US Patent 7992025 Power control circuit

A power control circuit for supplying power for a computer component of a computer includes first to sixth switches. In response to the computer changing to a normal work state, a power state signal changes from low level to high level and a motherboard state signal is at high level, the fourth switch is turned on, the fifth switch is turned off, and the sixth switch is turned on, and power of the computer component is stably supplied by a system power supply. The motherboard state signal and the power state signal are at low level in response to the computer changing to a sleep state, the second switch is turned off, the first and third switches are turned on, and power of the computer component is stably supplied by a standby power supply.