The equation of the circular spiral coil, motivated by the Archimedean spiral coil can be described by. In all cases, the current is assumed to flow in the outer surface of the. This calculator based on Rosa's straight wire self-inductance formula. Rearranging and simplifying, where ρ is the wire’s resistivity (2. 2 x d2x N2) / (3d + 9l =10b) L = Inductance (in μH) d = Diameter of the inductor coil (Inches) l = Length of the indutor coil (inches) b = Diameter of the coil winding wire (inches) N = Total turns of wire. The calculator uses Bob Weaver's equation with round wire corrections. Find the value of the absolute permittivity of the material between the plates ε. The first thing to know when calculating the impedance of a wire is whether it's a coaxial or twisted pair cable. While this calculator will provide a baseline, any final design considerations should be made towards loss, dispersion, copper roughness, phase shift, etc. 2. My first calculations were less but when I measured it I got 3. Some of them were designed to be used in static solid-state NMR probes operating at 1 H frequencies of 300 and 600 MHz, see Solenoid 1–5 in Table 1, which were tested with a inductance measurement circuit []. This algorithm is applied in Coil64, online calculator, as well as in versions Coil32 for Android and Linux, to increase the accuracy of the calculation of the inductance of single-layer air core inductor. 75mm which equates to 23. 70 or 2. 00? to 10. Dimensional units:. The n gauge wire diameter d n in inches (in) is equal to 0. 79 ohms/1 000 ft. An alternative formula is:This calculator is designed to measure the wire coil inductance, given the number of turns, the diameter of the loop, the diameter of the wire, and the permeability of the medium. This method is derived by solving Neumann’s integral formula in a cylindrical coordinate system, and a numerical tool is used to determine the value of mutual inductance. 84µH. For very high frequencies the inner inductance gets zero and the overall inductance tends to its outer inductance. Biplanar Inductance Model Inductance of the loop bounded by two biplanar flat conductors is: Units: Henries. c. where N is the number of turns, r is the inside radius in cms, and L is the inductance in uH. according to Rosa, 1,4,5 • A round wire mutual-inductance correction factor k. design parameters resulting in the required inductance must be found. The mutual partial inductance is calculated as mutual inductance be-tween two filaments and provides exact values [1]. 0344 x 2. The permeability of a vacuum is exactly 1. Many radio fans in the constructions as chokes apply the multilayer coils with the. Low frequency, perfect conductor: no skin effect. The size of the loop is determined by a, the radius of the loop. Lwire=2l⎧⎨⎩ln⎡⎣(2LD)⎛⎝1+√1+(D2L)2⎞⎠⎤⎦−√1+(D2L)2+μ4+(D2L)⎫⎬⎭Lwire=2l{ln[(…[μH] where L flat: inductance of the conductor [μH] ℓ : length of the conductor [mm] w: width of the conductor [mm] t: thickness of the conductor [mm]This tool is designed to calculate the inductance of a square loop of wire given its dimensions (width, height and diameter of the wire used). 2. Two parallel wires with currents in opposite directions. Planar coils are mostly used in high frequency applications and designed as tracks on a circuit board. Can we obtain the same low inductance by twisting two wires at audio frequencies?. The inductance calculated in this tool is the loop inductance created with the wire and its return path on the ground plane. Six Inductor Parameters 4. Enter the number of turns (windings). Assumptions and Limitations Dimensions are in meters. Meander line inductors have lower inductance per unit area than coil inductors. Jewett. Two parallel wires. The impedance ZL of an inductor of inductance L, in complex form, is given by ZL = j XL. A flat spiral coil is a type of an air core inductor usually incorporated in the primary of a tesla generator, RFID tag, and proximity detectors. A precision laboratory resistor is made of a coil of wire 1. Conductors is assumed to have zero. Matching Pi Attenuator A two part calculator which gives ideal and preferred value resistors, showing most formulas used and a link to the others. The calculation is based on the classic Wheeler's formula for single-layer inductance (air core, tightly wound), which dates back to the radio days of the 1920s: L = 0. The length of the secondary coil is used to calculate the wire weight. Internal inductance is not included in this model, but may be calculated using the Wire Internal Inductance tool. For each case, we use a different cable impedance formula: To calculate the impedance of a coaxial cable, we use the following formula: Impedance = 60 × ln ( D 2 / D 1) ε r. Elliptical Integrals of the First Kind Calculator. Step 2: To calculate the resonance frequency, click the "Calculate x" button. The capacitance calculated using this tool is the capacitance between a flat conductor and two equidistant ground planes. Available