Winfield Hill said:
colin wrote...
There's more, much more.
Someone else mentioned the slow diodes in the bridge and the high side
driver, but tbh i assume this isnt going to be switched at a very high
rate, - or sudenly switch from forward to reverse instantly, its just so
obviously not designed for it, but maybe it could use some dead time
control, just in case, a few tens of microseconds at least, then the diodes
would have plenty of time to recover before they were reverse biased, is
obviously not designed to handle the kenetic energy of the motor being
dumped back into it, so the bridge diodes just have to handle inductive turn
off transient, in fact i asume the mosfet internal diodes will be able to
handle that anyway, although thinking about it again the emf from the free
wheeling motor might reverse bias them imediatly after the curent has droped
to zero, im not sure the 0.1 uf capacitors would help much with the curents
involved, but its not like its 100v or more.
The supply to the high side driver could do with being modified slightly,
high transient curents flow through c8/c11 also d1/d4 wich is probably not
forseen.
Apart from the choice of power transistors im not sure what else there is
left to criticise perhaps it could do with an on/off switch maybe. or maybe
im missing something bigger? the 100k resistors in series with the scmit
trigers seem dubious, and perhaps some supply decoupling.. there doesnt seem
to be any at all for the main supply.
Colin =^.^=
