5.1.3. Impact of a Variation of the Coil Triggering Instants

Having a powerful coil gun is important, but its behaviour robustness is also a key factor. This is especially true for the triggering instants which are important parameters for optimizing power transmission and have to be tuned carefully.

In the case of a two-coil EML, simulations show that the second coil optimal triggering instant is 10 ms after the first coil. Table 3 shows that a variation of this triggering instant of ±1 ms has a very limited impact on the ball speed, which is only reduced by less than 2%, leading to a good robustness of this system.

**Table 3.** Impact of a variation of the second coil triggering instant in the case of a 2 coils EML.


In the case of a four-coil EML, the fourth coil optimal triggering instant is 15.5 ms after the first coil. Table 4 shows that a variation of this triggering instant of ±1 ms has an important impact on the ball speed which is reduced by 11% or more. Consequently, the EML using four coils is far less robust than the EML using two coils in terms of sensitivity to the coil-triggering instants.

**Table 4.** Impact of a variation of the fourth coil triggering instant in the case of a four-coil EML.

