Phone charger plugged in 110v/400hz...
 

Hey guys..

Just a quick question regarding using phone/tablet charges on board.
I know the planes generate voltage at 400hz. But is it safe to use e.g a IPhone charger on board that uses 50/60hz ?

Thanks for all the info.

I seriously doubt it - the inductor won't resonate properly.

Oh no
 

Nope, you cannot successfully use a normal 50/60 Hz device onboard at 400Hz.
Don't most planes have some USB sockets now, into which you could plug a more suitable charger lead? Please don't risk an incident by attempting to use sockets designed for 400Hz equipment for your domestic electrical stuff

If it's a socket for a passenger it won't be 400Hz and should be labeled accordingly.

Most modern phone/tablet chargers are switched mode power supplies and can accept a huge frequency range of input power. They do not have any problem at all with 400 Hz and work just fine. However, they are not officially certified for that use, nor are the power outlets.

It might be a customer mod, but our in seat power outlets for passengers have 110V with 60 Hz, same for the power outlets at each pilot seat, the maintenance outlet in the flight deck, same as the vacuum cleaner sockets and the medical outlet in the cabin have 400 Hz with 115 V.

We have to use the low frequency outlets for our iPad chargers, however the reason, according to our technical staff, is not the frequency but rather a grounding problem with the 400 Hz outlets that can lead to very high residual voltages and a high risk of electrical shock. For our former EFB we used the 400Hz socket, but needed specially protected power supplies to prevent that risk.

Woaw... and no cabin manufacturer had ever put a converter anywhere ?

Thanks for al the info..

Problem with my airline is that they provide an Ipad for aviobook and lido. But we do not have a proper charge socket for it. Also no usb port.

So thats why many of us do use the onboard socket. I have never had any problems, not even a warm feeling charger.
But just recently I had a duscussion with a colleague who was totally against using it.

So I thought, lets get some facts Straight.

In the Airbus the socket above the circuit breakers has 110V//400 Hz and may not be used, while those under the microphone where the flight kits are has 110V/60 Hz and may be used.
But those are an option, not all Airbus have them.

We use the iPad as an EFB. We are only authorized to use the Apple charger plugged into the rear panel plug for charging, no other charging devices may be plugged into that receptacle.

About 1/2 of our busses have tablet interface modules (one per pilot below moveable window) with two USB ports, a main (2.1 amp) tablet charging port and an aux (~.3 amps) charging port for another device. These TIM's also allow for blue tooth connectivity to the aircraft, but this feature hasn't been exploited (nor do I think it will be)

The rest of our non Airbus fleet is being retrofitted with 110 volt plugs. The concern is in the future USB charging will go away.

Step one of an AC to DC switch mode power supply is generally to rectify to DC/filter before chopping up at high frequency (in the KHz). It couldn't care less within reason the frequency of the AC input voltage. Whether certified or not is a different matter.

In the unlikely event you have a mobile device with a power supply which accepts only say 60hz/120v DO NOT use on 400hz. The switch mode PSUs will take say 110-240v 50-60hz.

I've used many chargers on a 400Hz circuit, with no problems.

Seems to be a lot of confusion about this.

We have been told we may only use the socket on the rear CB panel on the ground, NOT in flight. They cite interference as a reason.

Any Airbus B2s got any more info?

The chargers may/may not be officially certified. The use at 400Hz will shorten the battery life of the device significantly. With a iPad or other device without replaceable batteries, this is a significant issue.
In the case of Apple products, while they say it will work, and are certified for use on deck, they will not warrantee the use because of the battery issue.

There is a certified, approved, and warranted charger available.

Dutch50 and others, on inquires, tell them Brian sent you!

The GNS USB flight deck portable EFB charger is a simple and effective device born out of necessity for flight crews to charge their iPads in-flight after extended use. It uses the 28VDC bus, not the 115VAC/400 Hertz outlet that can be a potentially noisy EMI transmitter and a fire hazard for consumer grade chargers designed for 50/60Hertz. The internal DC-DC circuit is 85% efficient converting 28VDC to iPad voltage and supplying 10+ watts of power with overload and short circuit current limit protection. Each channel also has dual input fuse to protect the aircraft 28VDC supply bus at all cost providing fail-safe protection from an overload before, during and after the USB power conversion. See our product datasheet for additional specifications and lab reports. (hyperlink to product datasheet). Current models include 3 common aircraft plug configurations.

http://globalnavigationsciences.com/...products-1.jpg

Products - Global Navigation Sciences

I wonder, what does the frequency of the AC power supply to the charger that in turn produces DC supply to the device have to do with the devices battery life that only receives a DC charge, no matter where the charger is socketed in?

They had no problem with the normal warrante for our EFB iPads, and battery degradation was not a bigger problem than usual for the first generation iPad Air we just switched out after four years or so.

Shorten the battery life? How would that work?
While i doubt it the chargers may supply less than their rated current but that would only mean slower charging.
To shorten battery life you would need overcharging ... which would be dangerous and highly unlikely as the charge-controller is not even in the wall adapter but rather the device.

As there are dangerous and EMI emitting wall adapters out there higher standard chargers would of course be a good idea.

it is the 400hz issue vs 60 hz. Aircraft use 400hz, as the alternators can be smaller, (lighter) but the associated output is then subject to wide fluxuations in output.
The power at 400hz, when the voltage fluxuates, the reactive drops through the system are even more significant, up to 7 times the difference. Typical chargers are not set up to handle this voltage swing, especially the drops.
The batteries are then subject to this flux, and it degrades them in respect to 60hz charging.


Not to be flippant. In regards to battery degradation, not certain of the duration of flight/charge that your airline experiences. Did you experience the need to charge devices inflight very often?

I'm a bit confused. Why would you use the 400 HZ socket? Most pax jets have regular 50/60 HZ outlets in the cabin.

Possibly, because running an extension cable from a passenger seat all the way into the flight deck is going to raise all sorts of problems...?

I and many many colleagues have managed to use MagSafe and latterly, iPad 12w chargers from the 400hz socket, with much success for a decade or more. Some folk get all excited about it, but then, they're the type that expect an sop with exact measurements on how to wear a hat.

If your company SOP allows the use of these chargers in the cockpit, what's your point? You and your colleagues are simply complying with SOP as all good pilots do.

Would love a copy of that SOP, would not be surprised if it actually exists.

Long time ago I saw an ATT&T, aka 'the (American) phone company' manual that had over 10 pages on how to use a screwdriver. Wish I had kept a copy.

As to chargers, as many have stated almost all are now switch mode that have a very wide input range and frequency tolerance.

Suggestions that input power quality would affect the (typically) 5V output which in turn would affect the devices internal battery controller are false and possibly marketing driven. (Resist temptation to start a 'golden ears' flame war on gold plated welding cable for speaker wire :)

Grounding difference are possible but doubtful they would be a safety issue since any 2 prong device has to be double insulated to be safe in normal use.

Grounding could affect EMI but even that is likely more sensitive to cable placement than anything else.

All that said when it comes to cockpit use it is either SOP/approved or not and anyone deciding that it is not relevant is on their own.