the helical spring actually results in higher shear stresses on the inner surfaces of the spring than indicated by the formula above. You do so by subtracting the amount of wires in the closed coils from the free length and then dividing the result by the active coils. 923 respectively. Using the length of helical coil formula: Lw = π * Dc * N = π * 10 * 15 = 471. 1,2If fractional pitch is used, the emfs in the two coil sides are out of phase, which reduces the emf. Hence, the pitch factor or the coil span factor for the n th harmonic is given by, kcn = cos nα 2. Coil pitch or coil span is defined as the angular distance between the two coil sides of one coil. . p - winding pitch (distance between centers of neighboring turns = the gap between the turns + wire diameter) (mm) The formula gives an error of about ±5-10%. In simple words for n-plex lap windings, the value of commutator pitch Yc is given as. 038) ÷ 4 = pP = number of Poles. I There are 1 P total number of coils between two adjacent poles. In order to understand variable pitch springs, it’s important to know two key spring parameters: pitch and rate. 2. It should be noted that the main harmonic order of MMF is , which interacts with permanent-magnet flux linkage to product average torque. The formula is composed of a pattern’s metal thickness, single pattern width, total pattern width, and turn number, and is effective in the megahertz (MHz) frequency range. Select the suitable material. Define Pitch Factor /Distribution Factor and present the formula to calculate. L 0 = Free Length (m) L s = Solid Length (m) n t = Total number of coils n = Number of active coils p = pitch (m). It is the angular distance between two sides of a coil, measured in terms of armature slots. 4 Å observed. S 一 the cross-sectional area of the coil, in square meters. Pipe Coil Length Calculator is useful for Calculating reuired length of your pipe coil. (iv) Coil-sides are inserted into slots in a single or double layer. (2) 𝑘 𝑐 𝑛 = c o s 𝑛 α 2. This will directly scale with current. The following formula from R. where R is the resistance of the coil, V is the voltage across the coil, and I is the current flowing through it. This winding forms a wave with its coil, that’s why we call it as wave winding. Below C = 5 the spring will be difficult to make because of the large diameter. p = (L–2d) ÷ Na. Any variation in coil width will change the blank size and affect the location of the blank. The formula of Lap Winding. (1 – 0. As they are usually ran through a slitter to be broke down into coils of different widths. Slot pitch angle: Slot pitch is the distance between two adjacent slots. I is the current flowing through the coil, in amperes (A) R is the distance from the center of the coil to the point where the magnetic field is being. 961. Pitch factor. Back pitch (Y b): It is the span of the coil from the back end. Resultant pitch (Y R): Distance between the starts of two successive coils. ( 2) The harmonic voltages decrease in a short pitch coil, thereby improving the waveform of the induced voltage in the winding. Length = ( diam^2 * pi ^2 + pitch ^2)^0. An easy and Faster way to layout calculate length. Where d o is the coil's pipe external diameter. 2. This is the direction of the applied magnetic field. A way of understanding what I mean by maximum spring compression - the point before a permanent set occurs in the spring. Free length of spring is defined as the axial length of an unloaded helical compression spring. Total diameter of the coil and winding is 515mm. Set Removal Set removal or presetting is a process used in manufacturing a spring to induce useful residual stresses. Inductance. After one turn (an angle increases by 2π), the distance increases by 2πk. 4×10 4. Answer (1 of 2): My answer applies to the stator of poly-phase (3 or more phases) AC rotating machines (generators and motors) with distributed winding, of integral slot stator, either of single-layer or double-layer winding, either of full-pitch or short-pitch winding, and either of winding by p. However this can be automatically converted to compatible units via the pull-down menu. 2. Two main parts of motor are rotor and stator. When the coil span is equal to. 00625 in = 0. You can use either inches or millimeters and you can mix. Multiply the number of turns and diameter of the coil. NOTE: Sometimes, the "Path + Guide Surface" option will need to be used. ), which equals to pole pitch and the slot pitch . Lbs condensate per hour = BTU per hr of coil / *Latent heat of steam *Assumes saturated steam. 7 Distribution factor. D——parameter. For example, in a 4-pole generator with a 48-slot stator (12 slots per pole), if each coil in the stator winding spans 12 slots then the ratio is 1/1 and the winding is full pitch. Where SL is the spiral length. The Length of a Helix calculator computes the linear length of a spiral or helix where the helix is pulled into a straight line. 6) with the given linking number (475 in this case). 