David VanHorn <dvanhorn <at> microbrix.com> writes:

> On 4/1/07, wouter van ooijen <wouter <at> voti.nl> wrote:
> >
> > > - all relay kickback catchers must be expensive, large
> > > Schottky to have Vf <
> > > +0.3V during inductive kickback of 100 mA or more, if the relay is
> > > +driven
> > > directly by the PIC (5V, 3V etc).
> >
> > relays driven directly by a PIC????
> 
> I was wondering about that too..
> What's next, a stepper motor?

The stepper motor in e.g. a quartz wristwatch or desk clock can be driven 
directly by a PIC pin usually. Also galvanometer style mechanisms (e.g.
electronic iris) and much much more. 5 mA at 5 V (25 mW) is a lot of power in
2007. A nice high efficiency headphone will be very loud at this power level. A 
telephone capsule too. Remember how bright a LED will shine with this, for 
example. It is also possible to parallel several CMOS output pins and obtain a 
beefier driver like that. (sorry: the *used* to be a way to parallel *usual* 
(CMOS CD4xxxB style) outputs for that - now, I don't know). CMOS 'B' style IO 
pins were attractive because they were robust wrt. exactly what was lost with 
this 'new' feature.

Peter P.


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