Re: emf, potential, voltage

[brian whatcott <inet@INTELLISYS.NET>]

At 17:42 3/17/01 -0500, Bob Sciamanda wrote:
> /snip/
> V=C*I, a straight line in V/I space.
>
> How realistic is this (and for what type motors)?
> (Obviously, I also assume a constant mechanical load.)
>
> Bob Sciamanda

It's interesting to explore this concept of a 'constant mechanical
load'.
Could it be analogous to the load on the back of the donkey that
walks along at much the same speed, lightly or heavily loaded?
(varying power at constant speed)
Could it be like a paddle attached to a motor shaft, that stirs
a viscous liquid?
(Varying power with varying speed)
Could it be like an IC engine in a car with fixed throttle setting
so in third it drives the car at 30 up a hill, and in fourth it
goes at 50mph down a hill?
(constant power at varying speed).
I'm not absolutely sure, but I think Bob had in mind the first
alternative - to absorb varying power as needed to keep the angular
rate constant.
Because:
If an increased voltage leads to an increased current and an increased
speed in the usual way, the back emf then may have two multipliers:
 speed and flux, a patently non linear effect.




brian whatcott <inet@intellisys.net>  Altus OK
                Eureka!