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Is this safe? Answered

Hi Guys,

(Link: http://www.youtube.com/watch?v=bbWH0novdvA oh and can you check this one too? https://www.youtube.com/watch?v=YJVotolzaqU)

I found this cool and awesome charger on the internet and I wanted to make that until I saw the comments on the video. Can you guys please have a quick look on the video and tell me that will this work or not. Thanks in advance.

-Prickly Potato


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Best Answer 5 years ago

Will it work? Yes.

Is it safe for your phone? Maybe.

The voltage is not regulated. You get 4x the cell voltage that may be up to 1.65V (fresh alkaline cell) minus the drop at the diode (Uf = 0.7..0.9V) minus the voltage drop on the resistor (which is current dependent). So, worst case (fresh cell, low Uf, no load): 4 * 1.65V - 0.7V = 5.9V - a bit high . Under load (lets guess 0.5A) and nominal cell voltage: 4* 1.5V - 0.7V - 0.5A*1.2Ohm = 6V - 0.7V - 0.6V = 4.7V - okay, just a tad low. With 1A current, you'll get 0.6V less.

So, the unloaded voltage is a bit high. It is most certainly outside the spec of your phone. Nevertheless, it will most probably work, just ... there is no guarantee. You _may_ brick your phone.


5 years ago

Safe for you, if you still have two working eyes and good skin on your phalanges after that capacitor short :-)