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Posted to uk.d-i-y
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Exploding cigarettes.
wrote:
On Saturday, August 9, 2014 12:17:07 AM UTC+1, Dave Plowman (News) wrote:
In article ,
Graham. wrote:
If they should ONLY be used with the supplied charger then they
shouldn't be using the USB standard interface. The problem is the cigs
surely, not the chargers?
That point was made by the fire officer interviewee. He said something
along the lines of different USB devices give differing voltages
Which is nonsense. Unless faulty or designed by an idiot, all USB outlets
supply 5 volts.
Unfortunately not, 5.25v has been used for higher charging current apps.
Not every appliance is ok with that.
I imagine, like a lot of cheapy crappy stuff, the fudge is to do with
charging current, not the voltage. Instead of bothering with a charge
control circuit, just cripple the supplied charger to, say, 25mA and let
thermal dissapation sort itself out. Plug in a proper "unrestricted"
500mA laptop/charger and all hell will, literally, break loose.
--
Scott
Where are we going and why am I in this handbasket?
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