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DC to DC Convertor? Answered

Does anybody have a circuit that is able to turn solar power from a solar panel (preferably 1 watt) to make enough juice to recharge an iPad?

The iPad requires 10 watts of power to charge.

I wanted too use Adafruit's mintyboost but I don't think that has enough power to charge the iPad.

Any suggestions?

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steveastrouk (author)2011-10-26

If you want 10W from the charger, you need slightly more than 10W from the panel - nothing you can do can create more energy than you put in. All you could do is use a 1W panel to charge a battery, so that IT can be used to charge the Ipad - but if you need 10W for 1 hour to charge the Ipad, you'll need 12-14 hours of charging to get enough energy in the battery to do the job


Steve

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user

What if I have an 18 volt panel?

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user

10 W under full sun conditions - what's actually practical ? Usually less than half that on average (in the UK, its a LOT worse than that !)

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frollard (author)steveastrouk2011-10-26

I'm pretty sure the ipad is one of those annoying ones that won't even accept the power if it's not available to flow at 10w...it just won't accept a trickle charge.

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blinkyblinky (author)2011-10-27

I need a cheaper solution than a 12 watt panel.

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CameronSS (author)2011-10-26

If you need 10 watts, you need 10 watts, and 1W isn't going to do it.

A DC-DC converter changes DC voltage. You can increase voltage with a corresponding drop in available amperage, or decrease voltage with the opposite effect, but watts are power, volts times amps. Watts into a DC-DC mostly equal watts out, ignoring the efficiency loss.

In other words, you need to add power. If you need 10W to charge an iPad, you need a 10W (or greater) supply. Get a 10W solar panel, hook up ten 1W solar panels, hook it up to a bicycle generator, but you can't increase power with a just a circuit.

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