I'm producing an Arduino project that has two 5V inductive proximity sensors placed outside the project box.
The project is powered by a Meanwell 12V power supply then to a Murata 5V DC-DC converter which supplies the Arduino and other 5V components, including the two proximity sensors.
The Arduino inputs have a series 1k resistor, TVS diode to ground, and a 10k pullup.
Question
As the project is water-based there is a small risk that the 5V supply for the external proximity sensors could be shorted to the ground and cause the Arduino to"brown out" or reset.
I have considered adding a separate 7805SR regulator, a couple of 0.1uf caps, and a 0.5A PTC fuse as a dedicated supply for the external components powered from the 12V Meanwell PSU. (common ground connections)
Is this a suitable suggestion?
EDIT: sensors are 5v 200ma, the system is powered from a 48V battery.