Can you suggest another one?

I mean add another device to the simulation using the same op-amp.

 

I mean add another device to the simulation using the same op-amp.

Which device? Sorry I couldn't understand what you mean

 

In your original drawing you have device U5A and U5B.
Why not make U5B into U7A for example?

 

In your original drawing you have device U5A and U5B.
Why not make U5B into U7A for example?

I got it. I cannot, this is the way multisim program works, I cannot make U5B into U7A or U5B into U5A, etc.

 

hi MMM
Look at this option.
E

@MMM**MMM
If you need to set the Gain precisely, I use a 27R fixed resistor in series with a, 100R, 20 turn Cermet trim pot for Rg.
Remember the Load Cell is 1.2mV.V +/_0.1mV, so Rg may need to be adjustable.


View attachment 282608

Here is my simulation of your circuit, it gives an error. Also, the voltmeter PR1 shows a voltage of -24 (which is higher than the input supply). Could you please check my schematic?

 

hi MMM,
Try this Grounding, let's know how it goes.
I know that the inputs are both grounded but it should show if the problems lies eleswhere.

E

 

hi MMM,
Try this Grounding, let's know how it goes.
I know that the inputs are both grounded but it should show if the problems lies eleswhere.

E
View attachment 282674

I will try, but I think this will be considered as a short circuit because the upper and lower voltages are 0.

 

I will try, but I think this will be considered as a short circuit because the upper and lower voltages are 0.

As expected:



Error: Shorted voltage sources found: V6.

======= SPICE Netlist check completed, 1 error(s), 0 warning(s) =======

 

As expected:
View attachment 282675


Error: Shorted voltage sources found: V6.

======= SPICE Netlist check completed, 1 error(s), 0 warning(s) =======

It worked when I changed V8 to 10V

 

hi,
When I connect my test source voltage the same way as yours I get the same problem
E

 

hi,
When I connect my test source voltage the same way as yours I get the same problem
E
View attachment 282678View attachment 282678View attachment 282680

I am trying to understand where the problem is coming from. Anyway, when I connect the test source as shown in the first image (with no grounds), it gives an error.

 

hi MMM
I have put both options on one circuit to show you the difference.
I would use 1k resistors to simulate your load cell.
E

 

hi MMM.
Add the 4, 1k bridge resistors to your simulation

E