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Old 08-03-2014, 12:02 PM   #317
DNSB
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Quote:
Originally Posted by EndlessWaves View Post
It sounds like it's an Apple charger, that's one of the ways their nasty proprietary chargers worked.

Standard charging-only ports have the two data lines shorted together. If they're disconnected then the charger shouldn't be delivering more than half an amp (technically a tenth) whereas shorting them proclaims the charger is Battery Charging Spec compliant and can provide 1.5A.
Hmmm... minor nit. Chinese standard is to short D+ to D-. The European standard which came a bit later was to connect a 200 ohm resistor from D+ to D-. Apple's standard was to use a two pairs of resistive voltage dividers to hold D+ at +2.8V and D- at +2.0V for high current charging and both D+ and D- at +2.0V for low current charging. I ran into this with an old USB car charger that would not charge an iPhone 3 with the infamous charging is not supported with this accessory message.

Then we get into the mysteries of USB 3.0 charging...

Regards,
David
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