Shaft coupling

Equivalent circuit diagram

In electrical engineering , wave coupling is a combination of inductive coupling and capacitive coupling . This is understood as the spread of electromagnetic waves on neighboring lines, as well as the spread of one line circuit to another.

With the other forms of coupling , the transit time of the electrical signals on the interfering and the disturbed line is neglected. In certain special cases, if the wavelength of the disturbance variable is in the order of magnitude of the system dimensions, or the rise times of the disturbance pulses correspond to those of the signal propagation time, the wave coupling effect must be taken into account. The interference effect of the wave coupling rises rapidly with the frequency of the voltage in the system, and the length (marked with X in the equivalent circuit diagram) is a decisive factor.

The interference voltage can be calculated as follows:

${\displaystyle u_{st{\ddot {o}}r}=f\cdot \left(Z_{12}\cdot {\frac {\mathrm {d} i}{\mathrm {d} x}}\cdot {\frac {\mathrm {d} u}{\mathrm {d} x}}\right)}$

Countermeasures

By using shielded cables, the effect of the wave coupling can be reduced or even completely eliminated. The shielding must be carried out depending on the frequency range. With structured cabling , the frequency spectrum must be considered.

Web links

• Shaft coupling. German Society for EMC Technology, accessed on February 4, 2010 . 
• Shaft coupling. Rittal, accessed on February 4, 2010 .