USB adapter Question

[Richgj3]

Friend just bought an airplane with a 28 volt system. Will a standard off the self adapter run on 28 volts or is there a special one? Google has me confused.

Thanks

Rich

[wireweinie]

Some do, some don't. You'll need to check the 'voltage in' spec on the adapter. Most will say something like '12 volts DC only'. You need one that gives a voltage in spec that covers 28 volts, such as '14 to 28 VDC' or '9 to 33 VDC'.

Web

[Richgj3]

Thanks Web

i searched better and did find some that say 12/24. Many of them as advertised don’t say the input voltage. But all good now.

Rich

[frequent_flyer]

Friend just bought an airplane with a 28 volt system. Will a standard off the self adapter run on 28 volts or is there a special one? Google has me confused.

A search for "28 volt USB port" answered the question for me.

First thing to check would be the voltage at this aircraft's "cigarette lighter" socket. If it is 12 V then any of the car USB adapters will work. If the voltage is 28 V then a USB adapters specified as 28 V compatible would be needed. Most of these adapters use switching regulators and some produce more RFI than others. I have a couple of Anker adapters and have not noticed any RFI problems. Have not checked them with a spectrum analyzer though.

Some discussion here - https://mooneyspace.com/topic/18393-...8-volt-system/

edit to add - I see you found the answer while I was typing.

[Richgj3]

The plane is an L19 and doesn’t even have a socket now, so we probably will install a panel mount. I did find at least one that is 12/24.

Rich

[dgapilot]

A lot of automotive USB adapters will create a lot of noise in your radios. They aren’t well shielded and the switching circuits create a lot of RF.


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[jrussl]

A lot of automotive USB adapters will create a lot of noise in your radios. They aren’t well shielded and the switching circuits create a lot of RF.


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A somewhat related issue……..I bought some aftermarket GoPro batteries and they came with a charger that allowed them to be charged by power supplied by a usb cable. I thought this was going to be great as I could charge batteries while flying. No go. When the charger was plugged in, the comm radio was completely unusable. Talk about noise! Took me a couple of minutes before it dawned on me what was going on.

Jeff


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[Farmboy]

And now you know why they make 25ft usb cables. lol. Yes, I have one too.


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[Cub Builder]

Friend just bought an airplane with a 28 volt system. Will a standard off the self adapter run on 28 volts or is there a special one? Google has me confused.

Thanks

Rich

FWIW, I installed two of these dual port adapters in each of my planes, one of which is 28V. No PMA, but works well and doesn't create any noise or interference. $20 from Aircraft Spruce. <https://www.aircraftspruce.com/catalog/pspages/usb-adapter.php?clickkey=27926>

[behindpropellers]

In addition to radio interference, you should also be looking to see if a USB adapter uses charge negotiation. Charge negotiation allows for the max current delivery to be made to the device.

I once sent in a radio to get repaired. The radio was fine. The friend that I took with me to OSH had plugged in his cheapo USB charger...

Tim

[frequent_flyer]

FWIW, I installed two of these dual port adapters in each of my planes, one of which is 28V. No PMA, but works well and doesn't create any noise or interference. $20 from Aircraft Spruce.

One Aircraft Spruce review for this product reports "static on headphones". Switching power supplies usually generate RFI in fairly narrow frequency bands. If the emission is not at, or close to, a COM frequency that you use then you won't hear it. If it is close to a frequency you use then you'll be out of luck.

It's not just switching power supplies that can interfere with COMs. All clock oscillators of tablets and cell phones also radiate at discrete frequencies. You may be lucky and you may not be. Switching supplies usually produce "hash" but tablet and phone clock oscillator will usually radiate a clean signal on one stable frequency. They can produce a beat tone in the same way as a stuck mic does.

[bcone1381]

I am not a tech guru. I have a son who is though. He taught me that if I install the typical USB plug (that I always try to insert upside down) that has been around since about 1996 into my Patrol build, then next year I'll probably wish I had installed a USB-C type of a plug....different from the 1996 version. (it can be inserted either way).

This one has both and is manufactured by Radient. They make electronic light weight airplane stuff so I imagine they know about radio buzz and switching. Its not 28V though. It requires 9-13V.

[Farmboy]

Well if you’re going to spend the big buucks….


Transmitted from my FlightPhone on fingers…

[frequent_flyer]

It's not just switching power supplies that can interfere with COMs. All clock oscillators of tablets and cell phones also radiate at discrete frequencies.

I used a spectrum analyzer to sweep the tablet and cell phone that I often use in the airplane as an "EFB". I could find no significant radiation in the aircraft band. The offender that I had looked at a few years ago was my Stratux ADS-B receiver. This is Raspberry Pi based kit that has quite strong radiation in the aircraft Coms band. Later models may have improved shielding. (Note Stratux, not Stratus)

[wireweinie]

Well if you’re going to spend the big buucks….


Transmitted from my FlightPhone on fingers…

With that name on it, you will.

Web

[wireweinie]

FWIW, I installed two of these dual port adapters in each of my planes, one of which is 28V. No PMA, but works well and doesn't create any noise or interference. $20 from Aircraft Spruce. <https://www.aircraftspruce.com/catalog/pspages/usb-adapter.php?clickkey=27926>

I've put a bunch of these in airplanes over the last few years. I've had two that made noise, so I can live with that ratio. At less than $20 I'm also ok with the bill when I give it to the customer. Pretty tough telling the owner that you're going to charge him $200+ for a unit that works the same way as the cheap ones. Always size the breaker to protect the wire and check for noise before the customer picks up the airplane.

I suppose that I'll need to source ones that have the newer style port, now.

Web

[Farmboy]

Yeah my 20’dollar one worked great as well. Of course not much to disrupt, one comm.. But if you find a good type C version let me know as the power output is much better
I’ve also found some cords don’t allow the same charge rate that others do, sadly.


