Can i use strain gauge as weight sensor?

[Chris zhi]

Hi all,

Can i use strain gauge as weight sensor? I would like to use it in my project.
Anyone have any idea on strain gauge?? Anyone have the schematic or circuit diagram for strain gauge?
Need your help cuz i do not have idea on strain gauge.
Thanks

 

[IanP]

Of course you can ..
The key issue will be the selection of matching signal conditioner/instrumentation amplifier ..

Have a look at:
**broken link removed**
and then:
http://www.scribd.com/doc/14256112/AN002OpAmp-LM358-as-Instrumentation-Amplifier

Rgds,
IanP

PS. there are much better opamps than the LM358, but for learning purposes almost anything will do ..

 

[Chris zhi]

ic..but how to use op-amp in the strain gauge? i am lack of idea with it..
Furthermore how to connect the strain gauge to the microcontroller PIC16F877?
This is because i am doing an elevator which contain weight sensor to limit the number of passenger. Do you have any idea?
Thanks

 

[IanP]

To start the ball rolling, try a simple opamp (LM358) as an instrumentation amplifier and the second link from the previous post describes how to utilize it as the strain gauge signal conditioner ..
It may be connected to the 10-bit A/D pin of your PIC, but, as I said before, it is just for a good start ..
The sensitivity may be not there, so later on consider proper (more expensive) instrumentation amplifier and an external (higher resolution, say, 16-bit) A/D converter ..

Rgds,
IanP

 

[Chris zhi]

oo..ok,by the way,do u have any email address? so i am possible to have some advice from you. The op-amp is used to amplified the voltage sending to the microcontroller? or other function.

Is there any cheaper strain gauge in the market? or is it possible to build it myself?
do you any reference or notes about building a strain gauge?

 

[welove8051]

hi chris, you can contact any user by sending them a PM(private message). there will be a link call PM, just click it and send it.

regards
kj
free8051projects.blogspot.com

 

[Abhishekabs]

You can check any engineering book on operational amplifier design.
It explains working of strain gauge ( piezo)

**broken link removed**
Check this out.