| 摘要 |
PURPOSE:To eliminate a noise with a simple configuration by applying the secondary induced voltage of a transformer connected in series with a load to the control terminal of a switching transistor and providing a transistor for drawing the base current of the transistor. CONSTITUTION:An AC voltage supplied through an inductor L2 and a capacitor C5 is rectified by a rectifier REC, and applied to both ends of a series circuit of transistors Q1, Q2. When the voltage at both ends of a capacitor C11 exceeds the prescribed value, a transistor Q2 is turned ON, a current is flowed to a transformer CT, and a capacitor C12 for forming a time constant circuit is charged by the secondary induced voltage. When the voltage of the capacitor C12 exceeds the prescribed value, the transistor Q2 is turned OFF, and the transistor Q1 is turned ON. The transistors Q1, Q2 are alternately turned ON and OFF to supply an AC power to discharge lamps LA1, LA2. When a variable resistor YR is regulated, the lamps LA1, LA2 are dimmed. |
