Design and analysis of an exploding foil initiator (efi) based ignition safety device for missile system

Increasing insensitivity demands on designing and producing munitions necessitates utilizing primarily insensitive initiation trains specifically in missile systems. Exploding Foil Initiator (EFI) is a high voltage detonator that is used as the initiation element of rocket motor and warhead initiation trains of modern insensitive missile systems. Depending on the temperature and manufacturer, while low energy EFI can be fired at between 700 Vdc and 1250 Vdc, high-energy ones can be fired between 1400 Vdc and 2500 Vdc voltages. In this thesis, instant high power density flyback topology converter design and development has been made to convert 28V DC supply voltage of the missile electronics to 2500V DC voltage level. The firing capacitor is charged by a flyback converter with an output voltage of 2500V DC after the ignition safety device has detected the safety conditions in fuse system. After the ignition command isreceived, EFI will be ignited via the trigger switch with the energy on the firing capacitor. A design has been made to allow measurement of electrical characteristics such as high current and voltage in the ignition line at the time of ignition. Safety and charging time are the most important requirements in the design of the capacitor charging circuit. To increase efficiency and reduce the size of the PCB, the electrical strength characteristics of the components have been selected to meet the instantaneous high current and voltage requirements. In particular, the flyback transformer is designed to charge the firing capacitor at maximum speed in a minimum space to meet the requirements of instantaneous power density at high output voltage. The transformer winding architecture and structures are examined to obtain optimum parameters for high voltage capacitor charging application. In addition, since the ignition safety device is the most critical unit in terms of safety in missle system, it is designed in accordance with the STANAG 4187 NATO standard, which sets out the requirements for safe design in missile systems.