Patent ID: 8484489

Claim:
A power signal detecting system comprising: a power supply, for providing a power signal; and a portable electronic device electrically connected to the power supply and used for receiving the power signal; the portable electronic device comprising: a sensing element for passing through the power signal; a detecting module electrically connected to the sensing element and used for detecting the power signal passing through the sensing element, wherein the detecting module is a charger IC; and a power management module electrically connected to the detecting module, calculating watts of the power signal according to a voltage signal of the detecting module, and identifying a supplying watt of the power supply and performing a power management for the portable electronic device, wherein the power management module determines that if a value of the power signal is above a first predetermined value being set for the portable electronic device, gradually reducing the frequency of a CPU of the portable electronic device or gradually stopping charging of the portable electronic device, wherein the first predetermined value is a maximum watt allowed by the portable electronic device and the power supply.