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???
11/12/09 02:34
Modified:
  11/12/09 02:37
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 		 #170713 - Not only...
Responding to: ???'s previous message
Per said:
If you have 30mA for each active character, then the total cost may be less to use four LED at 7.5mA then a single LED at 30mA just because you get less area to cover for each LED, making the light more uniform without spending time on lenses, screening etc.

I doubt this. It could also result in an undesired partial overlap of the four light cones. It would make sense, though, if an increase in intensity would be needed, and one LED alone couldn't provide this.

Per said:
The design requires a wide border outside the characters, just as you have a passepartout around a framed photo, or some of the great paintings have very wide frames.

Chacun à son goût...

Per said:
The LEDs are most probably mounted on a PCB. The processor, crystal etc can be mounted either on the same side, but in the border outside all characters. Or on the other side of the PCB.

There are optical lense modules on the market, which have to be mounted over the LED, which drastically help to diffuse the light and to make it homogenous. These modules are rather extensive and thick. If such an arrangement is used, there wouldn't be much room for electronics right where the LEDs are. So, I think the electronics is sitting at the border.

Kai Klaas



List of 126 messages in thread
TopicAuthorDate
Student project idea?            01/01/70 00:00      
   Being German in Nature...            01/01/70 00:00      
   rather costly for a student project, isn't it?            01/01/70 00:00      
      not necessarily            01/01/70 00:00      
         Dont you think that would be too difficult for a student?            01/01/70 00:00      
            Why moving-message?            01/01/70 00:00      
               How can he display all the text?            01/01/70 00:00      
                  Then you've entirely missed the point!            01/01/70 00:00      
                     BTW: It actually does 1 minute resolution            01/01/70 00:00      
            Moving ????            01/01/70 00:00      
               Maybe you could be more specific            01/01/70 00:00      
                  Why so specific?            01/01/70 00:00      
                     but entirely too expensive ...            01/01/70 00:00      
                        who gives a friggin hoot            01/01/70 00:00      
                           and how does your 8x8 array apply?            01/01/70 00:00      
                        Up to student to decide cost.            01/01/70 00:00      
                           Other options            01/01/70 00:00      
                              Interesting ... how does the student do that?            01/01/70 00:00      
                                 I'm sure they'd figure that out...            01/01/70 00:00      
                                    Maybe you can enlighten me            01/01/70 00:00      
                                       Mechanical Engineering            01/01/70 00:00      
                                          Yes, that's the kind of thing.            01/01/70 00:00      
                                             I once had a complete machine shop too ...            01/01/70 00:00      
                                                what sort of engravers/routers do you mean? [edited]            01/01/70 00:00      
                                                   We keep forgetting about the costs            01/01/70 00:00      
                                                      Old news            01/01/70 00:00      
                                                         Apparently things have changed.            01/01/70 00:00      
                                                         eMachineShop.com ?            01/01/70 00:00      
                                                            Maybe            01/01/70 00:00      
                                                               Another option ...            01/01/70 00:00      
                                          Darn straight.            01/01/70 00:00      
                           look at the model again ... there is no matrix            01/01/70 00:00      
                              of course there is            01/01/70 00:00      
                                 but it's not the 8x8 LED matrix ...            01/01/70 00:00      
                                    One LED per character            01/01/70 00:00      
                                       If not cheaper than at least way faster            01/01/70 00:00      
                                       Gee ... I'm not sure I follow ...            01/01/70 00:00      
                                          Simple, simple, simple            01/01/70 00:00      
                                             Why multiplex ... there are so few words ...            01/01/70 00:00      
                                                Really is applicable            01/01/70 00:00      
                                                   Wait a minute ...            01/01/70 00:00      
                                                      I never did            01/01/70 00:00      
                                                         well, then, you should clarify            01/01/70 00:00      
                                                            proof of concept, not product            01/01/70 00:00      
                                                               Backpedalling on what?            01/01/70 00:00      
                                                                  Tiny budget for tiny clock            01/01/70 00:00      
                                                                     Now go to the next step ... the word arrangement            01/01/70 00:00      
                                                                        I did my best            01/01/70 00:00      
                                                                           I caught that only after I asked            01/01/70 00:00      
                                                                              Many, but quite simple steps            01/01/70 00:00      
                                                                              At last!            01/01/70 00:00      
                                                                                 I wasn't asking you , Andy ...            01/01/70 00:00      
                                                                                 I believe you overestimate the challenge, Andy            01/01/70 00:00      
                                                                                    Not a first-year project            01/01/70 00:00      
                                                                                       I'm not so sure ... maybe I'm out of touch ...            01/01/70 00:00      
                                                                                    RE: I believe you overestimate the challenge            01/01/70 00:00      
