> > This got me wondering in the case of power measurement with other
> > things, is the momentum taken into account in the case of e.g. a
> > spinning disc in cycles, is it averaged over a certain time, or is it
> > only the power added at that instant (i.e. sufficiently short time) tha=
t
> > is measured?

> Well, if E =3D mgh, then doesn't matter how he got the mass in in the air=
, the
> fact is, he got a certain mass m against a gravity g to a height h in a
> certain time t. So he must have given the object a certain amount of ener=
gy
> to reach that height. Average it over some amount of time and you get
> energy. But maybe the power output isn't linear over that time. Maybe the
> power output was maximum at the first millisecond and decreased for the r=
est
> of the second.

Oli was asking about the case where you have equipment that stores energy.
On the system I designed power is considered to be torque x speed
(although torque was inferred via a proxy) so it's the instantaneous
power that the system as a whole is delivering. If your user suddenly
stops pedalling the power reported will be the stored power being
delivered by flywheel or whatever. However, in many cases power is
averaged over a number of seconds with the display being updated
periodically, so short term variations are smoothed out.


            R
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.