Design Sarah's security system and use your LVPS to power the system you design.
You could install your alarm circuit in a model house to test it for Sarah.
Model for Sarah
Corrugated cardboard works well for building model houses. Your model must have
at least one window or door that you can alarm. It's also convenient if the roof detaches
so you can access your circuit easily. Add other flourishes--you
may want lights to go on as well as an audible alarm; you may want a deck.
Sarah wants a volume control.....
Test out your alarm system thoroughly, so when a burglar tries to enter
the alarmed part of your house the alarm goes off reliably.
If you're stuck...
Think about what parts of the circuit you DON'T want the thief to
break. Make sure these aren't around your alarmed window.
Think about what part of the circuit you DO want the thief to break,
and put that part around the window.
If you add extra components, like light bulbs, do you want them wired
in series or parallel? Check both ways and see if your ideas were correct.
Make your alarm system easy to reset once its been tripped.