                                                                                       You'd be right ... except ...            01/01/70 00:00      
                                                                                          Trivial?            01/01/70 00:00      
                                                                                             Those may not be as important as you think            01/01/70 00:00      
                                                                                                Zero-crossing detection isn't suited...            01/01/70 00:00      
                                                                                                   Complexity quickly grows with scale            01/01/70 00:00      
                                                                                          Frequency reference            01/01/70 00:00      
                                                                        SIGH            01/01/70 00:00      
                                                                           have you counted lines and characters            01/01/70 00:00      
                                                                  Not spinning-arm display printing in air...            01/01/70 00:00      
                                                                     are you missing a critical word?            01/01/70 00:00      
                                                                        The word you require is...            01/01/70 00:00      
                                                                           Oh! OK ... that works.            01/01/70 00:00      
                                                                  signs for dummies            01/01/70 00:00      
                                                                     Better selected dioder at custom locations for production            01/01/70 00:00      
                                                      See each character as a bit in a small 11x10 bitmap            01/01/70 00:00      
                                                         This is where you should explain a bit more            01/01/70 00:00      
                                                            overly complex            01/01/70 00:00      
                                                               I don't see it as overly complex.            01/01/70 00:00      
                                                                  "MUCH" is relative            01/01/70 00:00      
                                                                     if you squint just right ...            01/01/70 00:00      
                                                            I don't see how multiple LED's per character help anything.            01/01/70 00:00      
                                                               That seems reasonable            01/01/70 00:00      
                                                      options            01/01/70 00:00      
                           That might work, but it would cost            01/01/70 00:00      
                              Cold optical process keeps plastic flat            01/01/70 00:00      
                                 That looks like the most straightforward way to do it!            01/01/70 00:00      
                              If you think that's a lot of LEDs, ...            01/01/70 00:00      
                                 just for fun            01/01/70 00:00      
                              once again, who gives a hoot            01/01/70 00:00      
                                 Shouldn't a "proof of concept" demonstrate feasibility?            01/01/70 00:00      
                                    What nonsense!            01/01/70 00:00      
                                       Good project - relatively easy but much room for own ideas            01/01/70 00:00      
                                          what the hell is REAL company???            01/01/70 00:00      
                                             A real company            01/01/70 00:00      
                                             Not at all!            01/01/70 00:00      
                                 No matter how well it works ...            01/01/70 00:00      
                                    That would be a very bad professor            01/01/70 00:00      
                                       Unfortunately, you're wrong ...            01/01/70 00:00      
                                    What nonsense!            01/01/70 00:00      
                                    Look at some real examples - "Made In Brunel"            01/01/70 00:00      
                                       These items most certainly are well-finished            01/01/70 00:00      
                                          Exactly            01/01/70 00:00      
                     Not all the characters are used            01/01/70 00:00      
                        8x8 modules don't care about unused characters            01/01/70 00:00      
                           other arrays are cheaper            01/01/70 00:00      
                              Depends on expectations of total size            01/01/70 00:00      
                                 that seems very nearly feasible ... and almost affordable            01/01/70 00:00      
   original site            01/01/70 00:00      
      Two languages not full            01/01/70 00:00      
         It works for me...            01/01/70 00:00      
            Filler characters            01/01/70 00:00      
   I was going to buy this guy....            01/01/70 00:00      
      Very expensive!            01/01/70 00:00      
         Yes, designer niches allows very high prices            01/01/70 00:00      
      Do you really think that manufacturing costs are low?            01/01/70 00:00      
         That's why I was complaining about cost!            01/01/70 00:00      
            You forget the costs...            01/01/70 00:00      
               Not exactly ...            01/01/70 00:00      
                  Mass market or unique low-volume status product            01/01/70 00:00      
                     I think a backlit LCD would work.            01/01/70 00:00      
                     Assumptions...            01/01/70 00:00      
                        Border needed for the look            01/01/70 00:00      
                           Not only...            01/01/70 00:00      
                              Cost of lenses including mounting?            01/01/70 00:00      
                                 about those costs ...            01/01/70 00:00      
                                 Individual taste...            01/01/70 00:00      
                                    And one implementation            01/01/70 00:00      
                                       illuminating...            01/01/70 00:00      
                                       Man, look at how the light spills over            01/01/70 00:00      
   Or something more traditional, perhaps...?            01/01/70 00:00      

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