I have a power circuit that implements an AC-to-DC rectifier and a non-isolated buck converter to convert a 120 VAC 60Hz signal to 12V and then a linear voltage regulator to step the 12V down to 5V.
The 5V will be used to power a micro controller and there is a possibility that people will touch the pins of the micro controller. I realize that it is not ideal to use a non-isolated power converter, but due to size constraints I do not want to put an isolated power supply with a transformer in the design.
The question is:
Will a 500mA fuse after the 12-to-5V linear voltage regulator make the design safe against electric shock since the buck converter is non-isolated?