Hello every body,
I want to calibrate my bridge for sensor data acquisition. For that i have three resistors of 350 ohms in the bridge circuit and fourth one is the variable resistor. I always have to set it manually. I want to use programmable resistor instead of potentiometer but unable to find it, that can go upto 350 ohms.
Can any body of you suggest any other method through which i can do the nulling or calibration? or any programmable resistor ?
Looking forward for your suggestions.
Regards
Awais
A manual calibration does not frequntly used and a precision of components applays. To avoid manual calibration it is needed to use a program calibration. In this case PC (MC, PCU, MCU, FPGA) has algorithm for set zero on your bridge. Sometimes when a response is nonlinear from bridge to use a combination of a step driver with a variable multi-turn resistor. But this is expensive. Maybe digital resistor will be enought.
Take a look to max5483 and/or ad5262, or consider to offset the bridge amplifier with the programmable digital resistor.
If the bridge is DC you can use (DC Electronic load instrument) which it may be suitable for your project
Hello Mohammed,
You can use some DAQ equipment which can bridge your circuit.
Or you can measure your resitsor voltage in realtime by using real time toolbox in matlab and you can simulate the other resistors.
Hope this helps
Dmytro Snizhko : yes you are right but i am unable to find a digital resistor that can go upto 350 ohms. If you know one then please let me know .
Looking forward for your reply!!!!
Osman Çakıroğlu: I have no idea about it. Can you give me some more detail?
or any links that i can refer?
Consider using AD8403 4-Channel Digital Potentiometer in parallel adding 100 Ohm in series.
The DAQs can complete the quarterbridge strain gauge (one arm of the wheatstone bridge) in software and so you can bridge the strain gauge first value.
In matlab realtime toolbox you can create a wheatstone bridge and put some resistor values to the formula and you can bridge your circuit.
Just like calculations of bridge structure, but one of the value resistors can be changed by you in order to bridge your circuit.
Like manual bridging but with matlab or a DAQ.
Thank you so much everybody for your valuable suggestions. It helps me a lot.
Hello Muhammad,
You can try this : http://www.sge-translations.de/attachments/File/Translation_Example.pdf with the DS3906 page 2.
Or this, but not cheap : http://info.pickeringtest.com/programmable-resistors-sensor-emulation?utm_campaign=Programmable%20Resistors&utm_source=ppc
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