REFRIGERATOR DOOR-OPEN ALERT
Categories : Series 9 Generally Electronic Project ,  Alarm , 
Accidentally leaving a refrigerator or cool room door open can be costly in terms of energy but even more expensive if a compressor motor should fail due to overheating. Losses arising from spoiled or unsalable stock add to the financial burden of such an accident. This simple circuit monitors the refrigerator door light and sounds a warning if it is on too long.
Technical Specification