Item 44. [Art.91.05] Axial length of pole face, l_p
l_p = l_a - 1.5d
Should be somewhat less than the gross axial length of armature, l_a.

Item 45. [Art.91.06] IX Drop (armature slots) volts per phase winding, E_s
E_s = I_c x 0.8 x p² x f x C_s² x n_s x p x l_a x [ (8s + 3b) / 12s + P₂ + P₃] x 10^-8
Where: vector E_s = vector DF = IX_slots
a = 0.5 ( d - 1/8)
b is usually equal to zero
2c is d_c - 1/8
The permeance of the slot above the winding: P₂ = a / s
The permeance of the slot on the air gap: P₃ = d / l
Increase the d_x if the P₂ is deemed too small.

Apparent Developed Voltage, OE'_d
OE'_d = [(OE_t cosq + E_tP)² + (OE_t sinq + PF)²]
Where:
OE_t = vector OE_t, see item 06
(IR) = vector E_tP, see item 39
PF = vector E_dP + vector DF
E_dP = IX_ends, see item 42
E_s = vector DF = IX_slots, see item 45

Item 46. [Art.91.07] Full Load Flux per pole, maxwells, F_FL/p
F_FL = F_NL x ( OE'_d / OE_t).

Item 47. [Art.91.08] Shape of pole face, p
Use cylindrical.

Item 48. [Art.91.09] Number of slots per pole (rotor), (S/p)_r
Assume a reasonable number of slots per pole. For design purposes, use: (S/p)_r = (S/p)/1.5. This should be an even integer when (S/p) is even.

Total Number of Rotor Slots, S_r
S_r = p × (S/p)_r

Item 49. Tooth pitch (rotor), l_r
l_r = p x D_r / S_r
Common practice is to make this equal to about 1.5l, when referred to stator.

[Art.91.10] Slot pitch (rotor), l_r
l_r = l x (S / S_r).

Items 50 - 51

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