Introduction: LED Backlit Cardboard WALL CLOCK Cum Night Light

Here's a simple yet elegant WALL CLOCK made just out of cardboard and a couple of L.E.D.s!  And what more!...it doubles as a NIGHT LIGHT !!!

To see the time at night is no longer a problem!!!!....

MY MOTIVATION came from the following instructables :-
https://www.instructables.com/id/LED-CLOCK-cum-NIGHT-LAMP/
https://www.instructables.com/id/Paper-mache-clock-face/
https://www.instructables.com/id/Glass-Clock-with-LED-backlight/

Step 1: Materials & Tools List

MATERIALS NEEDED:
1) Cardboard  (a lots of it!).

2) Black Sheet (of size lager than the diameter + twice the width of the clock you plan to make!)  (I took 36cm in diameter! ).

3) A Plain Sheet (A4 size).

4) Clock Mechanism with Clock Hands (I salvaged it from an old clock!).

5) L.E.D.s - 15 of them. (mine were 8mm straw hat LEDs with wide viewing angle.)

6) RED & GREEN Marker pens.

7) Fast drying glue / superglue (I used quickfix)

8) Wire.

9) Electrical Grade Tape.

10) Fevicol (or any adhesive for the paper-mache).

11) A power supply for the LEDs (I used an old mobile charging adaptor).

12) resistor(s) (according to your power supply and LEDs you are using----I've put a link to the resistance calculator!).

13) A two way switch (optional).

TOOLS NEEDED:
1) Soldering Iron with Solder (optional).

2) A pair of Scissors (optional).

3) A Cutter Knife.

4) A Compass with Pencil for marking purposes


Step 2: THE CARDBOARD PART OF IT !!!

So , you've gathered all the supplies!......Let's get started then!!!....

A) Make at least three similar circles of the desired size on the cardboard piece (mine was 28cm in diameter). (cut out 1,2,3)

B) Now Cut out these circles with the help of a cutter knife (or x-acto or a laser machine!).

C) Take one of the circles and divide and mark it's central 360 degree angle in 12 equal parts. (in case of any problem , feel free to ask!!... :D). (on cut out 1)

D) Now make a circle on each of these divisions with a pencil. (Again, the size of circle to be made, is your choice!....mine were 34mm in diameter). (on cut out 1)

E)Cut out these smaller circles and do the same with yet another one of the larger circular pieces(on cut out 2)

F) Now paste the circles (cut out 3, cut out 2, cut out 1 respectively) together with the glue in such a way that the smaller 12 circles on thecircular cut outs 1&2coincide completely with each other!!).

Step 3: THE PAPER MACHE PART OF IT (OPTIONAL) !!!

I wanted a sturdy and hard base for my clock!....that is why I put in some paper soaked in a glue+water (1:1) mixture , on every part of the carboard cut out.

let's call it step-3 product!!!.....

Step 4: THE NUMBERS !!!

For the numbers , I first tea dyed the plain white A4 sheet. (this gives an awesome look even when the LED lights are off)

Then just print all of the required numbers(with ample clearances for cutting purpose!)

Now , to make the paper more stronger , I just applied a fevicol (or any other clear adhesive) coat over the whole sheet.

Now just cut out the numbers such that they can be fitted onto the smaller circles on the cardboard cut out!





Step 5: THE FACE OF IT !!!

Initially, I had decided to paint the face of the clock black!....But changed my mind later on.....

Now , place the black paper of appropriate size on the final step-3 product....and with the help of a pencil, trace the circles , all twelve of them (by simply sketching on them!---refer the pics!!!----I first tried this trick on a waste paper...pic 2&3).

then just make some random thin cuts inside(pic-2&3) each of the circles so that they can be folded back, to give a nice and clean circular shapes.

let's call it step-5 product...

Step 6: THE AWESOME LED BACK-LIGHTS !!!

Colour six LEDs in RED , and six in GREEN with help of marker pens ( using diffused LEDs would have been better!)
Now just punch a little hole in the centre of  each of the twelve circles and place the LEDs in their places and secure them with help of a superglue.

Now paste the printed numbers carefully above the smaller circles in the step-3 product.
Now paste the step-5 product over the numbers already pasted , just as in the pic!!!... (DON'T FOLD THE BLACK COVER BACKWARDS YET!!!).

Place the remaining three LEDs over the numbers '12' , '8' and '4' . (or any other combination of numbers of your  choice!!!).

Flip over the clock base now and bend the legs of all the LEDs as required. Also , now fold  the black cover backwards and secure it with help of glue.


