Gadget Freak Case 110: A Fridge That's Alert for Midnight Snacks

By: 
October 22, 2007

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.

Build Instructions | View Parts List | Post a Comment


Amt Part Description

2 PCB Mount holders for 1xN cell 839-3078
1 10k 0.33W Carbon Film Resistor 296-6300
1 Photo Resistor (ldr) 699-0002
1 100k 0.33W Carbon Film Resistor 296-4743
1 10 nF 100V Polyester Capacitor 995-0018
1 100 uF 10V Electrolytic Capacitor 859-0122
1 1N4148 75V 150 mA Diodes 935-0242
1 74HC4060 14-bit Binary Counter & Oscillator IC 236-1836
1 BC337 45V 800 mA NPN Transistor 431-0466
1 Piezoelectric buzzer, 13.7 mm 623-1957
1 1.5V N Alkaline battery 884-5175
1 Black ABS potting box with lid, 64 x 43 x 25 mm 806-6955

Get Build Instructions

Add new comment

By submitting this form, you accept the Mollom privacy policy.