I made a solar cell phone charger, connected a 220μF capacitor in parallel to the input of the circuit, and then connected L7805CV in series! A 100μF capacitor was connected in parallel at the output terminal, and 1N4001 was connected in series at the output terminal, and finally the output was connected to the mobile phone! Requires output current of 4.8~5.1V around 450~500mA! How many V and how many mA solar panels should be selected? What specifications of solar panels should I choose?
Well do you want it to work in overcast conditions or only in direct sunlight?
In the former case about 5A rating, latter only 500mA.
The 7805 needs 7V at least on the input so 18 cell array would be enough
(in overcast conditions about 0.4V per cell, direct sun about 0.5V, for silicon PV cells)
You may want to consider what happens if the light level is somewhat too low - does the phone handle this gracefully?
If you put the diode before the regulator you'll get the full 5V out.
Your circuit will eventually get very hot and fail. You need high frequency bypass capacitors on the 7805 for starters. The datasheet shows them in the application drawing.
Thank you for your answer. I want it to work in direct sunlight and now I know how to handle it. Appreciate it!
Ok, I see that. Thank you!
You are welcome, have a great week!