BW Cutting Tools www.tool-tool.com: English Inductance www.tool-tool.com

Bewise Inc. www.tool-tool.com Reference source from the internet.

Electric charge · Coulomb's law · Electric field · Electric flux · Gauss's law · Electric potential · Electrostatic induction · Electric dipole moment ·

[show]Magnetostatics

Ampère’s law · Electric current · Magnetic field · Magnetic flux · Biot–Savart law · Magnetic dipole moment · Gauss’s law for magnetism ·

[show]Electrodynamics

Free space · Lorentz force law · EMF · Electromagnetic induction · Faraday’s law · Displacement current · Maxwell’s equations · EM field · Electromagnetic radiation · Liénard-Wiechert Potential · Maxwell tensor · Eddy current ·

[show]Electrical Network

Electrical conduction · Electrical resistance · Capacitance · Inductance · Impedance · Resonant cavities · Waveguides ·

[show]Covariant formulation

Electromagnetic tensor · EM Stress-energy tensor · Four-current · Four-potential ·

[show]Scientists

Ampère · Coulomb · Faraday · Heaviside · Henry · Hertz · Lorentz · Maxwell · Tesla · Weber ·

This box: view • talk • edit

Inductance is that property in an electrical circuit where a change in the current flowing through that circuit induces an electromotive force (EMF) that opposes the change in current (See Induced EMF).

In electrical circuits, any electric current i produces a magnetic field and hence generates a total magnetic flux Φ acting on the circuit. This magnetic flux, due to Lenz's law tends to act to oppose changes in the flux by generating a voltage (a back EMF) that counters or tends to reduce the rate of change in the current. The ratio of the magnetic flux to the current is called the self-inductance which is usually simply referred to as the inductance of the circuit. The term 'inductance' was coined by Oliver Heaviside in February 1886.^[1] It is customary to use the symbol L for inductance, possibly in honour of the physicist Heinrich Lenz.^[2] ^[3]

In honour of Joseph Henry, the unit of inductance has been given the name henry (H): 1H = 1Wb/A.

[edit] Definitions

The quantitative definition of the (self-) inductance of a wire loop in SI units (webers per ampere) is

$\displaystyle L= \frac{N\Phi}{i}$

where Φ denotes the magnetic flux through the area spanned by the loop, and N is the number of wire turns. The flux linkage λ = NΦ thus is

$\displaystyle N{\Phi} = Li$ .

There may, however, be contributions from other circuits. Consider for example two circuits C₁, C₂, carrying the currents i₁, i₂. The flux linkages of C₁ and C₂ are given by

$\displaystyle N_1\Phi_1 = L_{11}i_1 + L_{12}i_2,$

$\displaystyle N_2\Phi_2 = L_{21}i_1 + L_{22}i_2.$

According to the above definition, L₁₁ and L₂₂ are the self-inductances of C₁ and C₂, respectively. It can be shown (see below) that the other two coefficients are equal: L₁₂ = L₂₁ = M, where M is called the mutual inductance of the pair of circuits.

The number of turns N₁ and N₂ occur somewhat asymmetrically in the definition above. But actually L_mn always is proportional to the product N_mN_n, and thus the total currents N_mi_m contribute to the flux.

Self and mutual inductances also occur in the expression

$\displaystyle W=\frac{1}{2}\sum_{m,n=1}^{K}L_{m,n}i_{m}i_{n}$

for the energy of the magnetic field generated by K electrical circuits where i_n is the current in the nth circuit. This equation is an alternative definition of inductance that also applies when the currents are not confined to thin wires so that it is not immediately clear what area is encompassed by the circuit nor how the magnetic flux through the circuit is to be defined.

The definition L = NΦ / i, in contrast, is more direct and more intuitive. It may be shown that the two definitions are equivalent by equating the time derivative of W and the electric power transferred to the system.

