Linear amplification for kids robo project

[Wim]

For a kids robo project i need to amplify the analog signal of maxbotix range finders from 0 to 500 mV. to 0 to 9 volts as linear as possible.

I tried to hack this with a 5532 opamp, as a non inverting amplifier with two resistors but i am missing a point here as this did not work.

I tried to google this. But cannot find a suitable solution.

Please suggest

On behalf of the children many thanks.

 

[BobK]

Show us the circuit. A simple op amp circuit should work fine.

Bob

 

[Wim]

Ok here it is.

 

[BobK]

The NE5532 is designed to operate with ±15V. It's output can only go to within 2-3V of the power rails, so it will not work they way you are trying to use it.

You either need to use dual supplies, or switch to an op amp designed to operate on a single power supply with rail-to-rail inputs and outputs.

Bob

 

[Wim]

I investigated that option.
As i see this now it will never be to the standard i wish.

Decided to switch my strategy and use an external adc with built in gain (sold by adafruit)

 

[BobK]

A properly designed op amp circuit will be as accurate as the resistors you use. If you need an analog signal out, then it will be better and fare simpler than and ADC / DAC combination.

Bob

 

[AnalogKid]

Ok here it is.

OK circuit, wrong opamp. Hunt around for one with rail-to-rail inputs *and* outputs, and that can run on a single 12V supply. Also, to go from 500 mV to 9 V you need a gain of 18, not 11.

ak