So, this is something that I shouldn't need to do, but I do. As far as I understand, it should be trivial, bit I'm hazy on the details.
I have a 2kW mains AC power tool with a rotary output. Its reliable, works well, does its job.
Unfortunately it seems to have skipped some kind of surge suppression or energy dump in the electrics, because if the rotary spindle jams in the material it's working on,it blows the mains fuse in the plug. Then I have to stop using it, hunt down a spare 13A cartridge fuse (UK mains style), replace, and continue.
It happens pretty easily, its usual use makes it that way, and I consider the tool safe but poorly designed from that point of view - other rotary tools I own don't blow fuses if they briefly jam.
In an ideal world, I'd switch to a competing model but there isn't an affordable competing model for this specific tool, and the tool itself is quite usable. It just runs through 13A fuses at a rate of 5-10 a day on a busy day.
Now, I routinely strip down, repair, and at times fix and update my equipment. I build my own electrical items. It occurs to me that adding some kind of appropriate surge handling inline between tool and mains plug, would be a tiny item, maybe 2-3 components, to handle it better. I'd trust myself to do this safely, and robustly, but I have no idea of a suitable design.
What would I need to do, so that the transient surge from a jammed output spindle abruptly and temporarily stopping the motor, wouldn't blow the fuse, but current draw from other fault conditions would still blow it, so that it would still perform its safety function correctly?