BFL13 wrote:
A laptop uses a brick so why would an Apple care if were MSW?
As I understand it, the laptop itself doesn't--it's just getting DC power from the power brick--but the active power factor correction circuitry in some power bricks (and some other switchmode power supplies) can behave badly when the input waveform is not at all sinusoidal, as they try like mad to adjust their current consumption within an AC cycle to be sinusoidal even though the applied voltage is anything but sinusoidal. Supposedly (some) Apple power supplies are rather notorious for self-destruction under those circumstances.
Most switching power supplies, for sure any older/cheaper ones without active power factor correction, are perfectly happy with MSW power.
