> Date:    Sun, 10 Nov 1996 16:35:27 -600
> From:    Zhahai Stewart <zhahai@HISYS.COM>
> Subject: LED matrix multiplexing
>
> I am considering building a small LED matrix sign, probably
> using 12 stackable 8x8 LED matrix blocks (approx 2"x2").  This
> would produce a display surface of 8 rows each 96 wide - enough
> for 16 chars of 5x8 with one space between.  (One use would be
> a Caller ID I could read at night with my glasses off :-)
>
[part of message supressed]
>
> Questions:
>
> Is 1/8 duty cycle enough?
>
> That would mean an average of 2.5 ma current for each lit
> LED, which seems rather small; would I need higher current?
> (50 ma/LED means 5 amp drivers!).
>
> Is there a prefered direction for scanning, like top row to
> bottom row (vs side to side within each 8x8 block)?
>
> Other suggestions?
>    Thanks, Zhahai
>
>
> @ Zhahai Stewart       zhahai@hisys.com
> @ A Meme Gardener      http://rainbow.rmii.com/~hisys/zhahai.html
> @ Standard Disclaimer  YMMV - Your Maya May Vary
>
Hi Stewart:
                 I suggest that you use the MAX7129  DIP24 (from MAXIM). This is
 a
SERIALLY INTERFACED, 8-DIGIT LED DISPLAY DRIVER and you can get a free sample
from WWW.MAXIM-IC.COM or PHONE 1-800-998-8800.
                Do you have any information about CALL ID system that you
mention ? I'm interested in this class of information, and other user on the
list too. (Have you Technical Specifications about CALL-ID?
                Bye, Hugo




-------------------------------
Hugo J. Muller
E-mail:    hjmuller@satlink.com
Parana - Entre Rios - Argentina
-------------------------------