MP3 player fried by USB car charger... Common problem???? Answered
Just fried my MP3 player, by sticking its mini USB cable in a compound outlet: 3 cigarette lighters, and one USB outlet. The car outlets measure 12.3 V, the USB outlet measures 4.7 V. It is specified for 2000 mA.
I put a switch between the battery and this outlet. The (scooter) battery is wired in series with a similar one, for powering a 2 X 15 W amp; each battery can be switched to a separate compound outlet (described above) for powering gadgets, or to be charged. The plugs of the compound outlets (containing a fuse) have been removed.
The player was playing, connected to the amp; the USB was plugged into the compound socket when the switch was activated. A very loud pop sounded. Now the sound of my MP3 player is very weak and extremely degraded.... :(
I used to charge it via my computer or by means of the mains USB charger provided with it. Never any problems!!!
My 1st theory is: destruction by peak voltage... But should the electronics not have prevented this (I did not open it, but it is probably based on a 7805 circuit)???
2nd theory: Current too high. USB is normally 500 mA??? This would mean the USB player behaved like a LED (very low resistance, needs current control????)
I bought my nice former 8 GB player for E 15... But it is now discontinued... Before I connect another one, I would want to know how to keep it alive while playing it hard!