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RE: [TCML] Newbie question - Where does all the energy go?



I would try simplifying your spark gap. Multiple gaps, if not set up/tuned just right, can diminish your output to nothing. Try a simple two electrode gap hooked up directly to your transformer.  Try widening the gap just to the point where it seems to be struggling to fire, then move them back together a bit until it is firing consistently again. Then hook it all back up and see what you get. 
You might have to retune after this. And I would use a small fan for quenching. A raft/mattress inflator or most any kind of blower will work. Sometimes too much air isn't better, so you might try varying the distance between the fan and the gap to see if it increases/decreases performance. 

This was the absolute last thing I checked on one of my first coils I built. I was using a 4 element copper pipe gap that seemed to be working fine, but I got zilch out of the topload. Removed the gap and replaced it with a simple 2 element and it worked like a charm. 
Its worth a shot. 
You can always go back and improve the gap later once you know that everything is working as it should, but for this power level I don't know if you'll see much increase in performance by doing so. 

Shannon
Klasdja Intelligent Innovations

-----Original Message-----
From: Peter Sutter [mailto:peter@xxxxxxxxxxxx] 
Sent: Thursday, April 19, 2012 6:26 PM
To: Tesla Coil Mailing List
Subject: [TCML] Newbie question - Where does all the energy go?

Hello Coilers,

I finally finished my first coil and I am trying to produce some sparks. This seems not to work.

Initial powering up the coil produced some massive, noisy sparking between the primary and the bottom winding of the secondary, and some racing sparks. Coupling factor .138 according to Javatc.

Lifting the secondary coil by 20 mm fixed this problem, coupling factor is now .120 according to Javatc.

Powering up the coil with a breakout point on the toroid produces a very weak spark of about 25 cm (10 inches), with very little noise. The spark is lacking in energy, it is barely noticeable in the dark. However there seems to be a 'sweet spot' on the primary coil between  14 3/4 and 14 7/8 turns, where the weak spark reaches its maximum length and intensity. JavaTC suggests the tap at
15.08 Turns. There is no noticeable corona effect on the toroid. So the coil appears to be tuned. Very very rarely, the safety gap fires briefly.

It looks as if something is absorbing the energy, like e.g. a short circuit winding. After several minutes running, there is no noticeable warming of any of the components. The capacitors stay cool. The spark gap becomes about hand warm.

I used no metal fasteners, washers, nuts etc. in the construction of the coil, to avoid any possible short circuit windings, these are all plastic. There is a strike rail 6 cm above the primary, which has a 5 mm gap. The base of the coil is made up of plywood and acrylic plastic.

The transformer is a 12KV 30 ma NST, make F.A.R.T. The center of the secondary is on ground. This ground is not connected to the mains ground, but to RF ground. (1.2 m of 1 inch copper pipe in the ground, also connected to the center of the safety gap and the strike rail).

The primary is 1/2 inch copper tube as used in refrigeration.

The capacitors are homemade, three liquid paraffin filled tubes of approximately 60 nF each in series giving 18.1 nF in total.

The spark gap consists of 8 pieces of 1 inch round copper pipe, the segments are spaced .7 mm apart for a total spark gap length of
.5 cm.

The secondary form is a piece of 160mm outside diameter high pressure water pipe as used by the shire, it is a white plastic, the windings are coated with polyurethane varnish.

The Top Load is a toroid, lesser diameter 10 cm, outer diameter 36 cm. It is made of Dryer Ducting, where the gaps between the 'fins' has been filled with wood filler. The resulting toroid was sanded and covered with Aluminium tape. This is the only part on the coil that could form a 'short circuit' winding.

What do I try next?

Many thanks for your hints and suggestions.


Peter

----------------------------------------------------

Here are the details of the coil

J A V A T C version 12.5 - CONSOLIDATED OUTPUT Fri 20 Apr 2012 08:55:16 AM WST

Units = Centimeters
Ambient Temp = 25°C

----------------------------------------------------
Surrounding Inputs:
----------------------------------------------------
254 = Ground Plane Radius
254 = Wall Radius
381 = Ceiling Height

----------------------------------------------------
Secondary Coil Inputs:
----------------------------------------------------
Current Profile = G.PROFILE_LOADED
8.1 = Radius 1
8.1 = Radius 2
6 = Height 1
93.5 = Height 2
1750 = Turns
0.05 = Wire Diameter