Winding Area of the Core: W A c. Effective equivalent circuit; effective equivalent circuit: effective series inductance at the design frequency from Corum’s sheath helix waveguide formula, corrected for field non-uniformity and round wire 1,3,6,7 (L_{ ext{eff,s}}) µH: effective series reactance of the round wire coil at the design frequencyAir Cored Inductor Calculator - Includes Q - Size units in mm - Computes Inductance, Q and wire length AL Inductance Calculator ### - Input two values and get the third - Inductance units: mHenrys,. The calculator allows calculating the number of windings of the multilayer air core coil on a rectangular former at the design stage. Dimensions are in meters. density of steel. The figure below shows the overall inductance over frequency for a 1m single wire over ground plane in the unit Henry. The outer diameter of the wire (with insulation) should be using in this calculator. Overview. radius. 85 mΩ or 1. 65 mm without insulation and 0. Mean Length of Wire Turn (MLT) on the particular core 3. 00mF capacitance, 0. • A round wire self-inductance correction factor k. A sample 14 turns, half radius of 3 inches and a width of 12 inches yield an inductance of. Z = Impedance in ohms. Place two equal lengths of wire (each approximate three-feet long) flat on a non-metallic table (or wooden board) such that the wires are parallel and spaced 2. where: L = inductance in μH. HCV power inductors. (We are only concerned with the external inductance here. The inductance calculated using this tool is the inductance of the loop bounded by the two biplanar flat conductors. 7. Only loop inductance can be measured. A microstrip is created by etching a trace on a printed circuit board and is mostly used in microwave applications. As is known, such a structure is defined as the small inductances and capacitances distributed along the line length. The effective diameter Deff obtained from here is used to calculate the inductance of the single-layer helical coil: where: μ: permeability of the coil core. The inductance calculated using this tool is the inductance of the loop bounded by the two coplanar flat conductors. Calculate the Number of Turns and Winding Length From the Given Inductance, Coil Former Diameter, and Diameter of Wire Example: Calculate the number of turns and winding length of a 10 μH coil with 2 cm former diameter wound with 22 AWG magnet wire (0. A round wire self-inductance correction factor k s according to Rosa, 1,4,5; A round wire mutual-inductance correction factor k m according to Knight, 1,6; A reduced effective coil diameter for modelling the current quenching in the wire under the proximity effect of nearby windings, Since self inductance is all about the magnetic flux created by current flowing in the wire interacting with the wire, when you have less magnetic flux you have lower inductance. Enter at least any two input values and click calculate to solve for the remaining values. Any length of wire has some inductance, however, at low frequencies, 1-30 MHz, the added effect of this inductance is usually minimum. Note: Get to know what is self inductance from the following video: Cable impedance formula. Wheeler’s spiral formula is 1% accurate for c>0. Inductance is the ability to store energy in a magnetic field, and coils are a common way to create inductance. 00? to 10. Two parallel wires with currents in opposite directions. Tavakkoli et al. Value of inductance is normally directly proportional to diameter of the coil and a square of number of turns. (OpenStax 23. Round Wire Inductance Calculator. Benefits include greater wire density in the gap, and a single layer of flat wire has less inductance than two or more layers of round wire. Wire is assumed to have circular cross section. The value of M neatly encapsulates the physical properties of circuit elements and allows us to separate the physical layout of the circuit from the dynamic quantities, such as the emf and the current. Capacitive Reactance/Admittance. W. For each case, we use a different cable impedance formula: To calculate the impedance of a coaxial cable, we use the following formula: Impedance = 60 × ln ( D 2 / D 1) ε r. Description. As opposed to deliberate inductance, which is introduced into the circuit by the use of an inductor, parasitic inductance is almost always an undesired effect. Units for M are (V ⋅ s)/A = Ω ⋅ s, which is named a. Wire Loop Inductance Description. D = Coil diameter in centimetres. The round-wire geometries are loops of wire with various shapes. 