Capacitance and inductive influence of fusing behavior

A fusing technique is currently being investigated at the Energy Systems Institute that will utilize a thin film planar geometry. The film is capacitor grade, metallized polypropylene at seven microns thick, and was cut to sizes of 12" /spl times/ 3/4". The metallization consists of aluminum and has a surface resistance of 7 /spl Omega//square. The fusing technique under evaluation consists of a 2 /spl mu/F 12.5 kV/sub dc/ filter capacitor which is used to supply the 2500 V/sub dc/ to cause the desired fusing action. Initial measurements show an impulse current of 6 A and pulse duration of 50 /spl mu/s. As this was a filter capacitor, the inductance was assumed to be higher than an energy discharge capacitor and thus the energy discharge time would be slower. To confirm a high inductance, a GENRAD 1689 Precision RLC Digibridge was used to measure the stray inductance of the capacitor. The stray inductance was found to be approximately 12 mH, which is extremely high. An energy discharge capacitor will be inserted into the experimental setup to lower the inductance and decrease the energy discharge time.