On 10/14/05, William Chops Westfield wrote: > On Oct 14, 2005, at 1:37 PM, Olin Lathrop wrote: > > > I saw a bunch of other replies, but I think they are answering the > > wrong > > question. I don't know what a SN754410 DNE motor driver chip is, but > > it sounds like the wrong tool or maybe its not driven the best way. > > > The 754410 is TI's "improved" L293-style quad half-h-bridge chip, with > darlington output stages, and the associated significant voltage drops > and power dissipation. I don't think it's possible to drive it > "improperly" > in the linear region, but the specs in the datasheet don't quite match > up; total power dissipation is 2W, but there are 4 drivers with ~1V > voltage drops, which is 4W at the rated 1A. And even 2W seems like > quite a bit for a plastic dip16 package. > It's not a question of matching up, you just can't use all four drivers at maximum current at 100% duty cycle. I think datasheet writers like to put the advantageous specs in bold on the front page, and hide the gotchas in the fine print. That's why you must read the whole datasheet, of course. Regards, Mark markrages@gmail -- You think that it is a secret, but it never has been one. - fortune cookie -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist