Patent ID: 8339821
Filing Date: 2012-12-25
Classification: H02M,Y02B

Abstract:
1. A power supply operable to power a load controlled by a control unit, the power supply comprising: an adapter operable to receive an input voltage and convert the input voltage into a first operation voltage to power the load, the adapter comprising a filter capacitor configured to smooth the first operation voltage; and a delay module configured to detect the input voltage, and supply a second operation voltage to the control unit when receiving the input voltage, and continue supplying the second operation voltage to the control unit for a predetermined time period after the input voltage is no longer supplied to the adapter, whereby the load operates for at most the predetermined time period and the filter capacitor discharges via the load after the input voltage is removed, and the control unit continues controlling the load during the predetermined time period after the input voltage is no longer supplied to the adapter; wherein the delay module comprises: a detect circuit configured to generate a first signal when receiving the input voltage, and a second signal when the input voltage is removed; a sub power supply operable to supply the second operation voltage; an output circuit; and a control circuit configured to control the output circuit to output the second operation voltage when receiving the first signal, and further control the output circuit to continue outputting the second operation voltage for the predetermined time period when receiving the second signal.