how to construct a low voltage protection system using annunciator?

Hi in our college for our first year mini project , we were given a problem statement and based on it we have to find a solution , but i am not able to ,so here is the problem statement
"low voltage protection system using annunciator
generate 5volt power supply from 230volt ac and activate beeper when
power supply is below 180volt.choose components with appropriate
materials.list the important property based on which the material is
chosen for the components .draw the waveforms of current and voltage
at specific branches and node.find the laplace transformations ."
so if any one  does come across some ideas please help i have my first review coming by so reply ASAP guys

I don't see the relevance of "finding laplace transforms" in the context of the question.

The load on the PSU isn't specified, so its meaningless.

Just use a linear regulator like a 7805 on the back of a 12V transformer and filter cap. Take the rectified and smoothed 12V (now around 18V DC and feed that into a comparator powered by the 5V supply. On nominal volts (230AC in), the output DC is 18, on 180V in it will be ????