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Formulae: Voltage induced in coils |
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| The following units have to be used in all equations: | ||
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all lengths (L, R, SQRT F): all frequencies (f, f0, Df0) The voltage V will be calculated in |
[cm] [Hz] [V] |
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1. Simple air coil |
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U = generated voltage µeff = effective permeability (=1 in air coils) N = number of windings F = area of a winding Q = quality factor (=1 in air coils) f = frequency of the AC-field  |
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2. Coil in resonance |
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f0 = resonance frequency Df0 = bandwidth in  The field in dependency of the distance from the coil centre (Z) is shown in Figure 1 for single and double ring coils. |
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3. Coils, filled with ferromagnetic material |
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µa = permeability of the material L = length of the coil R = radius of the coil  The effective permeability versus length/diameter ratio p is shown in Figure 4 for materials with various permeability's. |
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 Figure 4: Effective permeability in dependency of L/R ratio and permeability of the material. |
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