| 摘要 |
PROBLEM TO BE SOLVED: To provide such a discharge lamp lighting device as being capable of reducing the distortion of an input current in a simple structure and supplying proper power even in thinned-out lighting. SOLUTION: When only one of fluorescent lamps FL1, FL2 is removed, a closed circuit is open because no fluorescent lamp FL1 or FL2 exists so that the voltages of capacitors C25, C32 are decreased because the fluorescent lamp FL1 or FL2 is removed, base currents in transistors Q11, Q12 are decreased and a base current in a transistor Q5 is decreased. The gate voltage of a field effect transistor Q3 is decreased, the operating, frequency of a transistor Q1 is increased, the output voltage of an inverter circuit 14 is decreased and proper power is supplied to the fluorescent lamp FL2 to light the fluorescent lamp FL2. |
