Arduino Nano DC Electronic Load V2

Siple DC electronic load based on Arduino Nano, this electronic load is analog and the Arduino nano job is to display information, controls the relay on output when the button is pressed ( ON/OFF ), it also controles the cooling fan speed acording to temperature. and finally offers over-current protection and over-temperature protection, over-current protection is activated when the load it reached over 3A ( you can set it in the cod acordig to your needs ) and it will deactivate the load, and the over-temperature protection is activated when the temperature reaches over 75  degrees Celsius.