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inductive charging problems
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Please be positive and constructive with your questions and comments.

inductive charging problems

by Addman on Wed Sep 24, 2014 11:40 pm

I got the Inductive Charging Set (5V @ 500mA max) for a phone charging projects. after reading the tutorial and some forum post on the subject. i first tied the charger on a 9v battery and led red, which glowed fine but wouldn't power my phone(A Nexus 5) when i tried. i measure the output of the charger and got ~5v. I surmised the 9v battery just wasn't sufficient so I tested with a wall adapter (12v 500mA). but the chip got hot i unplug it immediately but i think i fried the chip. was i out of spec ? if so how much would you recommend powering the transmitter?

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Re: inductive charging problems

by adafruit_support_bill on Thu Sep 25, 2014 6:28 am

It is rated for 9-12v DC (If using a wall adapter, make sure that the output is regulated DC. Some are AC, or sometimes just rectified AC.)

Keep in mind that these are only about 40% efficient. So to get 5v@500mA (2.5W) out to charge a phone, you need to put 6.25 watts in. At 12v, that would be about 550mA. All that excess power has to go somewhere. So it gets dissipated as heat.

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Re: inductive charging problems

by Addman on Thu Sep 25, 2014 2:21 pm

How would u suggest displacing that heat. Could i use a heat sink?

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Re: inductive charging problems

by adafruit_support_bill on Thu Sep 25, 2014 2:39 pm

Not sure about these, but most power components can tolerate pretty high operating temperatures. But a heatsink never hurts. We have some small ones - and some thermal adhesive tape to go with them in the store.

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Re: inductive charging problems

by Srinivasa on Tue Sep 30, 2014 7:41 pm

Hi,

Recently we purchased 10x mini Heat sink #1515 and we are interested using the same , However we did not much Information form your website such as ,
RoHS and also manufacture details. Is it possible to provide Techincal information along with RoHS and Manufacture details for documentation ?

Thanks
Regards,
Srinivasa Govndha

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Re: inductive charging problems

by adafruit on Wed Oct 01, 2014 12:56 pm

we will request this.

cheers,
adafruit support

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Please be positive and constructive with your questions and comments.