METHOD AND APPARATUS FOR PROTECTING A LOAD AGAINST AN OVERCURRENT

A hybrid load protection apparatus (1) comprising a primary power supply path (1A) provided between an input terminal (2) and an output terminal (3) of said hybrid load protection apparatus (1) and having a controllable mechanical switch (5A) connected in series with a primary coil (4A-1) coupled inductively to a secondary coil (4A-2) providing a voltage, U, corresponding to a current rise speed of the electrical current flowing through the primary power supply path (1A), wherein the provided voltage, U, is applied directly to a driver input (IN) at a low voltage side of a first driver circuit (6A) associated with the primary power supply path (1A) to trigger automatically a switch-off of the mechanical switch (5A) within a first switch-off period (Δt1) to interrupt the primary power supply path (1A); and comprising a secondary power supply path (1B) provided in parallel to the primary power supply path (1A) between the input terminal (2) and the output terminal (3) of said hybrid load protection apparatus (1) and having a further coil (4B) connected in series with a semiconductor power switch (5B). wherein a second driver circuit (6B) associated with the secondary power supply path (1B) is provided to detect an increasing electrical current, I, flowing through the secondary power supply path (1B) caused by the interruption of the primary current path (1A) on the basis of a voltage drop (ΔU) generated by the further coil (4B) and a non-linear voltage drop (ΔU) along the semiconductor power switch (5B) applied as a sum voltage (U) directly to a driver input (DESAT) at a high voltage side of the second analog driver circuit (6B) to trigger automatically a switch-off of the semiconductor power switch (5B) provided in the secondary power supply path (1B) within a second switch-off period (Δt2) to interrupt the secondary power supply path (1B)