Power supply with disconnect fuse

A power supply in which a feed voltage (Us) is routed through at least one longitudinal branch to at least one output, the at least one branch having a disconnect fuse formed as a controlled main semiconductor switch (SW1) and a monitoring unit (UWE) being set up to supply a disconnect signal (s1) to the semiconductor switch when there are changes in voltage or current beyond pre-defined tolerances,

• wherein
• the controlled main semiconductor switch (SW1) is addressed with said disconnect signal (s1) if the limit current is exceeded, so that the controlled main semiconductor switch (SW1) leaves the saturation state and holds the output flow constant in a limit state for a short period of time, and
• wherein
• at least one series circuit of an auxiliary semiconductor switch (H1A), likewise triggered by the monitoring unit (UWE), and a ballast resistor (RA1), is connected in parallel to the semiconductor switch (SW1), the monitoring unit (UWE) being configured to keep the auxiliary switch (H1A) continuously switched on during normal operation, but in the event of a short circuit or a state similar to a short circuit to lock the semiconductor switch (SW1) and to lock the auxiliary switch (H1A) via a disconnect signal after the short period of time.