----------------------------------------------------
Primary Coil Inputs:
----------------------------------------------------
Round Primary Conductor
9 = Radius 1
37.678 = Radius 2
6.7 = Height 1
6.7 = Height 2
15.0541 = Turns
1.27 = Wire Diameter
0 = Ribbon Width
0 = Ribbon Thickness
0.0181 = Primary Cap (uF)
76.2 = Total Lead Length
0.508 = Lead Diameter

----------------------------------------------------
Top Load Inputs:
----------------------------------------------------
Toroid #1: minor=10, major=36, height=103, topload

----------------------------------------------------
Secondary Outputs:
----------------------------------------------------
120.27 kHz = Secondary Resonant Frequency 90 deg° = Angle of Secondary
87.5 cm = Length of Winding
20 cm = Turns Per Unit
0 mm = Space Between Turns (edge to edge)
890.64 m = Length of Wire
5.4:1 = H/D Aspect Ratio
79.0925 Ohms = DC Resistance
55756 Ohms = Reactance at Resonance
1.555 kg = Weight of Wire
73.783 mH = Les-Effective Series Inductance
84.483 mH = Lee-Equivalent Energy Inductance
84.811 mH = Ldc-Low Frequency Inductance
23.734 pF = Ces-Effective Shunt Capacitance
20.728 pF = Cee-Equivalent Energy Capacitance
48.802 pF = Cdc-Low Frequency Capacitance
0.2024 mm = Skin Depth
12.677 pF = Topload Effective Capacitance
194.7943 Ohms = Effective AC Resistance
286 = Q

----------------------------------------------------
Primary Outputs:
----------------------------------------------------
120.27 kHz = Primary Resonant Frequency
0 % = Percent Detuned
0 deg° = Angle of Primary
2207.59 cm = Length of Wire
3.06 mOhms = DC Resistance
0.635 cm = Average spacing between turns (edge to edge)
0.24 cm = Proximity between coils
3.09 cm = Recommended minimum proximity between coils
96.345 µH = Ldc-Low Frequency Inductance
0.01809 µF = Cap size needed with Primary L (reference)
0.861 µH = Lead Length Inductance
390.991 µH = Lm-Mutual Inductance
0.137 k = Coupling Coefficient
0.136 k = Recommended Coupling Coefficient
7.3  = Number of half cycles for energy transfer at K
29.99 µs = Time for total energy transfer (ideal quench time)

----------------------------------------------------
Transformer Inputs:
----------------------------------------------------
240 [volts] = Transformer Rated Input Voltage 12000 [volts] = Transformer Rated Output Voltage 30 [mA] = Transformer Rated Output Current 50 [Hz] = Mains Frequency 240 [volts] = Transformer Applied Voltage 0 [amps] = Transformer Ballast Current 0 [ohms] = Measured Primary Resistance 0 [ohms] = Measured Secondary Resistance

----------------------------------------------------
Transformer Outputs:
----------------------------------------------------
360 [volt*amps] = Rated Transformer VA
400000 [ohms] = Transformer Impedence
12000 [rms volts] = Effective Output Voltage
1.5 [rms amps] = Effective Transformer Primary Current
0.03 [rms amps] = Effective Transformer Secondary Current 360 [volt*amps] = Effective Input VA
0.008 [uF] = Resonant Cap Size
0.0119 [uF] = Static gap LTR Cap Size
0.0207 [uF] = SRSG LTR Cap Size
20 [uF] = Power Factor Cap Size
16971 [peak volts] = Voltage Across Cap
42426 [peak volts] = Recommended Cap Voltage Rating
2.61 [joules] = Primary Cap Energy
233.1 [peak amps] = Primary Instantaneous Current
77.8 [cm] = Spark Length (JF equation using Resonance Research Corp. factors)
89.1 [peak amps] = Sec Base Current

----------------------------------------------------
Static Spark Gap Inputs:
----------------------------------------------------
8 = Number of Electrodes
2 [cm] = Electrode Diameter
0.5 [cm] = Total Gap Spacing

----------------------------------------------------
Static Spark Gap Outputs:
----------------------------------------------------
0.071 [cm] = Gap Spacing Between Each Electrode
16971 [peak volts] = Charging Voltage
15271 [peak volts] = Arc Voltage
35899 [volts] = Voltage Gradient at Electrode
30542 [volts/cm] = Arc Voltage per unit
90 [%] = Percent Cp Charged When Gap Fires
39.276 [ms] = Time To Arc Voltage
25 [BPS] = Breaks Per Second
2.11 [joules] = Effective Cap Energy
451260 [peak volts] = Terminal Voltage
54 [power] = Energy Across Gap
63.9 [cm] = Static Gap Spark Length (using energy equation)



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