13 -- Right-hand rule model. Since this machine has 8 poles and a pole-pitch of 48/8 = 6 slots, the coil pitch here is 5/6 = 0·833 p. 5 mm . N is the number of rings. = 100/1. Steam pressure (psig) Latent Heat. It can also be observed that, coil sides are connected in series in such a way that emf induced in coil side at 1 and 10 are additive. Back pitch (Y b): It is the span of the coil from the back end. This distance is measured in terms of armature slots or armature conductors that come between two. Pitch of Limpet Coil (P) It is limpet coil pitch onwhich it is going to fitted on dish ends. L−HS The pitch factor is seen to be: \(\ k_{p n}=\sin \frac{n \alpha}{2}\) Now for breadth factor. Area = cross-sectional area of CT pipe wall. Inductance is the property of the coil and tells how good the coil can store magnetic energy. The standard is about ¼ inch per 10 feet. c. where: SP is the spring pitch (in/coil) L is the length of the spring (in) D is the diameter of the spring (in) NA is the number of active coils in the springSpring pitch (p p p): Refers to the space between two adjacent coils and is directly related to the free length value (L 0 L_0 L 0 ) of a spring. These coils are short, fat (large-diameter) solenoids. Here is how the Pole Pitch calculation can be explained with given input values -> 0. ). coil pitch in terms of slots4. Add downspouts. where N is number of turns, pi =3. 8 and for single pass(l. If the coil. of polesNo. Steam pressure (psig) Latent Heat. f. Width can be trimmed on request, but is usually in one of the standard sizes: 1000, 1250, or 1500 mm. The. Since it has a non-contact force and very low stiffness, it is widely used for precision positioning devices including magnetic levitation systems. 1,2Geometry of spring: d, wire diameter; D, mean coil diameter. 050 T) = 2. P = No. Back pitch should be either lesser than or greater than front pitch by 2m, where m is the multiplicity of the winding. Within the spring design, wire diameter, number of coils, and spring free length L0 are designed for a specific load, material and assembly dimensions, or spring diameter. The coil is referred to as a fractional pitch coil when the angular distance between the sides of the coil is less than the angular distance between adjacent field pole centers. 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. Spread the love. Spring pitch formulas usually take into account the: Geometry of the spring; Stress; Amount of force the spring will experience; Height; Amount of coils; Density of the. Introduction. As we discussed earlier that every set of windings in lap windings has no parallel paths equal to poles in a machine, so in duplex lap winding the current paths will be twice. This advancement is measured in terms of armature conductors and is called back pitch. After setting the coil ID, alloy, gauge, and width then alter the OD size to see the resulting coil. 50 x OD Vessel TL legth 3050 mm Limpet coil PCD 2700 mm Limpet coil OD 80 mm No. The basic parameters of the coiled-coil are its pitch (periodicity of the supercoil), the associated pitch (or supercoil) angle (angle of the helix with respect to the supercoil axis), and the. For example, if there are 36 slots and 4 poles, then the coil pitch is 36/4 = 9 slots. This lecture will discuss;1. The formula for the commutator pitch in any simplex winding is given as. 64 × 10 − 27 k g) ( 3. Generally, the calculation is based on the assumption that the pitch of the coil spring is fixed. L = Length; d = Wire Diameter; Na = Active Coils; p = Pitch; Example: Based on the given formula. You can easily derive a more accurate formula by using the Pythagorean theorem. I'm just looking for a simple expression formula for how maximum spring compression changes with free length of a coiled helical spring, say a Compression spring. 8 and 1. The Back Pitch for DC Machine formula is defined as the coil advances on the back of the armature. Distribution factor is defined as the ratio of phasor sum of coil emfs to the arithmetic sum of coil emfs. The coil pitch factor represents the effect of coil distribution on the induced voltage. S = No. β is the angular distance between a full pitch and short pitch coils. Verify that the pitch of the spring is notA screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. In varying the coil pitch to examine the behaviour of the coil resistance, the coil’s width and thickness are kept constant. Coil pitch or coil span is defined as the angular distance between the two coil sides of one coil. 1) Winding Will be done in a single slot. 2. Therefore, the