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[Utah-Jay]

I had a USB/cigarette lighter unit, it created lots of noise when I used it to power my GoPro that had the plane audio hooked up. Maybe I was just unlucky

Here is an example of the noise: https://youtu.be/zFGLkdIs2So

[40m]

And remember that some draw power whether a device is plugged in or not, may not be much but over time in a plane not flown much it may be best to have it switched.

[bcone1381]

Thanks! I will power mine from the main bus to ensure no power draw when the battery master is off.

I just saw that Sporty's has a cigar lighter plug in unit with both old and new USB receptacles, works with 12v and 24V. inexpensive, displays system voltage.

https://www.sportys.com/flight-gear-...e-charger.html

[behindpropellers]

Thanks! I will power mine from the main bus to ensure no power draw when the battery master is off.

I just saw that Sporty's has a cigar lighter plug in unit with both old and new USB receptacles, works with 12v and 24V. inexpensive, displays system voltage.

https://www.sportys.com/flight-gear-...e-charger.html

Sometimes.... you just need to spend some $$ and buy a decent one. I would not even put one of these in my car. No chance they include charge negotiation for $15. Anker makes decent auto units, and they will actually charge your Ipad while using it.

[CamTom12]

No issues with this one. Charges my iPad while the screen is on. No radio noise, either.

Car Charger, Anker Quick Charge... https://www.amazon.com/dp/B01K9MQ8WW...p_mob_ap_share

[hotrod180]

I installed a couple of micro-USB adapters, hardwired to the avionics circuit,
to power my stratux adsb-in and to keep my tablet charged.
They seem to work flawlessly.
I also bought a 2-port cigar-lighter usb adapter, similar to the pic.
The voltage display is a nice feature.
Clued me in once to a popped generator breaker.
It's been in place for months, but I don't think I've ever actually used it for it's intended purpose
(charging my phone if required).
Think I'll try it out today to see if it generates any radio static etc.

Speaking of charging phones, a hardwired usb adapter that's not on the master
(on a separate circuit like an electric clock) would be handy.
For when you're camped out (or whatever) & need to charge your phone (or whatever).
I know a guy who alligator-clips a USB adapter to his battery for this purpose,
but that's not a very elegant solution.

[wireweinie]

Speaking of charging phones, a hardwired usb adapter that's not on the master
(on a separate circuit like an electric clock) would be handy.
For when you're camped out (or whatever) & need to charge your phone (or whatever).
I know a guy who alligator-clips a USB adapter to his battery for this purpose,
but that's not a very elegant solution.

If you need to do that, consider using a jump pack and the proper adapter. They are made for that and it will insure that you don't run your aircraft battery low.

Web

[Farmboy]

I thought I posted this, but I installed this in my first cub and it worked great.


Transmitted from my FlightPhone on fingers…

[hotrod180]

....I also bought a 2-port cigar-lighter usb adapter...
The voltage display is a nice feature.
Clued me in once to a popped generator breaker.
It's been in place for months, but I don't think I've ever actually used it for it's intended purpose
(charging my phone if required).
Think I'll try it out today to see if it generates any radio static etc.....

Tried it out today-- hooked my phone on to charge while flying to lunch.
No static on any of the radio freq's I tried.
I bought this at Walmart a year or two ago,
I think it was less than ten bucks.

[Steve Pierce]

So I installed this USB charger under the panel like I have done many times before and this one makes a lot of noise when the owner's iPhone is plugged in. This airplane has a master relay on the firewall so I wired off the switched side of it and grounded to the firewall at the base of the relay. It is close to the Becker radio. Ideas" Bad charger, to close to the radio? https://www.aircraftspruce.com/catal...sb-adapter.php

[sjohnson]

So I installed this USB charger under the panel like I have done many times before and this one makes a lot of noise when the owner's iPhone is plugged in. This airplane has a master relay on the firewall so I wired off the switched side of it and grounded to the firewall at the base of the relay. It is close to the Becker radio. Ideas" Bad charger, to close to the radio? https://www.aircraftspruce.com/catal...sb-adapter.php

Start by checking or changing the cable. There are some really crummy ones out there. Note that USB cables that support higher charge currents have internal digital circuitry to negotiate charging rate, including most USB-C and USB-Apple cables.

[wireweinie]

So I installed this USB charger under the panel like I have done many times before and this one makes a lot of noise when the owner's iPhone is plugged in. This airplane has a master relay on the firewall so I wired off the switched side of it and grounded to the firewall at the base of the relay. It is close to the Becker radio. Ideas" Bad charger, to close to the radio? https://www.aircraftspruce.com/catal...sb-adapter.php

I've had a couple of charge ports do this to me over the years. Both times I swapped it out with another charge port and the noise went away. I guess it's the downside to using a $30 charge port instead of a $200 one. I can live with that.

As for checking if it's to close to the com, temporarily connect it up with long wires and move it around the cockpit to see if the noise goes away.

Web

[gdafoe]

I have used maybe close to 30 of these and not had a problem yet. Blue Sea makes some good stuff aimed at the marine industry. I have had problems with others. https://powerwerx.com/blue-sea-1045-...gaAuH4EALw_wcB

[supercub1999]

I used this one flying on two flights this week on a 28v system to charge my ipad and no noise issues at all
https://www.amazon.com/gp/product/B01N00I4TM
12/24 volt

[mvivion]

I wouldn't worry TOO much about loss of USB-A functionality. USB-C has been around a long time, and some time back, all the chatter was that USB-A was going away to be replaced by USB-C. Hasn't happened yet.

My brand new super compact HP laptop has TWO USB-A ports, and one USB-C port if that's a clue.

MTV