Abstract: A motor stator has an annular stator core, and a plurality of tooth portions spaced on the inner surface of the annular stator core which has a slot formed on each of two sides of each of the tooth portions. Each of the tooth portions has a coil wound and a portion of the coil is located in the two slots of each of the tooth portions. Each of the coils is formed by a metal wire coiled around a bobbin several times from the inner side to the outer side. The bobbin has an inner guide frame and an outer guide frame, both of them have a structure with a bottom plate and a side plate that are arranged vertically so that the coil can be attached to the bobbin to miniaturize the motor stator.

Abstract: An apparatus for switching connectivity of fans to be sensed includes a primary control board (2) and a secondary control board (4). The secondary control board is connected to the primary control board via sensing lines (3) and control lines (5), and connected to the fans via sensing lines. The secondary control board includes a control circuit (41) that includes a counter, and a switch circuit (42) that includes two data selectors each of which has a channel selection port, input ends and an output end. The channel selection port is connected to an output port of the counter for determining which fan is to be sensed. The input ends are connected to the fans to be sensed in one-to-one correspondence. The output end is connected to the primary control board via one of the sensing lines. A method for switching connectivity of fans to be sensed is also disclosed.

Abstract: An apparatus for switching connectivity of fans to be sensed includes a primary control board (2) and a secondary control board (4). The secondary control board is connected to the primary control board via sensing lines (3) and control lines (5), and connected to the fans via sensing lines. The secondary control board includes a control circuit (41) that includes a counter, and a switch circuit (42) that includes two data selectors each of which has a channel selection port, input ends and an output end. The channel selection port is connected to an output port of the counter for determining which fan is to be sensed. The input ends are connected to the fans to be sensed in one-to-one correspondence. The output end is connected to the primary control board via one of the sensing lines. A method for switching connectivity of fans to be sensed is also disclosed.