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Old January 7th 05, 05:19 PM
Roy Lewallen
 
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Cecil Moore wrote:
Roy Lewallen wrote:

"Time-multiplexed" means that they're turned on in sequence, without
all being on at once. That would be as opposed to simply pulse
modulated all at once.



The most trivial case of binary time multiplexing would be a
single LED being turned on for a logic 'one' and off for a logic
'zero'. That "binary time multiplexing" concept is a carry over
from 40 years as a digital engineer, 13 of them at Intel.

Are they really time-multiplexed, or are they all pulsed at once?



It appeared that they were all pulsed at once. Perhaps I should
have used the word "pulsed" to avoid confusion in the RF analog
(non-digital) world.


Yeah, digicats have their own language. In analog parlance, multiplexing
basically means sharing. As in telephony, where you share one line among
many users by connecting each to the line for a short time in sequence
(time division multiplexing or TDMA - time division multiple access),
breaking the spectrum into pieces and giving each user his own channel
(frequency domain multiplexing), or more complex methods such as spread
spectrum code domain multiplexing, or CDMA (code division multiple
access). There's no sharing when there's only one user, channel, or LED
involved, so no multiplexing. Except, I guess, for digital types who can
share an LED between a 1 and a 0.

Just out of curiosity, what does your revered IEEE Dictionary have to
say about it?

Roy Lewallen, W7EL