Graynomad:
Me to as I've been using logic levels rather than just looking at the state of the transistors, ie on of off.So your last circuit will work I think, even without the pull up resistors. As long as the OK1 transistor is driven hard enough to drive a LED.
Rob
Yeah, it got my head all turned around - but it's looking pretty clear now. I think you're on to something with the transistor's ability to handle that much power - the maximum dissipation is 150mW, and at 1.1v/20mA that's 176mW for 8 LEDs. I'd run them lower, but experience has proven problems with the triggered devices when I run the NTE3086's this low! (Too much voltage drop for some of them, the best performance from the left-hand side with a wide range of triggered devices has been running @ 30mA.)
So, now the only trick is to get enough power flowing through there... Much easier problem, I think =)
!c
EDIT: N/M the above - fully within power spec- recalling there are two transistors input, that means 4x LED per transistor, or 132mW @ 1.1V/30mA.