US Patent 11927431 Firing switch for compact capacitive discharge unit

A capacitive discharge unit (CDU) for detonating an explosive in response to a control signal comprises a set of CDU components, including an exploding foil initiator (EFI), a trigger circuit, a firing capacitor, and an insulated-gate bipolar transistor (IGBT) firing switch. In various embodiments the components are arranged on a board for mechanically and electrically supporting the components in an ordered arrangement along a CDU axis where the CDU having an axial length defined by the ordered arrangement of two or more of the EFI, the firing capacitor, and the IBGT firing switch, wherein the trigger circuit is offset from the CDU axis such that the trigger circuit does not contribute to the axial length.