Help fitting a low voltage indicator into this circuit? Answered
I know very little about circuits and electrical components, so please be kind.
Attached is a picture of a simple circuit. "A" is a 4,5V AAA alkaline pack, "B" is a latching pushbutton switch and "C" is a nicrome wire.
In the simplest and cheapest way possible, this circuit needs to alert the user if the battery pack goes below 3V. The indication signal needs to be a "beep", just like a 9V fire detector. (I can't have a LED signal).
After some googling, I found that a 3V "low signal relay" could be one option. I prefer to use wires, and not a PCB in my circuit.
My questions follow below:
1. Is a low signal relay this the cheapest and simplest way, or are there others?
2. What components do I need to achive the "beep" and where in the circuit do these components go?
3. Will these components draw any power in standby mode, or do they only consume some power when the "beep" goes off? Because if they draw power continuously, I will need to add an extra (coin cell?) battery, as I need to save my alkaline pack for the nichrome wire. The extra battery shoud last for min 3 years.
All help highly appreciated.