In this I will show you how to make a TV remote that uses solar energy to recharge its batteries. The batteries need to be rechargeable, I used nimh batteries.
before we begin I would like to say that you shouldnt modify any remote that isnt yours. what do I mean exactly? glad you asked! Odds are you want to make your cable remote solar rechargeable and while its a fun and green idea, that remote isnt yours entirely (in most cases), it belongs to the cable company so I advise you not to modify your cable remote in any way because you might end up buying it if you change cable companies or something like that. I however did use my cable remote which belongs to the cable company but i did it in a way in which no damage was inflicted on the remote. I used hot glue to attach everything so when and if the cable company wants their remote back alls I have to do is peel off the glue. If you own your remote then feel free to do what ever you want, I would also like to say do this project at your own risk, I am not responsible for any damage to anything, if you do everything properly and insure everything works properly then you shouldnt have any problems. do this projectat your own risk!
ok lets begin.
Step 1: Things Needed. Some Are Optional.
So its time to gather the things needed and get a move on!
Solar panel ( I used a 5 volt one)
resistor (optinal. the rating of the resistor depends on what current youre trying to limit)
3.3 voltage regulator
one spdt slide switch
one spst (on/off) slide switch. (optional)
rechargeable batteries. (I used two 1.2 volt nimh double aa batteries)
Step 2: The Schematic.
Ok, so lets talk about what we see here. first off I would like to explain the role of the spdt switch, This switch has two positions, one posistion allows for the five volts to run to the 3.3 voltage regulator(adjust the voltage according to your battery ratings) , that position should be used to charge the batteries in direct sunlight and the other position is what I like to call a bypass, it simply skips the regulator and goes right to the batteries, this position shouldnt be used in direct sunlight because the 5 volts will go straight to the batteries which in some cases might not be good. this positons allows the batteries to charge in a well lit room where there wont be as much voltage output. For example you can possibly charge the batteries while in the normal lighting of your home, my panel outputs two to 3 volts when under normal lighting which is perfect for a non direct sun light chagre, I do recommend testing the various outputs before putting everything together. the spdt isnt really needed but i like it because it offers a bit of variety. Now let me explain the diodes role, it plays a rather important role, it doesnt let the batteries discharge back into the solar panel which could be damaging to the panel, I suppose you could go with out but I highly recommend using one. Now let me explain the resistor (i noticed i spelled it wrong in the schematic sorry about that), the resistor might not be needed in your case but for me I felt it was needed because my batteries in series are 2.4 volts (1.2 by them selves) and I wanted to get as close as I could to that rating and with the resistor it brought the voltage down to 2.7 volts which is near perfect. so the resistor dropped 3.3 to 2.7. The resistor might not be needed in your case, it all depends on your battery ratings which you should know before starting this. The spst switch is a on off switch, it isnt needed I just used it because I like switches lol. Technicaly the solar shuts off by itself when you dont have the panel facing any light.
Step 3: Putting the Circuit Together.
Now to save space I decided to assemble the circuit right on the back of the solar panel. You could use a PCB but it would take up more room so to save room just assemble everything on the back of the solar panel and ensure there are no shorts!
In the picture you can see evertything fits on the back perfectly, I used hot glue to secure the switches and other componets
Step 4: Important Notice. (adding the Solar Panel to Your Remote)
now this is an important step and you must do it right to avoid a short. The batteries in remotes are connected in series meaning both batteries are connected in one spot and its important to find the right connections on the remote, you want the neagative and positive connection that lead to the remotes circuit board not the connection that joins the two batteries together! I cant figure out a way to word that any better so if you need help just comment or message and I can walk you through it. if you wire them improperly it could lead to a short or damage to your remote.
Step 5: Adding the Solar Panel to the Remote.
since the remote I used isnt technicaly mine I just attached the panel using hot glue, then I ran the wires to the battery connections and squeezed them into the battery springs and once the batteries are in place the wires stay in place aswell.
Step 6: DONE :)
You are now finished and can charge your remote near a window and never have to worry about feeling guilty when using wall power :p. The charge time on this isnt as fast as using the charger for the wall, it charges the batteries gradualy and since remotes dont really draw much from batteries it should be very simple to keep the same batteries in your remote for a while :) My batteries take ten hours to fully charge on the wall so I simply just place my remote on the windowsill when I go to bed and by the time I get home from morning routines it will have charged quite a bit. I hope you enjoyed this project and I hope I helped :) If you have any questions just feel free to ask.