Abstract: A transmission device includes a holder, a pivot shaft, and an elastic member. The holder defines a receiving hole. The pivot shaft is received in the receiving hole. The elastic member is received in the receiving hole, fixed to the holder, and tightly enfolds the pivot shaft. When torques applied to the holder or the pivot shaft are larger than a predetermined value, the elastic member is deformed such that the pivot shaft rotates relative to the holder.

Abstract: A power control apparatus for automatically turning on and off a motherboard, the power control apparatus includes a power supply supplying electric power to the motherboard periodically, a control circuit including a first switch element, a second switch element, a first capacitor, a second capacitor, a first resistor, and a second resistor. When the power supply is powered up, the second capacitor is charged, the second switch element is turned on, a second terminal of the second switch element outputs a low level signal to power up the motherboard. When the motherboard is powered up, the first capacitor is charged, the first switch element is turned on, the second switch element is turned off, the second terminal of the second switch element outputs a high level signal. The motherboard is powered off when the power supply is powered off.