Potable 9v Dark Activated Light





Introduction: Potable 9v Dark Activated Light

Hey all!This is my first instructable and i am starting with a very simple one. It is a simple, easy to make potable dark activated light, powered by a 9v battery.

Step 1: Get the Materials Required

IC 1-----------ne555
R2-------------10kilo ohms
R4-------------4.7kilo ohms
B1--------------9v battery(and clip)
small pcb
soldering equipment
rubber band

Step 2: The Schematic

There are 2 circuit boards; the dark sensor board and the led board. Ne555 in the dark sensor functions in mono-stable mode. Once the resistance across ldr decreases when the light falling on it is blocked, the trigger pin receives a pulse and the light turns on. When there is light the resistance across ldr increases and the light is turned off, however it gets off after a few seconds till the 100uf capacitor gets discharged completely.

Step 3: Solder the Stuff

Carefully solder all the components and wires according to the schematic.

Step 4: Testing!

Connect the battery clip to the battery and turn off the lights of the room; the light should glow. If somehow it doesn't, check the wiring properly and also check if the battery is dead. Now point a lighted torch to the ldr, the light  will turn off again. 
After testing, place the two boards side to side on the two faces of the battery and put a rubber band around to keep them in place.

Step 5: Finish!

Now you have your small potable dark sensitive light ready. You can use them anywhere you like; for example you can put it inside your cupboard so whenever you open it the light turns on and you can see your things inside.
Feel free to comment.




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Questions & Answers


Can i use more led lights for getting more intensive light ?

Not sure may be 10hrs if turned on continuously.

Interesting project. How many hours lasts the 9V battery?