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Topic: quick charge 3.0 phone drawing pulsing current (Read 872 times) previous topic - next topic

sir_guy123

We recently bought our first caravan (we love it) and one of the projects that I decided to do fairly soon was to make a few USB sockets. The 'van only has 2 mains sockets and (at the time) no 12v sockets. So a quick peruse on eBay and I was the owner of a car USB charger. It got immediately dismantled for its innards and I put it in a nice 3d printed enclosure on the wall.
Well it worked for a while but occasionally when phones were charging the lights in the 'van would pulse once a second, as though a drain or surge was occurring at 1hz. I started investigating this and found that it was when my friends smartphone was plugged in, it's QC3.0, the charger had one socket labeled iPhone and one socket labeled iPad, when the phone was plugged into the top one (can't remember which one this was) it would charge without pulsing. Well shortly after this the charger stopped working, (blown cap - replacement did not fix - probably IC gone) I assumed it was due to the phone trying to take too much power and the charger collapsing or the phone cutting off when the voltage dropped.
So I bought a 5A buck converter, wired it in, data lines floating, and I get the same symptoms (1hz pulse) now I'm convinced this is not the phone trying to take 5A (tested the buck converter to 4.5A on the bench) so it must be something to do with the QC. All the other phones and devices charge no problem on both setups. I will probably end up just copying the voltage divider from the socket that previously worked. It is made harder by the fact that the phone I need to experiment on is not mine and the owner doesn't want me 'experimenting' on it.
Basically does anyone have any idea why the phone's doing this? The 2 voltage dividers on each socket were different (3.something volts if I remember correctly) so the pulsing is occuring on both floating and connected data pins. I've done lots of research on QC but with it being proprietary I've only found data from people trying to get different voltages out, and nothing to help me here.

Paul_KD7HB

While FAR from an Arduino problem, perhaps you are powering the caravan from the mains through a converter to get 12 volts and battery charging. I suspect the mains converter is acting up. You did not try your charger directly off the battery. Do it.

Paul

sir_guy123

The 'vans not connected to the mains at the moment, so it's basically straight to the 12v battery through a fuse.
The vans thermostat is Arduino controlled. And I thought about putting a little oled dispay on the charger but considered it overkill. And I don't know where else I could have asked this.

Paul_KD7HB

The 'vans not connected to the mains at the moment, so it's basically straight to the 12v battery through a fuse.
The vans thermostat is Arduino controlled. And I thought about putting a little oled dispay on the charger but considered it overkill. And I don't know where else I could have asked this.
The what is left is a possible self resetting overload circuit breaker in the line you are connected to. Probably no schematic of the van wiring?

Paul

sir_guy123

There is, no resettable fuses. Just one standard fuse and a switch. I'm sure it's the phone.

sir_guy123

Got it! Shorting D+ and D- together works. Thanks for the help.

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