| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce a rectifier of an A.C. power source and arc extinguishing reliability of a thyristor of an incandescent lamp circuit. SOLUTION: A fluorescent lamp 4, controlled by a high-frequency lighting circuit 3 connected from an A.C. power source 1 via a rectifier 2, is provided, and also constitution is provided wherein the output of a synchronizing detection circuit (or power source brake detecting circuit) 6, connected from an A.C. power source 1 via a second rectifier 5, is inputted to a microcomputer 7, and a candescent lamp 9 such as a miniature lamp is controlled by a switch element such as a thyristor 8 by a microcomputer 7. The output of the rectifier 5 is also supplied to the circuits of the lamp 9 and the thyristor 8. A capacitor component is connected in parallel to the input side of the synchronizing detection circuit (or the power source breaking detection circuit) 6 by a capacitor 6b via a resistor 6a, and also a level shift element 10 such as a diode is connected in series to the thyristor 8.</p> |
