Patent ID: 6163087
Filing Date: 2000-12-19
Classification: G06F,H02J

Abstract:
A power supplying system, comprising:a power-supplying unit;a heat-dissipating fan connected to said power-supplying unit;a stand-by power source;a switching control circuit connected to said stand-by power source so as to receive electrical power therefrom, said switching control circuit being further connected to said power-supplying unit and being adapted to be activated to control operation of said power-supplying unit in a selected one of an ON state, where said power-supplying unit supplies electrical power for operating said heat-dissipating fan, and an OFF state, where said power-supplying unit ceases to supply the electrical power to said heat-dissipating fan; anda delayed closing device connected to said power-supplying unit, said heat-dissipating fan and said stand-by power source, said delayed closing device receiving a power-OFF signal from said power-supplying unit at an instant said power-supplying unit is operated from the ON state to the OFF state, said delayed closing device connecting said heat-dissipating fan to said stand-by power source upon receiving the power-OFF signal to enable said heat-dissipating fan to receive electrical power from said stand-by power source and permit continued operation of said heat-dissipating fan even after said heat-dissipating fan ceases to receive the electrical power from said power-supplying unit;wherein said delayed closing device comprises:a temperature sensing circuit for generating an overheating detect signal when ambient temperature exceeds a predetermined reference temperature;a timer connected to said power-supplying unit and enabled by the power-off signal from said power-supplying unit to execute a timing operation during which said timer generates a timing signal, said timer terminating generation of the timing signal after a predetermined time period has elapsed;a controller connected to said temperature sensing circuit and said timer, said controller generating a driver enable signal when said controller receives the overheating detect signal and the timing signal simultaneously; anda fan driving circuit connected to said controller, said heat-dissipating fan and said stand-by power source, said fan driving circuit being enabled by the driver enable signal from said controller to connect said heat-dissipating fan to said stand-by power source.