Armature resistance ($R_a$):

• Directly given in the table: $0.16 Ω$

Armature inductance ($L_a$):

• Directly given in the table: 0.367 mH (convert to H: 0.367 * 10^-3 H)

Motor constant ($K_t$ or $K_e$ or $\Psi_{pm}$):

• Equivalent to the torque constant: 139 mNm/A
• Can be calculated from Speed constant too by converting from rpm/V to V/rad/s

Moment of inertia ($J$):

• Directly given in the table: 650 $\text{gcm}^2$ (convert to $\text{kg.m}^2$: $650 \times 10^{-7}$ $\text{kg.m}^2$)

Therefore, the DC motor parameters are:

• $R = 0.16 Ω$
• $L = 0.367 \times 10^{-3} H$
• $\Psi_{pm} = 139 \text{mNm/A}$
• $J = 650 \times 10^{-7} \text{kg.m}^2$

Calculating Friction Coefficient B from No-Load Data

Understanding the Relationship

The friction coefficient, B, in a DC motor represents the viscous friction torque that opposes the motor's rotation. It's directly proportional to the motor's rotational speed.

Equation at no load condition ($T_L = 0$):

$T_e = B\omega_{m} \\ B = \dfrac{K_tI_{noload}}{\omega_{m0}}$