Hello,
I have a pressure sensor (PX137-100DV) which I would like to read using Arduino.
With input voltage of 12V, output voltage is 0-100mV in FS.
This would require amplification gain of 50 to be in range 0-5V.

I will very much appreciate if someone posts an amplification circuit.

Thanks.

Z

 

Have you searched for DC voltage amplifier schematics, or read any opamp application notes, or, well, anything?

ak

 

Hi Zeus. Take a look at this page.

http://www.electronics-tutorials.ws/opamp/opamp_3.html

 

Yes, I was looking at this post, where MrChips posted a circuit, but I think circuit I need is little different than this one.
Now I am trying to figure out the changes.

@johndeaton thanks for the link!

 

For that low signal voltage you will want to use an op amp with a low input offset voltage (Vos<1mV).

What supply voltages do you have available?

 

@crutschow yes, I guess LM358 is answer.
Supply voltage to sensor should be 12V.

 

Now I have two OpAmps with me:
UA741CP
LM301AN.

Can someone help me build the circuit?

Thanks.

 

What power supply voltages are available for the opamp circuit?
Both the LM358 and uA741 have relatively high input offset voltage error. The LM301 is a little better, but still not by much. Where are you located?

ak

 

@AnalogKid Supply voltage to sensor is 12V.
In FS, sensor Vout will be 100mV.

 

Those op amps have offsets of several mV so the offset error will be several percent of the full-scale signal.
You need to look for lower offset op amps.
The also need to be rail-to-rail types if you want to operate from a single 12V supply.
If you tell us where you would buy parts, we can help with that.

 

@crutschow I can order online from any website..

 

@crutschow or maybe you guys suggest the best and easy option if rail-to-rail is not ideal.

 

@AnalogKid Supply voltage to sensor is 12V.
In FS, sensor Vout will be 100mV.

That is not what Wally or I am asking. What power supply voltages are available for the interface circuit? IOW, is anything other than +12 V available?

ak

 

@AnalogKid 5V, 3.3V from Arduino.
I can also arrange 9V.

 

One of these should work for you.
Post the one you select and we'll check to make sure it will work in your application.

 

@crutschow Thanks.
I can buy OPA2191ID. This one is on the list.
How do I wire it?

 

One of the most common and a very popular amplifiers for what you wish to do is the INA12x Precision, Low Power Instrumentation Amplifiers. The INA 128 would fit your needs and only requires a single external resistor to set the gain. While not the lowest priced it comes in an eight pin dip and is easy to use. They run about $10 USD.

<EDIT> Sorry, I see you got a solution while I was slow crawl typing. </EDIT>

Ron

 

@Reloadron Thanks.
Using this figure and INA128, Rg = 1Kohm.
How exactly do I wire my sensor with this opamp?



ps. I can try multiple solutions.

 

One of the most common and a very popular amplifiers for what you wish to do is the INA12x Precision, Low Power Instrumentation Amplifiers. The INA 128 would fit your needs and only requires a single external resistor to set the gain. While not the lowest priced it comes in an eight pin dip and is easy to use. They run about $10 USD.

That's not a single-supply device.

 

@crutschow Thanks.
I can buy OPA2191ID. This one is on the list.
How do I wire it?

That's a low offset, rail-rail device which should work for you.

Below is the connection for a gain of +50.