Patent ID: 7995362

Claim:
A circuit apparatus for providing an AC voltage to a load, comprising: a first, second, third and fourth switch, wherein the first switch is connected between a first node and a first terminal of the second switch and the fourth switch is connected between a second node and a first terminal of the third switch; a voltage source, wherein the voltage source is electrically connected between the first node and the second node; a resistive divider connected across the voltage source; a first resistor connected across the first switch a second resistor connected across the third switch; first connecting means for configurably connecting a second terminal of the second switch to the second node; second connecting means for configurably connecting a second terminal of the third switch to the first node; third connecting means for configurably connecting the second terminal of the second switch in series with the second terminal of the third switch; a first jumper connected between a first connector of the first connecting means and a second connector of the first connecting means, said first connector of the first connecting means being electrically connected to the second node and the second connector of the first connecting means being electrically connected to the second terminal of the second switch; and a second jumper connected between a first connector of the second connecting means and a second connector of the second connecting means, said first connector of the second connecting means being electrically connected to the first node and the second connector of the second connecting means being electrically connected to the second terminal of the third switch.