Helmholtz T.F. IV

Electromagnet calculation


Electromagnet parts kit Narika


Demagnetization field coefficient X as a function of core length divided by diameter (cylindrical core)


How to maintain the gap under this much vibration force?

Bolt joint preload-> self loosing Nu with locking ring of Nylon1

1. Bickford, An introduction to the design and behavior of bolted joint.

Bobbin dia: 0.007m
Enamel wire dia: 0.00035m
Bobbin length: 0.026m
Number of turns per layer: 74T
Total number of turns: 800T
Number of layers: 10.8
Max dia of coil: 0.0145m
Ave dia of coil: 0.0108m
Nagaoka coeff (k): 0.845
L for coil: 0.00239H
f 100Hz
0.015Ω
R 3.35Ω
Relative permeability of iron μ: 200
X 0.06
Effective relative permeability μ’ 15.4
B @i=0.65A 0.36T
F @S=70×10-6m2 3.55N

Total wire length ~20m
Cu resistivity 1.55×10-8Ωm

(18-3.35*0.65)
V/15.4/1.5 Ω =0.65A
J=1/2 3.35*0.65^2=0.7(W)

Oxide Corporation

Speckle contrast Measurement System