R je polmer tuljave NI je N*I l je dolžina tuljave (z2-z1)
Formula za izračun polja v osi tuljave je:
$$ {B_z} =\frac{{{\mu _0}NI}}{{2l}}\left( {\frac{{{z_2} - z}}{{\sqrt {{{\left( {z - {z_2}} \right)}^2} + {R^2}} }} - \frac{{({z_1} - z)}}{{\sqrt {{{\left( {z - {z_1}} \right)}^2} + {R^2}} }}} \right)$$from IPython.display import Image
from IPython.core.display import HTML
Image(url= "https://raw.githubusercontent.com/osnove/Slike/master/oe2_solenoid.png")
import numpy as np
import math
import matplotlib.pyplot as plt
NI=6000 # tok
R=5e-2 # polmer
mi0=4*np.pi*1e-7 # permeabilnost
z1=-5e-2
z2=5e-2
l=z2-z1 # dolžina
z=np.arange(-15,15,0.11)*1e-2
B=mi0*NI/(2*l)*((z2-z)/np.sqrt((z-z2)**2+R**2)-(z1-z)/np.sqrt((z-z1)**2+R**2))
plt.figure(figsize=(15,10))
plt.title('Polje v osi tuljave',fontsize=18)
plt.xlabel('Razdalja / cm',fontsize=18)
plt.ylabel('Gostota magnetnega pretoka / mT',fontsize=18)
plt.tick_params(labelsize=18)
plt.plot(z*1e2,B*1e3)
plt.grid()
plt.show()
po http://info.ee.surrey.ac.uk/Workshop/advice/coils/air_coils.html
Image(url= "https://raw.githubusercontent.com/osnove/Slike/master/mult_layer_air_coil.png")
Image(url= "https://raw.githubusercontent.com/osnove/Slike/master/Brooks_ratio.png")
d= 0.05 # premer tuljave
c=0.03 # debelina (višina) ovojev
b=0.10 # dolžina tuljave
N=1000 # število ovojev
a=(d+c)/2 # srednji polmer v m
S1 = (c/(2*a))**2
L = 4E-7*np.pi*a*N**2*((0.5+S1/12)*np.log(8/S1) - 0.84834+0.2041*S1)
L # v Henryjih
0.06274480469336968
I=6 # Tok v žici
NI=N*I # A-ovoji
nl=15 # Number of layers (debelina žice * nl = c)
Il=NI/nl # tok v enem layerju
Ball=0
def B2(r,z):
# This function returns B for specific radius and position z
B2=mi0*Il/(2*l)*((z2-z)/np.sqrt((z-z2)**2+r**2)-(z1-z)/np.sqrt((z-z1)**2+r**2))
return B2
for i in range(1,nl):
r=(d/2)+i/nl*c
Bl=B2(r,0)
Ball=Ball+Bl
print(Bl)
print("Polje v sredini je ",Ball*1e3, "mT")
0.004422886933014146 0.004348121006897477 0.004272076884079683 0.0041952044484340045 0.0041179087729422 0.0040405500882946055 0.003963444883078566 0.0038868678558097542 0.0038110544684693097 0.003736203886890232 0.003662482130919684 0.0035900252936793744 0.003518942722485669 0.0034493200830061493 Polje v sredini je 55.015089458000865 mT