[edit] Properties of inductance

Taking the time derivative of both sides of the equation NΦ = Li yields:

$N\frac{d\Phi}{dt} = L \frac{di}{dt} + \frac{dL}{dt} i \,$

In most physical cases, the inductance is constant with time and so

$N\frac{d\Phi}{dt} = L \frac{di}{dt}$

By Faraday's Law of Induction we have:

$N\frac{d\Phi}{dt} = -\mathcal{E} = v$

where $\mathcal{E}$ is the Electromotive force (emf) and v is the induced voltage. Note that the emf is opposite to the induced voltage. Thus:

$\frac{di}{dt} = \frac{v}{L}$

$i(t) = \frac{1}{L} \int_0^tv(\tau) d\tau + i(0)$

These equations together state that, for a steady applied voltage v, the current changes in a linear manner, at a rate proportional to the applied voltage, but inversely proportional to the inductance. Conversely, if the current through the inductor is changing at a constant rate, the induced voltage is constant.

The effect of inductance can be understood using a single loop of wire as an example. If a voltage is suddenly applied between the ends of the loop of wire, the current must change from zero to non-zero. However, a non-zero current induces a magnetic field by Ampère's law. This change in the magnetic field induces an emf that is in the opposite direction of the change in current. The strength of this emf is proportional to the change in current and the inductance. When these opposing forces are in balance, the result is a current that increases linearly with time where the rate of this change is determined by the applied voltage and the inductance.

Multiplying the equation for di / dt above with Li leads to

$Li\frac{di}{dt}=\frac{d}{dt}\frac{L}{2}i^{2}=iv$

Since iv is the energy transferred to the system per time it follows that $\left( L/2 \right)i^2$ is the energy of the magnetic field generated by the current.

[edit] Phasor circuit analysis and impedance

Using phasors, the equivalent impedance of an inductance is given by:

$Z_L = V / I = j L \omega \,$

where

j is the imaginary unit,

L is the inductance,

$\omega = 2 \pi f \,$ is the angular frequency,

f is the frequency and

$L \omega \ = X_L$ is the inductive reactance.

[edit] Induced emf

The flux $\Phi_i\ \!$ through the i-th circuit in a set is given by:

$\Phi_i = \sum_{j} M_{ij}I_j = L_i I_i + \sum_{j\ne i} M_{ij}I_j \,$

so that the induced emf, $\mathcal{E}$ , of a specific circuit, i, in any given set can be given directly by:

$\mathcal{E} = -\frac{d\Phi_i}{dt} = -\frac{d}{dt} \left (L_i I_i + \sum_{j\ne i} M_{ij}I_j \right ) = -\left(\frac{dL_i}{dt}I_i +\frac{dI_i}{dt}L_i \right) -\sum_{j\ne i} \left (\frac{dM_{ij}}{dt}I_j + \frac{dI_j}{dt}M_{ij} \right).$

[edit] Coupled inductors

Further information: Coupling (electronics)

The circuit diagram representation of mutually inducting inductors. The two vertical lines between the inductors indicate a solid core that the wires of the inductor are wrapped around. "n:m" shows the ratio between the number of windings of the left inductor to windings of the right inductor. This picture also shows the dot convention.

Mutual inductance occurs when the change in current in one inductor induces a voltage in another nearby inductor. It is important as the mechanism by which transformers work, but it can also cause unwanted coupling between conductors in a circuit.

The mutual inductance, M, is also a measure of the coupling between two inductors. The mutual inductance by circuit i on circuit j is given by the double integral Neumann formula, see #Calculation techniques

The mutual inductance also has the relationship:

$M_{21} = N_1 N_2 P_{21} \!$

where

M₂₁ is the mutual inductance, and the subscript specifies the relationship of the voltage induced in coil 2 to the current in coil 1.

N₁ is the number of turns in coil 1,

N₂ is the number of turns in coil 2,

P₂₁ is the permeance of the space occupied by the flux.

The mutual inductance also has a relationship with the coupling coefficient. The coupling coefficient is always between 1 and 0, and is a convenient way to specify the relationship between a certain orientation of inductor with arbitrary inductance:

$M = k \sqrt{L_1 L_2} \!$

where

k is the coupling coefficient and 0 ≤ k ≤ 1,

L₁ is the inductance of the first coil, and

L₂ is the inductance of the second coil.

