A power supply device with a system switch circuit includes a primary power system, a stationary power system and a power management unit. Additionally, through the inclusion of a timing module, a user can record a plurality of candid images about these events at regular or irregular intervals. Both over current and leakage protection are thereby achieved. 12 mm, wherein P is a pitch of the groove section G or the land section L, \u03bb is a wavelength of reproducing light beam and NA is a numerical aperture of an objective lens.