Virtual Secondary Database

TSSP: Virtual Secondary Database

A database of simulated performance of around 13,500 secondary resonators, for the purposes of establishing empirical relationships between coil geometry and the various equivalent reactances and performance measures.

Updated: 19 Jul 2008

Summary

The range of typical Tesla secondary resonator dimensions or 'configuration space' is spanned by the seven parameters of length, diameter, base height, wire size, spacing ratio, toroid width, and toroid height. We explore this space by analysing a representative sample of imaginary resonators modeled with the simulator. The database is intended to contain sufficient samples along each axis of the configuration space to enable reliable curve fitting to be done.

Resonators are simulated as if they were in free space above a ground plane of radius equal to the height of the top of the secondary above the ground plane. This database only covers coils driven directly through their base terminal. Only coils with up to 3000 turns are considered. Data generation required about 30 days of computation using a 14 processor Beowulf Cluster.

Some graphs of the data are available - see view. Some of the results of curve fitting can be found in formulae

Download

The database contains 13578 records. These can be downloaded through the following link.

vsd.data.gz Unix format, gzipped, 662 Kb. Space separated fields, newline separated records.

If you discover any interesting relationships amongst the data, or find a useful curve which fits, then do let us know.

Data Record Format

Each record contains the following fields, shown with field number in brackets. First the record header info...

(1) system: System name. This is a file name prefix which identifies the input and output files of the simulation run from which this record was obtained.
(2) version: The version number of the model software which generated this record.

Next are the input parameters - the resonator description...

(3) h: Secondary winding length - metres. This is the only absolute length measurement employed - all other dimensions are given relative to this.
16 values: 0.1, 0.1259, 0.1585, 0.2, 0.2518, 0.317, 0.4, 0.5036, 0.634, 0.798, 1.0, 1.265, 1.593, 2.0, 2.525, 3.179.
(4) b: Secondary base height, in units of coil length h. In other words the ratio of base height to coil length.
3 values: 1/30, 1/5, 1/2.
(5) hd: The length/diameter ratio.
6 values: 1, 2, 3, 4, 6, 10.
(6) awg: The secondary wire gauge - AWG.
4 values: 12, 20, 24, 32.
(7) sr: Spacing ratio of the secondary winding, sr = turns * wire_diam/h
3 values: 0.95, 0.75, 0.55.
(8) td: Outer diameter of toroid, in units of h. A value of zero means no toroid used. The chord diameter of the toroid is automatically chosen so that the inner diameter is always 5% larger than the secondary diameter.
3 values: 0 or an empty field (no toroid), 1.2, 1.5.
(9) tb: Height of plane of toroid above secondary winding top, in units of h. With this definition, the height of the toroid plane above ground is (b*h + h + tb*h) metres.
2 values: 0.1, 0.3. This field will be empty if there is no toroid.

Now for the output results, starting with the resonant frequencies...

(10) f1: Frequency of quarter wave resonance, Hz.
(11) f3: Frequency of three-quarter wave resonance, Hz.
(12) f5: Frequency of five-quarter wave resonance, Hz.

Then the equivalent reactances of the resonator...

(13) Ldc: The low frequency (Nagaoka) inductance - mH, at DC.
(14) Lee: The equivalent energy storage inductance - mH, at f1.
(15) Les: The equivalent series inductance - mH, at f1.
(16) Cdc: The bulk low frequency capacitance to ground - pF, at DC.
(17) Cee: The equivalent energy storage capacitance - pF, at f1.
(18) Ces: The equivalent shunt capacitance - pF, at f1.

And finally, some performance measures...

(19) Q: Q factor at the quarter wave resonance f1.
(20) Rin: The base input resistance at f1, ohms
(21) Zft: The magnitude of the forward transfer impedance, |Vtop/Ibase|, ohms, at f1.
(22) gain: The magnitude of the voltage gain, |Vtop/Vbase|, at f1.

Notes: The fields given above are in the order in which they appear across a record. If data is imported into a database, it is recommended that the suggested field names are used, so that queries can be exchanged more easily. The records are stored in no particular order within the data file. The fields 19, 20, and 22 are of limited accuracy due to the lack of an effective model of resonator losses.

Maintainer Paul Nicholson, tssp0807@abelian.org.