RE: MMC Question

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>

Could the NST be a high frequency solid-state inverter type?  If it is,
it's probably not useful for a Tesla Coil.

Regards, Gary Lau
MA, USA

> Original poster: "huil888" <huil888@xxxxxxxxxxxx>
>
> Mark -
>
> A few questions on your TC:
>
> 1. Are you absolutely sure that your HV transformer is rated 15kV at
> 20ma?? This is an extremely unusual rating for a NST, in 10 years of
> Tesla coil building I have never heard of a NST with this rating in
> North America, Europe, or the UK. Or is it not a NST? There are some
> relatively small (8" X 8" X 8") DC power supplies for air ionizers
> that have similar ratings, but these may not be suitable for driving
> a Tesla coil. Double check the nameplate, let me know who the
> manufacturer is and what the nameplate says.
>
> 2. How did you determine that 0.0042uF was a "resonant" capacitor
> value for your transformer? My data indicate that 0.0035uF would be
> the resonant value with a 15/20 transformer.
>
> In any case, these variations in tank capacitor "value" (technically
> more correct than "size") have no significant affect on eventually
> tuning your system. The inductance of the primary coil is "adjusted"
> (via variable tap point) to make the resonant frequency of the tank
> circuit match the resonant frequency of the secondary coil with
topload.
>
> Are you using one of the Tesla coil design programs to design all the
> critical parameters of your coil? If you don't have an oscilloscope
> and RF signal generator, it is VERY important to carefully calculate
> the dimensions and values for each component, or you will have a very
> difficult time "tuning" your coil to achieve resonance.
>
> WINTESLA is a very simple but useful program, JAVATC is even more
> powerful but slightly more complex. I would suggest that you design
> your coil COMPLETELY on paper before you proceed with any more
> construction. The biggset single source of failure with tesla coils
> is not having the primary and secondary circuits tuned to EXACTLY the
> same resonant frequency. This will not happen by lucky accident;
> these circuits need to be very carefully designed and constructed to
> achieve resonance. Without resonance, there will be no sparks. Period.
>
> Regards,
> Scott Hanson
> Costa Mesa, California
> USA
> ----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Monday, April 23, 2007 12:26 PM
> Subject: MMC Question
>
>
> >Original poster: mark@xxxxxxxxxxxxxxxx
> >Hi,
> >
> >I've just built my MMC for my first Tesla coil, and I have yet
> >another question
> >regarding its construction and use.  From what I've read the MMC
makes part of
> >a tuned circuit.  My original question, was regarding the size of
> >MMC required,
> >and someone from the list recommended making it 1.5 - 2x bigger than
required.
> >
> >so my original size was
> >
> >0.0042uF for a 15Kv 20mA 50hz xfmr
> >
> >so timed this by 1.5 and got 0.0063uF
> >
> >However I mucked up the calculation and didn't realize until after I
built my
> >MCC, I've ended up with 0.0055uF
> >
> >So my question really is, will this still work correctly or do I need
to start
> >again ??
> >
> >And if this needs to be in tune with the rest of the circuit, surely
even
> >increasing this 1.5 would muck the tuning up??
> >
> >Any comments appreciated.
> >
> >Mark
> >
> >
>
>
>