Patent ID: 9013897
Filing Date: 2015-04-21
Classification: H02M

Abstract:
1. A power supply applied to an electronic device, comprising: a transformer unit; a connector electrically connected with a secondary side of the transformer unit for outputting a first output voltage; a pulse-width modulation (PWM) control unit outputting a pulse signal with a first period; and a switch unit electrically connected between the PWM control unit and a primary side of the transformer unit; a feedback control unit connected to the connector includes: a light-emitting element connected with the voltage regulator; and a light sensor electrically connected with the PWM control unit for sensing the light emitted from the light-emitting element; wherein, when the electronic device is connected to the power supply, the connector receives an external control signal, and the PWM control unit adjusts the pulse width of the pulse signal to a second period and transmits the pulse signal with the second period to the switch unit to control the connector to output a second output voltage to the electronic device.