jit_singh_tara
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In one application we ended up using separate sealed lead acid batteries to power a load cell (plus associated circuits) and a DC motor as the only way to remove noise
hello
The spike seen on your post #1 , with an oscilloscope show high frequency disturbation.( 1µS/div )
so the loadcelle doesn't care with this high frequency.
As recommanded in previous post, you must add filter on the power supply for the MCU , and power suply for loadcell.
Do you have a DC amplifier on the output loadcell signal , before your ADC ?
or direct connection to ADC ?
You must use a LOW PASS FILTER for this kind of signal .. maybe maximum 10Hz !
so analog filter or parameter inside ADC system , or averaging by MCU ..
Do you have "Electronic Earth (Separate Ground) in your factory ?
Because AC leakage current comming from AC motor, Heaters ..etc .. must not pass in the same way as in electronic parts.
It's usual in France to use Electronic grounding , separate from THE main Earth Ground also connected yo every metalic parts.
(sometime difficult to keep realy separated!)
Hi jitender,
I hope there are few more options available,
Use few capacitors in output of 7805 and 7812, with lower values than 0.1uf; you may need to use several of them.
Avoid power unit of transformer and bridge; try to use different type of AC to DC power regulator to power your uC circuit.
You can simply use a computer power unit (ATX power unit) to power your uC; it has +12V,-12V and +5V outputs. They are not sensitive to that type of noise.
Let us know the result.
Hello
did you try to install schaffner EMC filter on 230V AC of power supply as wp100 suggested ?
can you try to power you application by a DC battery (maybe 4,5V is enough) to check
the influence of Motor ON ?
How long cable do you have between loadcell and ADC1230 input ?
Shilded cable ?
0V insulated from Ground (Earth) ?
How is made your 12V power supply ?
can you separate REFP + brige power supply from the main 5V DC ?
any Drawing ?
For software application
are you using recommended 10 FPS maxi sample rate.
Don't forget to use averaged value, never instantaneous value, to reject the maximum of noise.
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