| 摘要 |
PURPOSE:To simplify circuit consumption by making a safety circuit and a soft start circuit having a part in common between them and using a detecting coil in common between both circuits. CONSTITUTION:In lighting apparatus having two discharge lamps 20a, 20b, detecting coils 28a, 28b are rolled on inductors 19a, 19b for ballasts, a soft start circuit 31 and a safety circuit 43, which are connected to the inductors, are so formed to have a structural part in common between them, and the detecting coils are used in common between both circuits. Diodes 29a, 29b, and a capacitor 30 are connected to connection terminals (a), (b), (c), (d) of each detecting coils 28a, 28b to form the soft start circuit 31 and using of a part of it in common, a safety circuit 43 is composed of resistors 44, 46, a capacitor 40, a transistor 47, and a Zener diode 48. |
