Design and construction of a pulse forming network, pulse transformer power supply for the Texas Tech railgun

A pulse forming network (PFN), pulse transformer power supply has been designed, constructed, and tested to supply high current for the Texas Tech railgun. The power supply can deliver 500 kA to 1 MA for almost 1 ms to the railgun load. The current level is dependent upon the charge voltage of the PFN and the turns ratio of the transformer. The PFN is a Type E and has five stages. Comprised of 11 kV, 50 kJ Maxwell capacitors, the capacitor bank can supply a total of 500 kJ at 10 kV. The PFN is designed to deliver 100 kA at half voltage, or 200 kA for the full 10 kV. The total current delivered to the railgun depends on the transformer ratio, which can be altered from 5:1 to 10:1. This type of power supply is unique for railgun loads. Generally, homopolar generators or distributed capacitor banks have been used. PFNs have been used to drive railguns, but without the pulse transformer. The addition of the transformer increases the power transfer efficiency, and boosts the current without affecting the pulse length. The advantages of this system are as follows: it provides high constant current without complex controls, the output current can be increased without changing the system, and the PFN waveform is tunable.