Patent ID: 7019419

Claim:
An apparatus for preventing damage to a motherboard due to installation of a higher voltage card into a card slot on the motherboard designed for operation with lower voltage cards, the apparatus comprising: a first power controlling circuit coupled to allow power to pass to the motherboard in a closed circuit state and further to disallow power to pass to the motherboard in an open circuit state, the first power controlling circuit in communication with the card slot to receive a signal indicative of whether a card is installed in the card slot, wherein the first power controlling circuit is in the open circuit state when a card is installed and in the closed circuit state when a card is not installed; a detection circuit in communication with the card slot to receive a signal indicative of whether an inserted card is a higher voltage card, from which the detection circuit generates a control signal; and a second power controlling circuit coupled to allow power to pass to the motherboard in a closed circuit state and further to disallow power to pass to the motherboard in an open circuit state, the second power controlling circuit in communication with the detection circuit to receive the control signal, responsive to which the second power controlling circuit is in the open circuit state when a higher voltage card is installed and in the closed circuit state when a lower voltage card is installed.