That would probably be a self-resetting positive-temperature-coefficient fuse. Those are available for a wide range of currents. They're simple, cheap two-termi

That would probably be a self-resetting positive-temperature-coefficient fuse. Those are available for a wide range of currents. They're simple, cheap two-terminal devices.[1] Those are safety devices. If you're worried about a sudden load introducing a glitch on the 48VDC rail, you may need faster response. It wouldn't have worked in my application, because I need something that will current limit before the overload detector at the power source end trips. Here's a bigger current limit switch.[2] Versions are available that can handle 48VDC 5A. Texas Instruments calls it an "e-fuse". Not two-terminal, though; it needs some external resistors and caps, plus a connection to ground. Turns off in 280 nanoseconds on a short circuit. This is functionally similar to the part I used, but for higher voltages and currents in industrial applications. TI has many useful tech notes available. [1] https://community.element14.com/technologies/experts/b/comprehensive-guides/posts/a-comprehensive-guide-to-resettable-fuses https://community.element14.com/technologies/experts/b/compr... [2] https://www.ti.com/product/TPS1663 https://www.ti.com/product/TPS1663