So much trouble, so little time...

[PlaneCrazy]

Sorry, that's what pressure does...

OK, so here is conlusive proof that the 10 left-most LEDs light up as I vary the input from 0-6V. As far I remember, I still need to connect a resistor to Pin 7 and Pin 8 on LM 2.

From your simulator I get 3.5kΩ for each LM. So, I'll have to go get 3.5kΩ resistors.

But I still don't understand how LM 2 is going to get a 3-6V portion of the 0-6V signal. And the pot at Pin 4, what is its purpose?

I am trying, and I am learning.

EDIT:

You're right, ericgibbs, I am that dumb...

Ref Out V for LM 1 can serve as Ref Hi to LM 1 and Ref Lo to lm2, can't it?

So, if I understand correctly, for LM1, Ref Out ≈ 2.5V means (R1/R2) ≈1, and Ref Out ≈ 5.0V for LM2, (R1/R2)≈3.

And the order of magnitude for R1 (and therefore R2) is determined by I_LED, so that LM doesn't exceed 1365mW? Or is it irrelevant, since 10kΩ is a pretty big R for a 12V system?

 

[PlaneCrazy]

Moderators may close this thread if they see fit.

 

[ericgibbs]

Moderators may close this thread if they see fit.

Hi,
I have drawn this circuit for your project.
Check your layout against the circuit.

If you have only 10K pots, they can be used in place of the 2Kpots, but they will give a coarse adjustment.

I cannot see any reason why the Mods would consider closing this read.

EDIT:
Thanks for the PM, letting me know its now working.

 

[tvtech]

Eric you are a patient Genius. Hat's off to you. Your Moderator status is richly deserved.

Cheers