Hi All.
After searching through the forums i can see this is a common problem - but i cant seem to work out what i need to buy to resolve my issue. I have a Velleman USB 8005 board which has an onboard ADC (8 bit) which takes 0-5v
Ive interfaced an LM35, but due to the low outputs i cant get the results i need ( im measuring temps circa 40-60 degrees celsuis ) - im only getting circa .4 to .8 volts for my temps so im unable to get any meaningful results from the ADC.
I see that i can use a 2 resitors across + and ground and take a reference of 2.5v which may increase the output scale by 2.
I also see that i can use an Op-Amp and scale the output from the LM35 by a factor of 5 which would give me the resolution required by both my application and the ADC.
My (rather long winded) question is - what op-amp and components would i need to buy to fabricate a 0-5v op-amp.
The LM35 and the ADC are all being fed from a 5v supply.
as you can tell, very new to all of this and still trying to get good electronics selection purchased to avoid the frequent trips to maplins.
thanks
David
After searching through the forums i can see this is a common problem - but i cant seem to work out what i need to buy to resolve my issue. I have a Velleman USB 8005 board which has an onboard ADC (8 bit) which takes 0-5v
Ive interfaced an LM35, but due to the low outputs i cant get the results i need ( im measuring temps circa 40-60 degrees celsuis ) - im only getting circa .4 to .8 volts for my temps so im unable to get any meaningful results from the ADC.
I see that i can use a 2 resitors across + and ground and take a reference of 2.5v which may increase the output scale by 2.
I also see that i can use an Op-Amp and scale the output from the LM35 by a factor of 5 which would give me the resolution required by both my application and the ADC.
My (rather long winded) question is - what op-amp and components would i need to buy to fabricate a 0-5v op-amp.
The LM35 and the ADC are all being fed from a 5v supply.
as you can tell, very new to all of this and still trying to get good electronics selection purchased to avoid the frequent trips to maplins.
thanks
David