Protection for fan outputs?



  • As another user requested; "more stupid proofing" for the fan outputs could be possible by combining the low side FETs with a common high side switch that has some protection built in.

    I've previously seen this used to protect banks of mosfet ouputs with success, there is even room for self diagnostic and recovery; however even the simplest device should benefit the Duet boards.

    I looked up the part used for a prehistoric project from memory, but been discontinued (IR3315) , so I tried looking around to see what new players might fit the bill. Maybe Infineon-ITS4200S_ME_P_01092012S-DS-v01_00-en.pdf

    If it is tested and deemed an effective protection, I suppose one could make a tiny board to plug in on the voltage selector jumper to retrofit protection to older boards - or for that matter only offer it as a add-on for current and future boards.

    I'm sure this forum has several ideas on pros/cons of how to skin this particular cat if we get the cat rolling!



  • @bearer said in Protection for fan outputs?:

    https://www.infineon.com/dgdl/Infineon-ITS4200S_ME_P_01092012S-DS-v01_00-en.pdf

    Stupid proofing is great! .... but I can't seem to get to that document you are referencing 😞



  • Whops, a little eager on stripping query strings off links there; updated.



  • Without trying to break too many gray cells trying to digest the entire spec sheet, are you proposing to use this unit as a current limiting device? If so, it limits at a maximum of 9A, what would the on-board FET think of 9A?



  • PMV40UN2 can do a 16A peak current so in theory it might be able to deal with short circuit current of 9A.

    But as I said; I'm in no way sure that the infineon part is the part to use, but I'd like to see someone with a bit more electronics wizardry going on take a look to see if its a worth while adittion.

    Edit: it wont just limit the current, it'll also cut the positive supply, and the idea is to find a part that cuts the power before the FET break.



  • It seems to me like this is a lot of technology for something that only requires a simple current limiting circuit. I do not however have a better solution to offer.


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