.

I warned you not to be surprised. Tesla coilers proudly (as you're
learning, for good reason) proclaim "first light" when that happens.

The kid was a bit disappointed, but the glowing florescent suggest to
him that he was on the right path. I think he'll pull it off with a
little tweaking.

From your discussion of his previous experience in school, some
encouragement is definitely in order. Even if nobody else praises his
efforts (many will rag him without admitting it's because he did
something they can't) the satisfaction of "first light" will boost his
self-confidence dramatically.

snip

I'll have to get the schematic from the kid when he gets home from
school today. I'm trying to keep him in the drivers seat on the
project. I'm pretty excited about it myself. I can imagine that his
excitement is about 100-fold since he built the thing.

Good for both of you. Just riding along can be a thrill, and knowing
that the fruit of your loins can do things like this won't hurt _your_
self-confidence, either! ;&gt

I'll get that schematic and post later. We'll try removing the coating
on that magnet wire where it connects to the toroid. Any chance that's
the problem?

It's certainly _a_ problem.

I read that "tuning" can be done by adjusting the spark gap and by
moving the connecting wire to different locations on the primary.

Yep.

Somebody mentioned using some sort of tesla coil math to figure out
the "sweet spot". I don't have the slightest clue where to start on
tuning this thing.

I could point you to webpages with equations all over the place, but
it's likely a bit beyond your son unless he's in a high-school honors
math program. Save that until after he wants to know how to build a
really big one, then he can work them backwards to discover why you
won't pay for an extra 100 amp power hookup.

The plans you have should suggest where on the primary coil to attach
the connection going to it, and that's a good place to start. Watch for
corona on the toroid as you adjust the tap. The point where you achieve
resonance (and breakout) will be unmistakable.

I'll try to get some close-up pictures in addition to the schematics.

Wouldn't hurt, if for no other reason to make sure you are reading
the diagram properly.

thanks for you help

You're very welcome. I keep thinking back to my youth when I could
have used some pointers.

Mark L. Fergerson

 

[Vidor Wolfe]

"Blackbeard" <Blackbeard_The_Great@Lycos.com> wrote in message
news:6ov501pt8l5m5i2ofmqk7u9lvosstmsig9@4ax.com...

We built our caps using the salt water/beer bottle trick. When we
fired it up, the bottles started to glow purple.

We never got any streamers. At the toroid, we noticed some slight
sparking between the magnet wire and the connection to to toroid. Out
of curiosity, we place a florescent bulb on top of the toroid. The
bulb glowed on our test....but still no streamers. Since the bulb
glowed, I assume it was getting power to the toroid. But we let the
thing run for at least 30 seconds and never saw lightening.

So we're stymied. Don't have a clue why we have no streamers. We had
approx. 2mm on our spark gap.

Here's how it's built...

Primary coil - 15 turns using 1/4OD Copper tubing
Secondary - 1500 turns using 24-gauge wire
Magnet wire from secondary connect to toroid at the top
Magnet wire from bottom of secondary goes to ground

Capacitors = 6 bottle filled with salt water, wrapped with aluminum
foil all daisy-chained together with wire.
One single wire on the daisy chain connects to the transformer
The second wire on the transformer connects to an aluminum pan that
makes a connection with those bottles where the aluminum makes contact
with the aluminum pan.

Spark Gap - the spark gap doesn't make a whole lot of sense to me. We
pulled a second wire off the two posts from the transformer and the
spark gap was not connected in-line with anything. This is how our
plans show this is supposed to be done.

It sparked at the spark gap
Bottle glowed purple
florescent light lit up
...No streamers.

We have to be close. Doesn't that florescent light glowing suggest I'm
getting power up there?

the toroid is made from a piece of semi-rigid aluminum duct attached
to a 5-gallon paint buck lid to hold it's shape. We connected the
toroid using an a plastic toilet flange connected to that 5-gallon
bucket lid. The tolet flange fits right onto the 4" PVC pipe we used
for the secondary coil.

Any help or suggestions would be appreciated.
Blue/purple glow suggests corona discharge.

Power is being robbed here.
The cap is very leaky (as I suggested it would be.)
2mm is not enough gap.
The cap is not getting a high enough charge before the gap fires.
Do you mean 2mm total, or 2mm between each pipe? 7 pipes = 12mm if you're
going with your original gap design.
The toroid should stop sparks at the top of the coil, so either you have a
poor connection or the toroid needs to be larger.
A glowing bulb is not a brilliant indicator of tune or power transmission. A
gas filled bulb can be excited by the energy fronm the gap alone.
However, I think that maybe you're going the right way.
Do you get flashoever between the primary and lower secondary or sparks
jumping between the turns in the middle of the secondary?
Do you actually know the value of the capacitor or is this a poke and hope
affair?
The gap is the essential.
It's a switch to switch the power from the capacitor to the primary coil.
The cap charges to the breakdown point of the gap and current flows back and
forth round the primary till the voltage is low enough to stop the flow and
the cap charges again.
Mark H.

 

[Vidor Wolfe]

"Blackbeard" <Blackbeard_The_Great@Lycos.com> wrote in message
news:cdk801d68ed0a143g6nj250pjg85lnuedo@4ax.com...

I think I may have found a problem with the design. The bottles used
for the bottle capacitor had two wires running down inside the bottle
instead of just one. The idea was to daisy-chain. But having the two
wires down inside each bottle, it looked like there was an arc between
those two wires. He's re-doing the bottle capacitor with only a single
electrode inside each bottle. That should eliminate that arc problem.
And I assume that might have been the source of a major power draw and
possible why the bottles were glowing purple.

We did shave the coating off the magnet wire. At this point, the only
problem that was noticable was the arc problem inside the bottle
capacitors. And I'm not sure my "best guess" on that is correct. But I
guess we'll see.

It feels like we're getting closer. Might have streamers before the
weekend is out. Any other ideas?
Brilliant!

One wire in the bottle, one wire outside the bottle. This connects to the
next bottles inside wire etc.
That'll give you 6 in series. Can't say what the value is off the top of my
head, but I'm sure someone on the list knows the dialectric constant of
bottle glass.
Work out the glass area and you can work out the value.
All you have with the original setup is a high voltage gas generator. Bad,
especially with sparks around.
Another poster mentioned X-Rays.
I think (IMHO) this is not an issue.
The bottles are not under vaccuum. Hoever, a lightbulb that's not gasfilled,
that's on the toroid should be avoided. Likewise old vaccuum tubes.
If there's any green glow from the glass... Switch off.
The X-Rays should only be soft, but you never know and you'll not know the
accumalative amount either.
Cheers.
Mark H.