Non Mame/Arcade electronics question

[mclaught]

I know this is not exactly forum appropriate, but I also know there are some pretty bright people here that will know this answer, and I need to know asap. I am traveling by air tomorrow morning, it is my understanding that the airlines provide 15v empower plugs. My portable DVD player has a 12v to 10.5v DC adapter. How much damage am I going to do if I plug that into a 15v source. I figure a typical 12v auto system fluctuates from 10-15v anyway, so it shouldn't hurt it, yes? Worst case scenario, does if blow the fuse in the DC adapter, or does it blow the DVD player. BTW, I have the empower to cigarette lighter adapter. Again, sorry for being off topic, thanks for any help

[RacerX]

I know this is not exactly forum appropriate, but I also know there are some pretty bright people here that will know this answer, and I need to know asap. I am traveling by air tomorrow morning, it is my understanding that the airlines provide 15v empower plugs. My portable DVD player has a 12v to 10.5v DC adapter. How much damage am I going to do if I plug that into a 15v source. I figure a typical 12v auto system fluctuates from 10-15v anyway, so it shouldn't hurt it, yes? Worst case scenario, does if blow the fuse in the DC adapter, or does it blow the DVD player. BTW, I have the empower to cigarette lighter adapter. Again, sorry for being off topic, thanks for any help

I'm no electronics genius by any means, and somebody may shoot me down here, but personally, I would not even try it.  In my unknowledgable opinion, you will probably fry something.  

[Beley]

If the 12->10V converter is ment for car use, it will work fine(if you can find the appropriat connector) since the voltage coming from a car can go all over the place.  Even if its not for a car it will still probably be fine.  

[grafixmonkey]

If you have an empower-to-cigarett-lighter adapter, it's possible that it converts 15v to 12v before it even hits the cigarette lighter.  I can't see them making it otherwise, unless it has a warning that says "Only plug a cigarett-lighting device in to this cigarette lighter."  

Here's why I say this...   Diodes are available that can handle many amps, and all it takes is diodes to step the voltage down from 15v to 12v.  (specifically, four of them, or one 3v zener diode.)

The real trick will be in the power consumption.  You might be ok if that cigarette lighter adapter uses diodes to step down, but if that DVD player takes a lot of juice to run then the adapters you're using have to suck up all of the excess power as the 15v is stepped down to 12v.  (if all components are perfect, that's 20% of the total power consumed in the empower-->cigarette adapter and another 11% in the cigarette-->DVD one.  Realistically, it's probably more like whatever power the DVD player consumes, 45% to 55% on top of that will be consumed by the adapters.)  

So take the power requirement of the DVD player in watts, and multiply it by 1.5, and that's the power you'd pull from the plane.  Make sure that the number you get is under the maximum power the plane will supply.  Then, while the DVD player is on, constantly check those adapters to see if they are getting hot.  I had a laptop plugged in to a car using a funky scheme like that, and it overheated.  (had cigarette lighter --> power inverter --> laptop power plug w/ DC converter --> laptop.  The inverter burned up and died after half an hour even though it was rated good enough to handle it.)

If nothing gets real hot and 150% of your DVD player's power requirement is still safe for the plane, you should be good to go.