Hi Karen,

If you take a look at the charger for your DVD player it might well be a universal voltage type one, in the way most mobile phone ones are. No guarantees but it's worth checking.

If it says something like the input voltage being OK from 110 - 240V, 50 - 60Hz then you should be fine using your UK charger over in the US. All you'll need is a US (2 pin) to UK (3 pin) adaptor.