In one aspect of the present invention a capacitor (C1) is placed in series with the ballast (L) and the lamp. The capacitor (C1) lowers the impedance during lamp starting and is shorted out when final arc conditions of the lamp are reached. Method and device for improvement of lumen maintenance of high intensity discharge lamps through minimizing the wall blackening during lamp starting is disclosed. Reducing the electrode material sputtering during the thermionic arc phase of the lamp starting process was achieved by decreasing the cathode fall voltage. The cathode fall voltage in these lamps was decreased by increasing the current flowing through during the starting phase. The increase of starting current was achieved by increasing the open circuit voltage or by decreasing ballast impedance. <IMAGE>
申请公布号
EP0458338(A1)
申请公布日期
1991.11.27
申请号
EP19910108370
申请日期
1991.05.23
申请人
GTE LABORATORIES INCORPORATED
发明人
BYSZEWSKI, WOJCIECH W.;DALE, BRIAN;GREGOR, PHILIP D.;BUDINGER, A. BOWMAN;LI, YAN MING