Patent ID: 7602084

Claim:
A power switching circuit comprising: an output switch comprising: an output switch first end for receiving a first power from a power source; an output switch control end for receiving a first activation signal; and an output switch second end for outputting the first power when the first activation signal received on the output switch control end; a user switch comprising: a user switch first end for receiving a second power from the power source; a user switch control end for receiving a second activation signal; and a user switch second end for outputting the second power when the second signal received on the user switch control end; a control circuit comprising: a control circuit control end coupled to the output switch second end; and a control circuit second end coupled to the output switch control end and applying the first activation signal to the output switch control end according to whether a first voltage and a second voltage applied on the control circuit control end; a first timer circuit coupled between the control circuit control end and the user switch second end, the first timer circuit applying the first voltage to the control circuit control end when the time duration of the second power applied through the user switch second end is longer than a first predetermined duration; and a second timer circuit coupled between the control circuit control end and the user switch second end, the second timer circuit applying the second voltage to the control circuit control end when the time duration of the second power applied through the user switch second end is longer than a second predetermined duration.