-----Original Message-----
From: Omar Martinez <OMARTINEZ@HARTFORD.COM.AR>
To: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
Date: den 23 februari 2000 17:16
Subject: How to drive big led displays


>Gentlemen:
>
>I'm making a device that show the time and temperature with a 16F84 and it
>work fine with led display of 1" in size, so when I try to use led displays
>of 4" size, the segments don't
>turn on...
>In the led display spec's, I saw the connection diagram and it's made with
5
>leds connected in serial mode for each segment (common cathode), except for
>the decimal point that have only one.
>All the device is powered with standard +5 Volt regulator, the segments are
>driving directly from PortB thru limiting resistors and each display is
turn
>on every 3 mSec. via transistor from portA.
>
>Can anyone please help me with this problem?? I will appreciate it!!!
>
>Thanks & excuse for my english....
>
>Omar


I suggesting You to use an UDN 2982/84A between the PIC
and that big LED display and connect power of 12V on it.

Regards
keN