In article , Danny D.
wrote:
I would just like some advice since I melted a USB cable today
and I realized I don't have the proper troubleshooting skills.
I bought over a half-dozen "Hype Volt" 6.8Amp USB chargers for
stuffing the Christmas stockings:
https://i.imgur.com/Zavgm4B.jpg
I kept one for myself, but, when I used it last night on an iPad
and on an Android phone, the iPad lightning cable melted!
was it an mfi-compliant cable or a noname one?
When I pulled it off the iPad, it was noticeably extremely hot,
but it doesn't seem to have damaged the iPad (AFAIK).
probably not.
So, I'm just wondering what happened, and, more importantly, when
I look at the specs for this device, they don't make sense to me,
so, I have difficulty troubleshooting what the problem is/was.
Here are all the specs off the package and off the device:
DGL Group Ltd. Hype Volt HV-6PT
Model: HC363-5U (also listed as HV-6PT-WHT)
Input: AC 110VAC/60Hz - 220VAC/50Hz (800mA max)
Output: DC 5V, 6.8A total
Maximum Power: 40W
Supercharge: maximum
Universal: 5V@1A maximum
Description:
http://www.amazon.com/Hype-Compact-A...ter/dp/B00T3FQ
BHO
http://www.walmart.ca/en/ip/hype-vol...b-ports/600019
3376994
My questions are varied, because I don't understand how it works,
from what you've said, it doesn't work.
nor how it could have overheated the cable to the tablet.
Here's what it says on the package:
"Smart USB Technology: This adapter automatically adjusts power
output to fit your charging device. Tablets and e-readers require
2 Amp charging, and this adapter will reroute power to the
appropriate USB port you use."
"Charging Combinations:
- 2 tablets + 3 mobile devices
- 1 tablet + 4 mobile devices
- 5 mobile devices
- 3 tablets"
I am confused about both the pure math and how this operates.
Q1: Since 6.8A times 5VDC is only 34Watts (not 40 Watts), how
can they very clearly label it as a 40Watt device?
probably what it consumes, not what it outputs.
Q2: How does the device "know" to give tablets 2.4 Amps
(12 Watts) but a "mobile device" only 1Amp (5 Watts).
usb devices initially get 100ma and then request how much power they
really want. the charger responds with how much it can supply.
some non-compliant devices ignore the negotiation phase and either
output whatever power is needed and/or the device uses whatever is
available. that's probably the case here. however, that alone is not a
problem.
an easy way to think about this is a lightbulb. if you screw in a 15w
bulb, it will use 15w. if you screw in a 60w bulb, it will use 60w.
with a 200w bulb, it will use 200w. nothing about the light socket or
the house wiring has changed. it uses what it needs. a 15w bulb won't
be overloaded because the socket *can* supply more power.
Q3: What if a mobile device "wants" more than 1 amp?
Does the charger give more than 1A to the device?
a properly designed charger won't because it can't. it tells the device
"all you're getting is 1a" and the device says "ok".
a ****ty charger might, which can cause it to overheat.