Part 1: the system and how it's connected
I'm working on a system that would monitor the water level of a water well in remote areas . Here's what the system is designed ( drawn briefly ) ,
On the left side are the microcontrller , External I2C Analog to digital converter ( isolated with ADUM1250 ) & the Water level sensor ( 4- 20 mA) which has a very long cable . The right side has the solar panel which then enters through a linear regulator based circuit (MIC29752) lead acid battery charger that is controlled by a mosfet that is switched on/off by the microcontroller which is monitoring the battery level so as not to overcharge the battery, the output of the 12V battery enters the Isolated 5V regulator which then at this stage the output is now 5V .
Part 2: my findings for far
Here's my guess,
- I've been reading alot that we may have a problem when working near water pumps and generators, this may or may not affect the system ( analog readings flicker , electrical instability) which would destroy the circuit thus deciding to use those isolator ICs.
- Found claims that coating the enclosure box with an EMI/RFI nickel based spray will shield the system from the stray Electromagnetic interferences outside the box .
Part 3: My questions
- Am i going in the right direction for protecting my system from External EMI from say nearby pumps and generators ?
- All of the isolation Solutions used in circuit , do i really need them for my applicaiton or is it just plain overkill ? .
- EMI/EFI Coating , it is useful in my case ?