Patent ID: 7443646

Claim:
A power supply circuit to supply power to internal components of a device, said power supply circuit comprising: a power block for converting received power from an external power source to a voltage to be used by the internal components of the device, said power block comprising: an external power connector having a positive power line, a negative power line and an earth ground, said external power connector receiving power from the external power source; at least three uni-directional solid state transient voltage suppressors each of which is connected in parallel with a corresponding one of at least three metal oxide varistors and a corresponding one of at least three capacitors, said uni-directional transient voltage suppressors and varistors clamping both differential and common mode high voltage transients to acceptable levels for the internal components of the device by clamping the positive power line to the earth ground, by clamping the negative power line to the earth ground and by clamping the positive power line to the negative power line.