======================================================================= INFORMATION FOR BUILDING CAPACITORS: Comments | Puncture Voltage | Material Dielectric strength per Mil | "K" (0.001 inch) | | | | ----------------------------------------------------------------------- Miscellaneous ------------- Vacuum 1.0 Paper, bond 3.0 200 Paper, Royal Grey 3.0 200 Paper, telephone, treated 2.5 - 4 200 - 250 * Paper, Parafin Coated 2 -3.5 Paper, Kraft 2.2 Oil, Castor 4.67 Oil, Mineral, Squibb 2.7 200 Oil, Mineral 2.2 Oil, Transformer 2.1 - 2.5 75 * Rubber 3.0 Rubber, Hard 3.0 160 - 500 * Rubber, Vulcanized 3.2 - 3.9 1 Fibre 5.0 - 7.5 150 - 180 Fibre, Red 5.0 Mica 4.5 - 8.0 3800 - 5600 Mica, Ruby 5.4 3800 - 5600 Quartz 3.8 - 5.0 1000 Quartz (Fused) 4.2 150 - 200 * Shellac 2.5 - 4.0 200 - 400 Spar Varnish 4.8 - 5.5 Steatite, low loss 5.8 150 - 315 Steatites (Magnesium silicate,etc) 5.5 - 7.5 200 - 300 Cambric (Varnished) 4.0 2 Alsimag 196 5.7 Gutta Percha 4.0 3 Amber 3.0 - 7.0 4 Resin 2.48 - 2.57 Enamel 5.1 450 Mycalex 7.4 250 Silicone RTV 3.6 550 Wood 2.0 - 5.2 Wax (Parafin) 2.1 - 2.5 250 - 450 * Beeswax 2.9 - 3.0 Slate 7.0 5 Barium titanate(25 C) 1200 Bariam titanate 6000 Titanium dioxide 125 Cellulose acetate 3.3 - 3.9 250 - 600 Casein, Moulded 6.4 6 Polytetraflourethylene 2.0 A Aluminum oxide 8.7 Tantalum pentoxide 22 Glass ----- Glass 4.8 - 10 300 Plate Glass 6.8 - 8.4 Pyrex Glass 4.8 - 10 335 Window Glass 7.6 - 7.8 200 - 250 Ceramics -------- Cordierite ceramics 5.0 - 5.5 100 Magnesium titanate ceramic 12 - 18 150 Porcelain 5.1 - 7.5 40 - 280 Titanium dioxide ceramic 70 - 90 100 Titanium-zirconium dioxide ceramic 40 - 60 150 Plastics -------- Bakelite 4.4 - 5.8 300 Bakelite, Mica filled 4.7 325 - 375 Epoxy Circuit Board 5.2 700 Formica 4.6 - 4.9 450 7 Nylon (lowest values of 3 types) 3.2 407 PVC (rigid type) 2.95 725 Plexiglass 2.8 450 - 990 Polyethylene 2.2 - 2.3 450 - 1200 Polycarbonate (Lexan) 2.96 400 Polyethylene Terphthalate (Mylar) 3.0 - 3.1 7500 Polystyrene 2.5 - 2.6 500 - 700 Teflon 2.1 1000 - 2000 Gases -------- Air (dry air at 1 atm) 1.0006 30 - 70 Air (20 atm, 19 deg. C) 1.0108 500 * Carbon dioxide ( 1 atm, 0 deg. C) 1.000985 36 * Carbon dioxide (20 atm, 15 deg. C) 1.020 Hydrogen (1 atm,0 deg.C) 1.000264 26.1 * Liquids -------- Amonia (liquid) 22 Benzene 2.28 Carbon tetrachloride 2.24 8 Chlorinated diphenyl 6.5 9 Ethyl Alcohol (O C) 28.4 Ethyl alchohol (20 deg.C) 25.8 Methyl alchohol 33.1 Water (distilled) 80 - 81 LEGEND: * = Measured in Kilovolts per centimeter. All others are Volts per mil (.001 inch) unless otherwise stated. 1 = Vulcanized means it has been melted, or heated in some way. 2 = Cambric is a finely woven white linen or cotton fabric. 3 = Gutta Percha is a rubbery substance made from the latex of tropical trees and is used in insulation, waterproofing, and dentist use it in thin sheets sometimes when working on teeth. 4 = Amber is a hard, translucent, yellow, orange, or brownish yellow fossil resin, used in making ornamental objects like jewelry. 5 = Slate is a fine grained metamorphic rock that splits into thin smooth faced layers. Black Boards for writting are made of this. Also used as roofing material in some areas. 6 = Casein is a white, tasteless, oderless milk and cheese protein used in the manufacture of plastics, glues, paints, and food. The word 'moulded' means it has been shaped by a mold. 7 = Formica is a trademark for any of various high-pressure laminated plastic sheets of melamine and phenolic materials used for chemical and heat-resistant surfaces. 8 = Carbon tetrachloride is a very toxic substance. It has also been shown to cause cancer in lab animals. It is banned in most labs. It is a liquid that was used as a strong solvent. 9 = Chlorinated diphenyl is a liquid dielectric that is used to impregnate Kraft paper in small A.C. capacitors. This is a PCB and may cause cancer, handle carefully. A = Polytetraflourethylene films retain good properties even at 200 degrees Celsius (200 C). atm = atmospheres (pressure of air at sea level is 1 atm). deg.C = degrees Celsius. Warning - Some liquids and gases listed may be explosive under the right conditions. Many solids can catch fire and burn. Use CAUTION and GOOD COMMON SENSE. Note: Some books gave very different values for each substance so I have given you the highest and lowest values reported. The values will depend on the purity of the substance your using. If you know your substance is very pure then use the higher value reported. If you know your substance is contaminated or of poor quality then use the lower values reported. If you have unknown purity then use the average of the values given. ======================================================================= EXPLAINATION OF EQUATIONS: Here are some real handy equations. They are very simple and easy to use. x = Multiply by / = divide by ( may also use line seperating terms above and below line as in standard mathematics). ( ) = Terms in parentheses should be calculated first as in standard algebraic equations. pi = 3.141592654. The circumferance of a circle divided by it's diameter will always give you this constant. 2 Z = means the term "Z" multiplied by itself one time,"Z x Z". Note: In some cases I do not use the symbol "x" but instead simply put the terms close together, example: "LC" instead of "L x C". This is standard for algebraic equations and means "multiply by". ======================================================================= MATH FOR TESLA COILS 1. Determine your neon sign transformer (or other transformer's) Impedence: E Z = --- I Z = Impedence E = volts I = current in Amps Note: divide milliamps by 1000 to get Amps. 30 milliamps = .030 Amps. The Impedence of the primary capacitor should match the Impedence of the transformer at 60 Hz (60 Hz is the AC cycle rate of common household wall sockets, at least in America). 2. To match Impedence and determine capacitor value: 1 C = ------------------- 2 x pi x Z x .00006 C = capacitance in microfarads needed for primary capacitor. Z = Impedence from equation one (Transformer Impedence) pi = 3.141592654 Note: The .00006 is the 60 Hz AC, if you live outside the US then substitute your cycle rate. Next you need to find the Reactance of the primary capacitor at the frequency you have choosen. Many times the frequency is decided by the length of wire used on the secondary coil. See below fo...
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