ELECTRONIC BALLAST STARTUP OUTPUT CURRENT-LIMITED CIRCUIT FOR HIGH VOLTAGE SODIUM LAMP

摘要

A electronic ballast startup output current-limited circuit for high voltage sodium lamp (4), which includes a triggering circuit (1) and a startup circuit (2), the startup circuit (2) has two transformer T3, T4, the triggering circuit (1) supplies starting signal to startup circuit (2); which characterized by connecting two relays J1, J2 between two transformers T3, T4 of startup circuit (2), secondary coils in said two transformers being connected in series, two relays acting due to the signal supplied by control circuit (3) after the startup circuit (2) generating strike voltage, the primary coil in two transformers which has the current limited function being converted from series connection to parallel connection. In this way, on the one hand, the bulb is able to trigger startup reliably, and the output power of electronic ballast can also meet the challenge; on the other hand, the resistance drops to one quarter which is in series connection after parallel connection, controls the heating-up of T3, T4, electronic ballast's whole temperature rise drops above 30%, improves stability and reliability of electronic ballast.