Abstract: An expandable backplane is provided. The expandable backplane includes a baseboard management controller for connecting several disks, a first expansion board, a second expansion board, and a multiplexer. The multiplexer is connected between the baseboard management controller, the first expansion board, and the second expansion board. The multiplexer is used to control the second expansion board to be connected to the baseboard management controller via the first expansion board or control the second expansion board to be directly connected to the baseboard management controller according to a connection state of a Mini-SAS Cable connected between the first expansion board and the second expansion board.

Abstract: A system of computer fan control reduces vibration values and prominence ratios of a number of computer fans. A control chip outputs a phase setting control instruction to a PWM chip. The PWM chip outputs a number of out-of-phase PWM signals to rotate the number of computer fans according to the phase setting control instruction.

Abstract: A fan holder for mounting a fan, includes two opposite sidewalls defining a receiving area therebetween, each of the sidewalls defining a through hole therein; two or more polygonal auxiliary members arranged in the through hole of each of the sidewalls and located about an axis; and wherein the polygonal auxiliary members are rotationally offset from each other.

Abstract: A fan holder for mounting a fan, includes two opposite sidewalls defining a receiving area therebetween, each of the sidewalls defining a through hole therein; two or more polygonal auxiliary members arranged in the through hole of each of the sidewalls and located about an axis; and wherein the polygonal auxiliary members are rotationally offset from each other.