Once this mutual inductance factor M is determined, it can be used to predict the behavior of a circuit:

$V_1 = L_1 \frac{dI_1}{dt} + M \frac{dI_2}{dt}$

where

V is the voltage across the inductor of interest,

L₁ is the inductance of the inductor of interest,

dI₁ / dt is the derivative, with respect to time, of the current through the inductor of interest,

M is the mutual inductance and

dI₂ / dt is the derivative, with respect to time, of the current through the inductor that is coupled to the first inductor.

When one inductor is closely coupled to another inductor through mutual inductance, such as in a transformer, the voltages, currents, and number of turns can be related in the following way:

$V_s = V_p \frac{N_s}{N_p}$

where

V_s is the voltage across the secondary inductor,

V_p is the voltage across the primary inductor (the one connected to a power source),

N_s is the number of turns in the secondary inductor, and

N_p is the number of turns in the primary inductor.

Conversely the current:

$I_s = I_p \frac{N_p}{N_s}$

where

I_s is the current through the secondary inductor,

I_p is the current through the primary inductor (the one connected to a power source),

N_s is the number of turns in the secondary inductor, and

N_p is the number of turns in the primary inductor.

Note that the power through one inductor is the same as the power through the other. Also note that these equations don't work if both transformers are forced (with power sources).

When either side of the transformer is a tuned circuit, the amount of mutual inductance between the two windings determines the shape of the frequency response curve. Although no boundaries are defined, this is often referred to as loose-, critical-, and over-coupling. When two tuned circuits are loosely coupled through mutual inductance, the bandwidth will be narrow. As the amount of mutual inductance increases, the bandwidth continues to grow. When the mutual inductance is increased beyond a critical point, the peak in the response curve begins to drop, and the center frequency will be attenuated more strongly than its direct sidebands. This is known as overcoupling.

[edit] Calculation techniques

[edit] Mutual inductance

The mutual inductance by circuit i on circuit j is given by the double integral Neumann formula

$M_{ij} = \frac{\mu_0}{4\pi} \oint_{C_i}\oint_{C_j} \frac{\mathbf{ds}_i\cdot\mathbf{ds}_j}{|\mathbf{R}_{ij}|}$

The constant μ₀ is the permeability of free space (4π × 10^-7 H/m), C_i and C_j are the curves spanned by the wires, R_ij is the distance between two points. See a derivation of this equation.

[edit] Self-inductance

Formally the self-inductance of a wire loop would be given by the above equation with i =j. However, 1 / R now gets singular and the finite radius a and the distribution of the current in the wire must be taken into account. There remain the contribution from the integral over all points where $|R| \ge a/2$ and a correction term,

$L_{jj} = L = \left (\frac{\mu_0}{4\pi} \oint_{C}\oint_{C'} \frac{\mathbf{ds}\cdot\mathbf{ds}'}{|\mathbf{R}|}\right )_{|\mathbf{R}| \ge a/2} + \frac{\mu_0}{2\pi}lY$

Here a and l denote radius and length of the wire, and Y is a constant that depends on the distribution of the current in the wire: Y = 0 when the current flows in the surface of the wire (skin effect), Y = 1 / 4 when the current is homogenuous across the wire. Here is a derivation of this equation.

[edit] Method of images

In some cases different current distributions generate the same magnetic field in some section of space. This fact may be used to relate self inductances (method of images). As an example consider

A) A wire at distance d / 2 in front of a perfectly conducting wall (which is the return)
B) Two parallel wires at distance d, with opposite current

The magnetic field of the two systems coincides (in a half space). The magnetic field energy and the inductance of system B thus are twice as large as that of system A.

[edit] Self-inductance of simple electrical circuits in air

The self-inductance of many types of electrical circuits can be given in closed form. Examples are listed in the table.

