Dear sir
We Intend to design following project Please suggest suitable application note
Load cell circuit with 350 ohm bridge to produce +/- 5V output depending on tensile or compression measurment with zero and full scale setting by trimpot
there is seperate display so it will not have on board ADC or display
The circuit will have to oeprate fro 20V DC to 40V DC source so we need to have power supply of +/- 12V-50 ma)from 20-40V
rgds
Juzer Gandhi
Raj Overseas
Katy,Houston-USA
Hi Ammar,
We have a TI Precision Design that should provide a good starting point. You can find it here: 
You will need to make some minor adjustments for zero and full-scale adjustment. For the full scale adjustment, you can just make the gain setting resistor, RG, a trimpot.
For the zero adjustment you can add a large resistor and trimpot to balance the bridge as shown in the schematic below:
You can adjust the values to achieve the desired sensitivity and you can use the attached simulation file to evaluate the performance. Bridge Amplifier with Zero Trim.TSC
For the power supplies, you could use a buck converter in a split rail configuration as described in this application report: 
In addition, here is a calculator that will simplify the design of the split rail:
