We've designed out all fuses and are now using PTC thermistors for all
overcurrent protection (other than high current AC line applications,
where we use circuit breakers). We use Raychem PolySwitches for low
voltage and BC Components for line voltage (up to 260VAC) applications. No
more false fuse blows!

Harold


>>> Does anybody use these?  Find them at Digikey, or Mouser, or etc?
>
>>Such as the Raychem/tyco "Polyswitch" series, available at digikey/etc.
>>
>>I have some from dumpster diving.  They seem a bit slow to me, taking a
>>couple seconds to open (that may be something you can select, though.)
>
> Yeah, they are really designed as a safety device to handle long term
> overloads, rather than used like a normal fuse. Not sure what the minimum
> current rating is, but I doubt that they will really suit the OP desires.
> There are surface mount ones that might get close though.
>
> The other trick to them is that they are designed to work close to max
> current rating, but if you try and grossly exceed that, then they will act
> rapidly as they then heat up fast. Makes them good for protecting
> transformaers in power supplies from short circuit outputs, instead of
> using
> fuses.
>
> --
> http://www.piclist.com hint: The PICList is archived three different
> ways.  See http://www.piclist.com/#archives for details.
>


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