Many a times we need a device which should activate itself according to outside light (like when we open door of drawer it should lit up). We sometimes feel the [[wysiwyg_imageupload::]]need of some light activated device, such a device could be made from circuit presented here. This light detector circuit project uses a light sensitive element which activates the circuit in light and switches it off in absence of light.The light detector project presented here can be used in these applications: Such circuit can be used in refrigerators to automatically switch their light on or off corresponding to the status of door of refrigerator .It could be used as morning alarm, which switches on with morning sunlight. In drawers and wardrobes, on opening their door some light should automatically switch on.