7563 mm (~30 mils). Input the values into the formula and calculate the self-inductance. Dimensions are in meters. area = the cross sectional area of the core in square meters*, including some of the coil as shown in the diagram. Select the measurement units (inches or centimeters). What is. 1 inch = 0,0254m=2,54cm = 25,4mm. In [16,17], the wire diameter is included in the calculation of the self-inductance. Internal inductance is not included in this model, but may be calculated using the Wire Internal Inductance tool. Figure 2 illustrates the space savings achieved by the high winding factor with minimal wasted space in the flat wire cross-section. A twisted-pair cable is simply two wires that are twisted together so as to reduce radiated EMI (electromagnetic interference) and mitigate the effects of received EMI. 5, we can see the significance of the earlier description of mutual inductance (M) as a geometric quantity. 7 mm with insulation). 2. Dimensional units: mm mils d1 (outer diameter) = d2 (inner diameter) = N (number of turns) = L (Inductance, nH) =. Reactance Calculator. Air Core Flat Spiral Inductance. One formula for inductance is as follows: Where: L = inductance. e. Equation. To calculate the inductance of a single-layer, air-core coil: 1. The inductance allows one to understand the amount of energy that can be stored in magnetic fields. Wire Loop Inductance Description. A wire self inductance calculator is a tool that allows you to calculate the self-inductance of a wire or conductor. L is the specific inductance in mH for 1000 turns of wire 2. Please feel free to use them. Having this in consideration, together with the particularities of planar coils previously mentioned, the complexity associated with the auto-inductance calculation for flat. The auto-inductance of a coil is dependent on the mutual inductance between each current turn, the self-inductance of the coil’s wire, and the environment surrounding it. Regards JimFlat Spiral Coil. The formula to Calculate the inductance of parallel wire ( Power and Ground System) L = 10. 95 J, 0. One trace is the signal and the other is the return path applied to this inductance calculator. Find Wire Self Inductance Calculator at CalcTown. If the windings are fixed in place, then this force is unable to do work (i. From the formula it is visible that the choke should have a greatest possible inductance, the it above, the better it "choking" AC. Engineering Paper (Printable PDF)the inductance of short-circuited two-wire lines. for air core flat spiral coil inductor. Using the Ampere-Turn Calculator to compare two coils. The Magnetic field linking the Ground wire is Zero and hence the Inductance of the Ground conductor is Zero. The self-inductance is calculated from one of two possible formulae: one applicable to solenoids; the other to pancake coils. Lcoil = μrμ0N 2A l = μrμ0N 2πr2 l L c o i l = μ r μ 0 N 2 A l = μ r μ 0 N 2 π r 2 l. This calculator can also calculate the inductance of an inductor if the reactance and frequency of the supply voltage is known. The auto-inductance of a coil is dependent on the mutual inductance between each current turn, the self-inductance of the coil’s wire, and the environment surrounding it. 081 uH. The loop self inductance, distributed per inch of circumference, is roughly 150nH / 6 inches, or 25nH per inch of circumference. Any material that has current flowing through it and produces a magnetic flux has inductance. To use this calculator, just enter the required values and press the "calculate" button. μ₀ is the permeability of free space, approximately equal to $4π × 10^ {-7} , ext {H/m}$. ZL = XL ∠90 ∘ or ZL = XL∠ π 2. 3 mm, the inductance of the loop between the planes tends to be small relative to the connection inductance above the planes. EXAMPLE#1 single layer coil inductor calculator: INPUTS: LOOP DIAMETER = 10 inches, COIL LENGTH = 20 inches, NO. Trace Inductance Calculator. Wire Size (AWG/in/mm) Wire Length (in/mm) Inductance = 0. 0 cm diameter solenoid having 1000 loops. length = length of the coil in meters*. P. This tutorial explores coil inductance, including the. Assumptions and Limitations Dimensions are in meters. But our calculator uses Maxwell's formula in the same way as the flat spiral coil calculator and the multi-layer coil calculator . Flat PCB coils are most often used in the VHF and UHF bands to reduce the size of the device. Reset the calculator after each calculation for best results. The formula can be used for practical calculations of the toroidal air core coils with round cross section. Wire Loop Inductance Description. 0. The wire may be flattened to various aspect ratios, with. The inductance of the inductor is calculated by the following empirical formula: where: L – inductance of meander (µH) N – number of turns; a – length of a lead (mm) h – height of the meander (mm) d – width. To learn more about the capabilities of EMI Analyst, sign up to access our download area. The self-inductance of a straight wire may only be defined as so-called partial inductance [1, 2]. w = wire diameter in inches. The capacitance calculated using this tool is the capacitance between two coplanar flat conductors. To use this tool, just fill in the required fields and click on the "calculate" button. Inductance: mH: Wire Gauge: AWG: Inner Coil. Rule of Thumb # 7: In the special case of two flat, wide conductors, adjacent to each other, with a spacing comparable to their line width, the