Inductance of simple electrical circuits in air

Type
Inductance / μ₀
Comment

Single layer
solenoid
$\frac{r^{2}N^{2}}{3l}\left\{ -8w + 4\frac{\sqrt{1+m}}{m}\left( K\left( \frac{m}{1+m}\right) -\left( 1-m\right) E\left( \frac{m}{1+m}\right) \right) \right\}$

$=\frac {r^2N^2\pi}{l}\left( 1 - \frac{8w}{3\pi} + \frac{w^2}{2} - \frac{w^4}{4} + \frac{5w^6}{16} - \frac{35w^8}{64} + ... \right)$

N: Number of turns
r: Radius
l: Length
w = r / l
m = 4w²
E,K: Elliptic integrals

Coaxial cable,
high frequency
$\frac {l}{2\pi} \ln{\frac {a_1}{a}}$
a₁: Outer radius
a: Inner radius
l: Length

Circular loop
$r \cdot \left( \ln{ \frac {8 r}{a}} - 2 + Y\right)$
r: Loop radius
a: Wire radius

Rectangle
$\frac {1}{\pi}\left(b\ln{\frac {2 b}{a}} + d\ln{\frac {2d}{a}} - \left(b+d\right)\left(2-Y\right) +2\sqrt{b^2+d^2} -b\cdot\operatorname{arsinh}{\frac {b}{d}}-d\cdot\operatorname{arsinh}{\frac {d}{b}} \right)$
b, d: Border length
d >> a, b >> a
a: Wire radius

Pair of parallel
wires
$\frac {l}{\pi} \left( \ln{\frac {d}{a}} + Y \right)$
a: Wire radius
d: Distance, d ≥ 2a
l: Length of pair

Pair of parallel
wires, high
frequency
$\frac {l}{2\pi}\operatorname{arcosh}\left( \frac {d^{2}}{2a^{2}}-1\right)$
a: Wire radius
d: Distance, d ≥ 2a
l: Length of pair

Wire parallel to
perfectly
conducting wall
$\frac {l}{2\pi} \left( \ln{\frac {2d}{a}} + Y \right)$
a: Wire radius
d: Distance, d ≥ a
l: Length

Wire parallel to
conducting wall,
high frequency
$\frac {l}{4\pi}\operatorname{arcosh}\left( \frac {2d^{2}}{a^{2}}-1\right)$
a: Wire radius
d: Distance, d ≥ a
l: Length

The constant μ₀ is the permeability of free space (4π × 10^-7 H/m). For high frequencies the electrical current flows in the conductor surface (skin effect), and depending on the geometry it sometimes is necessary to distinguish low and high frequency inductances. This is the purpose of the constant Y: Y=0 when the current is uniformly distributed over the surface of the wire (skin effect), Y=1/4 when the current is uniformly distributed over the cross section of the wire. In the high frequency case, if conductors approach each other, an additional screening current flows in their surface, and expressions containing Y become invalid.

[edit] Inductance of a solenoid

A solenoid is a long, thin coil, i.e. a coil whose length is much greater than the diameter. Under these conditions, and without any magnetic material used, the magnetic flux density B within the coil is practically constant and is given by

$\displaystyle B = \mu_0 Ni/l$

where μ₀ is the permeability of free space, N the number of turns, i the current and l the length of the coil. Ignoring end effects the total magnetic flux through the coil is obtained by multiplying the flux density B by the cross-section area A and the number of turns N:

$\displaystyle \Phi = \mu_0N^2iA/l,$

from which it follows that the inductance of a solenoid is given by:

$\displaystyle L = \mu_0N^2A/l.$

This, and the inductance of more complicated shapes, can be derived from Maxwell's equations. For rigid air-core coils, inductance is a function of coil geometry and number of turns, and is independent of current.

Similar analysis applies to a solenoid with a magnetic core, but only if the length of the coil is much greater than the product of the relative permeability of the magnetic core and the diameter. That limits the simple analysis to low-permeability cores, or extremely long thin solenoids. Although rarely useful, the equations are,

$\displaystyle B = \mu_0\mu_r Ni/l$

where μ_r the relative permeability of the material within the solenoid,

$\displaystyle \Phi = \mu_0\mu_rN^2iA/l,$

from which it follows that the inductance of a solenoid is given by:

$\displaystyle L = \mu_0\mu_rN^2A/l.$

Note that since the permeability of ferromagnetic materials changes with applied magnetic flux, the inductance of a coil with a ferromagnetic core will generally vary with current.

