Magnetorquer Magnetic Moment Estimation - spacecraft-design-lab-2019/documentation GitHub Wiki

Estimated Magnetic Moments

X = 8.8 x 10^-3 A-m^2

Y = 1.37 x 10^-2 A-m^2

Z = 8.2 x 10^-3 A-m^2

Magnetic Moment = n x A x V / R

Set V = 3.3 V (bus voltage)

Took other values from table below

Board Values

Board Name	Number of Turns	Resistance of Coil (ohms)	Enclosed Area (mm^2)
+/- X	100	60	1600
+/- Z	92	60	1622
+ Y	104	27.7	1225
- Y	68	46	2622

NOTE: These values are approximations based on the KiCad for the first iteration of boards ordered. The area is the average area enclosed by the trace.

Sample calculation for the Y boards:

Boards are in series so total resistance is 27.7 + 46 = 73.7 ohms

Therefore current running through coil is 3.3 / 73.7 = 44.8 mA

+Y board's magnetic moment is n x A x I = 104 x 1225 x 10^-6 x 44.8 x 10^-3 = 5.7 x 10^-3 A-m^2

-Y board's magnetic moment is n x A x I = 68 x 2622 x 10^-6 x 44.8 x 10^-3 = 8.0 x 10^-3 A-m^2

Total Y magnetic moment is 1.37 x 10^-2 A-m^2