Hmmmmmmm... Your at the airport. Your hugging the wall as you try to figure out which adapter to plug in, the one for you iPod, our our Galaxy S4... Hard decision, right? Which one has more music, better apps, etc. Eventually, you choose. The samsung won. Well, what about you iPod? It has good music and apps that you would also like to use. Oh well, the 7 hour flight will be used up with the phone...
NOT ANY MORE!
Thanks to on-off-on switches (and our amazing minds here on the website), I was able to come up with a way to combine an iPod and Samsung charger. Not only is it battery powered, but it can be solar powered! With the male headers soldered to the battery clip and solar panel, I can plug it into the main board of the circuit and power it either way I want! Sunny day? Solar.
Crummy day? Night time? Battery.
So, this thing is a win-win. Pack your battery and solar panel, and if your airport (some reason, let you take this on a plane, which I doubt, and you do too probably. Why did I use that kind of a story? Oh well, I'm not going to go back and think of a whole different story...) lets you bring it past the metal detector, you will never ever have to go through that decision again!
Step 1: Get some parts!
There are a few parts to this project...
1- 9V battery clip
1- Switch (if you want to control the current. It may heat up, I recommend one)
1- LED (If you get one, you will need a 330-350 ohm resistor)
1- 22uF capacitor
1- 7805 Voltage Regulator
1- 10nF capacitor
1- ON-OFF-ON toggle switch (not optional)
2- 33k resistor
1- 22k resistor
1- 10k resistor
1- Female USB (There are a few that are pre-wired, like a phone USB connector. You can open it and use those wires for the charger. If you get a regular one, you will need to find a USB pinout on Google Images...)
Small perf board(s)
-Casing (I used an Altoids tin)
Step 2: How do we build it?
To build it, take your 9V battery clip, and solder the red (+, anode, etc) wire to the toggle switch. When done, take a wire and solder it to a perf board. Make sure you have measured it to be a good fit for the enclosure. Now take the black (-, cathode, etc) to the perf board. Now, you have control of the overall circuit. Now, take your LED resistor (the 330-350 ohm) and solder it to the + wire. That resistor will keep the LED running longer. Solder the longer leg of the LED to the other end of the resistor. Solder the shorter leg of the LED to the - input. Now you have an indicator that the circuit is on. Test it real quick to see if the switch is working. Now solder your 22uF capacitor to the circuit. It will come after the LED, but not hooked up to the 330-350 ohm resistor. The side with the shorter leg and arrow is the - side. The longer leg is +. Now take the 7805 and solder it after the 22uF. If you look at the side of the 7805 with the letters and numbers, the leg on the left is the input leg. The middle is your ground (YOU MUST SOLDER IT!), and the right sided leg is your 5V output. Now, solder the 10nF capacitor. The one I got had no-polarity, so I could solder either leg to the ground and the output. That may be enough for many devices, but for Apple and Samsung, they decided they would make us pay $20 for a wall charger. Smart idea for the fat cats, but for tinkerers, we'll find the loop-hole. And we did. A voltage divider will do do the trick. But before we do that, we will need to use the on-off-on switch. This will control the current to the voltage divider. And with two devices, two voltage dividers. So, take a wire coming from the + side of the 10nF capacitor and solder it to the middle leg of the switch. Take 2 more wires and solder them to the other 2 legs of the switch. Now, take another perf board and solder the 2 outside wires of the switch and solder them apart. Give them some space, the 33k resistors are going to get their own wires. After you soldered the 33k resistors, take the 10k and 22k resistors and solder them next to each other, with a holes space between them for the - wire. Take that wire from the 10nF that is the - input and solder it to the 10k and 22k... They do not need to be separated nor need a switch. The voltage divider is almost done. All we need now is to take 2 wires (I know, a lot of wires), and solder it to the two middle pins of the USB. You can solder the USB to a board. You may need to take a dremel and drill some bigger holes for the two outside holders. I used a perf board on the USB. Now, the last two wires. The last ones are (again) soldered to the 10nF. Hook them up to the + and - of the USB. Now, if you don't want a V.D. on, you may be able to charge a few devices... Look up a USB pinout on Google images if you don't know what it is. Now all you have to do is use a dremel to cut out the holes for the switches, LED, and USB. If you want, put the LED in a bezel, which will be a nice mount for it. That is what I used.
Step 3: DONE!
If you want to, spray paint it. I did not, just because it takes a lot of time. But, it is a nice charger, it works, and is nice to keep in your pocket. It will not charge as fast as a wall charger, just because the battery is not powerful enough, but it will help!
What should I build next?