lm3916 calculation help

[fkuk]

hi

this is my set up for my lm3916

**broken link removed**

i got the idea from here: instructables!

i have aaplied increasing voltage to the signal line until each light has lit up and the result are on the side, but what i want to know is that how do i get this result theoretically

because part of my college project work is to show some planning and not do everything by trial and error

so if there a formual that i can use which applies to the schmatic above


thanks

 

[birdman0_o]

Did you look at the datasheet?

 

[audioguru]

The datasheet has a list of input voltages like you made except its max voltage is 10V instead of 1.25V like you have.

The datasheet tells you how the IC works and even has a schematic with resistor values for its resistor ladder for the comparators.

Simply use Ohm's law (didn't you learn it?) with 1.25V at the top of the resistors and calculate the voltages that would feed the comparators.

 

[fkuk]

i have learnt ohms law its that we havent done anything from scratch from datasheets
most of the time its here is a circuit and then we do a assignment based around it.
and for me its the first time ive ever done a project so its the first time ive actually looked at a datasheet

 

[audioguru]

Do you understand anything about what I posted?

Datasheets tell you everything about an IC and how to use it.