Refrigerator Alarm Assembling

Refrigerator alarm circuit so that we know if the refrigerator is closed or not. Refrigerator sometimes likes to play or open the lid by children, and this resulted in the refrigerator room temperature decreases and will add electrical load, so the power consumption becomes wasteful. For that we need this alarm circuit.

Placement and How it Works The circuit:
This circuit save it into a small box, placed in the refrigerator near the lamp (if any) or opening.
With closed doors inside the refrigerator in the dark, photo resistor R2 serves high resistance (> 200K) so that the clamp holding the pin 12 of IC1 high.
When a beam of light enters when opening, or the refrigerator light is lit, photo resistors to reduce resistance (2K), pin 12 so low, IC1 starts counting, after a predetermined delay (20 seconds) buzz speaker beeps sound for 20 seconds. then stopped during the same time interval and the cycle repeats itself until the refrigerator door closed. D2 is connected to pin 6 of IC1 enables buzz speaker beeps 3 times per second.


List of Components:

• R1 = 10K 1 / 4W Resistor
• R2 = Photo resistor
• R3, R4 = 100K 0.5 Watt
• C1 = 10nF 63V Capacitor Polyester
• C2 = 100μF 25V Electrolytic Capacitor
• D1, D2 = 1N4148 75V 150mA
• IC1 = LM4060
• Q1 = BC337
• BZ1 = Buzz Speaker
• SW1 = SPST Slide Switch
• Batt1 = 3V Battery

Ok,,, Good Luck...