The latest “Gadget Freak” from Design news is a fridge alert! –
When you’ve popped in your fridge alarm, getting peckish in the middle of the night and forgetting to close the door — along with escalating electricity bills — will be a thing of the past. Italian inventor Flavio Dellepiane has designed a 3V battery-powered fridge alarm that beeps if you leave the door open for more than 20 seconds. When the fridge lamp illuminates, the alarm’s photo resistor lowers its resistance, the IC starts counting down and, after a preset delay, the piezoelectric buzzer beeps for 20 seconds.
HOW TO – Make a fridge alert – Link.