| US 7,602,596 B1 | ||
| Various methods and apparatuses for a surge protection scheme | ||
| James T. Schley-May, Nevada City, Calif. (US); Richard Barry Angell, Nevada City, Calif. (US); and Steve Maher, Nevada City, Calif. (US) | ||
| Assigned to 2Wire, Inc., San Jose, Calif. (US) | ||
| Filed on Aug. 25, 2005, as Appl. No. 11/212,161. | ||
| Int. Cl. H02H 9/00 (2006.01) | ||
| U.S. Cl. 361—119 | 4 Claims |

| 1. An apparatus, comprising:
a digital subscriber line modem comprising a surge protection circuit having a first voltage protection device coupled to
a first TIP wire of a Public Switched Telephone Network (PSTN), a voltage protection device to conduct when voltage applied
across the voltage protection device at least meets a set voltage threshold, a second voltage protection device coupled to
a first RING wire of the PSTN, the second voltage protection device coupling to the first voltage protection device, and a
third voltage protection device coupled to the first voltage protection device and second voltage protection device in a wye
configuration; and
an external power supply, wherein the modem is connected to the external power supply to power the modem using a cable comprising
a modem side two pin connector, wherein the cable further comprises:
a positive voltage conductor having a first end coupled to a first one of the two pins of the modem side two pin connector,
wherein the positive voltage conductor has a second end coupled to a first conductor in the power supply;
a neutral conductor having a first end coupled to a second one of the two pins of the modem side two pin connector, wherein
the neutral conductor has a second end coupled to a second conductor in the power supply; and
an earth conductor having a first end coupled to the neutral conductor and the second one of the two pins of the modem side
two pin connector, wherein the earth conductor has a second end coupled to a third conductor in the power supply being different
than the second conductor in the power supply, wherein the second end of the earth conductor is further connected to earth
ground through the power supply to provide a return path for surge return current.
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