[edit] Inductance of a coaxial line

Let the inner conductor have radius r_i and permeability μ_i, let the dielectric between the inner and outer conductor have permeability μ_d, and let the outer conductor have inner radius r_o1, outer radius r_o2, and permeability μ_o. Assume that a DC current I flows in opposite directions in the two conductors, with uniform current density. The magnetic field generated by these currents points in the azimuthal direction and is a function of radius r; it can be computed using Ampère's Law:

$0 \leq r \leq r_i: B(r) = \frac{\mu_i I r}{2 \pi r_i^2}$

$r_i \leq r \leq r_{o1}: B(r) = \frac{\mu_d I}{2 \pi r}$

$r_{o1} \leq r \leq r_{o2}: B(r) = \frac{\mu_o I}{2 \pi r} \left( \frac{r_{o2}^2 - r^2}{r_{o2}^2 - r_{o1}^2} \right)$

The flux per length l in the region between the conductors can be computed by drawing a surface containing the axis:

$\frac{d\phi_d}{dl} = \int_{r_i}^{r_{o1}} B(r) dr = \frac{\mu_d I}{2 \pi} \ln\frac{r_{o1}}{r_i}$

Inside the conductors, L can be computed by equating the energy stored in an inductor, $\frac{1}{2}LI^2$ , with the energy stored in the magnetic field:

$\frac{1}{2}LI^2 = \int_V \frac{B^2}{2\mu} dV$

For a cylindrical geometry with no l dependence, the energy per unit length is

$\frac{1}{2}L'I^2 = \int_{r_1}^{r_2} \frac{B^2}{2\mu} 2 \pi r~dr$

where L' is the inductance per unit length. For the inner conductor, the integral on the right-hand-side is $\frac{\mu_i I^2}{16 \pi}$ ; for the outer conductor it is $\frac{\mu_o I^2}{4 \pi} \left( \frac{r_{o2}^2}{r_{o2}^2 - r_{o1}^2} \right)^2 \ln\frac{r_{o2}}{r_{o1}} - \frac{\mu_o I^2}{8 \pi} \left( \frac{r_{o2}^2}{r_{o2}^2 - r_{o1}^2} \right) - \frac{\mu_o I^2}{16 \pi}$

Solving for L' and summing the terms for each region together gives a total inductance per unit length of:

$L' = \frac{\mu_i}{8 \pi} + \frac{\mu_d}{2 \pi} \ln\frac{r_{o1}}{r_i} + \frac{\mu_o}{2 \pi} \left( \frac{r_{o2}^2}{r_{o2}^2 - r_{o1}^2} \right)^2 \ln\frac{r_{o2}}{r_{o1}} - \frac{\mu_o}{4 \pi} \left( \frac{r_{o2}^2}{r_{o2}^2 - r_{o1}^2} \right) - \frac{\mu_o}{8 \pi}$

However, for a typical coaxial line application we are interested in passing (non-DC) signals at frequencies for which the resistive skin effect cannot be neglected. In most cases, the inner and outer conductor terms are negligible, in which case one may approximate

$\frac{dL}{dl} \approx \frac{\mu_d}{2 \pi} \ln\frac{r_{o1}}{r_i}$

[edit] See also

[edit] References

^ Heavyside, O. Electrician. Feb. 12, 1886, p. 271. See reprint
^ Glenn Elert (1998-2008). "The Physics Hypertextbook: Inductance". http://hypertextbook.com/physics/electricity/inductance/.
^ Michael W. Davidson (1995-2008). "Molecular Expressions: Electricity and Magnetism Introduction: Inductance". http://micro.magnet.fsu.edu/electromag/electricity/inductance.html.

[edit] General References

Frederick W. Grover (1952). Inductance Calculations. Dover Publications, New York.
Griffiths, David J. (1998). Introduction to Electrodynamics (3rd ed.). Prentice Hall. ISBN 0-13-805326-X.
Wangsness, Roald K. (1986). Electromagnetic Fields (2nd ed. ed.). Wiley. ISBN 0-471-81186-6.
Hughes, Edward. (2002). Electrical & Electronic Technology (8th ed.). Prentice Hall. ISBN 0-582-40519-X.
Küpfmüller K., Einführung in die theoretische Elektrotechnik, Springer-Verlag, 1959.
Heaviside O., Electrical Papers. Vol.1. – L.; N.Y.: Macmillan, 1892, p. 429-560.

