Solar USB charger

[point5]

Hi,

A question for you

This summer we went camping and I wanted to be able to charge some usb devices whilst away from mains (phone, mps player etc). I had a 12V/250mA solar cell kicking about and connected this to a usb car charger - worked great..... except it killed my mp3 player When the sun was not intense enough or going in and out behind clouds the mp3 charge circuit was switching very fast sometimes - ie going from charging to not in a matter of seconds or less. I think it is this that killed the mp3 player - less intelligent' devices didn't mind this kind of abuse and charged as expected.

So to the question: what would be the best way to avoid this? Are there any circuits already designed to smooth out the solar charging process? I'm guessing that charging a capacitor and then passing this on to the device might work?

Look forward to thoughts

[sarma]

Perhaps you need to pre regulate your solar panel yo 5V , and then apply through usb socket for charging other devices. when under bright light the panel can deliver much higher voltages and currents( power)

I feel sad that you had your MP3 damaged. any USB supported charger should face %V supply.
as it is solar panel and at times the voltage can come down, better you may use Low drop out (LDO) regulators like LM1117
2930 or some device for 5V output
these LDOs can work with minimum of 5.6V to give you 5V output.

[thanx]

Perhaps you need to pre regulate your solar panel yo 5V , and then apply through usb socket for charging other devices. when under bright light the panel can deliver much higher voltages and currents( power)

[celinaaniston86]

Well, solar charge controllers for the 12v 260ah solar power are regarded one of the most vital elements of any solar system. Unfortunately, many people are unacquainted with its relevance and what it can actually do for the 12v 260ah a solar power supply.