Patent ID: 6868501

Claim:
A power supply control system for supplying electric power to and starting a plurality of disk drive groups having at least one disk drive, comprising: a power source; a plurality of power supply circuits for supplying said plurality of disk drive groups individually with the electric power from said power source; and a control circuit for controlling said plurality of power supply circuits. wherein said control circuit generates, when said power source is turned ON, a circuit signal for turning ON said plurality of power supply circuits sequentially, wherein said individual power supply circuits supply, when they receive said circuit signal, the corresponding disk drive groups with the electric power so that the starts of said plurality of disk drive groups do not overlap in time. wherein said control circuit outputs, when a first set time elapses after said control circuit outputs the circuit signal for turning ON the power supply circuit corresponding to a certain disk drive group, the circuit signal for turning ON the power supply circuit corresponding to a next disk drive group, wherein each of said disk drive groups outputs a disk drive start initialization signal when each of said disk drive groups initializes its start, and wherein said control circuit includes: a first timer circuit, which resets with the circuit signal for turning ON the power supply circuit corresponding to a certain disk drive group, for outputting a first time lapse signal when said first set time elapses after reset; a second timer circuit, which resets with the circuit signal for turning ON the power supply circuit corresponding to said certain disk drive group, for outputting a second time lapse signal before a second set time which is shorter than said first set time elapses after reset and where said disk drive start initialization signal is not received from said certain disk drive group, said first timer circuit being reset with said second time lapse signal; a first counter circuit, which increases a counted value by one (1) each time said circuit signal is inputted, for designating a number of a disk drive group to be started; a first compare circuit for comparing, when said first time lapse signal and said second time lapse signal are inputted, a preset maximum number of disk drive groups and the number of the disk drive group designated by said first counter means, to output, where the number of the disk drive group designated by said first counter means is smaller than said preset maximum, the number of the disk drive group designated by said first counter circuit as the number of the disk drive group to be started next; and a selector circuit for outputting the circuit signal for turning ON the power supply circuit corresponding to the number of said disk drive group to be started next.