SURGE PROTECTION ARRANGEMENT FOR ELECTRICAL CIRCUITS

1 . In an electrical circuit having a power source and an electrical load, a surge protection arrangement for protecting against an overvoltage condition, said surge protection arrangement comprising:

a reactive component; and

a switching circuit connected to said reactive component, wherein said switching circuit causes surge energy to flow to said reactive component in response to an overvoltage condition in said electrical circuit so that said surge energy is stored in said reactive component.

2 . The surge protection arrangement of claim 1 wherein said reactive component is a capacitor and said switching circuit comprises a series enabling device connected in series with said capacitor, said capacitor and said series enabling device being connected in parallel with said electrical load, and a control circuit that activates said series enabling device in response to an overvoltage condition in said electrical circuit, wherein surge energy flows through and is stored in said capacitor when said enabling device is activated.

3 . The surge protection arrangement of claim 2 further comprising a resistor connected in parallel across said capacitor.

4 . The surge protection arrangement of claim 2 wherein said control circuit comprises means for sensing a line voltage in said electrical circuit and at least one comparator for comparing said sensed line voltage to a reference signal.

5 . The surge protection arrangement of claim 2 wherein said series enabling device is an IGBT.

6 . The surge protection arrangement of claim 5 further comprising a diode connected in antiparallel across said IGBT.

7 . The surge protection arrangement of claim 2 wherein said series enabling device is a MOSFET.

8 . The surge protection arrangement of claim 2 wherein said series enabling device is a thyristor.

9 . The surge protection arrangement of claim 2 wherein said series enabling device is a TRIAC.

10 . The surge protection arrangement of claim 2 wherein said series enabling device is a SIDAC.

11 . The surge protection arrangement of claim 1 wherein:

said reactive component is an inductor connected between said power source and said electrical load;

said switching circuit comprises a transistor and a diode connected in series and is connected between said power source and said electrical load parallel to said inductor; and

current flows from said power source to said electrical load via said switching circuit during normal operation, but when an overvoltage condition occurs, said switching circuit shuts off and current flows through said inductor so that said inductor stores surge energy.

12 . The surge protection arrangement of claim 11 further comprising a resistor connected in series with said inductor.

13 . The surge protection arrangement of claim 1 wherein:

said reactive component is an inductor connected between said power source and said electrical load;

said switching circuit comprises a first branch connected between said power source and said electrical load parallel to said inductor, said first branch comprising a first transistor and a first diode connected in series, and a second branch connected between said power source and said electrical load parallel to said inductor, said second branch comprising a second transistor and a second diode connected in series; and

alternating current flows between said power source and said electrical load via said first and second branches during normal operation, but when an overvoltage condition occurs, said first and second branches shut off and current flows through said inductor so that said inductor stores surge energy.