[edit] Links

Clemson Vehicular Electronics Laboratory: Inductance Calculator

歡迎來到Bewise Inc.的世界，首先恭喜您來到這接受新的資訊讓產業更有競爭力，我們是提供專業刀具製造商，應對客戶高品質的刀具需求，我們可以協助客戶滿足您對產業的不同要求，我們有能力達到非常卓越的客戶需求品質，這是現有相關技術無法比擬的，我們成功的滿足了各行各業的要求，包括：精密HSS DIN切削刀具、協助客戶設計刀具流程、DIN or JIS 鎢鋼切削刀具設計、NAS986 NAS965 NAS897 NAS937orNAS907 航太切削刀具,NAS航太刀具設計、超高硬度的切削刀具、醫療配件刀具設計、複合式再研磨機、PCD地板專用企口鑽石組合刀具、粉末造粒成型機、主機版專用頂級電桿、PCD V-Cut刀、捨棄式圓鋸片組、粉末成型機、主機版專用頂級電感、’汽車業刀具設計、電子產業鑽石刀具、木工產業鑽石刀具、銑刀與切斷複合再研磨機、銑刀與鑽頭複合再研磨機、銑刀與螺絲攻複合再研磨機等等。我們的產品涵蓋了從民生刀具到工業級的刀具設計；從微細刀具到大型刀具；從小型生產到大型量產；全自動整合；我們的技術可提供您連續生產的效能，我們整體的服務及卓越的技術，恭迎您親自體驗！！

BW Bewise Inc. Willy Chen willy@tool-tool.com bw@tool-tool.com www.tool-tool.com skype:willy_chen_bw mobile:0937-618-190 Head &Administration Office No.13,Shiang Shang 2nd St., West Chiu Taichung,Taiwan 40356 http://www.tool-tool.com / FAX:+886 4 2471 4839 N.Branch 5F,No.460,Fu Shin North Rd.,Taipei,Taiwan S.Branch No.24,Sec.1,Chia Pu East Rd.,Taipao City,Chiayi Hsien,Taiwan

Welcome to BW tool world! We are an experienced tool maker specialized in cutting tools. We focus on what you need and endeavor to research the best cutter to satisfy users’ demand. Our customers involve wide range of industries, like mold & die, aerospace, electronic, machinery, etc. We are professional expert in cutting field. We would like to solve every problem from you. Please feel free to contact us, its our pleasure to serve for you. BW product including: cutting tool、aerospace tool .HSS DIN Cutting tool、Carbide end mills、Carbide cutting tool、NAS Cutting tool、NAS986 NAS965 NAS897 NAS937orNAS907 Cutting Tools,Carbide end mill、disc milling cutter,Aerospace cutting tool、hss drill’Фрезеры’Carbide drill、High speed steel、Compound Sharpener’Milling cutter、INDUCTORS FOR PCD’CVDD(Chemical Vapor Deposition Diamond )’PCBN (Polycrystalline Cubic Boron Nitride) ’Core drill、Tapered end mills、CVD Diamond Tools Inserts’PCD Edge-Beveling Cutter(Golden Finger’PCD V-Cutter’PCD Wood tools’PCD Cutting tools’PCD Circular Saw Blade’PVDD End Mills’diamond tool. INDUCTORS FOR PCD . POWDER FORMING MACHINE ‘Single Crystal Diamond ‘Metric end mills、Miniature end mills、Специальные режущие инструменты ‘Пустотелое сверло ‘Pilot reamer、Fraises’Fresas con mango’ PCD (Polycrystalline diamond) ‘Frese’POWDER FORMING MACHINE’Electronics cutter、Step drill、Metal cutting saw、Double margin drill、Gun barrel、Angle milling cutter、Carbide burrs、Carbide tipped cutter、Chamfering tool、IC card engraving cutter、Side cutter、Staple Cutter’PCD diamond cutter specialized in grooving floors’V-Cut PCD Circular Diamond Tipped Saw Blade with Indexable Insert’ PCD Diamond Tool’ Saw Blade with Indexable Insert’NAS tool、DIN or JIS tool、Special tool、Metal slitting saws、Shell end mills、Side and face milling cutters、Side chip clearance saws、Long end mills’end mill grinder’drill grinder’sharpener、Stub roughing end mills、Dovetail milling cutters、Carbide slot drills、Carbide torus cutters、Angel carbide end mills、Carbide torus cutters、Carbide ball-nosed slot drills、Mould cutter、Tool manufacturer.