total inductance of either one is just 10 nH/inch. 489. inductor or choke on the design stage. Successively, different wire solenoids with radius below 1 cm were simulated for calculating inductances. Following equation or formula is used for inductor calculator for singlelayer coil type. Always bear in mind that there is a tolerance on the stated AL value of a core. The geometrical mean distances for a round conductor with radius r, for a flat wire of width a, and for a square wire with side b are: R e . Dimensions are in meters. Calculate the inductance using a mathematical formula. Inductor Design Spec’s I L r L L} AWG # Choice for inductor wire windings. This correction, in microhenrys, is added to the inductance. Please provide a rating, it takes seconds and helps us to keep this resource free for all to use. Conductor is assumed to have zero thickness and to have uniform height. Description The inductance calculated using this tool is the inductance of the loop bounded by the. These equations apply for when the length of the wire is much longer than the wire diameter (look up wire diameter here). To help you work most efficiently, we've created a number of calculating tools to aid in your wire and cable installations. Inductance of flat ground strap decreases as length-to-width ratio is decreased. 44x10-8 Ω-m for gold and 1. Two -Wire Transmission Line The two -wire transmission line is just two long -straight wires running parallel to one another. Where: Lwop L w o p = inductance of the wire over plane in henries (H) μ0 μ 0 = permeability of free space = 4π×10−7. Click Calculate. Two parallel wires. b R ae . It is similar in function to capacitors and inductors but only for very high frequencies. To learn more about the capabilities of EMI Analyst, sign up to access our download area or send us a request . 8d)*105 where, L = Inductance, r = Coil Mean Radius, N = Wire Coil Number of Turns, d = Coil Depth. In this tool, the variables required are length and wire diameter. In our wire resistance calculator, we have listed some materials, which you can select to find their resistivity and conductivity at 20°C. d (coil diameter in inches) (inches) l (coil length in inches) (inches) n (number of turns) Inductance: Equations. Round Single Round (Parallel 2 Strand) Round (Triple 3 Strand) Round (Quad 4 Strand) Flat Ribbon. Ohm’s Law Calculator. W. Or even simpler: l = c, D = 2c. Finally, we have two equations for the inductance of microstrip and stripline traces. These two signals make a complete loop. This formula is used in the calculators linking below. An induction or inductive loop is an electromagnetic communication or detection system which uses a moving magnet or an alternating current to induce an electric current in a nearby wire. He derived a simple formula for calculating the inductance of such. As the frequency goes above 10MHz, the formula becomes less accurate, because parasitics dominate the circuit. Relative Permeability is assumed to be 1. 4. Straight conductor. Maxwell equation: a = d/2 is the radius of the wire cross-section, half of the wire diameter (m) However, in the Coil32 calculation of the loop inductance is carried by a simple empirical formula, which was first brought by F. 4. Select whether to calculate inductance or capacitance. 5 ohms resistance 60Hz frequency thank you. Posted on July 28th 2023 | 2:17 am. A is the cross-sectional area of the coil in square meters (m 2)L = √ [(L 1 *Sin(X)) 2 + (L 2 *cos(X)) 2] - aggregate inductance of coil Inductance in µH, dimensions in inches. And you can input any four of the five components of the inductance formula to retrieve the fifth. Equation $$L_{coil} = frac{ mu_{r} mu_{0} N^{2}. N is the number of turns in the coil. However on high frequencies there are some features. For coil inductance in Henrys: L = N 2 * µ * A / Cl. wire inductance L int = µ 0/8π, and the resulting inductance is higher than the inductance at high frequency when the skin effect becomes dominant. Wire is assumed to have circular cross section. Select your coil geometry, enter the dimensions, and select the units. Some people call it "magnet wire". The round-wire geometries are loops of wire with various shapes. Figure 14. Inductance is the ability to store energy in a magnetic field. To find out how much inductance a coil has, do the following: Step 1: Enter the coil radius Rc or the coil diameter Dc (in Advanced mode). Ferrite toroid calculator. With an LCR meter, I am measuring the inductance of the cable. It is assumed that this shield is sufficiently thick. Introduction of Coil Physical Properties Calculator. Inductance of a Square Loop of Wire. Enter the coil diameter (form diameter + wire diameter - see diagram). 2. 2. Voltage (V)A circuit element used to provide self-inductance is known as an inductor. The inputs to this calculator are length distance between the two conductors and diameter of the wire. By understanding the microstrip transmission line, designers can. The calculator allows calculating the number of windings of the multilayer air core coil on a rectangular former at the design stage. Here you can see the formulas that the calculator uses to calculate the inductance. Many magnetic field coupling circuits, such as chokes and transformers, take advantage of a coil’s magnetic storage properties. Loop Inductance Calculator. (Copper is non-magnetic, just like air, and stores. In all cases, the current is assumed to flow in the outer surface of the conductors. E. The twisted pair helps create a more uniform inductance and capacitance per unit length of wire to ensure a constant impedance, by keeping the return path as close to the signal as possible. Note 7: Enter the core relative permeability constant, k. At high frequencies, a real inductor is usually modeled as the LRC circuit shown in the figure. 00pF to 100. In this paper, an analytical calculation of the inductance of an air-core planar spiral coil is presented. It is more difficult to calculate the mutual inductance of the rectangular coils with lateral or angular misalignment. 56MHz by adjusting your matched parallel capacitance. US $37. Grover's Inductance Calculations - Working Formulas and Tables, is used. Use the formula L = R * sqrt(3) / (2 * pi * f). L = Inductance, nH. Ground wire is adequate for power frequency applications while flat ground straps perform better at higher frequencies. Reference: “Analysis of Multiconductor. First you calculate the self inductance which is dependent on the physical parameters as you just described. 99This calculator will determine the inductance of a coil with know length, number of turns and diameter. The LCR meter measures the inductance of two cables. s = distance between windings in inches. The inductance of a wire loop is a common textbook example of a circuit with inductance. 1. Use our free online app Wire Self Inductance Calculator to determine all important calculations with parameters and constants. Single layer inductor calculator. Current creates a magnetic field, which subsequently exerts force on other current-bearing structures. A coil inductance formula is based on the basic loop inductance. Wires are assumed to reside in a homogeneous medium. 2. According to Eq. Because the material is working well under 48 twists. Our tools will help simplify the process. The inductance for the two wire inductance might be useful in measuring the inductance for a signal and ground on a ribbon cable. An inductor is typically made of a wire or other conductor wound into a coil, to increase the. Parallel Wire Impedance (Zo) = Ohms. When the effective cross sectional area of a wire gets larger, current flowing on one edge of the wire can produce a small. Note: This calculator is also suitable for flat spiral (pancake, spiderweb, etc. presents a calculation tool called antenna design to calculate the equivalent inductance of rectangular antennas, taking into account an approximation of the stray capacitance. Also, please read our Disclaimer at the bottom of the page. Due to its geometry, the coaxial cable impedance requires you to know the inner wire's diameter and the outer shielding. 67r and the frequency is less than 10 MHz. 99 – £ 29. 393 mm, the required trace width for this particular inductance value is w = 0. All conductors have inductance. 8 µH. The variables needed in calculating this inductance are center conductor diameter, distance to outer shield, and length. Edge Coupled Trace Inductance Calculator. The figure below shows the overall inductance over frequency for a 1m single wire over ground plane in the unit Henry. INPUT DATA. 5Turns 25-100MHZ. 5 times larger cross section to be selected. 5 cm apart (about one inch). To use this tool, just enter the diameter of the loop, the diameter of. m. Inductor calculator equation and structure for singlelayer coil type. Instructions say I. An insulated coil of N2 turns is wrapped around it, as shown in Figure 11. 6 Band Resistor. Having this in consideration, together with the particularities of planar coils previously mentioned, the complexity associated with the auto-inductance calculation. 01 pF - 100mF. doc. Thanks to the flat wire winding, the chokes have very compact dimensions of only 33 x 33 x 15 mm. Step 1: In the input field, enter the capacitance, inductance, and x for the unknown. For number of coil turns: N= square root (L. L is the inductance, so you need the resistance (R) and the. You might notice that the diameter of the outer shield is not required. So, that is, 25 x OD x 2 times. . Example 1: Find the inductive reactance of a coil that has an inductance of 320 µH (0. For example, the electrical conductivity of copper is σ ≈ 5. If you have any suggestions for improvement please email [email protected]. . The inductance calculated using this tool is the inductance of the loop bounded by the two coplanar flat conductors. m. Use our free online coil inductance. Use the formula for self-inductance of a wire: L = (μ₀μr * π * r²) / length, where