Hi Seb, The board will be less general with the two 4k7 resistors on RB1-2... BTW, is here a chance to have a Software SPI library?
Vasi On Feb 6, 1:48 pm, Sebastien Lelong <[email protected]> wrote: > Hi Kiste, > > Thanks for the figures. I hope not to forget them :) > > I had a look at last Arduino design (Uno). They use a 500mA polyfuse, > resettable, claiming it'll add a proctection layer, in addition to the one > included in USB host. From Jaluino Medium discussion, I understood polyfuse > doesn't act fast enough, that's why it uses a "standard" one. This would > make two reasons Arduino wouldn't be suitable to USB regarding fuse > protection. Unfortunately, polyfuses remain the most interesting option: > easy to find, small, reusable... > > Cheers, > Seb > > 2011/2/6 Oliver Seitz <[email protected]> > > > > > >So I'd need 300mA to protect 500mA ?... Or I could 500mA knowing it'll > > blow at 800mA > > > It takes it's time to blow a fuse. For a super fast acting SMD fuse I > > already gave some numbers, here a bit more detail, example is a 500mA fuse: > > > It will *not* blow within 1 hour at 625mA, > > it will blow in less than 5 sec. at 1000mA, > > it will blow in less than 1 msec. at 5A. > > > Some numbers for a time-lag fuse: > > > It will *not* blow within 4 hours at 500mA, > > it will blow in less than 5 sec. at 1000mA, > > at 5 A it will blow in less than 100ms, but not before 10ms. > > > So, if you put those two in series, only the super fast fuse will blow at > > very high currents, while at modest overload any of the two can blow. If you > > want to protect a 500mA fuse in your computer, you would have to use an > > external fuse rated not higher than 300mA. > > > There are books about connecting fuses in series :-) > > > Greets, > > Kiste > > > -- > > You received this message because you are subscribed to the Google Groups > > "jallib" group. > > To post to this group, send email to [email protected]. > > To unsubscribe from this group, send email to > > [email protected]. > > For more options, visit this group at > >http://groups.google.com/group/jallib?hl=en. > > -- > Sébastien Lelonghttp://www.sirloon.nethttp://sirbot.org -- You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
