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RE: [TCML] poor coil performance again- help!



Thanks... What kind of cable can you use for the primary connections? Would a copper braid (normally used for earthing) be okay?

Cheers

Thomas

-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf Of DC Cox
Sent: 21 April 2008 03:52
To: Tesla Coil Mailing List
Subject: Re: [TCML] poor coil performance again- help!

The caps are causing massive losses.  The corona losses you can see.  The
losses you can not see is the dielectric heating of the glass by the RF
currents which is wasting at least 25% of your input power.  Without good
power and RF currents even the best primary design can not transfer the weak
energy into the secondary coil.  Massive primary caps losses produce
restricted current flow in the pri, especially in the pri coil.  Low pri
coil peak currents produce weak magnetic fields with less energy.  Less
energy to transfer into the sec where the high potential is produced by the
collapsing magnetic field (weak from your inefficient pri caps).

Good performance from even a small coils demands:

Hi-Q caps such as MMC caps especially designed for RF  peak currents
Largest possible dia on secondary inductor as potential produced is   L x
dI/dt      The inductance L is produced by a large radius sec inductor.
Using at least #6 AWG wiring on all of the pri to handle the high peak pri
currents efficiently without resistive losses
Good spark gap design to provide effective quenching

I do carry MMC caps --- contact me off-list if you need some.

Regards,

Dr. Resonance




On Sun, Apr 20, 2008 at 3:09 PM, Thomas Ryckmans <thomas.ryckmans@xxxxxxxxxx>
wrote:

