AVR-Chat

Yes, I think you missed something.  LOL

There is NO problem with the current design.  Works perfect.  If I
plugged the LED's into the AVR directly there would be NO problem.  

What I was saying, was when I was designing the "dimmer" circuit
(shown previously with the 7 transistors), that I couldn't use 1
transistor to dim the 7 LED's without the number of LED's illuminated
effecting the overall brightness.


--- In AVR-Chat@yahoogroups.com, Peter Jakacki <peterjak@...> wrote:
>
> tymebrit wrote:
> <snip>
> > The problem is
> > when more segments come on they share the same output current.
> <snip>
> > As I understand it, the problem with having 2 LEDs sharing
> > the voltage is eliminated because only one LED segment is on at a
> > time, correct?
> 
> Am I missing something here? I seem to be a bit confused, you are
saying 
> that it is a problem when more than one segment comes on. What is the 
> problem with two or more segments coming on? The circuit should be able 
> to have all the segments on without the brightness being affected, 
> unless of course you are running off a very low current power supply.
> 
> Please include as complete a description of your circuit and 
> power-supply etc as possible.
> 
> BTW, the shift register can have all 8 outputs on at a time driving the 
> leds but the brightness control comes from controlling the led common 
> whereas you have tied your led common directly to +5V and tried to 
> control each individual line.
> 
> 
> *Peter*
>