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The problems with cheap 5v adapters

humptybump

Well Known Member
There have been a few posts regarding the use of the 5V cigarette plug chargers for mobile devices. One issue is that some of these generate interference in radios and other electronics.

The fact is they do.

Some are better made and better filtered than others.

I recently diagnosed an issue that was directly related to a noisy cheap 5V adapter (thankfully not in my airplane).

http://thesalmonfarm.org/blog/p/5790

wpid-Photo-20151205064427866.jpg


I still like the convenience and flexibility of using a 5V cigarette plug adapter but I now keep "the good one" in the plane.
 
Very same thing happens in my wife's car. Tire Pressure Monitor System (TPMS) light comes on after a while of using a cheap cigarette lighter adapter. Took quite a while before I figured out what was causing it.
 
Linear...

Does this mean we have to go back to the "7805" linear regulators instead
of the switchers just to keep noise out of our comms?

John
 
We use these in our panels:

http://www.commitlift.com/

Sometimes you get what you pay for.

Rob Hickman
Advanced Flight Systems Inc.
N402RH RV-10

I just flew with one of these in my RV7 on Tuesday, powered my iPad Air and charged my iPhone just fine. It is mounted under the panel then the two lightning connectors pass over the SCAT tube for the vent and are stored in the side pocket. WORKS GREAT! I'm happy!!!
 
How does one distinguish the good plug-in chargers from the bad?

Buy from an aviation related or other known source or take your chances.

I was at OSH a couple of years ago and saw a double outlet charger in Sporty's booth that was cheaper than many automotive units I have observed.
Bought it. Works great. It is in their catalog.

Last week I decided to add a permanent USB charger outlet because SWMBO has commandeered the current single 12V outlet. Just ordered from Stein. Do I expect problems from that unit? I don't think so.
 
Re MyGoFlight DualMicro USB adaptor.
Is ther a problem with these?
This is a customer review from Amazon:

http://www.amazon.com/DualMicro-28V-Rapid-Charger-Output/dp/B00O3KF1XE

"1.0 out of 5 starsFortunately the flight was in VFR conditions and nothing in ...
By Gary L Miller on October 12, 2015
On September 20, 2015 on a flight from w95 to KAGC we loss the ipad,
iphone, and the stratus. All three will have to be replaced.
During the flight my wife observed the ipad smoking at the charger
connection. She disconnected the ipad and we started using the iphone.
Not thinking that the problem might be the cigarette lighter charger
we plugged the iphone into the charger. It very shortly it stopped working.
Still not realizing the problem was the charger we did not unplug the Stratus
from the charger. Fortunately the flight was in VFR conditions and
nothing in the panel was effected and we were able to complete the flight.

I took the apple produces to the apple store and they could not get either of
them to respond and suggested I replace them. Kal at Appareo said
about the Stratus "the USB protect chip was blown which resulted in
damage to the circuit board". The failure seems to be the charger,
a mygoflight, it is outputting 24.4 volts when it should be only
outputting 5 volts. Ignoring the financial cost this a very
dangerous. We often fly long distances and find it convenient to just leave
the ipad and Status plugged into the charger."
 
If I recall a conversation I had correctly, a friend who flies charter jets mentioned that one of the conditions that FAA imposed on its approval to use ipads for charts in flight was that they NOT be plugged in to a charger.
 
I just changed my intercom to a Dynon. I have an adapter for my iPad that isn't a USB. It has a Lightening Cable hard wired directly to it and it was relatively quiet with the old intercom. Not so with the Dynon. It was really noisy.

I swapped it out with a Volmate USB adapter and Lightning Cable and it quieted right down.
 
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Or install one of these and have two USB charging ports with a total of 4.2A and no interference at all. Full disclosure, these come from my company, but they work and don't have interference problems.

http://aircraftproducts.wicksaircra...sb-panel-mount-charging-jack/usbchg?forward=1

http://www.aircraftspruce.com/catalog/elpages/eadualusbpanel.php?clickkey=264635

Thanks for posting. I installed one of these in my -7A but not yet flying. I wondered if I would have interference issues in the future.
 
Not just shielded; you need a decent quality and quantity of copper in the cable too.

We have a cheapy conspicuity gadget in the UK that receives ADS-B, detects Mode C, and RX/TXs a low powered signal too, all based on an educational credit-card computer called a Raspberry Pi. I think there is something similar state-side.

Aaaaanyway...
The R Pi is powered from a USB connection and it has been found that a cheap and lightweight USB cable causes a sufficient voltage drop to cause the computer to malfunction (brown-out).
A 20awg USB cable is specified / supplied by the group making and circulating these devices. The cable is sold by an outfit called Juicy Bits.

The other thing to be careful of is the current draw of some USB devices (including the R Pi) can reach around 2 amps. A lot of the ciggie lighter USB adaptors are only rated around 1.1 / 1.2 amp.
 
I have found the StarTech cables to be really good quality. My phone and Tablet as sensitive to "insufficient power" to charge properly errors when using most cables but not the StarTech cables. The cable is .220" in diameter. This supports your comment about the wire quality.
 
I have one of those. It can keep up with the phone but not with the largest iPad. No noise.
 
I have one of those. It can keep up with the phone but not with the largest iPad. No noise.

It charged the iPhone 6S+ (was at 16%) and the iPad (was at 56%) BOTH AT THE SAME TIME all the way to 100%. They both had screen brightness at 100% and were both downloading the latest databases for WingX at the time. It took about an hour total but at least I know it will charge while I'm flying and using it.
 
It charged the iPhone 6S+ (was at 16%) and the iPad (was at 56%) BOTH AT THE SAME TIME all the way to 100%. They both had screen brightness at 100% and were both downloading the latest databases for WingX at the time. It took about an hour total but at least I know it will charge while I'm flying and using it.

I just installed the same one and it works very good. I plugged one of the adapters into my first 12 and it sounded like the Amazon Rain Forest at night time in my headset.
 
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