Now for the CIRCUIT PART , refer to pic-4.

Connect all the LEDs (15 of them) in parallel.

I had a 5.3 volt power supply(old mobile's adaptor) lying around. According to the calculationsthen , i needed an 8ohm resistor with power rating of at least 1W.(I used three 24ohm resistors rated at 0.5W in parallel!---that makes it 8ohm @ 1.5W).
I even added a switch at the back of the clock , to make sure I could turn it off , whenever required!..

NOTE: YOU ARE FREE TO PLAY WITH CIRCUIT AND COME UP WITH YOUR OWN!

Step 7: YOU'VE MADE IT!!!

Now just carefully punch a hole in the centre of the clock base you've made and put the clock mechanism at the back , lock it in place or simply glue it in place , and put the hands (I painted them silver---they were originally black) in place.
For the hanging part , I took two cardboard pieces (3cm X 2.5cm) stuck together with glue , and pierced them as shown in the pic-2.

YOU'RE DONE NOW!!!
HANG THE CLOCK ON THE WALL AND SIT BACK AND ENJOY!!!...

Step 8: THE COST INVOLVED!

Cardboard---salvaged from the old fridge's packaging box.
Clock mechanism---salvaged from an old clock. (Rs.50---the cost on a local store for a new one.....).
Black sheet---costed me Rs.10.
Plain white A4 sheet---costed me Rs.0.26 (I usually buy the 500 sheets pack for Rs.130).
LEDs---costed me Rs.17.25 (I bought 100 straw hat 8mm LEDs for Rs.115).

Marker pens, Glue, Tape, Wire, Power Supply and resistors and all the tools were just lying around in the house....

Total money spent----
Rs.27.51 OR $0.5 !!!.....
Even with nothing at hand or lying around, the cost should not exceed $15.... :D




THANKS FOR TAKING OUT TIME TO READ THIS INSTRUCTABLE!...(IT IS MY FIRST!)....  :D

REVIEWS AND SUGGESTIONS IN FORM OF COMMENTS ARE WELCOMED !!!....  :D

PLEASE DON'T FORGET TO RATE MY INSTRUCTABLE!!!.....  (:

Comments

author
DIVYA GARG (author)2012-10-03

waw........! nice explanation ........... ........thanks for ..............it......................... I am very happy that you did not ignore my question.............................! ............................................................................but ....I thought you would ignore my question....................because you are more intelligent and more qualified then me..............! but I was wrong....................................! you are not only a good teacher but also a good human...........................................................................................thanks ...........sir..................................................

author

Oh!..I'm not habitual of digesting that much sugar in a single go!!. :P

but thanks!!!. :D

author

haha most epic reply seen on instructables :D

author
DIVYA GARG (author)2012-10-04

you should post any new project .............! I shall wait your new project..............................! ................I hope you will do it soon................

author

yup!...It's coming soon!. :D

author
DIVYA GARG (author)2012-10-02

it's looking very nice..................! but I want to know that why does A simple pn-juction diode not emit of light as LED, because LED is also a pn-juction diode as a simple diode................................... ?

author

Because when an electron crosses the PN junction and falls into a hole, it emits a photon. The frequency depends on the energy, which is determined by the forward bias voltage. That is why a red LED requires more voltage than an IR LED, and less than a green LED.

So a regular diode with a forward drop of about 0.7V is emitting infrared (IR) light. However, most of the photons are reabsorbed in the semiconductor body or stopped by an opaque case. An LED is a special diode doped for a higher voltage and constructed to let as many of the photons out as possible, set in a reflector and usually with a lens cast into the plastic case.

....No, I didn't typed it all!!!..... :P
just googled it!!... :P

Hopes that answers your question!!!.... If not, well, then post it here.... you'll surely get some amazing answers!!!.... :D

author
SelkeyMoonbeam (author)2012-07-30

Very cool! How well can you see the hands of the clock at night?

author

Thanks a lot SelkeyMoonbeam!!!....  :D

Well, the hands are completely visible at night with no problems.....though, the visibility would have increased had I chrome plated the hands and/or used four outer LEDs instead of three.....though I didn't have a chrome spray paint bottle at hand and using four LEDs would have increased the night light's intensity to an uncomfortable level (as per bed's position)......so , this one just works good for me.... :D

About This Instructable

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Bio: I am an Electrical Enginnering student . Just love using things lying around to make new stuff!! :D I have been around here since 2009, though ... More »
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