Do these work - charge via an audio jack?

[ctmagnus]

I just saw these (Inflight USB Power Unit (http://www.inflightpower.com/products.asp)) and was wondering if they actually work? One end plugs into an airplane audio jack and the other end has a USB port to charge your devices.

I haven't been on a plane it twelve years, so I can't really recall all the ins-and-outs of their power/headphone setups.

[Edgar_]

OH WOW!

I leave on a 16hr flight to Kiev tomorrow morning. Iwish I had one to try. I'll check the airport gadget stores for this. I'd love it for my PPC.

No reason why it shouldn't work. Most PPC's are what? 3-4v batteries? Easily what is coming from a jack for powering headphones. Then just a small capcitor to clean the line and poof, youre done.

If I find one I'll report back on Sunday

[Sven Johannsen]

No reason why it shouldn't work. Most PPC's are what? 3-4v batteries? Easily what is coming from a jack for powering headphones.

There is current capacity involved here too. That's why there are AAA cells and D cells, both delivering 1.5v. It is already well known that the 500 mA max on most USB ports often has trouble charging or powering the heftier PPCs. You really think the audio that is supposed to drive a fairly efficient pair of headphones has the power to run your AXIM while it's playing a movie? I have my doubts. I would accept charging, slowly, while the unit is off, but I wouldn't expect much more.

[ctmagnus]

I have my doubts. I would accept charging, slowly, while the unit is off, but I wouldn't expect much more.

The front-page post that Darius Wey just submitted on this mentions trickle-charging.

[isajoo]

i think ur better off buying a spare battery or use a usb cable to a laptop or even a solar panel might work...better chance then the audio jack. u could see how much volts are coming out of ur home speakers by putting the cable ends on it tongue... i am not responsible for any injuries. try at it own risk.

[isajoo]

opps double post

[Guest979]

PPCs have an audio out jack... can they charge each other now? 8O

[Sven Johannsen]

or even a solar panel might work.... Got one o' them. drained my 2215 in full sunlight ;(

[Edgar_]

Well I read their write up. They do not claim to power your unit in use. It looks to trickle by charging capacitors that then feed at a useful voltage for a few minutes at a time.

So, for example. Me on a 16hr flight at 10a tomorrow. I watch a movie and read my ebook. that's four hours, max. I switch (THE HORRROR) to a hard bound paper book like grandpa used to read, or the movie on the screen. It sits there and charges nice and slow for two+ hours while I sleep and drool on my wife - poof back to full charge.


Sven - I am surprised the solar didn't work. They can easily in a good source, provide 5-10v. With the right capacitors your unit should CHARGE fine. Neither of these solutions (audio jack / solar) are to POWER your unit, merely trickle/sloooow charge. Your unit burns more than they produce. But not more than an idle battery, but it is a slow process. Considering on AC I can recharge a drained battery in under 30 mins. With USB recharge in an hour or so. This solution is more like 2+

You can buy systems that will charge a cell phne or PDA on a pair of AA batteries (some units require 4 AA cheap alkyline batteries), same idea - you shouldn't power your unit with them (well you can, but they last like 30-60mins mins - good disposables last equal to a full charge) or you can trickle charge the LiOn and it will last 4 hrs

-Edgar_

It's late, prices go up - this was my $0.03 worth vs .02. 50% surcharge for out of hour :)

[Sven Johannsen]

Sven - I am surprised the solar didn't work. They can easily in a good source, provide 5-10v. With the right capacitors your unit should CHARGE fine.Well, they aren't all created equal, either in capability, or price, which tend to be related. Still hung up on that voltage. You have to have the ability to drive some current backwards through the battery to charge it. The zap you get between your finger and the doorknob where I live is thousands of volts, but it isn't going to charge much. The current capability is too small.

Within the ability of the battery to keep from burning up, the more current you can drive through it the faster it will charge. At a very basic level, if you have a 1000mA-Hr battery, it will discharge in 2 hours if you draw 500mA, 4 hours if you draw 250 mA. Conversly if you can charge it with 1A it should take about an hour to charge, 30 minutes if you can drive 2 A into it. Look at your wall charger. Bet it's around a 2 -2.5 A rating. So you get 30min to an hour recharge with the wall wart. The USB tops out at 500mA so to charge a 1000 mA-Hr battery should take around 2 hr.

I know that leaves out a lot, but the idea is there. I just have a hard time seeing much current being delivered by a device that rectifies random AC, i.e. audio. It's probably easier to filter, I would imagine as it has higer frequency componenets than 60Hz, but you have to fight the constant amplitude variations. Just seems like a too good to be true thing. I just suspect it will work, but it won't be the answer to our dreams.

[isajoo]

ALRIGHT.... here is the answer to INFLIGHT charging...
bring a screw driver in ur bag and open up the radio unit on the armrest...then hard wire whatever charger u want to it. :devilboy:

:lol:

at the prices we are paying to fly travel they should have a electrical socket behind every seat or atleast a 12volt plug.
!!!wishful thinking!!!

[Sven Johannsen]

bring a screw driver in ur bagDon't think you can bring one of those anymore.

[Cybrid]

bring a screw driver in ur bagDon't think you can bring one of those anymore.Especially if you happen to be one of the many who qualify for racial profiling...wonder how long you might end up having to sit in the secirity office while they find a pair of white gloves to get friendly with. 8O