>Roman Black wrote...

>[snip]

>>Please argue, I appreciate anyone who has made SMPS's for
>>25 years, as I know that you learned X things in those
>>years and I learned Y things in those years and it sure
>>beats arguing the football scores... :o)

>Roman, this circuit is like one of those "Roach Motel" thingies:
>energy can check into that inductor, but it can't check out.  Under no
>circumstances does ANY of the energy stored in the inductor EVER find
>its way to the output circuit.  Nary so much as a picojoule.

>Going back over my previous post, I don't see how I could clarify my
>explanation any; it seems pretty straightforward.

I suspect that it is not so much a case of apples and oranges, as apples and
pears that are being compared :)))

In the case of the stepper motor, energy is being checked out while the
diode shorts the inductor, because the magnetic field is the exit route
(check out desk) for the energy. Remember that in a motor there is
significant air gap in this path which will "release" a certain amount of
the energy until the next current replenishment cycle. This energy will be
used to hold the rotor stable, or continue pulling it into the next
rotational position (which ever was in progress when the current drive was
turned off).

In a SMPS the diode will cause a loss of efficiency as the stored energy is
now being dissipated in the resistive portion of the inductor, instead of
being transferred to the output load.

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body