At 11:01 AM +1300 1/28/03, Jinx wrote:
>Just thinking.........
>
>If you're using just single LEDs then a 1A Darlington driver
>may be a little over the top. A logic buffer would do you just
>as well, eg 4050 or 7407 o-c output if you wanted to use any
>unregulated voltage available
>
>http://www.cedmagic.com/tech-info/data/7407.pdf
>
>Also, check out the power specs for the PIC. If you use high-
>efficiency LEDs it would be possible to make something
>absolutely blinding (like some bastard did to me the other
>day with super-super-bright greens - they hurt) which is well
>within the PIC's current capabilities

Thanks for this and the other responses.  I don't know why I didn't
think of just using a logic buffer...makes a lot of sense I think.

I'll have to do some napkin calculations and measure the current
involved, but a quick experiment yielded LEDs that visually didn't
look as bright when driven by the hardware PWM as when I just power
them up with 5V and a resistor.

Back to the breadboard!

Phil

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads