Ever wondered why photovoltaic solar panels were so expensive? Me too. So I decided to try and build my own panel and I learned some things in the process.
Materials (unfortunately the company that made my cells and shipped has closed, but any quick search on google or ebay should get you quick results for the following):
-Sodering iron (pref. 100 W) – I assumed you have one, and some solder (you’ll burn through solder in this)
-Flux pen (mine looks like this):
-0.5 V solar cells for 36 V maximum solar panel
-Frame (wood, steel, whatever)
I used also some meters of insulated copper wire to soder the terminal of the panel and make a long connection that can power stuff inside my house.
WARNING: These solar cells are fragile and should be handled carefully. I ordered a lot of them since they break easily. This is how they look:
Basically all you need to do is soder the tapping wire to the surface of the cells, using the flux pen (paint the white parts of the cell) and then put the tapping wire over than line and with the sodering iron press gently OVER the tapping wire and it will soder. Then turn the cell over and the cut the wire that is now protruding about the length of another cell. Put a new cell under the tapping wire and with a blob of solder, solder the tapping wire to the BACK of the new cell. Now the first cell and the new cell are in series. Now you just have to turn both over and keep doing this.
The front of the cells act as the negative terminal(anode) and the back as the cathode.
As you finish your setup, it should look like this (this example output a 9V voltage with a current of about 200 mA):
Now you just have to encase the panel (I would advice a frame much like a painting with a glass or plastic cover), glue the solar cells to the wood panel and you have a 9V generator. Now what uses can this have?
In series with a diode (I used a schottky diode much like this one: http://www.nxp.com/products/diodes/general_purpose_schottky_diodes_250_ma/ ,if you add more cells than mine be sure to use you amperemeter to check the current and get an adequate diode) the diode acts as a reverse polarity protection, which means you can use your solar panel to charge batteries without worrying about the batteries frying your solar panel.
I built an iPhone/iPod charger. The wire looks like this:
The data wires of the charger need to be connected with a 10k resistor (green and white wires, this is used to bypass some software details with the devices), the ground is the black one and VCC is red and this takes in about 5V to charge. These small multi strand wires are fragile and you’ll need patience to take the insulation off and soder them. Also be sure to hook up two potentiometers in series with your solar panel input (after hooking the aforementioned diode in series) to act as a voltage regulator. Alternatively you can use two resistors as a voltage divider for a fixed voltage, in this case 5 V. Since my setup outputs 9V, I used 2 potentiometers in series and regulated it until I got 5V, and your iPod/iPhone will light up and charge!