Re: [TCML] First tesla coil, some advice needed

[Gary Lau <glau1024@xxxxxxxxx>]

Hi Andreas,

I think the 60nF cap would be too large and would draw excessive mains
current.  While the 30 nF cap is close to resonant, that's only a problem if
you set the gap too wide and don't have a properly set safety gap.  I'd
recommend using the 30.

Regards, Gary Lau
MA, USA

On Tue, Sep 21, 2010 at 9:22 AM, Andreas Holmqvist <andreasho@xxxxxxxxx>wrote:

> Hello,
>
>
> Years since i last was here, my coil never got finished but now i want to
> complete it !
>
> My tesla coil is almost finished, only the terryfilter and making the wire
> connections are on the to-do-list.
> This is a SGTC with a static tungsten gap with two 30w fans running air
> true it.
>
> I need some advice on how much capacitance to use. I only got two options.
> 30nF or 60nF and i cant make my mind up on what to use.
> Orginally i was going to use a motstack but the parts got thrown away by
> accident after sitting years in the garage so now i have to use an nst and
> the caps dont match up as good with it.
> Will use somthing with more power later, i am building it to handle up to
> 1,5kva but i want to get it going first.
>
> 30nF is close to resonant and 60nF is too much ? Can i use 30nF without
> blowing things up if i use terryfilter and safetygaps ?
> The system is wired up with both caps in the calculation below. Will this
> couse problems ?
>
>
> Here is the coil specs.
>
> Generated by TeslaMap
> www.teslamap.com
>
> ----- NST Parameters -----
> NST Input Voltage: 230 V
> NST Input Frequency: 50 Hz
> NST Output Voltage: 7,5 kV
> NST Output Current: 60 mA
> NST Watts: 463 W
> NST PFC Capacitance: 27,1 uF
>
> ----- MMC Parameters -----
> Primary Capacitance: 60 nF
> MMC Capacitor Value (individual cap): 0.03 uF
> MMC Capacitor Voltage (individual cap): 35 kV
> Resonant Cap: 25,5nF
> Optimum LTR (static gap) Cap: 41,2nF
>
> ----- Primary Coil Parameters -----
> Primary Coil Wire Diameter: 0,8 cm
> Primary Coil Wire Spacing: 0,8 cm
> Primary Coil Center Hole Diameter: 16 cm
> Primary Coil Incline Angle: 0 degrees
> Required Primary Inductance: 8 uH
> Primary Coil Tap Turn: 5 - 6
> Primary Coil Diameter At Tap Turn: 35,2 cm
> Primary Coil Height At Tap Turn: 0,8 cm
> Primary Coil Wire Length At Tap Turn: 5,1 m
>
> ----- Secondary Coil Parameters -----
> Secondary Coil Magnet Wire AWG: 24,8
> Single Build Insulation
> Secondary Coil Magnet Wire Diameter: 0,501 mm
> Secondary Wire Length: 297 m
> Secondary Wire Weight: 450,45 g
> Secondary Coil Winding Height: 51 cm
> Secondary Coil Form Diameter: 10 cm
> Secondary Coil Turns: 947
> Secondary Coil Height To Width Ratio: 5,1:1
>
> ----- Top Load Parameters -----
> Toriod Ring Diameter 1: 10 cm
> Toriod Total Diameter 1: 33 cm
> Toriod Ring Diameter 2: 4,5 cm
> Toriod Total Diameter 2: 15 cm
> Top Load Sphere Diameter: 0 cm
> Toroid 1 Capacitance: 14,6 pF
> Toroid 2 Capacitance: 7,7 pF
> Top Load Sphere Capacitance:
> Total Top Load Capacitance: 22,3 pF
> Optimum Top Load Capacitance: 17,3pF
>
> ----- Tesla Coil Parameters -----
> Resonate Frequency: 230 kHz
>
> End of report
>
> /Andreas
>
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