Revive an Old Watch Into a New Long Last One

Hi, this is my first instructable and i'll show you how to rescue an old watch into a more efficient and portable one, I received a nice watch as a gift but later than a year it ran out of battery and damaged over time so I've decided to rescue it because I liked the interface and it can be saved from scrap materials, so lets begin.

1. An old watch, fully functional but without the main cover

2. (2) 4007 rectifier diode (this is because the clock uses a very low power compared to the power offered by the battery)

3. An old mp3 player (battery and the charge module for less than $2)
4. A screwdriver

5. A couple of neodymium magnets (optional)

6. Two pieces of wire

7. An enclosure for the clock (I recycled an old christmas deer hat and used the red nose as the enclosure)

8. Double side tape

9. Electrical tape

10. A hot glue gun
11. Soldering iron

The good thing about this cheap mp3 is that it cost no more than 3 bucks, you can get a battery and use the mp3 as a charge module so is a very inexpensive option to use, remove the screws and take the main component outside, you can discard or reuse the enclosure for another project, the clock will not fit there

Desolder the battery to prevent any issue working with the solder, then desolder for parts that you`ll not going to use as it helps you to gain space, also verify if the mp3 model that you have depends on the main switch to power the battery when charging, I desoldered the SD card reader, the headphone jack and the main power switch to be sure that the mp3 consumes no power.

Solder two strips of wire to the mp3 board in the same spot as the battery cables,then secure it all with hot glue, be careful with the battery (they're very sensitive to heat) procure use the glue before it starting to get too hot

Tape the spots were was the control buttons, our clock has no enclosure and when it touch them drives to a short circuit

In this step I wrote notes to the photos so you should read it ;)

The back metal cover of the clock has three functions
1. it secures the board to the screen
2.it has strip of metal to control the main functions when pressed (make direct contact to the main board)

3. THE ONE WE CARE ABOUT. It acts as a the positive of our watch.

because of that we taped our mp3 buttons, to prevent any sneaky piece makes contact, also be sure to prevent the clock frame touch the charge port.

the battery was not labeled but doing an internet research shows that these batteries has at least 3.7V and 500 mAh more than enough to power your clock, i couldn't fine any specs of my watch but usually consumes less than 2V, so you have to use your 4007 diodes to lower the main voltage below 3, if you don't do that the clock will be overpowered and will bright all the screen so it'll became unreadable (see the photo).

The tricky part

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NEGATIVE WIRE

As the device is small I recommend you deattach the back of the clock pulling the dent around it, you should see more clearly the three dents which are the negative ones, in this case these are aluminum so I can't solder it, also if you mess up with the solder it will create a bump making it to contact with the main positive body (you totally not want that happens) so the best trick is to make a knot with the negative wire to attach it to the dents, then put the back frame back and fill it with hot glue

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POSITIVE WIRE

The main body is the positive of the clock so you can attach the diodes where you want, this model have a suspended middle circle with three strips joining the body, used it yo wrap your diodes, it must have to be connected in series so it lowers about 1.4 volts due to each one will reduce around 0.7 V and no other strip should make contact with the body (as it will skip one diode and start overcharging the clock).

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Once you managed to accomplish that you'll have your beloved watch emerge from the dead

Good, now you have a fully functional clock running with a rechargeable battery, but now that frankenstein has awoken it need a proper skin right? no problem, you can use a box of matches or create a custom case, in my case I had the remains of a stored deer hat that I used in christmas so I took the "nose" and transformed it into the skin of franky. you just have to pull together the MP3 module and the clock (it'll not have a short circuit thanks to the electrical tape) and wrap it into the clock. If you like add a neodymium magnet to the back to make it stick into any metallic surface or another magnet, I attach one magnet to the wall with double-sided tape and you made it!

you manage to revive a clock from scrap.