Sciencemadness Discussion Board

I recommend the tesla coil science project

Pyro_cat - 15-1-2020 at 21:03

Its really interesting in real life even if there will almost be a bigger better one on YouTube.

Its worth doing with in real life, on YouTube its not the same. I had a lot of fun with it.




sodium_stearate - 16-1-2020 at 10:26

Yep. Tesla coils are a lot of fun!
The modern versions all seem to use semiconductors
of some sort in the primary circuit.

I vastly prefer the much older and much simpler method.

That method uses no semiconductors.
That method only uses a capacitor, a spark gap,
and the primary coil to create the high frequency
oscillations. It basically is an RF tank circuit.

B(a)P - 17-1-2020 at 01:05

Do you mean making one in general or are you referring to a specific kit? If not a kit, what did you make? I made a solid state coil based on the below link, it was a lot of fun learning the electronics. It generates about a 20 to 30 mm spark.
https://www.stevehv.4hv.org/SSTC5.htm

Big TC

sodium_stearate - 17-1-2020 at 07:51

There is a truly great article which was published
in the July, 1964 edition of Popular Electronics
magazine.

It's a 2 part article which gives complete plans
for building a small tabletop tesla coil, and a much
larger floor model!

The small one uses a TV flyback transformer, the larger
one uses a neon sign transformer.

I built "Big TC", and man, was it fun to have around!

It was too big to move when I moved away from
that city, so I took Big TC over to the high school
I'd attended and left it at their physics dept.

Right now, you can go on Google Images
and type in "July 1964 Popular Electronics"
and right there on Google will pop up the
pictures of the cover of that issue of that magazine.

Big TC uses no semiconductors.:D

wg48temp9 - 17-1-2020 at 12:21

Here is a clip of a big Tesla coil https://www.youtube.com/watch?v=RiwYvr7X0Yg
and an other one https://www.youtube.com/watch?v=VuP4KbUXACU

TCCapture.JPG - 41kB

and a clip of a bigish bipolar Tesla coil solid state and computer controller. So it can make tones and music. https://www.youtube.com/watch?v=bTkjgBRiCsE

[Edited on 1/17/2020 by wg48temp9]

Pyro_cat - 17-1-2020 at 21:15

Quote: Originally posted by sodium_stearate  
There is a truly great article which was published
in the July, 1964 edition of Popular Electronics
magazine.

It's a 2 part article which gives complete plans
for building a small tabletop tesla coil, and a much
larger floor model!

The small one uses a TV flyback transformer, the larger
one uses a neon sign transformer.

I built "Big TC", and man, was it fun to have around!

It was too big to move when I moved away from
that city, so I took Big TC over to the high school
I'd attended and left it at their physics dept.

Right now, you can go on Google Images
and type in "July 1964 Popular Electronics"
and right there on Google will pop up the
pictures of the cover of that issue of that magazine.

Big TC uses no semiconductors.:D


Lets see,




I got started with this back in the day




Was out of the back of popular science magazine all that send away stuff.

Pyro_cat - 17-1-2020 at 21:37

Quote: Originally posted by sodium_stearate  
Yep. Tesla coils are a lot of fun!
The modern versions all seem to use semiconductors
of some sort in the primary circuit.

I vastly prefer the much older and much simpler method.

That method uses no semiconductors.
That method only uses a capacitor, a spark gap,
and the primary coil to create the high frequency
oscillations. It basically is an RF tank circuit.



I had fun with the old method, I did not know what I was doing.

Just enough instruction to build all the components and get a result then tuning and lets see what happens if ...

All kinds of math in the book but there were so many variables building capacitors out of old storm windows and shower doors. The top a brass ball from a sewage plant float or fireplace andirons.

it was alot of fun.

Pyro_cat - 17-1-2020 at 21:46

Quote: Originally posted by wg48temp9  
Here is a clip of a big Tesla coil https://www.youtube.com/watch?v=RiwYvr7X0Yg
and an other one https://www.youtube.com/watch?v=VuP4KbUXACU



and a clip of a bigish bipolar Tesla coil solid state and computer controller. So it can make tones and music. https://www.youtube.com/watch?v=bTkjgBRiCsE

[Edited on 1/17/2020 by wg48temp9]


What would have happened if YouTube was around when I got the Tesla bug ?

OMG or e-bay !




Oh my lord !!


[Edited on 18-1-2020 by Pyro_cat]

Pyro_cat - 17-1-2020 at 22:10

Quote: Originally posted by wg48temp9  
Here is a clip of a big Tesla coil https://www.youtube.com/watch?v=RiwYvr7X0Yg
and an other one https://www.youtube.com/watch?v=VuP4KbUXACU



and a clip of a bigish bipolar Tesla coil solid state and computer controller. So it can make tones and music. https://www.youtube.com/watch?v=bTkjgBRiCsE

[Edited on 1/17/2020 by wg48temp9]



I found this one on YouTube https://www.youtube.com/watch?v=FY-AS13fl30



I can't help but wonder would I ever have built mine if Youtube and good instruction was around.

Energetic materials are impressive on video but videos of a tesla coils are just incredibly lame compared to the real thing in real life.

[Edited on 18-1-2020 by Pyro_cat]

Big TC

sodium_stearate - 18-1-2020 at 03:18

My version of the Popular Science's "Big TC" was
built on a 24 x 48 inch base made from 3/4 inch plywood.

There were two capacitors. Those each had a 24 inch
square piece of plain single strength window glass which
had 20 inch squares of galvanized sheet steel roofing
metal epoxy glued on both sides.

I had done lots of experiments making those capacitors
using aluminum foil taped and/or glued to the glass.
The big problem with using foil is that as it heats up it
starts to wrinkle, and that always makes a hot spot
and that will arc right through the glass.

