Patent ID: 8264211

Claim:
An apparatus for limiting power dissipation across a switch, comprising: a switch having a power supply input, a load power output, a switch control input, a current level through the switch output and a voltage level across the switch output; a current regulator having a current level through the switch input, a current regulation output, a power meter enable output and a power shutoff input, the current level through the switch input being connected to the current level through the switch output from the switch and the current regulation output being connected to the switch control input; and a power meter for the switch having a voltage level across the switch input, an enable input and a power shutoff output, the voltage level across the switch input being connected to the voltage level across the switch output from the switch, the enable input being connected to the current regulator power meter enable output, and the power shutoff output being connected to the current regulator power shutoff input, wherein the current regulator limits the current through the switch to a predetermined level and the power meter determines if power dissipation by the switch exceeds a predetermined level when the current regulator is limiting the current level through the switch by measuring a quantity related to the voltage level across the switch over time.