Freezer Alarm

You will need...
1. Water
2. Film canister
3. A pinch of salt
4. Wire
5. Small battery
6. Cheap alarm from Radio Shack

1. Connect alarm to battery
2. Cut wire connecting wire to battery in half
3. Place 2 exposed wires (One from the alarm, one from the battery) in the film canister
4. Fill canister with water
5. Add salt
6. Freeze

When your freezer stops working, the salt water melts, conducts current, alarm goes off



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    5 Discussions


    9 years ago on Introduction

    Great idea, thanks. Even better if you eliminate the battery/alarm and hook the wires to an X-10 powerflash interface (PF284). It allows dry contact closure (the saltwater melting) to trip and sends a signal to an X-10 appliance module. The signal is carried by your home ac wires to the appliance module, which will turn on whatever you want (light, radio, buzzer), wherever you want. My freezer lives in a remote outbuilding, rising temperature will turn on a radio in my house.


    10 years ago on Introduction

    this is actually a very good idea, as I have not realized that i have had a blackout until the night time. thank you, good Instructable, could have been better with the use of a diagram or some pictures


    12 years ago

    only one problem you have to wait for the water to melt in the mean time so will all your "yummies"

    1 reply

    Reply 12 years ago

    It's salt water; it melts at a lower temperature. Also, you only need some of the salt water to melt for the currrent to flow. I forgot to add that when you dunk the wires in the water, spread out the little copper wires inside of the main ones.