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Core Electronics Forum

Load cell balance with 12v motor and wheatstone bridge

#1

I want to couple 2 load cells about 8m apart.I want to set up one load cell to which I can apply, and vary, a load. I want to set up a 12v/10a motor and mechanical linkage to apply or reduce the load (run in forward and reverse) on the second load cell to achieve balance using the wheatstone bridge principle.
I have 4 50kg load cells, load cell amp, load combinator, Redboard, relays etc. The arduino requirement has lost me. Can anyone help with a simplistic solution?
Bruce Atkinson

#2

Hi Bruce!

I’m not entirely clear on what you are trying to accomplish, could you please draw up a simple sketch to help me get my head around it?

#3

Hello Stephen

Thanks for contacting me.

I have wired up the load cells, amplifier, combinator redboard. The two ‘spare’ load cells have screw loading arrangements as ‘trimmers’. I am unable to decifer what to do with my computer and redboard. Is there a relatively simple way I can get an output (

resistive?)to drive the motor. I have set up the system with ‘pots’ and it works ok, but my load sensing does not have sufficient movement , so I need to use load cells. I have not connected my computer to the redboard. I saw a suggestion I could wreck the board with the wrong o.s. ( I have windows 10).

Any advice on what to do or where to go is much appreciated.

Wiring schematic attached.

Cheers Bruce

IMG_2607.jpg2448×3264 1.09 MB

#4

Hi Bruce,

There is no danger of messing up your Redboard from connecting it to a computer. You will need to connect it to a computer to program it.

I recommend you check out our Arduino Workshop for Beginners, it has all the basics you need to get started using your Redboard for projects:

You can find some information on controlling a motor with Arduino(redboard) here:

#5

Hello again Stephen
I have failed to get a sensible resolution to my problem. I have been able to install a code into the redboard, but not one that does what I need. Writing my own code is beyond me. Can you please provide me with an appropriate code for the system, ie 4 load cells wired as wheatstone bridge thru combinator then to amplifier and to redboard. I want to be able to detect a variation in one load cell due to an applied force, then apply a force to a second load cell that achieves balance electrically via the wheatstone bridge principal. I need a code for the redboard that provides me with a workable dc (5v?) output on pins to operate the mechanical loading operation to achieve the electrical balance.
Cheers
Bruce Atkinson

#6

Hi Bruce,

Unfortunately I can’t write the code for you. If you break your problem down into parts I’m happy to help with any specific questions or take a look at any code that you’ve written and give feedback!