USB powered AAA battery

I was tired of replacing the AAA battery in my noise cancelling headphones. This thing replaces the AAA battery and gets power from a USB port on the computer the headphones are connected to. Now i have un-interrupted noise-cancelling and i can forget about the batteries!

Note that this is only practical if your headphone battery compartment is located in-line on the cord.

I didn't include any capacitors because i didn't think they would easily fit inside the battery. i'm not worried about it since USB power is pretty clean, you may want to try to include them.