The formula to calculate the Machine Constant is:
\[ K_{\text{f}} = \frac{Z \cdot P}{2 \cdot \pi \cdot n_{\text{ll}}} \]
Machine Constant refers to the parameter which usually has a constant value for a particular type of DC machine.
Let's assume the following values:
Using the formula:
\[ K_{\text{f}} = \frac{12 \cdot 9}{2 \cdot \pi \cdot 6} \approx 2.86478897565412 \]
| Number of Conductors (Z) | Machine Constant (Kf) |
|---|---|
| 10 | 2.387324146378 |
| 11 | 2.626056561016 |
| 12 | 2.864788975654 |
| 13 | 3.103521390292 |
| 14 | 3.342253804930 |
| 15 | 3.580986219568 |