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powering your laptop inflight

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Old 1st Oct 2006, 19:08
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powering your laptop inflight

Hy. In the 737 -700 there is an electrical plug ,marked 115V 400 Hz. What type of appliances are to be used with this source? Vacuum cleaner?
Is it good for powering a laptop? I remember seeing a pax charging his laptop inflight,but I can't remember what plane was or what says on the plug?
Brgds.
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Old 1st Oct 2006, 19:32
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I suspect many 110/120V 60Hz laptop power supplies (eg American) would cope with 115V at 400Hz. The first thing most electronic power supplies do is rectify it to DC anyway. Then they chop it up again to make AC in the 20KHz+ range. That way they can use smaller ferrite parts. Try it at your own risk. I've no idea how noisy it is or what the tollerance is. Wouldn't want a few spikes to take out your hard drive.
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Old 2nd Oct 2006, 07:58
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dont even try

the 115/400hz output is for vacuum cleaners and maintenance aids like boro equipment.dont plug laptops or you will pop a breaker .also depending on what type of aircraft it wont be powered inflight
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Old 2nd Oct 2006, 08:11
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Well I powered my lap top and charged my digital camera from the outlet on a 737-800. Worked fine.
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Old 2nd Oct 2006, 13:27
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no problem you can do it but remember that it is amercan plug , but no problem of voltage just problem of plug
so buy an "adaptater" ( not sure it is the right word).
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Old 2nd Oct 2006, 13:32
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Originally Posted by chemical alli
the 115/400hz output is for vacuum cleaners and maintenance aids like boro equipment.dont plug laptops or you will pop a breaker .also depending on what type of aircraft it wont be powered inflight
If it copes with a vacuum cleaner I would expect it to handle a laptop ok. To be sure you would need to know the current/power it was rated for.
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Old 2nd Oct 2006, 15:59
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Yoy can power whatever you like in the ac if you have a charger that says eg 100-240v. Disregard the frequency. I have powered laptops and phones without any problems. The only thing you need is an american plug.
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Old 2nd Oct 2006, 16:30
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No problems here, use it on the A340 and used to use it on the NG.
Cheers
NG_
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Old 2nd Oct 2006, 16:36
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Laptop power supplies are designed to work on both US (115v) and European (230v) input voltages and frequencies without difficulty or any switching, this helps international travellers and also avoids the manufacturer having to make more than one type for worldwide sales, apart from the mains plug on the end of the cable (which is why the cable is usually separately plugged in to the power supply).

All the power supply does is transform and rectify down to about 24v dc.

Unless you have a fault I cannot see how they could pop a breaker, especially on a main power 115v outlet. The maximum current draw is minimal, mine says 1.5 A. This approach also eliminates any frequency variation or spikes by the time you get to the PC.
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Old 2nd Oct 2006, 19:15
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Originally Posted by cwatters
I suspect many 110/120V 60Hz laptop power supplies (eg American) would cope with 115V at 400Hz. The first thing most electronic power supplies do is rectify it to DC anyway. Then they chop it up again to make AC in the 20KHz+ range. That way they can use smaller ferrite parts. Try it at your own risk. I've no idea how noisy it is or what the tollerance is. Wouldn't want a few spikes to take out your hard drive.
Would just like to confirm that the switched-mode power supplies on almost all laptops operate exactly as CW says. Frequency (50/60/400 hz) is not an issue - however switching off from engine/APU/ground power can generate the unwanted spikes mentioned here.

Older iron transformer coupled power supplies would not like 400hz - these are sometimes still used for cell chargers and some handheld computing devices. Compared to 50/60hz power levels, the internal voltages can increase 10-30 percent at 400hz - some devices will tolerate this increase better than others. If the adaptor seems heavy for it's size, it probably has an iron core transformer - use at your own risk !
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Old 2nd Oct 2006, 20:20
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I would agree with most of the above, however my Airline has gone to great expense to fit 3 sockets at 115VAC 60 Hz in the flightdeck specifically to power laptops, they do not spend money for no reason. In the past I have powered an old laptop from 400hz the transformer got quiet warm. Also caution 115VAC wires trailing about they could be cut be a seat track,but hopefully the CB would pop!!
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Old 2nd Oct 2006, 20:57
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Used the laptop I bought in the EU sometimes without any troubles on the NG.
Tried it first on ground at homebase, though. No specials, no overheats whatsoever.
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Old 4th Oct 2006, 14:09
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78deg. Don't know if your with the same company but mine is also fitting 115v 60hz sockets. This is to power company laptops and although cwatters is absolutely right in that switched mode power supplies work fine, my Sony one does, the manufacturer of the laptop would not guarantee or certify their supplies to run on 400hz hence the installation of standard US ac outlets.
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Old 15th Oct 2006, 19:44
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Unhappy

I think Boeing must have been reading this thread, I have just noticed this new limitation in the latest 737NG FCOM Vol 1 page L.10.7 dated Sept 28 2006:

"ELECTRICAL
The use of Flight Deck Auxiliary Power outlets in the flight deck requires operational regulatory approval."

Since this is an FCOM and hence AFM limitation there is no way around this. Make sure your laptop is fully charged before you come to work.
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Old 15th Oct 2006, 23:16
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We have a work station installed on our upper decks with a laptop and laserjet printer. They are used on the ground and in flight for load sheets, email via sat phone, and all manuals. (Mx & FOM) The only limitation is they must be turned off for takeoff and landing. After three years we have not had single problem with the power supply. 115v 400 cycles. This is all blessed by the FAA.
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Old 17th Oct 2006, 20:58
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The FAA can bless all they like! but remember that anything attached to your aircraft should be approved first by the manufacturer or by way of a major or minor modification and crertified as such. There is a fundemental problem with 'playing' (if that's the right word) with an aircraft or its systems in flight, especially if the system by nature is technically incompatable ie. 50HZ Vs 400HZ. Most of the outlets are powered by a service bus, which might at first seem incidental, but can also power important stuff like cargo smoke detectors and Navigation lights.
As for powereing a mobile phone, why can't you wait and do that at home or in the hotel? as for a laptop, well, shouldn't you be flying the aircraft? If the company wants to introduce such electrical stuff then hopefully they will have applied for the correct modification, that will have been assesed and approved by the manufacturer and appropriate airworthiness board. otherwise the use of such items may actually contravene the aircraft type certificate and thus make the C of A invalid. Your decision Captain!
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Old 18th Oct 2006, 00:41
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Get one of these http://www.elect-spec.com/fca250dx.pdf for a thousand quid, make sure it's FAA approved, and you can plug in what you like.

R
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Old 18th Oct 2006, 03:44
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I seem to recall the plug in the F/D is for a specific Vaccum cleaner.

At 400 HZ the power supply on your laptop will run hotter. In most situations I don't think there would be problem with that but that's not a blessing on going ahead and doing so. Power supplys do occassionally burn out from overheating. Take your chances.
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Old 18th Oct 2006, 05:47
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If the principal aim of the power outlet is to power standard domestic items like vacuum cleaners etc on the ground then I wonder why the outlet was not designed for domestic frequency 50/60 Hz in the first place instead of 400 Hz. Nowadays it just needs a few extra power electronics components inside the outlet to make the conversion.
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Old 18th Oct 2006, 07:30
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How about the 28 V DC outlets ?
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