B&B Electronics Strain Gauge/Load Cell Bridge Amplifier FBDA ユーザーズマニュアル

Documentation Number FBDA0797 Manual 

9 

 

 

Sensors that are based on a Wheatstone bridge need an 

excitation voltage to excite the bridge.  The FBDA provides an 
adjustable excitation voltage.  This excitation voltage is available on 
the terminal block labeled EXV.  The excitation voltage is set to 
5VDC ± 0.05VDC at the factory.  This voltage is referenced with 
respect to GND.  To adjust the excitation voltage, the following steps 
should be followed: 
 
1.   Remove the cover from the FBDA module using a small slotted 

screwdriver. 

2.   Make all of the required connections except the sensor 

connections and turn on the power. 

3.   Using a voltmeter, measure the voltage on the terminal block 

labeled EXV with respect to the GND terminal block.  Adjust P2 
to change the excitation voltage.  The terminal block labeled A/D 
1 can be used to measure the excitation voltage. 

 
 

Sensors that are comprised of Wheatstone bridges usually state 

the amount of output per volt of excitation voltage.  An example is:  
10mV output / 1V of excitation.  If a 5V excitation voltage is used, 
The full scale output of the sensor will be 50mV.  The gain of the 
FBDA should then be chosen, so that Vout does not exceed 5V (the 
maximum voltage that the SDAXX line of data acquisition modules 
can measure). 
 
 

If for some reason the excitation voltage source in the FBDA 

does not meet your needs, you can use an external excitation 
voltage.  If this is the case, then nothing should be connected to the 
EXV terminal block, and the GND lead of the external excitation 
voltage source should be connected to the GND terminal block on 
the FBDA module.