USB charger voltage question / red-black=3V, red-mesh=5V

[gthalassinos]

I am trying to provide 5 volts to a device from a retired iPhone charger. I have read that the red cable is V+ and the black V-/ground, providing the 5 Volts. In my case the difference between red and black is about 3 Volts but I get 5 Volts between the red cable and the mesh that surrounds the cable, which is obviously the grounding. Perhaps that is the reason that the charger is retired, as it would no longer charge the iPhone (given the mere 3 Volts).

Can you think of any reason I should not use the 5 Volts between red and mesh?

 

[FRITZHID]

No, it should be fine. I'd suspect that the black wire was damaged at some point so it's not allowing the full amount of power thru.

 

[gthalassinos]

Thank you Fritzhid!

 

[SemiMan]

I am trying to provide 5 volts to a device from a retired iPhone charger. I have read that the red cable is V+ and the black V-/ground, providing the 5 Volts. In my case the difference between red and black is about 3 Volts but I get 5 Volts between the red cable and the mesh that surrounds the cable, which is obviously the grounding. Perhaps that is the reason that the charger is retired, as it would no longer charge the iPhone (given the mere 3 Volts).

Can you think of any reason I should not use the 5 Volts between red and mesh?

Iphone charger cables have a voltage divider between + and -, that puts if I remember 3V on one of the signal lines. This is to tell the Iphone it's a charging cable.

 

[gthalassinos]

:twothumbs