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Topic: operational amplifier & offset (Read 710 times) previous topic - next topic

hi!

i'm trying to read an optical sensor (linear ccd-sensor in a scanner-circuit) to get rgb-values into processing.
the sensor-output range for each channel is between 5,87V (white) and 6,05V (full color).
i figured that i need to amplify the signal to be able to measure it via arduino analog-in.
but at last i have to offset the signal to 0-5V i guess, and i have no clue how to do that.

with all this googled knowledge i got myself this chip: LM 741CN

here's the datasheet: http://www.futurlec.com/Linear/LM741CN.shtml

there's something written about offset but i have no idea if that's what i'm looking for.

how do people know which parts to buy when they the have problem  like: transfering 5,87-6,05V into 0-5V ??? if someone knows, i wanna learn!!! guess, i'll have to face that more often when continuing arduino...

thanks a lot in advance,

jonathan

brainfart

I'm sure there is an easier way, but maybe you can subtract 5V from your signal and amplify the resulting signal?

http://en.wikipedia.org/wiki/Operational_amplifier_applications#Differential_amplifier


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