초록 ▼

A power supply typology in which the pulse width modulated invertor switches serve two functions; conversion of the a.c. input to a d.c. rail voltage in addition to inversion of the d.c. rail voltage to a regulated a.c. output. An a.c. input ground terminal is connected to a node between two of the

A power supply typology in which the pulse width modulated invertor switches serve two functions; conversion of the a.c. input to a d.c. rail voltage in addition to inversion of the d.c. rail voltage to a regulated a.c. output. An a.c. input ground terminal is connected to a node between two of the invertor switches and this node is also connected to the a.c. output to provide a common ground between the a.c. input and the a.c. output. A silicon control rectifier switch and one of the invertor switches connected to the ground node connect the back-up battery to the a.c. source during positive half cycles of the a.c. input in order to maintain a charge on the back-up battery.

대표청구항 ▼

An uninterruptible power supply, comprising in combination: a.c. input means including first and second a.c. input terminals and a.c. output means including first and second a.c. output terminals; first and second d.c. rails; boost convertor means for converting an a.c. power input coupled to said a

An uninterruptible power supply, comprising in combination: a.c. input means including first and second a.c. input terminals and a.c. output means including first and second a.c. output terminals; first and second d.c. rails; boost convertor means for converting an a.c. power input coupled to said a.c. input means to a d.c. voltage between said pair of d.c. rails at a d.c. voltage which is higher than the peak voltage of said a.c. power input; invertor means for inverting said d.c. voltage between said pair of d.c. rails to an a.c. voltage coupled to said a.c. output means; said invertor means comprised of four switches configured as a bridge between said pair of d.c. rails; means providing a common connection among a node between two switches in one arm of said bridge, said second a.c. input terminal, and said second a.c. output terminal; means coupling a node between two switches in the other arm of the bridge to said first a.c. output terminal; said convertor means comprised of an energy storage inductor connected to said first a.c. input terminal, a capacitor coupled across said pair of d.c. rails, and said two switches in one arm of said bridge; a chargeable, d.c. back-up power supply; means to couple said d.c. back-up power supply between said first and second a.c. input terminals during alternate half cycles of said a.c. power input, said means to couple including a first gate controlled rectifier coupling one terminal of said d.c. back-up power supply to said first a.c. input terminal, and one of said two switches in said one arm of said bridge coupling the other terminal of said d.c. back-up power supply to said second a.c. input terminal.