pitch should be 0. The mean coil radius of helix (R = D/2) and the cross-section can differ along the helix. To find : f, E ph, E LDesign Tips: Coil Count. The secondary of CT is short circuited and 100 volts is applied to its primary. Enter the number of turns (windings). of poles The coil pitch is fixed at the slot pitch; this winding is called concentrated winding. Internal diameter ID [mm]: External diameter OD [mm]: Density D [g/cm³]: Thickness T [mm]: Width W [mm]: Calculate. This formula is, however, a first approximation. A SIMPLE explanation of Full Pitch and Short Pitch Winding. To support tubes in heat exchangers. N 一 the number of turns of the coil;. Because spring pitch can be difficult and frustrating to measure on the surface of a spring, it might be best to use a formula or computer program to help you pinpoint it. This describes the fact that a winding may consist of a number of coils, each linking flux slightly out of phase with the others. Strictly, the length of each coil is the hypothenuse of a triangle having a base equal to the circumference of the pitch-diameter of the coil and an altitude equal to the pitch of the coil from center to center. Calculate the coil pitches and indicate the slots into which the first coils should be placed for the following armature windings: (a) 36 slots, 4 poles; (b) 57 slots, four poles; (c) 76 slots, 6 poles; (d) 132 slots, 8 poles; (e) 270 slots, 10 poles. A solar heater is made like a coil with 20 mm pipe inside a 1 m x 1 m window frame. 998, and 0. The coils are short pitched by 3 slots. The deflection before the coils are. On top of that: 1000 turns of 0. How to calculate Pole Pitch using this online calculator? To use this online calculator for Pole Pitch, enter Armature Diameter (Da) & Number of Poles (n) and hit the calculate button. Ends Ground or Not Ground: For closed coil springs, the ends can be ground or not ground. Therefore, the pitch for each coil will change as a function of D^3. Pitch Factor or Coil Span Factor or Chording factor (K p):. Know Weight, Thickness and Width of a Coil, want to estimate the LENGTH of Coil. It is clear that the pitch of coils has a significant effect on the inductance parameters, especially the mutual inductance parameters, and the deviation increases as the electrical angle between two coils increases. If the coil pitch is. 00” CD > Fin Pack FL – Fin Length Fin length can. The coil pitch is defined as the distance between two consecutive coils in the same phase. Below is the coil length formula: L = π * Dc * N. Y. The properties of the wire making up the spring coil that appear in Eq. Follow the formula below to calculate the spring pitch of a coil spring with open ends. The phase belt is defined as the group of adjacent coil-sidesVariable pitch springs are springs that do not have constant coil spacing. The basic parameters of the coiled-coil are its pitch (periodicity of the supercoil), the associated pitch (or supercoil) angle (angle of the helix with respect to the supercoil axis), and the. ; The number of slots for 2 layer winding is equal to the number of coils. Post Reply Tell a Friend (must be. The heat flux can be calculated knowing the flowrate, the in and out temperatures, the specific heat of the fluid, and the latent heat of the fluid to condensate. 2 mm wire = two layers of wire = 0. ∴ EC =. The Spring Pitch Calculator is a tool that helps engineers and designers to calculate the spring pitch of a helical spring. The coil pitch or back pitch must be approximately equal to the pole pitch. Let the coil sides are shortened by. Unit. are e. Now let E be the induced e. Typical calculation/design of the spring consists of the following steps: Set up the desired calculation units (SI/Imperial). R = R i + a θ, θ i ≤ θ ≤ θ o. induced in all the coils under one pole to the arithmetic sum of the induced e. First, using a semiempirical correction formula. 4” of coil / 12 = 1249. For a full pitch coil, β = 0, and hence k p is 1. magnet width to pole pitch ratio, efficiency, power factor, and the motor inner to outer diameter ratio, respectively. For a full- pitch coil α = π. The EMF generated per path for a wave winding & lap-winding; So the generalized equation for generated EMF of DC generator is: Eg = kΦω. The formula for calculating the spring pitch is: SP = (L – 3 * D) / N. Calculate the pitch (and therefore coils per inch) and the spring index. The angle \(\alpha = \alpha (\theta )\) designates the inclination of the helix with any plane perpendicular to the axis of the coil (pitch angle, lead angle). Spring Pitch Formula. pitch factor or coil. If the coil span is equal to the Pole pitch then it is called a full pitch coil. If Z A is the total number of conductor or coil side, then the average pitch is expressed by the equation, Where, P – number of polesA coil advances on the back of the armature. If the coil pitch is one pole pitch, it is called the Full Pitch Coil. Follow the formula below to calculate the spring pitch of a coil spring with open ends. FH. You do so by subtracting the amount of wires in the closed. What is flange pcd?From the active length, the total length of the machine can be calculated with Equation (10), where f wc is the winding coil factor L total = L k 1+ f wc (10) The winding coil factor is defined in. 0 mm thickness. 