Abstract: A programmable fuse system provides under-voltage/short-circuit protection, and comprises an electrical circuit sensor operatively in communication with a predetermined set of electrical circuits; a controller operatively in communication with the electrical circuit sensor, the controller comprising active logic, memory, and data representing a set of characteristic current/trip time curves; and one or more programmable fuses operative to completely disconnect a predetermined electrical circuit of the set of electrical circuits on detection of a fault, without the need to replace a programmable fuse and without reliance on any small current to maintain its protection, and to remain completely disconnected until commanded to turn back on.