[Elecraft] K3 inline fuse

[Ian White GM3SEK]

David Cutter wrote:
>
>I would use a current-limited power supply to connect up ANY equipment 
>for the first time.  No fuse is as fast as electronic limiting.
>
>Even the fastest semiconductor fuses require a huge overload to achieve 
>a sluggish response.  Busman 25A fuse: 340A^2t.  I'm not an expert, but 
>divide 340 by the time you want it break and then take the square root, 
>I think that's how it's done.  So, to blow in 100ms it takes 58A. 
>Someone put me right.  UK 13A plug fuses need 2.1 x 13A to guarantee to 
>blow in 30seconds!
>

The other important point is that fuses provide ZERO protection until 
AFTER they have blown. In the life and death of a semiconductor, even a 
few milliseconds is a very long time indeed.


-- 

73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek