Help me with op-amp configuration

[wizpic]

op-amp help

Hi everybody

I need some hlep I'm palying around at the moement with a LM35 temp sensor which gives out a 10mv/°C reading so at 55°C the output would be 550mv and when it goes below 0°C the output voltage revesres so at -55°C the output would be -550mv,
I want to be able to feed this into an op-amp and start of with 2.5V which would be 0°C and the temp raises to 55°C the output from the op-amp would increase to 5V and then when the temp sensor went below 0°C the output from the op-amp would decrease from 2.5V to 0V and i want to be able to feed this into a pic to show reading's on the lcd the software side of things is not a problem really it's just how to congfigue the op-amp if it can be doen that way or would there be an alternative method, I did considor the DS1820 but not 100% sure if this will give teh correct reuslts been in the air i thought that the DS1820 was contact realted

any help or advise i would be gratefull

cheers

wizpic

 

[btbass]

op-amp help

The LM60 is a similar IC but works off a single supply rail. Could you just power the sensor off a single rail, then you wouldnt have the negative swing to worry about?

 

[wizpic]

op-amp help

the lm35 does work of a single supply but produces a - voltage for 0c and below

cheers wizpic

 

[fobyellow]

Re: op-amp help

you could use a dual-op.
one work as a scale amplifier, one work as a summing amplifier.


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