μ₀ is the permeability of free space, μr is the relative permeability of the wire material, r is the radius of the wire, and length is the total length of the wire. The inductor impedance calculator calculates the impedance of an inductor based on the value of the inductance, L, of the inductor and the frequency, f, of the signal passing through the inductor, according to the formula, XL= 2πfL. To calculate the number of turns (N) required to make any specific inductance,Learn how to wind your own Inductor using thick copper wire for a low resistance coil. The above are rough calculation only. Another example, a distance of 25mm means the magnetic field is calculated 10mm outside of the coil (30mm/2+10mm = 25mm). The Reactance Calculator will calculate the inductive reactance and the capacitive reactance of a coil or capacitor, and display a live example of how to perform the calculation. The additional formulas: Where D1 D2 are the outer and the inner diameters of the toroidal coil-former, dw is the wire diameter. This paper presents a novel real-time power-device temperature estimation method that monitors the power MOSFET's junction temperature shift arising from thermal aging effects and incorporates the. 001 uH - 100H. The classic formula for single-layer inductance (air core) is called Wheeler's formula, which dates back to the radio days of the 1920s: where: L = inductance in micro-Henries (not nano-Henries!) N= number of turns of wire. Note: You can also use Inductance of. Figure 14. $0. [1] The. Select the box with the geometry that you would like to calculate. One formula for inductance is as follows: Where: L = inductance. The single layer air core coil formula is most accurate when the coil length is greater than 0. Impedance of the coil inductance is defined under the formula: XL = 2πƒL. Enter the coil length (distance from first to last winding - see diagram). This tool is primarily used to calculate coil inductance and volume using coil parameters. 12: Inductance. The straight wire inductance of "X" is reduced by 1/10th, and the same with "Y". The intensity B of the magnetic field of a solenoid composed of coils wound in air (that is, without a ferromagnetic core) can be calculated using the following formula: where: μ 0 = 4Π x 10 -7 H/m is the magnetic constant (vacuum permeability) N is the number of turns. Per se, partial inductance of a single wire cannot be measured. Coil Geometry: Select the geometry of your coil from the list. Note that the measurement unit may be chosen for the loop diameter and wire diameter. r = Coil radius in inches. Additionally, since the inductance is dependent upon its material surrounding, use Table-4 to determine an appropriate "K" factor (multiplier) for the inductance. And here is a picture of three power inductors found there: In this answer, by Rohat Kılıç, towards the end of his answer he explains that increasing frequencies demand more windings of thinner wire, but all of his discussion on skin effect is only for traditional circular-cross-section wire. When the spacing between the planes is less than ~0. 2：Conductor thickness shall be smaller than conductor width. Inductance is one of the transmission line parameters. Due to its geometry, the coaxial cable impedance requires you to know the inner wire's diameter and the outer shielding. Equation. 6. Its a little thought experiment. Assumptions and Limitations. AJ Design ☰ Math Geometry Physics Force Fluid Mechanics Finance Loan Calculator. At VHF and UHF frequencies the inductance of a wire may have a great effect on a circuit. On the left side, the LCR meter measures one cable. And a loop of wire is a typical model for inductive materials. This is difficult in most cases, because of the complexity of the field created. The formula used in this calculation is based on the. F. The only variables used in this calculation are the height of the wire from the reference plane, the radius of the wire, and the relative permeability of the medium around the wire. The magnetic field strength depends on the magnitude of the electric current, and follows any changes in the magnitude of the current. Wire can be. The inductance of an air core coil inductor can be also calculated using the below equation. Grover [2, pp. 2833 lbs/in3. Wire Over Plane Inductance Calculator. The following American Wire Gauge (AWG) calculator will calculate the diameter in mm, inches, cross sectional area in mm2, inches2 and kcmil or MCM, resistance per 1000 feet and per 1000 meters and the current rating in amperes for chassis wiring and power transmission applications. The transmission line geometries are cross sections and the values calculated are the inductance per unit length. Refer to the bottom of the page for explanation of input variables and other notes. The single-turn loop can be calculated by numerical methods using J. 11. Wire sizes, AWG # chosen to meet current specification. 000uH to 100. Model accounts for proximity effect of closely spaced wires.