On Oct 20, 2007, at 10:42 AM, William Beaty wrote:
On Sat, 20 Oct 2007, Jones Beene wrote:
I find Bill's T-coil comparison enlightening ;-) but lacking (in the
sense of apples-to-oranges) wrt to the latest experiment -- where
there
is NO, ZERO, NADA, signal... merely ground, or DrS's touch.
Ah, that's different!
:)
and ... that is probably not true that there is no signal applied.
If you will notice there is no mention of closing the loop or self
running in the video. In fact, it appears what has likely happened
is the pan potential has been made to float, providing a capacitive
or conductive linkage to the breadboard ground, the closed path to
the "ground" supplied by the clip or hand. The power is supplied
through the pan. Since the supplied power is AC, this is no
different from attaching the clip to the power supply and using the
capacitive link between the pan and ground as ground, even if the pan
is not grounded by wire, but rather by capacitive linkage to ground.
You can see about an inch of what appears to be a power supply lead
at the bottom right of the screen. It goes under the pan.
*Complete* documentation including a full circuit diagram and parts
info should be supplied.
Following is the dialog from the video:
http://www.youtube.com/watch?v=tdJm9QCVJHY
Quoted material below is from narrator on the video, assumed to be
Ron Stiffler.
"Sometimes a good ground really makes all the difference in the
world. There's my big fat ground lead hooked to that one little wire
on that coil. Eight beautiful white LEDs."
(Hand grabs insulated alligator clip and removes it, showing LED go
out.)
"Let's see if I'm a good ground too."
(Hand comes back into picture without clip, touches lead, the LED
glows dimly.)
"I'll be dared. Not too bad, right?"
(Repeats touch, no touch. Note little black wire at bottom right of
screen, going under pan, moving side to side a bit.)
"Fire up eight LEDs."
(Repeats touch, no touch.)
"That takes a lot of power doesn't it?"
(Lifts up breadboard with left hand to show no battery. Note what
appears to be a small black wire, going under the right half front of
the aluminum pan, shaking back and forth just prior to and after the
lifting of the board. )
"I still don't have that pink bunny under here either."
(Rotates breadboard. Places board back on pan. Wire at bottom right
of screen moves side to side some more in the process. Hooks
alligator clip back to coil lead.)
"Well, we'll put the ground back on it and be satisfied with it.
Lookn' better all the time. Maybe I'll light my house next week."
Horace Heffner
http://www.mtaonline.net/~hheffner/
