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???
02/07/09 23:56
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 		 #162176 - proper current to LEDs.
Responding to: ???'s previous message
Aamir Javaid said:
In a design i saw...

You saw it, but did you take time to understand it?

Why can't you just use that design?

using BDX54C, ULN2803 with some resistors (15ohm and 2.2k ohm and with a shift register HEF4094C for shifting) for providing proper current to LEDs.

It might have provided the proper current for the particular LEDs that they used, and under the particular conditions that they operated - but that doesn't mean that you can just arbitrarily copy those values into any other "design"

Have you verified your particular LED's current requirements and capabilities against its Datasheet?

List of 64 messages in thread
TopicAuthorDate
Help Needed:8051 and BDX54C            01/01/70 00:00      
   Draw it!            01/01/70 00:00      
      How to post a schematic            01/01/70 00:00      
   Reply to Aamir            01/01/70 00:00      
      SPDT switch?            01/01/70 00:00      
   the schematic            01/01/70 00:00      
      ground that emitter            01/01/70 00:00      
      PNP versus NPN            01/01/70 00:00      
         Basic electronics            01/01/70 00:00      
      See if this helps...            01/01/70 00:00      
         the circuit to the left is always on            01/01/70 00:00      
            woops...            01/01/70 00:00      
               so then            01/01/70 00:00      
                  you have options...            01/01/70 00:00      
                  no answer till ...            01/01/70 00:00      
            burning a hole...            01/01/70 00:00      
               Be cool!            01/01/70 00:00      
                  gimme, gimme            01/01/70 00:00      
                  proper current to LEDs.            01/01/70 00:00      
   The only way to use the BDX54C...            01/01/70 00:00      
      LED current - sweeping generalisation            01/01/70 00:00      
      Please explain            01/01/70 00:00      
         Just imagine how this high LED current...            01/01/70 00:00      
            Hence the reason...            01/01/70 00:00      
               I do not think so            01/01/70 00:00      
                  His "please explain" thread proves...            01/01/70 00:00      
                     cant u?            01/01/70 00:00      
                        You need to provide            01/01/70 00:00      
                        Do you mean this?            01/01/70 00:00      
                           Thanks Sir KAi            01/01/70 00:00      
                              10K SPI            01/01/70 00:00      
                                 Meaning of "SIP"            01/01/70 00:00      
                                    A 10K SIP Indeed !!!            01/01/70 00:00      
                                       How it works??            01/01/70 00:00      
                                          Short for what            01/01/70 00:00      
                                          Look again - and think!            01/01/70 00:00      
                                       so, what he has used?            01/01/70 00:00      
                                          Why more schematics?            01/01/70 00:00      
                                             But            01/01/70 00:00      
                                                10k SIP do not connect anything. They add something!            01/01/70 00:00      
                                                   what for 8051            01/01/70 00:00      
                                                      do you EVER bother to read the docs before asking questions            01/01/70 00:00      
                                                         Back to basics            01/01/70 00:00      
                                                      Yes, you will            01/01/70 00:00      
                                                RE: how those eight data lines are connected ?            01/01/70 00:00      
                                             But            01/01/70 00:00      
                                                as seen on the schematic            01/01/70 00:00      
                                             Not all SIL resistor packs are the same!            01/01/70 00:00      
                                                Yes, more than one type of SIL network            01/01/70 00:00      
                              looks exactly like what I would suggest            01/01/70 00:00      
                              Both, but take care...            01/01/70 00:00      
                                 what you think about this?            01/01/70 00:00      
                                    Post link            01/01/70 00:00      
                                       No no            01/01/70 00:00      
                                          Doesn't add up            01/01/70 00:00      
                                    Depends...            01/01/70 00:00      
                              it wont worked....            01/01/70 00:00      
                                 Still Doesn't add up!            01/01/70 00:00      
                                 Then you have done something wrong!            01/01/70 00:00      
                                    experimenting "wildly" ....            01/01/70 00:00      
                                       Basic electronics            01/01/70 00:00      
                                    You are right...            01/01/70 00:00      
                  Actually            01/01/70 00:00      
      Please explain            01/01/70 00:00      

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