AN ARRANGEMENT FOR PROTECTING A DC SOURCE

摘要

To protect a DC voltage source (1), connected to a load (2), against overcurrents, a first switch (SW1) in series with a current limiting resistor (R1) is connected in series with the load (2), and a second switch (SW2) is connected in parallel with the first switch (SW1) and the current limiting resistor (R1). Said first and second switches (SW1, SW2) are turned on in the absence of overcurrents. Upon an overcurrent, said second switch (SW2) is turned off. A transient detector (9) is connected to detect transient overcurrents. Upon a transient overcurrent, said second switch (SW2) is turned on when the current has decayed to a predetermined value (ION) to supply the load (2) with a decreasing current via the first switch (SW1) and the current limiting resistor (R1), and a correspondingly increasing current via the second switch (SW2) until the load (2) is supplied with current only via the second switch (SW2).