I'm trying to build my own cable lock alarm (for science!) and am having trouble figuring out a way to detect that a wire has been cut.

The circuit has to

1. Use no power at idle (or at least, very very little so that the batteries don't have to be changed every hour)
2. Sound a speaker when a specific wire is cut

My knowledge of electronics is minimal.. I know what capacitors, diodes, resistors and other basic stuff are and do, but I don't have a good grasp on how electricity flows in anything other than a single loop.

I seem to remember once making a circuit that was something like this.. (and oh geez, I don't even *know* how to do a proper diagram so forgive me folks)

```
/----------[battery]-------\
|                          |
|--------[light bulb]------|
|                          |
\-----[wire to be cut]-----/

```

And the bulb would only light up if the wire below was cut, because electricity always takes the path of least resistance.

Anyway, this is going to be a battery operated circuit and I'm pretty sure that diagram up there is a short. I think there was a resistor involved but I don't remember where it went.

If anyone can give me some pointers that'd be great!