Another variable with making those capacitors is that
during the startup transient, they can and will arc
clear around the edge of the glass. A 20 inch square
of metal centered on a 24 inch square of glass creates
a distance of 4 inches from plate to plate, going out around
the edge of the glass. You would not imagine an arc
could pop clear around that long of a distance, but it does!

Aside from that, the primary is 20 turns of heavy test-probe
wire would around a 10 inch diameter form. The secondary
of my coil was a single layer of #26 gauge enameled copper
wire wound around a phenolic tube 5 inches outside
diameter and 5 feet tall. Many thousands of turns.

It was powered by a 12,000 volt neon sign transformer.

It had an adjustable spark gap in the primary circuit.
Changing the spark gap distance tunes the resonant
frequency.

I still remember how awesome it sounds! When it's
in proper tune, that spark gap really talks up very nicely!
It makes a very loud sort of growl, with a hissing.
About 3/4 inch was the best spark gap.
There is no other sound like it.

On a cool, crisp, very dry winter day, I could easily
draw 14 inch arcs off the top ball, to my hand.
Then with the other hand I'd reach out and zap
an innocent bystander by giving them about a half inch
arc off the end of my finger!

That thing was a real chick-magnet, let me tell you...:cool:


[Edited on 18-1-2020 by sodium_stearate]

Morgan - 18-1-2020 at 08:30

This was an inventive variation for making sparks.

Wehnelt Interrupter
https://youtube.com/watch?v=m87-paje-ZI

Pyro_cat - 25-1-2020 at 20:22

Quote: Originally posted by sodium_stearate  
My version of the Popular Science's "Big TC" was
built on a 24 x 48 inch base made from 3/4 inch plywood.

There were two capacitors. Those each had a 24 inch
square piece of plain single strength window glass which
had 20 inch squares of galvanized sheet steel roofing
metal epoxy glued on both sides.

I had done lots of experiments making those capacitors
using aluminum foil taped and/or glued to the glass.
The big problem with using foil is that as it heats up it
starts to wrinkle, and that always makes a hot spot
and that will arc right through the glass.

Another variable with making those capacitors is that
during the startup transient, they can and will arc
clear around the edge of the glass. A 20 inch square
of metal centered on a 24 inch square of glass creates
a distance of 4 inches from plate to plate, going out around
the edge of the glass. You would not imagine an arc
could pop clear around that long of a distance, but it does!


I tried "sealing" with electrical tape on the edges sandwiched between the glass. Nope it finds a way.

My best capacitor ever, those shower doors I lost when the arc found a way through the glass and broke it.

So much math in that book but so much hit or miss, either your cap, primary and secondary resonate together well or they don't.

I used 4 inch PVC pipe and a roll of pretty heavy wire for one and then the other was that cardbourd concreate form tube. Thoroughly shellacked.

Cant remember of the size of the tube but lawnmower wheels fit snuggly in the ends then I rigged it so we could spin it and wind the magnet wire on.

First attempt at running it the arcs would skip turns and arc up the sides on the way to the top.

Then it was unwind the whole thing and put I think 25 lb test mono filament as a space betwwen the windings and that worked out well.

A rotary spark gap a compact music disk with 8 nuts and bolts on a circle saw motor controlled with a variac, that was the best result ever, it just caught the right tone just right once arks well over a foot long.

Powered by 23 ma oil burner ingition transformer , did I use 2 ? Cant remember but I did run 220 Vac instead of the 110 it was rated for.

Never had a problem running 220 through a 110 transformer. Only better results.

Never could repeat that.

Quote: Originally posted by sodium_stearate  
Aside from that, the primary is 20 turns of heavy test-probe
wire would around a 10 inch diameter form. The secondary
of my coil was a single layer of #26 gauge enameled copper
wire wound around a phenolic tube 5 inches outside
diameter and 5 feet tall. Many thousands of turns.

It was powered by a 12,000 volt neon sign transformer.

It had an adjustable spark gap in the primary circuit.
Changing the spark gap distance tunes the resonant
frequency.

I still remember how awesome it sounds! When it's
in proper tune, that spark gap really talks up very nicely!
It makes a very loud sort of growl, with a hissing.
About 3/4 inch was the best spark gap.
There is no other sound like it.

On a cool, crisp, very dry winter day, I could easily
draw 14 inch arcs off the top ball, to my hand.
Then with the other hand I'd reach out and zap
an innocent bystander by giving them about a half inch
arc off the end of my finger!

That thing was a real chick-magnet, let me tell you...:cool:


[Edited on 18-1-2020 by sodium_stearate]


"an innocent bystander "

After I noticed how the coil lights up florescent bulbs I would put one on the other side of the room then ask someone to bring it to me with the coil on it would light up in their hand and the reaction WHAT ?? !!!

And it was absolutely a chick magnet !

Pyro_cat - 25-1-2020 at 20:28

Quote: Originally posted by Morgan  
This was an inventive variation for making sparks.

Wehnelt Interrupter
https://youtube.com/watch?v=m87-paje-ZI





This is going to take me a bit to get but cool. How the heck does that work ??

Let the web searches begin !


Pyro_cat - 25-1-2020 at 20:39

Ok I get it. Easy to get but build and operate that has to be a challenge.

I love look of all that antique electrical stuff, brass wood and glass like fine furniture.

Pyro_cat - 25-1-2020 at 20:47

Still on it and wow that was cleaver the bubbles. I wonder if the bubble break effect was discovered first like experimenting with electrolyzing water with high voltage and then it was used as a interrupter after noticing that effect. That would be my guess.

Morgan - 25-1-2020 at 21:13

There's a lot of electrostatic devices on this site.
Electrostatic Machines
https://www.coe.ufrj.br/~acmq/electrostatic.html