wheatstone bridge

[MWTK]

i am new to LABVIEW.

i wish to create a wheatstone bridge. may i know how am i going to start ?

Should i create resistor, source, ... for the circuit.. or in labview there's already have the wheatstone bridge tool? or ???

please guide.

thanks.

[Rupali]

Hello... 🙂

Can you please tell me that you are going to simulate the Wheatstone bridge in software only or you preparing some hardware also..? If yes please tell which hardware...?

So that it will be easy to answer.. 🙂

[yenknip]

Do you mean you are trying to simulate a wheatstone bridge? LabVIEW is a programming language, not electronics simulating software.

[MWTK]

Hi, Thanks for the inputs. first of all, let me ask a few question first... 1. labview = labview VI code? 2. I just wan to "build" a wheatstone bridge using labview VI and do some simple simulation (e.g. change the value of one of the resistor) to see the changes of its output on a multimeter. Thanks.

[MWTK]

Hi...

someone please help me ...please.

[gnunesjr]

Labview is not the tool for this!! 

But if you insist:

    Put four numerical controls on your front panel.  These are your four resistors.  Add another numerical control to be your excitation.  Wire these five items together using the addition, subtraction, multiplication, and division operators from the Numeric palette and connect this result to an indicator which serves as your lock-in (or multimeter, if you are thinking that crudely).  Surround the whole thing by a while loop with a 100 msec delay, and you have your simulator. 

If you want to get fancy, you can use knob style controls for the numerical inputs, and a meter indicator for your output.

 (Although Ed is completely correct about LabVIEW not being a simulation tool, I have to confess to using it as such on multiple occasions.  The results can sometimes be rather nice...)

-GN 

[MWTK]

Hi,

thanks for inputs.

let take an example for question at http://www.ni.com/pdf/academic/us/me104_lab3_2003.pdf

referring to the figure 1,

1. is it the correct way to use labview Vi to simulate the whole diagram?

2. If yes, do i need to build the sensor circuit (as i call it as wheatstone bridge) using labview VI?

I am learning.. someone please guide me. thanks.

[yenknip]

 

The part of the sensor that communicates with the PC is the DAQ card in the top right box. You would build the circuit, and use the DAQ card to read the change in signal. I would create a potential divider with another resistor and read the change in voltage as the signal

The datasheet of the strain gauge will detail how the resistance relates to pascals. By using a fixed resistor in the potential divider, you can derive the change in resistance, and thus the strain.

Message Edited by yenknip on 09-25-2008 01:39 PM

[MWTK]

so wat the labview Vi can be used in this case?

I thought labview Vi is a simulation tools that can help us to design the circuit first before we decide to buy the real hardware. Is tat true?

Sorry for a lot of dummy questions.

[gnunesjr]

>I thought labview Vi is a simulation tools that can help us to design the circuit first before we decide to buy the real hardware. Is tat true?

Generally speaking, no.  LabVIEW is really designed to acquire data from the PC DAQ board in your figure.  It can do lots of other stuff, of course, but if you are not doing data acquisition of some kind, or machine control, then there are probably other ways to simulate a bridge that would be more effective.  For example, I would recommend SPICE.

But really, a Wheatstone is so simple, why simulate it?  Just work out the math.  Then you can see how the size of the signal depends on the choice of resistor values, the excitation level, etc.

-GN