2 × 10 − 19 C) ( 0. . It may be the full pitched or short pitch. I There is one coil between two commutator segments. coil pitch in terms of electrical angle3. To obtain The following formula from R. In conventional three-phase electric machines, coil pitch ratio is usually selected around 5/6 so as to minimize the 5 th and 7 th flux linkage harmonics. I If the commutator pitch is +1, it is called a progressive lap winding. In this paper, a new method to calculate the self-inductance of the Archimedean spiral coil is presented. Enter the coil length (distance from first to last winding - see diagram). A single-layer inductor is shown in the picture above: D c is the coil diameter, D is the coil former diameter, l is the coil length, p is the coil pitch, d is the wire without insulation diameter and d i is the wire with insulation diameter. The Coil64 application allows you to calculate 4 types of single-layer winding. A helix, sometimes also called a coil, is a curve for which the tangent makes a constant angle with a fixed line. The Length of a Helix calculator computes the linear length of a spiral or helix where the helix is pulled into a straight line. The angle of the spring coil relativeto the mounting. What is coil pitch formula? Coil Pitch or Coil span It is the angular distance between two sides of a coil, measured in terms of armature slots. Formula: Y R = Y b - Y f = ± 2m. The winding pitch of a single-layer coil is defined as [egin{equation} p equiv frac{ell}{N} end{equation}] The proximity factor (Phi) is interpolated from empirical Medhurst data. Constant or Variable Pitch: The pitch can be constant or variable. The Pitch of coil spring formula is defined as the axial distance between adjacent coils in uncompressed state of spring and is represented as p = L f /(N t-1) or Pitch of Coil Spring = Free Length of Spring /(Total Number of Coils-1). Fo r. Yc = 2(C+-1)/P , simplex wave. If the number of coil span is equal to pole pitch, then the winding is called full pitch whereas no. The trapezoidal permanent magnets are placed on the two rotor surfaces and the non-overlapping concentrated winding coils in the stator are held together using the epoxy resin composite material. 303K views 6 years ago. What is their mutual inductance? Solution: Notice that although M12=M21, it would have been muchUsing this formula, the inductance of a 1 meter circumference loop of 14 gauge wire is 1. pitch factor or coil. 6. m. A pole pitch is always 180 electrical degrees, regardless of the number of poles on the machine. Formula: Y R = Y b - Y f = ± 2m. R1 = Ri + aq1 (5) R2 = Ri + aq2 (6) q1 and q2 are the angle of revolution of the original and its fictitious spiral coil, respectively. For example, if there are 36 slots and 4 poles, then the coil pitch is 36/4 = 9 slots. 10. The outer diameter is given as: 5. ∴ e = E 1 + E 2 = 2E. 5D or smaller. I got this motor at my university. There are two variables that specify the number of coils. I 一 the length of the coil in meters. The formula is composed of a pattern’s metal thickness, single pattern width, total pattern width, and turn number, and is effective in the megahertz (MHz) frequency range. 8) T = 2 π m q B = 2 π ( 6. Therefore, for a square pitch (as if flow is parallel to the axis of the heat exchanger): [1] 2 PT π 2 o o T e d d P D π) 4. The second plot is the field strength at Z=0 along the x-axis. The rise angle of the spring coils (the angle between the coils and the base of the spring) is found from the arctangent of the coil-pitch divided by the spring circumference, The solid height of the spring is found by summing the widths of all the spring coils. Hence the distribution factor is defined as the ratio of the vector sum of the e. Remember to incorporate the high side of the OD tolerance when examining the work in hole requirements. 1. Preoxidized coils made from Kanthal® FeCrAl in such elements can be used tightly wound. Add the products of the coil diameter and 18 with wire length and 40 to get the denominator. The coil pitch is equivalent to the span, except that this term is used more often in a theoretical context and expressed in electrical degrees, or per-unit of a pole-pitch. • Coils typically. So, the ending point of a coil in a 4 pole wave winding should be associated just beforehand or just afterward the point midway around the loop from its initial point. The resistance of 1 coil is 16,5 ohms. To calculate the spiral length, multiply the number of rings by pi, then multiply by. Pp=360/p. If the blank size varies, so does the location. The total length of the wire used to create the coil. 3 τ p + 0. 