Patent ID: 8198817

Claim:
A lighting unit having a circuit composed of a plurality of electronic components for operating a lamp having an LED as a light source, wherein the plurality of electronic components include one or more heat receiving capacitors and one or more heat generating components, each heat receiving capacitor is configured to (i) perform a predetermined function during normal lamp operation and (ii) breakdown when raised to a predetermined temperature or higher responsive to heat from another of the electronic components, so that lamp operation is terminated or abnormal heat generation in said another electronic component is eliminated, each heat generating component is configured to undergo an excessive temperature rise when the lamp is operated under a predetermined condition, and at least one of the heat receiving capacitors is a foil-type dielectric evaporated film capacitor and not a foil-type electrolytic capacitor, wherein the dielectric evaporated film has a capacity to melt and carbonize into an electrical short-mode of operation, the foil-type dielectric evaporated capacitor is disposed close to or in contact with at least one of the heat generating components, so that said at least one heat receiving capacitor breaks down in the electrical short-mode when raised to the predetermined temperature or higher.