Abstract: An improved power supply device decreases the amount of power used in computer and computer peripheral devices by utilizing a control transistor which is set into a switching operation responsive to a pulse signal received from a power supply control circuit. The control transistor controls the voltage applied to the primary winding of the power transformer by a switch transistor, and issues an output voltage from the secondary winding. The power supply device includes a switch circuit which is connected in series to a starting resistor for supplying the output voltage rectified from the AC power source when starting up to the power supply control circuit. The power supply device includes a switch-control circuit which turns off the switch circuit when the output voltage rectified from the AC output of the tertiary winding of the power transformer reaches a voltage high enough for stable operation of the power supply control circuit.

Abstract: A quickly restartable power supply apparatus which can quickly restart with a power-saving integrated circuit in power-saving mode by utilizing the reference output signal of the power control circuit as a restarting control signal thereby rapidly restarting the power supply apparatus in power-saving mode with lower circuitry complexity and cost and good reliability. Further, the quickly restartable power supply apparatus can also decrease the power dissipated by the starting resistor by using the reference voltage signal to control the switch control circuit and the second switching means such that after the power supply control circuit is activated, the current in the starting resistor is cut off and no power is dissipated by the starting resistor.

Abstract: The present invention provides a dual switching power supply system that is immune to malfunction caused by the off noises of the switch control signals. The dual switching power supply system of the invention generates stable voltage outputs without the necessity of making any difficult and unsatisfactory adjustment in the PCB layout process. The dual switching power supply system of the invention preferably comprises: a first switch control means for outputting a first switch control signal; a second switch control means for outputting a second switch control signal; and a phase shifting means for shifting the phase of the second switch control signal by a predetermined amount while keeping the frequencies of the first and switch control signal equal.