Computers & Electronics

USB AC Adapter for Wireless

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  • Dec 22nd, 2019 9:07 pm
[OP]
Sr. Member
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Sep 15, 2012
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bv

USB AC Adapter for Wireless

Picked up some wireless charger and now realize that in order to get proper output I need to use a stronger USB-AC adapter. I’m using these on the iPhone 8 Plus so 7.5watts is the max.

Any affordable USB adapters to achieve this? The white Apple adapter doesn’t cut it and makes the wireless charger run like molasses and the charging pad is rated at 15watts..
7 replies
Deal Guru
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Nov 21, 2002
10183 posts
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Winnipeg
EdT586 wrote: That charger look dubious, have you try testing it at a load of 15W ?
yup use to use this on a first version rk3399 nanopi m4 which is very finicky with low power(5v vdroop) since it needs a dumb charger for max current. It worked perfect, now its used on an rpi 4. Every time there is a sale or freeshipping at prime cables these always go out of stock.

The harder part and more expensive that everybody neglects to consider. You need the proper rated awg cable to go with it. On USB Type A interface. Thats not very reliable for 3 amps to just find anywhere cheap. Basically with that interface it tops at around 2.5amps for most USB-A. you need a specialty cable for more amps(thicker gauge awg)
Penalty Box
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Apr 25, 2013
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lead wrote: yup use to use this on a first version rk3399 nanopi m4 which is very finicky with low power(5v vdroop) since it needs a dumb charger for max current. It worked perfect, now its used on an rpi 4. Every time there is a sale or freeshipping at prime cables these always go out of stock.

The harder part and more expensive that everybody neglects to consider. You need the proper rated awg cable to go with it. On USB Type A interface. Thats not very reliable for 3 amps to just find anywhere cheap. Basically with that interface it tops at around 2.5amps for most USB-A. you need a specialty cable for more amps(thicker gauge awg)
You're a perfect candidate for RuiDeng and similar USB testers and digital load meters if already don't own one, can also test the cable as well !
There is a larger problem with those USB-A to USB-C cables in that they used wrong resistor to trick the phone and charger to go into Quick Charge mode.
Nathan K. and Benson Leung two Google employees exposed this problem serveral years ago, even the large brands of cellphone companies provided improper cables with their phones.


Deal Guru
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Nov 21, 2002
10183 posts
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Winnipeg
I have a cheap one but it came with a wired usb cable(awg???) vs soldered hard end port. I wager it has cheap cable too so I don't give it too much validity. Only when I want to know roughly the power consumption.

The cheap ways sellers get around it is by selling under a foot cables. If the run is short enough you can alleviate the vdroop on cheap cables.

But then its a viscous cycle of cost saving once that became popular knowledge. Cause then they make even cheaper quality shorter cables and people still think it'll be fine. But basically inside probably scandinavian hairs for wires.

I found some old filtered mini usb cables with thicker gauge wires atleast 24awg. Stiff strong much thicker that what people see today. Back in the day people used heavier grade in the beginning of it all when people cared. I ordered some mini usb to usb-c adapters since they are just basically direct soldered port extensions no wires. I am going give them a try. No data speed or smart charging cables just raw current....maybe upto snuff and give some life for these old cables vs chucking them. I could strip and resolder my own ports but the adapters were cheap.
Penalty Box
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Apr 25, 2013
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Copper is a much sought after commodity so smaller gauge and less strands is the name of the game these days. From my test an USB cable should not be more than 3ft even "some" 6ft cables are passable after going through a dozen of them to find one good one.
A good cable is normally would round in the package, the crappy ones are bunched up with a twist tie.



Testing USB cable for resistance with a USB meter

[OP]
Sr. Member
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Sep 15, 2012
720 posts
160 upvotes
bv
Dollarama has some USB C/ Regular USB AC Adapter, rated for 3.1A for $4. Anyone use that, is this worth it?

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