>Hello,
>        I'm in the middle of designing a device that is going down into the
>deep, dark ocean. It's just a little quadrature encoder that is going
>on the end of a robotic arm to measure the revolutions of a torque
>tool. The problem I foresee is driving the LED's to really make them
>shine. Is there a device like the ULN2803 that I could use to drive
>the LED's to something higher than 25ma ?? The LED's are rated for
>30ma and I figure I can pulse them at something higher i.e. 50 to
>60ma. Of course I could do it with transistors but an IC would be
>more sanitary. I've been to all the local electronics shops looking
>for the 2803 or something like it. I've pulsed some IR LED's to 2 A
>with no adverse effects therefore I assume you can drive regular RED
>LED's at something higher than rated current. Any ideas ?? All help
>is appreciated.
>
>        Thanks in advance !!
>                                James Holbrook

Given the previous advice by others, if your still set on using an ic to
dirve these led's, have a look at the ULN2000 darlington arrays. Ive used
these ic for a number of led driving jobs lately, including 5inch high 7
segment displays. Some applications were at collector currents of up to
200ma strobing across 7 channels. Mind you we did stick a heat sink on the
top of it.

BTW, as a scuba diver, just how deep will this machine be going?

Philip Martin.
AOW