> Hello,
>
>
>
> I rewired my small coil to get this:
>
>
> http://lh3.ggpht.com/Thomas.Ryckmans/SAuuyEC3o6I/AAAAAAAAAXw/4l1Z3jR_wm8/s14
> 4/Tom_rewired_coil.JPG
>
>
>
> (I am adding the JavaTC file below)
>
>
>
> My NST is 6kV 50 mA
>
>
>
>
>
> Primary is 8mm copper tubing, spacing (centre to centre) is 1.8 cm; inside
> diameter is 11 cm, outside diameter is 30 cm, 5 turns (I am tapping at 2
> or
> 2.5 or 3 or 3.5 turns) as per scope and calculation). I modified the spark
> gap spacing, the spacing of the Terry Filter...
>
>
>
> I am using a salt water bottles cap at 11.6 nF
>
>
>
> Secondary is 3.2 uH with Diameter=70 mm, 480 turns, 15 turns/cm, 32 cm
> height (AWG 22)
>
> Top load is a cylinder 13 cm diameter, 18 cm high, 1 cm above end of
> secondary
>
> Secondary and Primary start at the same level - JavaTC gives me a k=0.129
>
>
>
> I have added a stationary spark gap
>
>
> http://lh4.ggpht.com/Thomas.Ryckmans/SAuuyUC3o-I/AAAAAAAAAYQ/h8QQxf8Wvzo/Tom
> _Spark_gap_on_PPE.JPG?imgmax=512
>
>
>
> and a Terry filter (with adjustable number of MOVs - I hope to get a
> bigger
> NST one day!)
>
>
>
>
> http://lh4.ggpht.com/Thomas.Ryckmans/SAuuyUC3o8I/AAAAAAAAAYA/ESiTnSNkQTg/Tom
> _Adjustable_Terry_filter.JPG?imgmax=512
>
>
> http://lh4.ggpht.com/Thomas.Ryckmans/SAuuyUC3o9I/AAAAAAAAAYI/JXld0yjBiC4/Tom
> _Adjustable_Terry_filter2.JPG?imgmax=512
>
>
>
> I am using a counterpoise (aluminium foil about 8 cm below the
> primary/secondary; radius about 60 cm or 2x height of coil). I have no RF
> ground in this apartment!
>
>
>
> but still get pathetic sparks! About 5 cm tops from top load to a
> screwdriver I am holding above it.
>
>
>
> On the other hand... I get massive corona on my saltwater bottles - it is
> much
> more spectacular than the coil! Here is a picture of my saltwater cap (off
> power)
>
>
>
>
> http://lh3.ggpht.com/Thomas.Ryckmans/SAuuyEC3o7I/AAAAAAAAAX4/gCKeTU3n5ek/Tom
> _saltwater_cap.JPG?imgmax=512
>
>
>
> Quite ugly but I'd like to see the coil working before I invest in a MMC.
>
>
>
> Could anyone help me nailing the issues with this coil?
>
>
>
> Many thanks!
>
>
>
> Thomas
>
>
>
> J A V A T C version 11.7 - CONSOLIDATED OUTPUT
>
> 20 April 2008 22:44:40
>
>
>
> Units = Centimeters
>
> Ambient Temp = 20°C
>
>
>
> ----------------------------------------------------
>
> Surrounding Inputs:
>
> ----------------------------------------------------
>
> 300 = Ground Plane Radius
>
> 300 = Wall Radius
>
> 300 = Ceiling Height
>
>
>
> ----------------------------------------------------
>
> Secondary Coil Inputs:
>
> ----------------------------------------------------
>
> Current Profile = G.PROFILE_LOADED
>
> 3.5 = Radius 1
>
> 3.5 = Radius 2
>
> 0 = Height 1
>
> 32 = Height 2
>
> 480 = Turns
>
> 22 = Wire Awg
>
>
>
> ----------------------------------------------------
>
> Primary Coil Inputs:
>
> ----------------------------------------------------
>
> 5.5 = Radius 1
>
> 15 = Radius 2
>
> 0 = Height 1
>
> 0 = Height 2
>
> 5 = Turns
>
> 0.8 = Wire Diameter
>
> 0.0116 = Primary Cap (uF)
>
> 50 = Total Lead Length
>
> 0.3 = Lead Diameter
>
>
>
> ----------------------------------------------------
>
> Top Load Inputs:
>
> ----------------------------------------------------
>
> Cylinder #1: diam=13, bottom_h=33, top_h=51, topload
>
>
>
> ----------------------------------------------------
>
> Secondary Outputs:
>
> ----------------------------------------------------
>
> 830.58 kHz = Secondary Resonant Frequency
>
> 90 deg° = Angle of Secondary
>
> 32 cm = Length of Winding
>
> 15 cm = Turns Per Unit
>
> 0.02287 mm = Space Between Turns (edge to edge)
>
> 105.56 m = Length of Wire
>
> 4.57:1 = H/D Aspect Ratio
>
> 5.545 Ohms = DC Resistance
>
> 15344 Ohms = Reactance at Resonance
>
> 0.305 kg = Weight of Wire
>
> 2.94 mH = Les-Effective Series Inductance
>
> 2.734 mH = Lee-Equivalent Energy Inductance
>
> 3.166 mH = Ldc-Low Frequency Inductance
>
> 12.488 pF = Ces-Effective Shunt Capacitance
>
> 11.405 pF = Cee-Equivalent Energy Capacitance
>
> 25.768 pF = Cdc-Low Frequency Capacitance
>
> 0.0784 mm = Skin Depth
>
> 8.506 pF = Topload Effective Capacitance
>
> 48.8876 Ohms = Effective AC Resistance
