please help with my first coil
kv, Wed May 30 2007, 09:20AMi have finally decided to build a coil but have many questions. first would an ignition coil circuit drive a tesla coil?. would these caps be suitable for a MMC configuration? http://jaycar.com.au/productView.asp?ID=RC5380&CATID=51&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=856
if the ignition coil won't work i could try to get a nst.
And tesladownunder i love your site its very informative and nice to know other people in Australia (like me) are actually interested in this stuff.
thanks
Re: please help with my first coil
EDY19, Wed May 30 2007, 09:30AM
Those capacitors may work, but for that price each, you really might as well try something that is proven- like the CD942 series, or the GE42 series. As for the ignition coil- if this is your first coil, I would say to get a NST- its one less thing to go wrong- less maintenence and troubleshooting if something fails
Good Luck!
EDY19, Wed May 30 2007, 09:30AM
Those capacitors may work, but for that price each, you really might as well try something that is proven- like the CD942 series, or the GE42 series. As for the ignition coil- if this is your first coil, I would say to get a NST- its one less thing to go wrong- less maintenence and troubleshooting if something fails
Good Luck!Re: please help with my first coil
kv, Wed May 30 2007, 10:37AM
ok, so i will go down to a neon sign place and see if i can get one free
or cheaply anyway. but as i said this is my first coil so i don't know what voltage/current nst i should get? any suggestions? is a 30 milliamp one dangerous/ lethal?
kv, Wed May 30 2007, 10:37AM
ok, so i will go down to a neon sign place and see if i can get one free
or cheaply anyway. but as i said this is my first coil so i don't know what voltage/current nst i should get? any suggestions? is a 30 milliamp one dangerous/ lethal?Re: please help with my first coil
kv, Wed May 30 2007, 10:40AM
also i tried google and could not find any info on the caps? are they not made anymore?
kv, Wed May 30 2007, 10:40AM
also i tried google and could not find any info on the caps? are they not made anymore?
Re: please help with my first coil
Sulaiman, Wed May 30 2007, 10:43AM
Adding to the above;
Making an ignition coil power supply for a spark gap TC is feasible, you will find quite a few people have done it,
you should get between 20 and 50 watts depending on coil type and your design,
which is enough for a working TC, but not very exciting.
An oil burner ignition transformer (OBIT) is a good alternative to an NST, with a little less power, but easy to find.
Whether you use an NST or an OBIT, for a first sgtc you MUST use a safety gap, any two smooth metal electrodes will do. (NOT 'pointy' electrodes such as nails etc.)
Set the safety gap as wide as possible but so that it 'fires' with nothing else connected.
I have killed NST and OBIT by having too large a spark gap.
When obtaining an NST or OBIT make sure that it's NOT one of the newer electronic types, an old-fashioned heavy transformer type is required.
I have made an sgtc using ceramic capacitors like the ones you're considering, they are not very good (quite poor).
The 'doorknob' transmitter types are good, but so expensive that I agree you'd be better to use good foil/film polypropylene capacitors.
You could use bottle capacitors which are cheap, but you will not know their capacitance, which will make designing a 'tuned' TC quite difficult for a first-timer.
Good Luck, don't be shy to ask for help, and stay safe.
Sulaiman, Wed May 30 2007, 10:43AM
Adding to the above;
Making an ignition coil power supply for a spark gap TC is feasible, you will find quite a few people have done it,
you should get between 20 and 50 watts depending on coil type and your design,
which is enough for a working TC, but not very exciting.
An oil burner ignition transformer (OBIT) is a good alternative to an NST, with a little less power, but easy to find.
Whether you use an NST or an OBIT, for a first sgtc you MUST use a safety gap, any two smooth metal electrodes will do. (NOT 'pointy' electrodes such as nails etc.)
Set the safety gap as wide as possible but so that it 'fires' with nothing else connected.
I have killed NST and OBIT by having too large a spark gap.
When obtaining an NST or OBIT make sure that it's NOT one of the newer electronic types, an old-fashioned heavy transformer type is required.
I have made an sgtc using ceramic capacitors like the ones you're considering, they are not very good (quite poor).
The 'doorknob' transmitter types are good, but so expensive that I agree you'd be better to use good foil/film polypropylene capacitors.
You could use bottle capacitors which are cheap, but you will not know their capacitance, which will make designing a 'tuned' TC quite difficult for a first-timer.
Good Luck, don't be shy to ask for help, and stay safe.
Re: please help with my first coil
Coronafix, Wed May 30 2007, 12:58PM
This is the best place to get good caps in Oz.
Here are the caps I use in my coil.
There is a bit of a wait for them though.
NST new is not cheap but worth it.
Coronafix, Wed May 30 2007, 12:58PM
This is the best place to get good caps in Oz.
Here are the caps I use in my coil.
There is a bit of a wait for them though.
NST new is not cheap but worth it.
Re: please help with my first coil
kv, Wed May 30 2007, 09:06PM
thanks for the link. i sort of knew a little bit about rs but didn't know they had that big a range. also which one of these did you use because the link just takes me to the homepage?. also was your tc a nst powered one?
thanks for all the help
kv, Wed May 30 2007, 09:06PM
thanks for the link. i sort of knew a little bit about rs but didn't know they had that big a range. also which one of these did you use because the link just takes me to the homepage?. also was your tc a nst powered one?
thanks for all the help
Re: please help with my first coil
GreySoul, Wed May 30 2007, 09:36PM
If you don't know the dangers of high voltage you should really start by reading this:
Classictesla's Tesla Coilers Safety page:
Sam's HV safety FAQ:
....
After reading those you should have a better idea of what you're gertting into as well as what you need in the way of an NST. In general if you're scrapping or scrounging you take what you can get. If you're paying, then bigger is better up to what you can afford.I use a 12kv/30ma NST for my stuff and it woks fine. I've intentionally grabbed one of the 6kv legs (center tapped NSTs are pretty common) and I can assure you that you don't want to do it, even if it doesn't kill you it's gonna sting.
For caps I too recommend the CDE 942 series of poly film caps. they seem indestructible, if only for a longer period of time than the ceramics are...
Good luck on your coil. Also, if you want to really protect your NST build a terry filter, it's not a big investment.
-Doug
GreySoul, Wed May 30 2007, 09:36PM
kv wrote ...
any suggestions? is a 30 milliamp one dangerous/ lethal?
any suggestions? is a 30 milliamp one dangerous/ lethal?
If you don't know the dangers of high voltage you should really start by reading this:
Classictesla's Tesla Coilers Safety page:
Sam's HV safety FAQ:
....
After reading those you should have a better idea of what you're gertting into as well as what you need in the way of an NST. In general if you're scrapping or scrounging you take what you can get. If you're paying, then bigger is better up to what you can afford.I use a 12kv/30ma NST for my stuff and it woks fine. I've intentionally grabbed one of the 6kv legs (center tapped NSTs are pretty common) and I can assure you that you don't want to do it, even if it doesn't kill you it's gonna sting.
For caps I too recommend the CDE 942 series of poly film caps. they seem indestructible, if only for a longer period of time than the ceramics are...
Good luck on your coil. Also, if you want to really protect your NST build a terry filter, it's not a big investment.
-Doug
Re: please help with my first coil
Coronafix, Wed May 30 2007, 11:38PM
Yeh sorry, RS does that, the page expires.
The part number is 940C30S47K
ER - Capacitor, Polypropylene Film, High dV/dt, 3000v, .047uf
I use a 15kV 60mA NST. New for about $170.
The caps, I used 3 strings of 8 giving 17.6nF total.
Coronafix, Wed May 30 2007, 11:38PM
Yeh sorry, RS does that, the page expires.
The part number is 940C30S47K
ER - Capacitor, Polypropylene Film, High dV/dt, 3000v, .047uf
I use a 15kV 60mA NST. New for about $170.
The caps, I used 3 strings of 8 giving 17.6nF total.
Re: please help with my first coil
kv, Thu May 31 2007, 03:19AM
would this transformer work? http://cgi.ebay.com.au/15KV-Neon-sign-transformer-tesla_W0QQitemZ230136467055QQihZ013QQcategoryZ105780QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
also would i need to change the cap configuration to work with this?
kv, Thu May 31 2007, 03:19AM
would this transformer work? http://cgi.ebay.com.au/15KV-Neon-sign-transformer-tesla_W0QQitemZ230136467055QQihZ013QQcategoryZ105780QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
also would i need to change the cap configuration to work with this?
Re: please help with my first coil
Coronafix, Thu May 31 2007, 05:44AM
That NST will work fine, if of course it works.
With that tranny you will need a cap bank of about 11nF,
being for a LTR static gap.
You could use just 2 strings of 8 giving 11.75nF.
Check out :
Coronafix, Thu May 31 2007, 05:44AM
That NST will work fine, if of course it works.
With that tranny you will need a cap bank of about 11nF,
being for a LTR static gap.
You could use just 2 strings of 8 giving 11.75nF.
Check out :
Re: please help with my first coil
Shaun, Thu May 31 2007, 06:05AM
Not to barge in, but my tranny has equal ratings, which comes to a 5.3 nF resonant cap. My LTR cap is 7.5 nF. 11.75nF is more than double resonant-how much of a difference will such a large cap make? Feel free to PM me instead of going off thread topic, but this would probly benefit kv too, anyway.
Shaun, Thu May 31 2007, 06:05AM
Not to barge in, but my tranny has equal ratings, which comes to a 5.3 nF resonant cap. My LTR cap is 7.5 nF. 11.75nF is more than double resonant-how much of a difference will such a large cap make? Feel free to PM me instead of going off thread topic, but this would probly benefit kv too, anyway.
Re: please help with my first coil
Coronafix, Thu May 31 2007, 06:33AM
My mistake, I thought it was a 12kV transformer.
Resonant @ 6.3nF, LTR of 9nF
Shaun, you have a higher line frequency of 60Hz, hence the
lower resonant cap value.
50Hz here in australia.
Coronafix, Thu May 31 2007, 06:33AM
My mistake, I thought it was a 12kV transformer.
Resonant @ 6.3nF, LTR of 9nF
Shaun, you have a higher line frequency of 60Hz, hence the
lower resonant cap value.
50Hz here in australia.
Re: please help with my first coil
Shaun, Thu May 31 2007, 08:26PM
My bad, I saw 15kV/30ma, not 60
Shaun, Thu May 31 2007, 08:26PM
My bad, I saw 15kV/30ma, not 60
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