lm3914 bar graph

[Ti Kan]

Brendan Walsh writes:
> Chris, check the spech sheet on that chip you'll see a three pins
> called Vref, V hi and V low, iirc. THe data sheet shows how to set up
> a voltage divider for the circuitwithrespect to Vref. all you'll need
> to do is the math for the correct resistance ratio to connect Vlow to.
> If you know teh voltage you need, say closer than roughy 1 volt, ie
> take a measurement, it will make it a lot easier. Just be sure to use
> a high enough impedance(aka resistance) so as not to interfere with
> the function of the ecu. I would try to keep current draw to <1-2mA.
> remember V=(R1xVt)/(r1+r2) which i'm sure you know since you're
> fooling about with chips already. Shoot me an email if you need the
> data sheet, one of my favorite chips, has about a million uses and
> counting...

The LM3914 datasheet is here:
http://www.national.com/ds.cgi/LM/LM3914.pdf

-Ti
-- 
Ti Kan
http://www.amb.org/ti
Vorsprung durch Technik