| 摘要 |
PROBLEM TO BE SOLVED: To provide constitution wherein one transistor is reduced out of transistors reacting a touch switch circuit. SOLUTION: A soft-starting transistor 16 is provided which is for limiting the output of an invertor, to a degree where the lamp 27 is inhibited from actuating, at the time of preheating a discharge lamp 27. A trigger circuit, a series circuit of a resistor 22 and a capacitor 21, is provided to control the transistor 16. A reset circuit is provided which is short-circuiting the output terminal of the trigger circuit at the time of conduction of an auxiliary transistor 12 via the transistor 12. A diode 24 constitutes a reset circuit, and also has a role for preventing an electric current, in a transistor 12 side circuit, from inflow into and interference to the capacitor 21 on the trigger circuit side via the reset circuit. |
