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???
02/23/07 05:47
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 		 #133527 - I am still CURIOUS
Responding to: ???'s previous message
Richard Erlacher said:
The decay isn't as effective as you might first think, and Erik's comment is probably correct for most cases.

I have enought experience with muxed displays to be aware that the human eye - and brain, because that's involved in this process, too - can easily see a lot of things, even if they are not there; but I am still CURIOUS... (OK this thing seems to be a sort of a slight psychosis, doesn't it... :-) )

Richard Erlacher said:
Unfortunately, the peak charge rate is at the wrong end of the curve, so the brightness decrease coincides with the maximal recovery of the retina.

I don't quite understand what do you mean. Can you please elaborate?

Richard Erlacher said:
There's no single-bit memory concept involved, BTW, in what I proposed.

Yes there is - in the same way as in dynamic memories.

However, for multiplexed (matrix) displays, you would need capacitor parallel to a LED+resistor series combination, plus a diode in series with this all; and the concept would be the reverse - a quickly charged capacitor would slowly discharge through the LED+resistor, the diode preventing it discharging through the rest of the matrix.

Jan Waclawek

List of 43 messages in thread
TopicAuthorDate
Components for Outdoor LED Display            01/01/70 00:00      
   What are the specs?            01/01/70 00:00      
   you are already scewed            01/01/70 00:00      
      any better suggestions?            01/01/70 00:00      
         are your LEDs capable of 200mA ?            01/01/70 00:00      
            Human eye perception            01/01/70 00:00      
               percieved does not matter            01/01/70 00:00      
                  Perception is everything            01/01/70 00:00      
               LEDs are extremely nonlinear, too!            01/01/70 00:00      
                  I covered this            01/01/70 00:00      
                     I wrote -extremely non-linear-...            01/01/70 00:00      
                     that makes no sense            01/01/70 00:00      
                        Example with LTJ-811            01/01/70 00:00      
                           let the sunshine in            01/01/70 00:00      
                              LEDs appear the same in all conditions            01/01/70 00:00      
                                 Err            01/01/70 00:00      
                                    actually we have one multiplexed, however            01/01/70 00:00      
                                    King of LEDS :)            01/01/70 00:00      
                                 mux vs. pulsed            01/01/70 00:00      
                                    better ask ERIK ...            01/01/70 00:00      
                                       well, this is not so 'new'            01/01/70 00:00      
                                       more bright than outdoor....            01/01/70 00:00      
   why I want to multiplex            01/01/70 00:00      
      assumption?            01/01/70 00:00      
         the way multiplexing works            01/01/70 00:00      
            what is required?            01/01/70 00:00      
               Requirements are what you should analyze            01/01/70 00:00      
                  Backwards?            01/01/70 00:00      
                     low-side cap, low-side NPN            01/01/70 00:00      
                        One-bit memory == DC filter ???            01/01/70 00:00      
                           slow decay            01/01/70 00:00      
                              you can have NONE            01/01/70 00:00      
                                 are you sure?            01/01/70 00:00      
                                    yes, I am, yes I have            01/01/70 00:00      
                                 I agree with Erik ... at least somewhat            01/01/70 00:00      
                                    I am still CURIOUS            01/01/70 00:00      
                                       it's like a camera flash            01/01/70 00:00      
      already answered http://www.8052.com/forum/read.ph            01/01/70 00:00      
         Averages            01/01/70 00:00      
   does the A6278 LED driver multiplex too?            01/01/70 00:00      
      if you want to make a nonmultiplexed display...            01/01/70 00:00      
         that clears up a lot            01/01/70 00:00      
            sorry            01/01/70 00:00      

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