Patent ID: 7391132

Claim:
An interruptible power supply comprising: an input for receiving an AC power source; an output for connecting to a load; a DC bus coupled with a DC power source; an inverter receiving the current from said DC bus to generate an AC voltage to said load; a control circuit responsive to the voltage and the current of said AC power source, the AC voltage of said inverter and a voltage at said DC bus coupled with said DC power source to generate control signals to said inverter; and a converter, responsive to control signals from said control circuit, drawing current from the input receiving said AC power source and delivering the current to said DC bus or said output; and wherein the input comprises a phase port and a neutral port; the DC bus comprises a first port, a second port and a neutral port; the output comprises a load port and a neutral port, wherein the converter comprises a first switching means, a second switching means and an indicator having a first port coupled to the phase port of the input and a second port, wherein the second port of the inductor in response to the control signals from said control circuit is coupled to the first or the second port of said DC bus through the first switching means of the converter or coupled to said load through the second switching means of the converter alternatively.