50” • For 1/2" tube coils, fins are available in increments of 1. Helix Angle [clarification needed]. In this video basic terminologies related to AC armature winding like coil, conductor, coil side, front pitch, back pitch, pole pitch, coil pitch, etc. We can therefore non-dimensionalize the forces and moment in the following way: C L = L q ∞ S. Share. What would be the formula to calculate coil/spring winding length with a constant pitch if the wire is a flat ribbon? Much appreciated. For air core coil, μs=1. You can investigate three-phase integer-slot, fractional-slot and concentrated windings, both with single and double winding layers where appropriate. The period of the charged particle going around a circle is calculated by using the given mass, charge, and magnetic field in the problem. It is also known as Belt or Breadth factor and denoted by kd. , 2011). You can refere standard reference input image shown in this calculator for your better understanding to this angle value. The coil pitch was determined to be two times the wire. In determining the total number of coils in the spring, the. through formula nes = N 2 mbnwcc n lay, (6) where bnwccis the largest integer less than or equal to nwc. Calculate the PPI according to the formula written above: PPI = dₒ/dᵢ = 800/5 = 160. The opposition to. m. 2: Pitch and spring index. The formula for calculating spring pitch is: SP = (L – 3*D) / NA. The formula is applied to calculate the ohmic resistance of helical and spiral coils and is verified by a 2-D finite-element-method. We have. Coil span is nothing but the distance between the two coil sides. H ewb. In the text areas provided, enter the Coil Diameter, Coil Length, and Number Of Turns. The spring is made longer than needed, then compressed to solid height, intentionally exceeding the yield strength. Force = applied. 966. Irrespective the of poles at machine pole pitch is has value of one eighty degree. Pitch Factor or Coil Span Factor is definite as the ratio of emf generated in short pitch coil to the emf generated in full pitch coil. Winding factor is defined as the ratio of emf generated in short pitch distributed coil to the emf generated in a concentrated coil. It is expressed in terms of electrical space degree. The flux linked is: (. An alternator having 10-poles, 3-phase, and 60 Hz has 8 conductors per slot in single layer arrangement with 4 slots/pole/phase. Our proprietary, customer portal is cost-free and offers 24/7 access to a host of valuable tools to help you manage logistics and streamline production schedules. The pitch can generally be estimated using the following simplified formula. 0357, pitch ratio = 1, ratio of the side length of equilateral triangle to tube diameter = 0. The formula that desertfox gave for the spring constant is valid and the spring will have a linear rate. Simply enter your numbers to determine flat rolled steel coil lengths and weights. 100. Y f = (2S / P) -1. 4. Hypothetical at the time, the coiled‐coil was proposed as a solution to the X‐ray fiber diffraction patterns of α‐keratin, which showed a strong reflection at 5. Distributed Winding. Pitch Formula Pdf below. 1 mm wire = 10 layers of wire = 1. Suppose the qualification for running and starting winding of 36 slots, 4 pole motor with running pitch 5-7-9 and starting pitch 8-10. Such a coil is called short-pitch (or fractional or partial pitched) coil. To estimate the mutual inductance, when the gap between the two coils is larger than wire diameter, the thick coil can be denoted by equation of planar spiral coil [ 23 ]. Q9. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the. This type of coiling design offers a number of advantages, and a wide range of products depend on variable pitch springs to deliver optimal performance. The calculator is designed to accept the total line voltage and current of the combined three cables. C, spring index: C = D/d. This formula is equivalent to the circumference each loop of the wire makes times the number of such loops in the coil. You Can save the Cost of Material by using this calculator. 7 times the inner coil diameter. Learn MoreCalculator. The variables used in this tool are the diameter of the wire conductor and the diameter of the wire loop. It is connected to one-third of the commutator bars. It is sometimes referred to as the Stationary Header. 