Lamp having fixed forward phase switching power supply with time-based triggering

摘要

A lamp contains a lamp voltage conversion circuit that is entirely within a base for converting a line voltage at a lamp terminal to an RMS load voltage at a light emitting element. The voltage conversion circuit includes a forward clipping circuit with a three-terminal thyristor that forward clips a load voltage to define the RMS load voltage, and a time-based pulse source that provides pulses the trigger conduction of the three-terminal thyristor at constant time intervals that are independent of the magnitude of the line voltage.