Build a Solar Powered Laptop Charger
A method for powering portable computers by photovoltaic means. Netbooks, notebooks, MP3 players charged by the sun....
Steps
- Start small until you understand what you are doing and work your way up. Read more on the solar cell they are interested in using and read up on panel design techniques. Basically the solar cells must be mounted inside a housing which has to be sealed from the elements to prevent dust and condensation from forming on the cells which will reduce the power output severely.
- Ascertain exactly what your power requirements are. If you are designing for a specific device, read the label on your device or its power supply; this will specify the voltage and watts required to charge your device. If you are trying to design a charger for multiply devices, you must use the maximum voltage and wattage of the most power hungry device in your target group. - it will require a sizable panel to charge multiple device simultaneously. If this is your goal, design the charger to produce 110 or 220, whichever is your normal power line voltage. Then just use the standard chargers and plug them into the panel - this will save you a lot of design time for making multiple d.c. voltages available for different devices, it will also give you more flexibility in adding future device.
- If you are designing for a single voltage/wattage combo, i.e., 12volt 12 watts, the conversion of Watts to Amps is governed by the equation Amps = Watts/Volts:
- For example, 12 watts/12 volts = 1 amp - so there is your design spec, you need to build a device that will output 12 volts - if you want to charge the device directly from the solar panel without using the power adaptor that came with your device, you also need to understand what sort of charge cycle your battery requires. Different battery chemistries require different charging techniques. This wiki explains some of this: http://en.wikipedia.org/wiki/Trickle_charging.
- Read up on parallel and series wiring - which is not very complicated - basically if you tie the "+" of one solar cell to the "-" of the next solar cell and repeat this your voltage will be a multiple of the number of cells tied together - i.e. if each cell is .5 volts and you tie 24 cells together like this, you will have a panel that is wired in series and produces 12 volts (24 x .5) - this does not multiply wattage/amperage, only voltage. So if your cells output .5 volts and 10 watts, your panel will output 12 volts and 10 watts. To increase wattage you tie multiply panels together using parallel wiring, in parallel wiring you tie the "+" wires from the other panels together and the "-" wires together with the "-" wires from the other panels - do not tie the plus and minus together or you will short out your panels. So if you tie two panels together (each panel is wired in series) in parallel, you will now have an output of 12 volts and 20 watts. You use this technique to combine cells into panels to produce your desired output voltage/amperage/wattage per your spec.
- If you are building an ac voltage panel, add an inverter which converts d.c. to a.c. and supplies a clean sine wave so that any device you plug into the panel will operate properly.
Warnings
- Solar cells can produce lethal voltages, understand what you are doing before you start. Use small cells and low voltages until you understand what you are doing. If you kill yourself, no one is at fault except you, so don't try this if you don't understand what you are doing. Millions of solar panels have been built and very few people have died, but you could be the unlucky one if you don't pay attention and understand what you are doing.
Related Articles
- Make Solar Cells
- Power a Standard Mp3 Player With Lemon Batteries
