DEVICE FOR STARTING HIGH-PRESSURE SODIUM VAPOR LAMP Russian patent published in 2005 - IPC

FIELD: electrical engineering; outdoor and indoor lighting units.

SUBSTANCE: proposed device for starting high-pressure sodium-vapor lamps inserted in lighting units designed for starting high-pressure mercury-arc lamps has autotransformer 1 one of whose winding leads is connected to first lead of lamp 2. Part of autotransformer winding 3 is inserted in circuit set up of series-connected change-over member 4 and capacitor 5 whose common point is connected to second lead of lamp either directly or through current-limiting member 6. Supply mains is connected through reactor 7 between second lead of lamp and other lead of autotransformer winding which is not connected to lamp. Inductance of autotransformer 1 is chosen to meet condition U/I = U₂/I₂ - U₁/I₁ at working current through lamp 2, where U₁ is reactor voltage for high-pressure mercury-arc lamp; I₁ is reactor rated current for high-pressure mercury-arc lamp under working conditions; U₂ is reactor rated voltage for high-pressure sodium-vapor lamp connected instead of high-pressure mercury-arc lamp; I₂ is reactor rated current for high-pressure sodium-vapor lamp connected instead of high-pressure mercury-arc lamp; U is RMS voltage across autotransformer; I is RMS current through autotransformer in working condition of high-voltage sodium-vapor lamp.

EFFECT: reduced power requirement due to use of existing lighting units with lamps of lower power.

2 cl, 2 dwg, 1 tbl