Experiments - Open Loop Pulse Triggering

Optical Triggering Results

Coil D

Table 1 shows the resulting speeds for each projectile type.

Projectile	Open Loop Speed (m/s)	Optical Speed (m/s)	Difference (%)
Solid	1.12E+1	1.07E+1	4.67E+0
4 mm Cored	1.15E+1	1.10E+1	4.55E+0
6 mm Cored	1.18E+1	1.12E+1	5.36E+0

Table 1. Comparison of maximum open loop speed and optical speed.

Again we can see that the speed values are still close to the optimal speeds obtained using the open loop triggering method.

Fig 1. Voltage, current and power curves.

Now we can see that the current reaches a peak of about 150A and the peak internal source loss is close to 1700W - more than double that of coil C.

Source Energy (mJ)	Supply Energy (mJ)	Projectile Energy (mJ)	Coilgun Efficiency (%)	Overall System Efficiency (%)
3.71E+4	2.55E+4	7.25E+2	2.84E+0	1.95E+0

Table 2. Efficiency comparisons for solid projectile.

Now we can see the price, in terms of efficiency, paid for the small additional speed offered by this coil over coil C. These efficiency values are the worst of all the coils.