Pressure transducer circuit

[rkovach12]

I have a pressure transducer that has an output of .1 volt at 0 psi and 5 volts at 250 psi. I want to read the output with a voltmeter with out using a conversion chart. Example; 0.1 volts output = 0 volts at meter and 5 volts output = 2.50 volts at meter. How can this be done with a simple circuit?

 

[sudan]

Hi,

You can solve your problem very easily with the help of simple micro controller with a LCD display.

Regards

Sudan

 

[rkovach12]

I do not want a dedicated display for this sensor. I will also connect this sensor to an oscilloscope at times, so I would rather have a circuit that would change the output to psi = millivolts that can be read easily on a voltmeter.

 

[IanP]

It can be done with opamps ..
Have a look:
Scale and Shifting Op-amp voltages


Rgds,
IanP

 

[rkovach12]

I think I have figured out a working circuit. My next problem is I want to use two 9 volt batteries for this project. The transducer needs 12 to 30 volts and the opamp needs -9 and +9 volts. How can I get the power needed from the two batteries?

 

[vfone]

I don't know what DC current needs your pressure sensor, but from the +9V battery you can use a small DC-DC upconverter to get a voltage in a range 12-30V.

 

[sudan]

HI,

Connect both the batteries in series , So you can get 18V . This is enough for your transducer. Then for OPAMP take the output across any one battery. For these your battery withstand the current rating. lease verify he current ratting of your battery........

Bye

Sudan

 

[vfone]

No way, in series? But the voltage from the transducer is referred to the ground which is between batteries.

 

[sudan]

Hi,

If we are connecting two batteries one end acts as + and the other acct as -. Ok ?. So you can shift your ground at the end (ie: now you connected at the middle of two batteries). I think it will work out. Please try.....


Sudan