6 × 10 − 6 s. l——Spiral length. Only the amendment to the resulting inductance is added: where: ΔL is the amendment to the inductance of the close-winding coil (always negative) (µH) N - number of turnsPitch α refers to the angular displacement between sides of the coil, expressed in electrical radians. Pipe Coil Length Calculator provide complete solution to Fabrication works. . Spec Name Spec Input; ID (16 - 36) OD (ID - 84) Width (0. Effect of Coil Throw (i. The helix angle references the axis of the cylinder, distinguishing it from the lead angle, which references a line. 707, 0. For the fundamental. • So coil span is 16/4 = 4. of height to diameter ratios, and the topic of heat exchangers of varying ratios of coil pitch to its diameter. f. The current sheet. The above recommendations assume that you have properly sized downspouts every 40 feet. It is not concentrated in a single slot. [1. Use this Aluminum Coil Calculator to simplify estimating your aluminum coil needs. 953. In the stator of a single phase motor, first running winding and later steering winding are put. • Winding pitch is the coil span divided by the pole. The figure below shows the voltage polygon of the induced voltages in the four coils of a group (m = 4) The voltages E C1, E C2, E C3, and E C4 are represented by the phasors AB, BC, CD, and DF respectively. For example, you can consider a coil with length = 1000 mm, where there are three parts: the. If N is 100 turns, l is 6 meters. 966. 5. Fo r. Steel Processing Portal WI Steel Connect. Now, computing the wire lengths using 2pi x r and the. The phase belt is defined as the group of adjacent coil-sides belonging to a phase, as shown in Fig. There are different views regarding the pitch of coil springs. ; 1 full pitch = 180° It is denoted by K p and its value is always less than unity. 3. 5. Coil pitch is 180 electrical space degree for full. By long is meant: length is much larger than the radius of the cross-sectional area . You can Save Time on your Fabrication Layouting process. Winding will be done throughout the slot. The practical d. 953. n = (0. al. For the lap winding shown in the Fig. By minimizing the metal resistance, a simple design equation for finding the proper line width of each coil is then presented. In the analysis, spacing values ranging between 0. . Based on the proposed vector model, the instantaneous electromagnetic torque of. These factors represent the effect of coil distribution on the induced voltage waveform. We can obtain the height of the coil with this expression: H = N * (S + Dw) Length (L). Let the angle α be the angle of inclination of the helix with any plane perpendicular to the axis of the coil (pitch angle, lead angle). μ0=4π*10-7. In this paper, a simplified method for the calculation of a mutual inductance of the planar spiral coil, motivated from the Archimedean spiral, is presented. 881. 56 x 10^-7. 0714 and Re = 19800 (Gunes et al. In general, coils enclosing the same perimeter with similar shapes will have approximately the same inductance. Coil diameter, pitch or spacing, wire diameter, coil height, and other design parameters can be used to make a helical coil. If the coil is with no space between the pipes the number of turns can therefore be calculated as . This planar spiral coil inductor calculator determines the inductance of one-layer circular, square, hexagonal and octagonal planar (flat) spiral coils, which are often used in near-field communication (NFC) and radio frequency identification (RFID) tags. 2 [5], for the square pitch, the perimeter is the circumference of a circle and the area is a square of pitch size ( ) minus the area of a circle. It is placed at the center of a long solenoid that has 15 turns/cm and a cross-sectional area of 10 cm2, as shown below. A coil is basically any number of turns. This operation sets the spring to the required final free length. A staggered pattern is more commonly used. Counting them is easy enough – every rotation of 360 degrees equals one coil (90 degrees = ¼ coil, 180 degrees = ½ coil). 71 m Total length of coil 63. Number of Coils. Therefore, the coil pitch (Yp) is: Yp = 144 / 4 = 36 slots Now, let's calculate the coil pitch factor (Kp). k 一 a coefficient depends on the ratio of the radius (R) to the length (l) of. A coil is said to be fully pitched when the coil span is made equal to the pole pitch of the machine. • To view the coil sides / coils, we must look below from above the slots as depicted in figure. Once the results are obtained from this calculator, the coil can be easily modelled as a Laplace load within any EZNEC antenna model. D is the coil former diameter in cm, l is the coil length in cm, N is the number of turns, and. 12 µH; for 16 gauge wire it’s 1. For a full pitch coil, each coil side lies under the opposite pole as shown in the figure below. L is the inductance in μH.