Thomas Stegen wrote on 27/01/2004 :-
> I am looking for and LED meter driver which operates
> based on a 0 to 12 volt squarewave. I want the number of
> LEDs to light up to be proportional to the frequency of
> the square wave. Ideal would be 15 outputs, but need not
> be excact. I have been looking in some catalogues, but I
> have a bit of trouble deciphering all those codes and stuff.
> If anyone can help me with some of this it would be appreciated.
> (Should be available from Britain btw).
That is not a very well written specification, however....
Take a look at a frequency to voltage IC such as the 9400. On the
voltage output of that you will need an LED bargraph IC. These allow
for 8 LED's per IC and the display can be set either for single point
lit or a solid bar. These IC's can be cascaded to produce 8, 16 or 24
LED diplays in a single bargraph.
It sounds as if you are trying to build a tachometer, if so beware that
the voltage pulse at the ignition coil will require some conditioning
before being fed into the 9400.
--
Regards,
Harry (M1BYT)...
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