Thermally-protected ballast for high-intensity-discharge lamps

摘要

A ballast for electrical lighting fixtures has improved thermal protection features. The ballast has ballast laminations, primary and secondary coils, and a thermal protector, the thermal protector being wired in series with the secondary coil. When the ballast is of the type having multiple input voltage taps on the primary coil, the electrical positioning of the thermal protector in series with the secondary coil causes the wiring assembly of the thermal protector (as part of the ballast) to be independent of the primary coil input voltage tap used in a particular application. Improved electrical lighting circuits for high-intensity-discharge lamps may be obtained, the circuits having the above-described thermally-protected ballasts.