Email: Password: Remember Me | Create Account (Free)

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
???
02/19/07 15:26
Modified:
  02/19/07 15:27
Read: times


 		 #133250 - LEDs are extremely nonlinear, too!
Responding to: ???'s previous message
Chris said:
This is not true as far as the perception of the human eye, since the eye's response to PWM is extremely non-linear.

As is the brightness of LEDs at high currents, too! Unless you have LEDs with an extreme current headroom you drive them into saturation when mulitplexing and nothing is really gained...

The only sense of using multiplexing, if at all, is the save of number of chips. There's no other advantage, but only disadvantages!

Kai

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      

Back to Subject List