Transistor Selection for Switching Relay Coil-with a little bit of info on my "ARSC"

[RussMartin]

BTW-the Texas Instruments datasheets I have for the ULN2004 and the ULN2803 don't list the thermal curves for either. I've been meaning to find another manufacturer's datasheet that lists them, but I haven't gotten around to it just yet.

You might start with Figures 14 and 15 on page 10 of this:

http://focus.ti.com/lit/ds/symlink/uln2003a.pdf

And Figures 11 and 12 on page 5 of this:

http://www.st.com/stonline/products/...re/ds/1536.pdf