20 Mar
2002
20 Mar
'02
4:11 a.m.
From: Ethan Dicks
--- Hans Franke <Hans.Franke(a)mch20.sbs.de> wrote:
Or an optical sensor mounted parallel the axis of the roll that would
trigger when the diameter was too low. How about a color-based sensor
that could detect the difference between the cardboard core and the
paper? What about a shaft encoder that measures angular velocity...
for low velocities, there must be lots of paper (when the roll is full,
3 squares per second produces, say, 1/60 RPM; but when the roll is nearly
empty, the same linear pull rate produces 1/20 RPM - kinda the opposite
of linear bit-density calculations on variable zone recording floppies
and hard disks). There's probably a way to embed an inertial sensor in
the holder to measure the force it takes to start the roll moving... the
possibilities are endless!
- How about a TP holder that measures the weight? Or a spring loaded
arm, that contacts a switch when it get near empty. With a wheel at the end,
you can also have it provide drag on the roll, for spin control. Then it
won't be so easy for my cat to run all around the house with it...
--- David A Woyciesjes
--- C & IS Support Specialist
--- Yale University Press
--- mailto:david.woyciesjes@yale.edu
--- (203) 432-0953
--- ICQ # - 905818
Mac OS X 10.1.2 - Darwin Kernel Version 5.2: Fri Dec 7 21:39:35 PST 2001
Running since 01/22/2002 without a crash
> On Tue, 19 Mar 2002, Ben Franchuk wrote:
> > Glen Goodwin wrote:
> > > 1 -- Build an interface for every device under the sun, including
> > > the toilet seat.
> > That is easy -- a micro switch ... now how do you tell if the ROLL
is
>
almost empty ?
> Press-fit roll spindle with shaft encoder attached to... a PDP-11...
> counting total turns, comparing against approximate turns-to-roll-
> exhaustion, and...printing out a TP-LO Warning.