Search This Blog

Powered by Blogger.

Translate

Home » , , » Fridge Door Open Alarm

Fridge Door Open Alarm

It beeps if the fridge door is left open for too long or hasn't closed properly, to stop food from spoiling. There are lots of other uses as well. A refrigerator or freezer door that is left open or ajar may cause the food contents to spoil. In some cases, the internal temperature of the fridge or freezer will be maintained if the refrigeration system can cope with the open door.

Complete project:



But without the door sealing in the cold air, it may be a losing battle. Running costs will certainly rise. Typically, refrigerators and freezers are in constant use in the summer months and so it is important to ensure that the door is not open for any longer than is necessary. Otherwise the fridge or freezer will not be able to keep the contents cool. And it will cost more money to needlessly run the fridge’s compressor in a futile effort to keep the contents cool.

Circuit looks like:



Even the most diligent fridge user may sometimes leave the door of the fridge or freezer open without realizing it. And tilting the fridge or freezer slightly backward so that the door will fall shut is not completely fool proof as there may be an obstruction inside the door. The obstruction could be because an item inside the compartment has moved or fallen over or because the compartment is too full. This is where the Fridge Alarm is useful.



It warns when the door of the refrigerator or freezer is left open for longer than a preset time period. It is great for indicating when someone is standing with the door open for too long and a real asset in warning when the door looks shut but is still partially ajar. The fridge alarm operates by detecting when any light enters the compartment area. Therefore it is just as useful for freezers (which normally do not have a light) as it is for fridges (which normally do). As long as there is some ambient light which the alarm can react to, it will operate.

Parts layout:



PCB layout:



Circuit diagram:


The alarm will sound if the light is present for longer than the preset period and will continue to sound until the door is closed. In practice, the preset period is adjusted so that in normal use the alarm will not sound. It will sound when the door is left wide open for too long or if left slightly ajar.

Note:

    You don't have to house it in a transparent box, as we did . . . but if you don't, you'll need another hole in the appropriate place on the box wall so light can strike the LDR inside.

UPDATE:

PCB layout has been added to download. Please click on the image below and get the PCB in EPS format. After downloading, you can view PCB in Corel Draw, Adobe Acrobat or Adobe Photoshop.
Share this on your favourite network

1 comments:

  1. Hi admin, it is very nice blog, very informative blog so thank you so much for this information. But there is another website with same concept of free ad posting www.helpadya.com www.helpadya.com Classified Free Ads.

    ReplyDelete

Write For Us

Submit a Guest Post

Find us on Facebook

Categories

555 Timer IC 7 segment Display 8051 Project AC Circuits Adafruit Alarms Amplifier Circuits Analog Circuits android Arduino arm processor Assembly Languange Atmel Atom Size Audio Circuits augmented reality Automotive Circuits avr Battery Circuits Bicycle Gurad bluetooth Cable TV Circuits Cambridge University Camera Technology Circuit Boards Clipping And Clamping Circuits Clocking And Timer Circuits Computing contact lens Contact Us Form Contests Controller Circuit Conversion Circuits Counter Circuits Digital Electronics diy circuits Downloads EFY EFYTimes Electronic Books Electronic Components Electronic Locks And Keys Engineering Fan Circuits Filter Circuits Fire Alarm free Frequency Fun And Game Circuits future Google Hack n Mod Ham Radio Circuits heart rate monitoring High Voltage Circuits Home Circuits IC Guide ieee Industrial Circuits Infrared Instructables Inventions ipad lcd Led Circuits Light Related Lighting Circuits Medical Circuits Meter Clocks Microcontrollers Microprocessors Mini Projects modules Movie maker NatGeo Navigation Notice Optical Fiber PC Circuits PCB Boards Physics pnp transistor Power Supplies Printing Projects Programmer Project Ideas Projectors Protection circuits Proximity Detectors Radar Radio Circuits Radio Transmitters Raspberry Raspberry Pie Remote Circuits Retis Lab RFID Robot Cars Robotics Science Science Alert Security And Safety Sensor Circuits Servo Motors Smallest Smartwatches sms Software solar cell sound application Spectram Switch Technology News Telephone Related Television Related Test And Measurement Circuits Thermal Projects Tone generator circuits Touch Screen Tutorials Wearables Wi-Fi Wireless
Like us on Facebook
Follow us on Twitter
Recommend us on Google Plus
Subscribe me on RSS