Bewise Inc. www.tool-tool.com

ようこそＢｅｗｉｓｅ　Ｉｎｃ.の世界へお越し下さいませ、先ず御目出度たいのは新たな

情報を受け取って頂き、もっと各産業に競争力プラス展開。

弊社は専門なエンド・ミルの製造メーカーで、客先に色んな分野のニーズ、

豊富なパリエーションを満足させ、特にハイテク品質要求にサポート致します。

弊社は各領域に供給できる内容は：

（１）精密ＨＳＳエンド・ミルのＲ＆Ｄ

（２）Carbide Cutting tools設計

（３）鎢鋼エンド・ミル設計

（４）航空エンド・ミル設計

（５）超高硬度エンド・ミル

（６）ダイヤモンド・エンド・ミル

（７）医療用品エンド・ミル設計

（８）自動車部品＆材料加工向けエンド・ミル設計

弊社の製品の供給調達機能は：

（１）生活産業～ハイテク工業までのエンド・ミル設計

（２）ミクロ・エンド・ミル～大型エンド・ミル供給

（３）小Ｌｏｔ生産～大量発注対応供給

（４）オートメーション整備調達

（５）スポット対応～流れ生産対応

弊社の全般供給体制及び技術自慢の総合専門製造メーカーに貴方のご体験を御待ちしております。

Bewise Inc. talaşlı imalat sanayinde en fazla kullanılan ve üç eksende (x,y,z) talaş kaldırabilen freze takımlarından olan Parmak Freze imalatçısıdır. Çok geniş ürün yelpazesine sahip olan firmanın başlıca ürünlerini Karbür Parmak Frezeler, Kalıpçı Frezeleri, Kaba Talaş Frezeleri, Konik Alın Frezeler, Köşe Radyüs Frezeler, İki Ağızlı Kısa ve Uzun Küresel Frezeler, İç Bükey Frezeler vb. şeklinde sıralayabiliriz.

BW специализируется в научных исследованиях и разработках, и снабжаем самым высокотехнологичным карбидовым материалом для поставки режущих / фрезеровочных инструментов для почвы, воздушного пространства и электронной индустрии. В нашу основную продукцию входит твердый карбид / быстрорежущая сталь, а также двигатели, микроэлектрические дрели, IC картонорезальные машины, фрезы для гравирования, режущие пилы, фрезеры-расширители, фрезеры-расширители с резцом, дрели, резаки форм для шлицевого вала / звездочки роликовой цепи, и специальные нано инструменты. Пожалуйста, посетите сайт www.tool-tool.com для получения большей информации.

BW is specialized in R&D and sourcing the most advanced carbide material with high-tech coating to supply cutting / milling tool for mould & die, aero space and electronic industry. Our main products include solid carbide / HSS end mills, micro electronic drill, IC card cutter, engraving cutter, shell end mills, cutting saw, reamer, thread reamer, leading drill, involute gear cutter for spur wheel, rack and worm milling cutter, thread milling cutter, form cutters for spline shaft/roller chain sprocket, and special tool, with nano grade. Please visit our web www.tool-tool.com for more info.

BW Cutting Tools www.tool-tool.com

Thursday, February 26, 2009

English Inductance www.tool-tool.com

[edit] Definitions

[edit] Properties of inductance

[edit] Phasor circuit analysis and impedance

[edit] Induced emf

[edit] Coupled inductors

[edit] Calculation techniques

[edit] Mutual inductance

[edit] Self-inductance

[edit] Method of images

[edit] Self-inductance of simple electrical circuits in air

[edit] Inductance of a solenoid

[edit] Inductance of a coaxial line

[edit] See also

[edit] References

[edit] General References

[edit] Links

No comments: