Protection circuit for DC voltage sources having a small short-circuit current/rated current ratio

摘要

For a protection circuit for DC voltage sources, which have a low short-circuit/rated current ratio and are connected to the loads via a fuse, it is proposed according to the invention that: - the fuse (6) is connected in parallel with the series circuit of a fuse tripping capacitor (7) and a switch (8), - the fuse tripping capacitor (7) is charged up at the commencement of use of the load current, via a precharging circuit (9, 10), and - the switch (8) is tripped in the event of a defined excess current above the rated current, or a high di/dt, detected by a measuring element (13, 14), and short-circuits the discharge circuit of the fuse tripping capacitor (7), which runs via the fuse (6). <IMAGE>