@Ceili,
No, it doesn't work at all.
Mind that his power supply has these characteristics:
◦Input:AC 220-240V,50 Watts.
◦Output :AC 110-120V 50/60Hz.
As Roger pointed out, voltage in the US is 110-120 V.
He cannot make 220-240 V out of 110-120 V with any kind of simple converter.
So, the easiest solution is to buy another power supply (less than 15 USD), like this one, provided its plug fits his shaver: