Tesla coil not working

[TungstenTesla]

Hi All,

Long time reader, first time poster. I'm currently building a tesla coil. here are the details:

1.) I'm using three parallel NSTs that each output about 6500 volts at .9 amps.

2.) I'm using 4 high voltage capacitors that I built using two sheets of aluminum siding with polypropylene as a dielectric between them. They are held together with a PVC ring, and submerged in mineral oil inside a 4" pvc tube. There are 4 of these.

3.) my spark gap is made from tungsten carbide held by mig welding tips (copper) threaded onto 6 gauge copper wire.

4.) my primary coild and secondary coil are in good shape, and for a topload I have a sphere and a tauroid.

I haven't been able to get it to work. When I connect the NSTs to the spark gap, it fires fine. but with I hook up the capacitor bank and the primary coil to the spark gap, the gap doesn't fire and there is no discharge. who can help me troubleshoot this? I would be most appreciative!

 

[itsmoked]

Hard to say without a picture.

What's you primary like?

What happens with just the caps and the gap?


Keith Cress
kcress -

http://www.flaminsystems.com

 

[MacGyverS2000]

What kind of job requires you to build a Tesla coil? I'm in the wrong business sector...

Dan - Owner

http://www.Hi-TecDesigns.com

 

[TungstenTesla]

Hmm, I'll upload a picture of the circuit once I get back to my place.

The primary is raised such that each turn of the coil is about a half inch above the last turn.

I haven't tried hooking up just the caps to the spark gap. Should the spark gap fire if I do that?

In response to macguyver, as of this week I'm officially in the tesla coil sector. The pay isn't great but it's fun so far

 

[OperaHouse]

If it doesn't spark, the effective capacitance is too large or the cap is shorting out.

 

[TungstenTesla]

Interesting. So I should just hook the two leads of the NSTs up to either end of the spark gap, and then the two leads of the capacitor bank to either end of the spark gap as well and see if it sparks?

I'll try that later today and let you know how it goes. I'll also upload some photos.

 

[itsmoked]

Yes it will arc with just the caps but at a lower voltage. So the gap needs to be reduced.

I always suspect the homemade caps. Lots to go wrong with them.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

Many years ago, my Tesla coil failed when my homemade caps (foil and window glass potted in paraffin) shorted out.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[itsmoked]

I always used commercial caps with outstanding success.

My Tesla coil terrorized the Science Fair judges as the primary arc was deafening and very intimidating. Alas I only got second place because the judges refused to believe I hand wound the thousands of turns on the 5 foot tall secondary.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[itsmoked]

P.S. That was eighth grade.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[MikeHalloran]

Your career path was preordained.



Mike Halloran
Pembroke Pines, FL, USA

 

[KiwiMace]

That was the best lab ever in physics; the lights were dimmed, three or so fat primary coils and this giant cone of wicked sparkles. Glad I got out of bed on time that morning.