Cigarette Lighter and USB Adapters

[Ed Kellock]

I believe the rear cig lighter is also disabled if you disable the rear
windows from the drivers armrest console.

Ed
 


-----Original Message-----
From: quattro-bounces at audifans.com [mailto:quattro-bounces at audifans.com] On
Behalf Of Marc Boucher
Sent: Friday, December 16, 2011 10:13 PM
To: quattro at audifans.com
Subject: Cigarette Lighter and USB Adapters


Just noticed that the rear cigarette lighter stopped working in my 1990 100.
Lighter is good, ground is good, but there's no power.  Fuse is good.  Was
wondering if anyone had experienced failures with this and knew the likely
failure locations and/or repair.  (Preparing for some holiday road
trips...Sister-in-law needs to keep nephew entertained/distracted with
movies on long drives).

On a related subject, this may be a little NAC, but I'm currently shopping
for USB adapter for ipod/iphone/ipad, etc.. You can charge an iphone on as
little as standard USB, ie 500mA.  On the other end, the max charge for an
iPad is 2A.  And there are some lighter adapters that have two usb slots.
Thus you can get adapters that put out 

as little as 
500mA x 5V = 2.5 Watts

or as much as
2A x 5V x 2 USB slots = 20 Watts.

The question I have is, would an adapter that's plugged into the cigarette
lighter draw power based on what it can supply, or based on what is demanded
from it?

ie

assuming I've got the dual USB adapter, which can output as much as 20
Watts, but I've got a single iPhone plugged in, which can draw a maximum of
5 Watts, is the draw on the car's electrical system going to be 5 Watts, or
20 Watts?  


Thanks
MC
_______________________________________________
quattro mailing list http://www.audifans.com/mailman/listinfo/quattro
http://www.audifans.com/kb/List_information