>
> 314 = Q
>
>
>
> ----------------------------------------------------
>
> Primary Outputs:
>
> ----------------------------------------------------
>
> 601.84 kHz = Primary Resonant Frequency
>
> 27.54 % high = Percent Detuned
>
> 0 deg° = Angle of Primary
>
> 322.01 cm = Length of Wire
>
> 1.1 mOhms = DC Resistance
>
> 1.1 cm = Average spacing between turns (edge to edge)
>
> 1.568 cm = Proximity between coils
>
> 0 cm = Recommended minimum proximity between coils
>
> 5.453 µH = Ldc-Low Frequency Inductance
>
> 0.00609 µF = Cap size needed with Primary L (reference)
>
> 0.576 µH = Lead Length Inductance
>
> 16.981 µH = Lm-Mutual Inductance
>
> 0.129 k = Coupling Coefficient
>
> 0.125 k = Recommended Coupling Coefficient
>
> 7.75  = Number of half cycles for energy transfer at K
>
> 6.37 µs = Time for total energy transfer (ideal quench time)
>
>
>
> ----------------------------------------------------
>
> Transformer Inputs:
>
> ----------------------------------------------------
>
> 0 [volts] = Transformer Rated Input Voltage
>
> 0 [volts] = Transformer Rated Output Voltage
>
> 0 [mA] = Transformer Rated Output Current
>
> 0 [Hz] = Mains Frequency
>
> 0 [volts] = Transformer Applied Voltage
>
> 0 [amps] = Transformer Ballast Current
>
> 0 [ohms] = Measured Primary Resistance
>
> 0 [ohms] = Measured Secondary Resistance
>
>
>
> ----------------------------------------------------
>
> Transformer Outputs:
>
> ----------------------------------------------------
>
> 0 [volt*amps] = Rated Transformer VA
>
> 0 [ohms] = Transformer Impedence
>
> 0 [rms volts] = Effective Output Voltage
>
> 0 [rms amps] = Effective Transformer Primary Current
>
> 0 [rms amps] = Effective Transformer Secondary Current
>
> 0 [volt*amps] = Effective Input VA
>
> 0 [uF] = Resonant Cap Size
>
> 0 [uF] = Static gap LTR Cap Size
>
> 0 [uF] = SRSG LTR Cap Size
>
> 0 [uF] = Power Factor Cap Size
>
> 0 [peak volts] = Voltage Across Cap
>
> 0 [peak volts] = Recommended Cap Voltage Rating
>
> 0 [joules] = Primary Cap Energy
>
> 0 [peak amps] = Primary Instantaneous Current
>
> 0 [cm] = Spark Length (JF equation using Resonance Research Corp. factors)
>
> 0 [amps] = Sec Base Current
>
>
>
> ----------------------------------------------------
>
> Rotary Spark Gap Inputs:
>
> ----------------------------------------------------
>
> 0 = Number of Stationary Gaps
>
> 0 = Number of Rotating Electrodes
>
> 0 [rpm] = Disc RPM
>
> 0 = Rotating Electrode Diameter
>
> 0 = Stationary Electrode Diameter
>
> 0 = Rotating Path Diameter
>
>
>
> ----------------------------------------------------
>
> Rotary Spark Gap Outputs:
>
> ----------------------------------------------------
>
> 0 = Presentations Per Revolution
>
> 0 [BPS] = Breaks Per Second
>
> 0 [kmh] = Rotational Speed
>
> 0 [ms] = RSG Firing Rate
>
> 0 [ms] = Time for Capacitor to Fully Charge
>
> 0 = Time Constant at Gap Conduction
>
> 0 [µs] = Electrode Mechanical Dwell Time
>
> 0 [%] = Percent Cp Charged When Gap Fires
>
> 0 [peak volts] = Effective Cap Voltage
>
> 0 [joules] = Effective Cap Energy
>
> 0 [rms volts] = Terminal Voltage
>
> 0 [power] = Energy Across Gap
>
> 0 [cm] = RSG Spark Length (using energy equation)
>
>
>
> ----------------------------------------------------
>
> Static Spark Gap Inputs:
>
> ----------------------------------------------------
>
> 0 = Number of Electrodes
>
> 0 [cm] = Electrode Diameter
>
> 0 [cm] = Total Gap Spacing
>
>
>
> ----------------------------------------------------
>
> Static Spark Gap Outputs:
>
> ----------------------------------------------------
>
> 0 [cm] = Gap Spacing Between Each Electrode
>
> 0 [peak volts] = Charging Voltage
>
> 0 [peak volts] = Arc Voltage
>
> 0 [volts] = Voltage Gradient at Electrode
>
> 0 [volts/cm] = Arc Voltage per unit
>
> 0 [%] = Percent Cp Charged When Gap Fires
>
> 0 [ms] = Time To Arc Voltage
>
> 0 [BPS] = Breaks Per Second
>
> 0 [joules] = Effective Cap Energy
>
> 0 [rms volts] = Terminal Voltage
>
> 0 [power] = Energy Across Gap
>
> 0 [cm] = Static Gap Spark Length (using energy equation)
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
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