Screw-in fluorescent lamp with magnetic arc spreading

摘要

A compact fluorescent lamp with a screw-in plug to fit conventional screw sockets which operates at 20-30 watts and provides the lumen output of a 75-100 watt lamp. The lamp is essentially a hollow cylinder with a glass envelope for the two outer walls. The space between the two outer walls is partitioned to constrain the arc discharge to follow a zigzag path around the surface of the lamp. The design parameters are such that the lumen output per square inch of phosphor is greater than from conventional tubular fluorescents. Efficiency is promoted by novel ballast design. The ballast fits into the hollow center of the lamp. The ballast is constructed of special shape to spread the arc within the evacuated glass envelope, thus reducing the current density and the total current, but maintaining the lumen output of the phosphor.