The 2DM860H chinese controllers vs the rest?

[Neale]

The obvious question to ask is why, if there was a fuse, it was not accessible from the outside for replacement purposes? The answer, I think, is for the same reason that I don't stick fuses everywhere in my own control box. The fuse in this case did not protect the mosfets - it protected the rest of the upstream wiring and power supply from a potentially dangerous overcurrent situation causing a fire. Pound to a penny that the mosfets popped first, then the fuse blew to protect the rest of the system. The manufacturer knew this - no point in a replaceable fuse if the driver is dead anyway. Fuses are very important and shouldl not be forgotten - but just remember what they actually achieve and use them accordingly.

On a more positive note it's interesting to see that these drivers use well-marked and easily available replacement mosfets, although I would be a bit hesitant about working on through-hole boards - haven't had to do that myself.

[Doddy]

MOSFETs due in tomorrow from Farnell... along with some other goodies. Neale - that's pretty much the purpose of a fuse - and anyone relying on one to protect semiconductors has a lot more optimism than me. The more I look at these drivers the more I like about the design - the accountants haven't got too close to these, just close enough to the training of the assembly workers :)