[TCML] Nearly First Firing

[Simon Dodd]

I am reading 35 ohms across the whole capacitor bank. I got the caps  
from rmcybernetics website. They were sold as ideal for tesla coils, I  
will be looking at getting some of the big pulse caps from RS as soon  
as my bank balance is healthier...  I now have 19 in parallel giving  
me .02uF give or take and my NST needs .01989uF for complete resonance  
so it should be OK. I will be waiting till later in the day to test  
again as there are a lot of businesses around me who would get very  
annoyed with me I feel...

Thanks again for all your help and anything else you can think of that  
may help me would be greatly appreciated.
-- 
Simon Dodd
Director/ Technical Manager
Yes Boss Music


On 22 Jan 2009, at 13:41, Lau, Gary wrote:

> Hi Simon,
>
> OK - it's clear that the cap value is not excessively high.  For an  
> 8/50 NST @50Hz, a mains-resonant cap would be .02uF, so for an LTR  
> design one would shoot for .03-.04uF.  I think you presently have . 
> 016uF.
>
> So the NST looks good, but I'm not so sure about the caps.  Are your  
> caps disk capacitors?  Ceramic caps are rarely suitable.  Some  
> doorknob caps are, but disk caps are never suitable.  They tend to  
> have high losses and consequently get hot, quickly, and die.  And  
> the temperature coefficient is awful, and change value as you look  
> at them.  Is it possible that one or more of them is shorted?  It's  
> not a definitive test, but what does an Ohmmeter read across them?
>
> Regards, Gary Lau
> MA, USA
>
>> -----Original Message-----
>> From: tesla-bounces at pupman.com [mailto:tesla-bounces at pupman.com] On
>> Behalf Of Simon Dodd
>> Sent: Thursday, January 22, 2009 5:21 AM
>> To: Tesla Coil Mailing List
>> Subject: Re: [TCML] Nearly First Firing
>>
>> Ok, I just got an answer back from Tunewell and it turns out my
>> transformer is only 8Kv @ 50mA!  I will be adding the relevant caps  
>> to
>> my MMC and hopefully the rain will stop so I can try for test  
>> firing 2
>> tonight! Hopefully with pictures or videos for you all to see!!
>>
>> On 21 Jan 2009, at 20:20, Simon Dodd wrote:
>>
>>> Cheers Gary,
>>> Its a conventional heavy core transformer as far as I'm aware. It is
>>> an old one and its very heavy!!   The caps are high voltage ceramic
>>> caps from rmcybernetics.com
>>>
>>> Thanks
>>>
>>> On 21 Jan 2009, at 20:06, Lau, Gary wrote:
>>>
>>>> Is the NST a conventional, heavy core and coil transformer or a
>>>> lightweight solid state inverter type?  You need the core and coil
>>>> type.
>>>>
>>>> What kind of caps are these?
>>>>
>>>> Regards, Gary Lau
>>>> MA, USA
>>>>
>>>>> -----Original Message-----
>>>>> From: tesla-bounces at pupman.com [mailto:tesla-bounces at pupman.com]  
>>>>> On
>>>>> Behalf Of Simon Dodd
>>>>> Sent: Wednesday, January 21, 2009 2:42 PM
>>>>> To: Tesla Coil Mailing List
>>>>> Subject: [TCML] Nearly First Firing
>>>>>
>>>>> Hi Guys,
>>>>>
>>>>> I went for first light this evening!! Unfortunately there was
>>>>> nothing!
>>>>> My spark gap fires when there is no capacitor bank in place but as
>>>>> soon as I put my MMC into the circuit and connect the main parts  
>>>>> of
>>>>> the coil, the spark gap stops firing :-(  I am using a 10Kv NST
>>>>> with a
>>>>> static spark gap and 16, 20Kv 1000pf capacitors in parallel. These
>>>>> are
>>>>> from the calculations on deepfriedneon.  The spark gap will fire  
>>>>> if
>>>>> the lead to the outer ring of the primary is left unconnected.
>>>>>
>>>>> Im sorry its not too clear, I can do a quick diagram if you want
>>>>> more
>>>>> info.
>>>>>
>>>>> Thanks for your help again
>>>>>
>>>>> Simon
>
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