> Tim Shearon wrote:
>
> > It would seem to be a vibratory frequency that there would not be
> > natural occurances of and thus our visual system isn't prepared, so to
> > speak, for what the jiggling means. i.e., it is a combination of the
> > resonance of the LEDs (a pretty slow refresh rate) and the speed at which
> > the visual system "updates" incoming information.
> >
Then Ben wrote:
> The only kind of LED (light-emitting diode) I know about is a DC device and
> doesn't have a refresh rate -- it stays on. It sounds like you're talking about
> a CRT (?)
>
This is right, I think, if you are talking about a single LED, but the
seven-segment displays that make digits such as those on a clock use multiple
LED's (just arranged in a particular way to make letters and numbers). And I
think the individual LED's that make up the display are indeed driven in a
cyclic fashion. So they can flicker...
**************************************************
Patrick Cabe, Ph.D.
Department of Psychology
University of North Carolina at Pembroke
One University Drive
Pembroke, NC 28372-1510
(910) 521-6630
[EMAIL PROTECTED]
