Note that the high noise levels are caused by the test environment, not by the charger itself. Mains voltage is nominally 220V/50Hz (Argentina, not Europe), measured to be in the range 217-220V.
Recovery from the load change from zero to 0.5A is remarkably quick, reaching nominal values within only about 100ns. The 100uF capacitor, which is ten times the maximum capacitative load permitted by the USB spec, slows down recovery by about three orders of magnitude.
The 470uF capacitor seems to trigger a short-circuit protection, causing the charger to disable its output for about 300ms.
In all cases, the USB voltage ramps up to nominal values within 2-3ms, without excursions.
2008-09-18