US Patent 7738229 Microprocessor-controlled multifunctioning light with intrinsically safe energy limiting

A method is provided for reducing the power rating of a current limiting resistor (R) in a branch circuit having at least one protected element and the current limiting resistor connected between first and second nodes. The method includes the steps of: determining a maximum fault current in the branch circuit; determining a total current limiting resistance to limit the current in the branch circuit having the short-circuited elements to the maximum fault current; inserting a fuse having an intrinsic resistance in the branch circuit; and dividing the determined total current limiting resistance between the resistor (R) and the intrinsic resistance of the fuse.