Tristated output to two common Base transistor issue

[Darrel Taylor]

20 LED's,... 20 Transistors, 20 Resistors. Start adding diodes, half-watt resistors.... Yuck!

I think I'd just go with 3 of these

<table><tr><td><a href="http://www.allegromicro.com/en/Products/Part_Numbers/6277/6277.pdf"><img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=1974&stc=1&d=118911366 1"></a></td><td>

Don't even need resistors on each LED.

Up to 24V for LED drive.

Set it for 50ma constant current.
Shiftout the LED states

And that's it.
</td></tr></table>

http://www.allegromicro.com/en/Produ.../6277/6277.pdf
About $1.50 each in single quantities.
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