PlaneCrazy
Member
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?
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?
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