[sdiy] WG: Voltage-limiting a comparator output.

[David G Dixon]

> Seems like opamp + series resistor + zener, or LM339 outputs 
> pulled up to +5V are the best solutions.
> The latter option has lowest parts count (I would need two 
> LM2339s for the 8 channels needed), and the LM is cheap and 
> widely available like the parts in the first option.

I think, if you're careful with your resistor values, you could probably use
a single 78L05 for your +5V source.  Those will source 100mA, which should
be plenty for 8 pullup comparators.