Using Arduino Uno R3 To Control Low Side Driver MOSFET

Should I be worried about protecting the Arduino Uno R3 board from a large ground leakage current in the attached application?

The Arduino board is controlling a low side MOSFET switch that is switching ON&OFF 48VDC at a low frequency. There is a 5ADC current flow through the loads and the MOSFET switch.

The Arduino board’s ground is referenced to the same ground as the 48VDC ground.

Will I get any large current flow in the Arduino board’s ground reference line that will damage the board?

Arduino_Control_Circuit.pdf (43.4 KB)

Hi,

Trace the current path with the main 5A current: Battery(+) -> Load -> (Switch or power FET) -> TB (Terminal Board?) - Battery(-).

None of that current flows through the Arduino ground. Only a tiny amount of current to turn the FET on.

You have a "Common Ground Point" at the TB. Good practice is to have the Common Ground Point at the power supply negative terminal. You show a wire from your TB to that. As long as that is short and large it should be no problem.

BUT! Where is the Arduino power coming from? It needs to be isolated from any other "ground"..

What environment is this all in? Indoors? Vehicle??

Terry,
The power for the Arduino comes from a AC to DC adaptor. The adaptor plugs into a wall outlet and creates 9VDC for the Arduino board.

The circuit will only be used internally in a lab environment, at room temp.

Remember, when you plug the USB connector into the Arduino, there is a good possibility PC earth GND will be connected to your circuit GND. This may or may not be an issue, just keep this in mind.

Remember, when you plug the USB connector into the Arduino, there is a good possibility PC earth GND will be connected to your circuit GND. This may or may not be an issue, just keep this in min

Good thinking, Larry!

To be Real Safe, can you power down the 48V system and THEN connect the USB to upload code, and THEN disconnect USB, reset and power up?

Other: Is the 48VDC system grounded to the BUILDING ground? It probably should be..