Danger Danger! {Flailing robot arms}
LEDs are sometimes pulsed to give the active semiconductor a portion of the duty-cycle to cool down. The actual material is soo small that the surface to volume ration it way huge and it cools quickly by BB radiation.
Converting the power to DC could shorten their life by keeping them too hot for too long.
Tinker with it. Open that box and pwn your property. If you wan't further help, post circuit diagrams of what you find.