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Thinking about placing a fuse on the 5 V input #17
Description
While the Mean Well PSUs are short-circuit safe, it may be wise to place a fuse on the 5V input as MLCCs can fail and become very hot. Some users use high-power PSUs for multiple Bitaxes, so I am unsure if that would be safe without an extra fuse.
A Littlefuse 217 Series (fast) with up to 40 A interruption rating has a voltage drop of 130 mV at 4 A:
https://cdn-reichelt.de/documents/datenblatt/C400/217_ENG_DATASHEET.pdf
I welcome any feedback from electrical engineers!
Activity
etkaar commentedon Nov 19, 2024
If addressed, this should be addresses as well, as it requires space on the PCB: #11
skot commentedon Mar 3, 2025
I don't think 130mV drop is going to be good with only 5V anyways.
Either way a traditional fuse is very bad user experience in my opinion. Also the overclockers are not going to like it. I would consider a resettable, adjustable eFuse... If you know of a good one.
We currently do have the ability to do overcurrent shutdown in the TPS546 voltage regulator.
etkaar commentedon Mar 4, 2025
Please have a look to the NerdQAxe:
https://github.com/BitMaker-hub/NerdQaxe
They actually use a SMD fuse, you can see it here:
Safety is an issue since people will print PLA based housings which could burn like hell in case of a catastrophic failure. But maybe I am wrong and it is not required. It would be great if there would be someone who is more experienced than me to evaluate this.
skot commentedon Mar 4, 2025
Yes, As I mentioned above I don't think the is the right approach.