You said:
Hi
I have recently been told that you can combine a number of wheatstone
bridges (load cells) conforming a multipoint weight scale.
Are the bridges paralled direct or are the signals mixed with serial
resistors?
regards
Jens
That is a common practice, we have hopper units that sit on
three load cells, they are all tied together into one signal.
with these cells, you simple zero each unit with the others
not plugged in. when completed, we just plug them all in afterwards.
they are all joint together via a network at which point, should be
balanced to a zero point. when ever any one of these units change it
alters the balanced and if one cell is much more than the other.
Basically, you get a very accurate reading with load shifting and so
on because the three cells will differentiate the value.
We do have another set up where each cell is a DeviceNet link, these
units are all combined via communications and talk to via an device
number to read, calibrate, zero etc.. these work good for a single
control process unit to indicate load imbalance if you wish to do so.